Scott, I’ve been a carpenter, welder, concrete man, electrician, plumber, excavator,heating and cooling , amongst everything else it takes to be a General Contractor. You, my friend, are a joy and a breath of fresh air!!keep up the good work!!👍🙏
Rule of thumb heat 2 contract 3 , and if you weld something and it pulls to much grind a little at the end half of the weld it will heat and release .Practice .
When I was a young man, my uncle was trying to teach me how to sight a wall while performing plumb and line of a building. He was running the braces on a particular wall while I was sighting it. As I was being wishy washy about whether the wall was straight or not, his patience ran thin and he shouted- "if it looks straight, it is straight! At that moment, learned what straight was. I never questioned my ability to know straight again...Well, until my eyesight was not young any more. Thanks for another insightful video.
I mean, you can get really really damn straight by eye sight alone with the right positioning and set up. How else is it possible for snipers to be so accurate?
With humility , gratitude , and a willingness to learn , I'm now successfully , a retired welder . Looking back , some days were brutal . But , boy , I got to do some cool things ! Like being on fire on a daily basis . Who else can claim that ? Been after this stuff for forty years . Thankfully , I got a lot of sage advise along the way . Never considered myself an expert , because no matter how much you know about welding , you only begin to realize how much more there is , - that you have no idea about ! To those who yearn to be a welder , I would offer this ... If you come into a shop , -or an approach to a problem , thinking you have all the answers , those who know , I mean really know , will just smile , sit back , and watch you fail ! Never hurts to ask for other's opinions . Welding is TRUTH . This isn't a " Fake it until you make it " situation , because that doesn't fly . Try your best , and swallow your pride if you need to correct your mistakes . I'm cleaning up my language here , as any Weld Shop survivor will surely recognize . Verbal brutality is as common as grinding dust . You best be prepared for it ! But as long as you're being razzed you're probably OK. If you're NOT being razzed you might have something to worry about . Carpenters who aspire to become welders face challenges . Cutting a 2X4 , is only an inch and a half by three and a half in their world . Getting back to truth here . And the saw dust probably won't start your pants leg on fire ! But I digress . Heat Sraightening : Hope this helps . Everybody knows that when steel is heated , it expands . What many don't realize is that if heated past a critical point where it turns cherry-red , as it cools , it shrinks just a tiny bit more than it expanded ! It's more of an art than a science , but if you picture an inverted catenary arch , heating and subsequent cooling in this area on beams or tubing can pull distorted structural members back into straight . Guessing the SPAN of said arch is the trick . Best thing though is if you over do it , you can pull it back from the opposite side . Cooling with wet rags , quenching , or even better , as Scott correctly demonstrated , a mist blaster of some sort will shock cool the material and enhance desired shrink . Maybe a little more distance along the flange ... ? Scott , not sure what you're planning to do with that beam , but sometimes it's good to have an engineer look at it , especially if that weld is critical in any way . A forty foot beam isn't exactly tiny . Structural weld failures can get people killed . PLEASE look up AWS D1.1 !!! Just as with Electrical and Plumbing , there are prescribed CODES to strictly be followed . @AMS had a very good point about " Fish-Plates " , and is a worthy , IMPORTANT topic for another discussion . ( A way to reinforce a weld joint . ) Sticking metal together is great fun , and it's a good start . But what you don't know can get you .
I've welded many beams for constructing commerciela buildings over the past 50 yrs. Depending on the load, we almost always welded "fish-plates" on the sides of the beam's web to strengthen the joint.
Good morning, I love watching your videos. I work with my hands and mind everyday also, sometimes with my hands more than my mind. Add a short piece of wire to that white wire to take the strain from it. As someone who works with steel on a regular basis it always amazes me how far the tiniest bit of heat will move a steal. Have a blessed day.
I think EC is one of the most entertaining and educational channel on RUclips. You’ll think the subject matter won’t interest you till you’re hooked watching it. Thank you!
Scott, try a steel mesh style strain relief with the cable connector. Should be able to thread in or with the lock nut go into your motor housing. You definitely need more relief for your motor control drop. Love the channel. 👍👍
Cut the end of of the wire and crimp a new end with a 3 inch extension. Let it loop on the inside, install a new spade connector, and zip tie the loop in a position that won't pull out. If you don't want to extend the wire, use a pair of pliers to squeeze the terminal closed, then force it onto its spot. Then zip tie it to something more secure. Those connectors tend to spread with cycles of heat and time, you can pinch them, or replace them to make a better connection.
It looks to me like someone cut that white wire and put a new spade on it, therefor that white wire is about and inch too short. Agree, add a couple inches of wire with a new spade.
And give the capacitor time to drain before you start working. I was once doing exactly as you said when I got a suprise poke while on a ladder from a hoist that I had just unplugged and locked out. I about went over backwards.
Oh how many if us can relate to polishing the opal. My grandfather layed hardwood floors by hand nailing and taught me that when i’m tempted to hit it one more time… don’t !
The crane controller needs to hang from a cable, something like 1/8” braided cable, swaged, eyelets, to isolate the electrical wires from the pulling around of the hoist, the electric wire gets a little “relief “ up by the hoist, slight bend or loop, then the wires don’t get jerked loose
I used to re-camber the beams on flatbed trailers all the time. Back when I lived in a steel town that produced a lot of sheet and tin. The coils were very concentrated loads and would sway back the trailers. I'd remove the bulkhead and turn them upside down with the front and rear sitting on RR ties. I used a #20 rosebud. The faster you apply the heat, the better it works. The way it works is, when heated fast it tries to expand, but it can't expand lengthwise because it is constrained by the cold metal. So it distorts the only way it can, by becoming thicker in section. So when it cools being that you have displaced the steel, it loses length. You do it to the flange in enough places and that flange becomes shorter. I've done it with brand new beams when building trailers also. Back in the day, some of the guys would want to run kind of heavy, and they wanted to use heavy beams with a big arch. They would load out about 2 truckloads on one truck and they didn't want to look swaybacked and heavy. Damn, I miss the America that once was.
It’s been a while since I was paid to weld. But I would have put in a root pass with 6010 (6011? Yeah it’s been a minute) rod and capped it with a few 7018 passes. I’ve also witnessed by dad straightening out I Beams that were warped like that by Laing down welds in a particular pattern to draw the steel back to straight. Never knew how he did it but it was frickin magic to see. Keep up the good work!
MIG is a poor choice for structural work. Stick or flux core would have been better. being on the west coast, he is in an earthquake zone so 7018 all the way or dual shield are probably the code for a beam splice.
@@peetky8645 Beat me to it. I'n not a pro welder but I wouldn't trust my life to a MIG butt weld. Stick all the way with a gusset plate reinforcing the joint
@@4110mahindra MIG is a short circuit process, hence the bacon noise. MIG is never used in structural welding because of limited penetration and a discontinuous arc. Duals Shield Process is not MIG, it is FCAWg. Stick, FCAWg and FCAWs are the only code structural processes in the USA.
Have used flame straightening quite a few times in the ski industry. To straighten bent tiller bars on the snow groomers (16 foot - 8 inch diameter rotating at 1200 rpm), correct lift tower lean ( 38 inch diameter 40 foot tall out of plum by a foot) and the most challenging was straightening a 14 foot diameter bullwheel while in horizontal position on a ski lift (not in tension). Always amazing to me what a little heat can do!
Very cool. I work for a steel bridge girder fabricator. We use similar techniques for heat-curving or straightening steel girders. I no longer work in production, but I've spent hours heating at strategic locations along the girder to reach design tolerances. Nice job in the winter!!
Flame and water can be so cool. There is a great story from George Philpott who worked in the Eveleigh Railway Workshops, in Sydney, building trains back in the days of steam. "In Carriageworks we had one bloke called Chutney. You might have an accident and the under-frame would be twisted and bent. Chutney would come along and have a look at it, and he'd say to the fellers, 'Put heat here, put water there,' and you would see the whole metal under-frame twisting back into shape. These people are gone, and there's no one left to show anyone how to do it." - Railways, Relics, and Romance: The Eveleigh Railway Workshops, Sydney, New South Wales
I'm not a welder!! Apparently my short term memory stinks. I always learn something from your videos when I actually get a chance to watch videos. Thank you. I am good at what I do and I will keep doing what I do. Good night and thanks.
Just love "hanging out" in the shop watching new and outside the "normal box" projects on a rainy day! Excited to see what that new beams task will be!!!!!!
for some strain relief on that cable; lift the cable up into the head of the crane more and place a wire clamp around it (think breaker box cable clamp or cable u-bolt), so all weight below it is held by the clamp/housing and wire above it is essentially just floating.
Another great video from EC. When metal is locally heated up to, say, red hot two things happen to the hot spot: the compressive strength decreases and the hot spot tries to expand. Put these two together and the hot spot fails in compression so that when the hot spot metal cools it is smaller and pulls hard on all the metal around it. Careful use of this fact allows bending or straightening of any metal object.
I had a super skilled stainless steel (s/s) pipe weldor show me the use of a wet rag to prevent s/s pipe from warping in 1986. S/s is bad to warp b/c the chrome grains are so close together...heat from the weld is slow to move. The opposite is copper and aluminum. In these two the, grains (pores) are open... hence...they are used in electrical wires. Carbon steel (c/s) A-36 (plate, structural) A-105 (seamed pipe)...the mild steel group...the pores are inbetween the s/s & the copper/alum non ferrous group. In c/s when the heat, then the wet rag is applied on the correct side...is very accommodating to move and so holding dimensions are very doable. I wrote..."the wet rag is applied on the correct side"... the waters job is to remove the heat that causes warping. This means...apply the wet rag...opposite to where the heat is. If water spills on the welded portion...the warping will be...encouraged. This water/wet rag takes practice. It is very satisfying. All the best, Pete 🙂
Pretty sure - I'll never actually do what he does. But he's fascinating to watch. Here's the thing.... Here's the value in listening to Scot..... His work wisdom, his work ethic, his commitment to getting it right, not going for perfect when good will work. It's not often you meet a man - you wish you knew much longer and as a close friend. Keep up the good videos.
Scott, since the hoist is pulled by the chain and the wiring, it's probable that the neutral wire is cut a bit short (likely from replacing the spade terminal at some time). If it were me, I would make up a short 3 inch extension, with spade terminals on both ends (1 male, one female) and install that on to the neutral wire (white wire), wrapping it with either heat shrink tubing or electrical tape at those new connections. You can get those spade terminals as a locking terminal if the male connector has a hole in it, that work really really well in a tension or vibration environment. The trick with the old sandblaster for a cooling gun is absolute gold. I'm stealing that one from you and Jon! Thank you for the knowledge sharing! Even us old dogs can learn new tricks!
I still think that process is as close to magic as you can get as an engineer/craftsman, and I say that as a retired toolmaker and design engineer. The time lapse footage was especially interesting.
Good job straighting the I- beam , heating in triangle and cooling is a good way , and the air / water mist is a idea I have not done yet but will next time . Welding a bead will also draw the metal smaller , that is done on mobile home frames on top to put some up bend in the frame so when the structural load is on it the it will be some where near straight . I had to straighten a heavy equipment trailer I was building , that got pulled out of flat from cutting out a and welding in a bottom plate to make room for the axles , the welding drawed the the beam down at rear of the trailer , did not see this until we turned the frame right side up and seen what had happened and did it nearly the same way to fix the problem , a old black smith told us how to heat and cool it . Got it nearly straight said that was good enough , loaded many big pieces of heavy equipment on that trailer for decades and it never bent , but always put blocks under the tail of the trailer when loading that takes that over the axle bending force out of loading. Must have been strong enough a the first time we load the 9 ton back hoe we did not use blocks under the tail and it actually lifted the wheels of the single axle dump truck off the ground 30 feet from the back of the trailer when backhoe drove on , always used blocks after that , even had a third air pusher axle added later to haul a 21 ton JD 750 track loader .
I lifted a trailer tail that was sagged 6" from the hind wheels back to the rear-end. I learned this method from an old welder that used to re-arch semi trailer frames. I stretched a chain on the top of the frame end to end, and kept it in tension with a bottle jack. That tension is important because it prevents the steel from moving when it is heated. I heated wedge-shaped portions of the frame 3" wide at the top, down across the width of the frame. Because the steel couldn't expand and bend the frame further due to the chain tension, the heated steel actually thickened. I quenched the heated wedge from red heat to cool. Three successive wedges of heat, spread along the bent portion of the frame lifted the tail 6 inches. I did that to both sides of the trailer and it looked good as new. Plumb, strait, square and level. Trailers are mild steel, so I wasn't concerned about heat treatment that might have occurred if the steel had been carbon steel.My old welder guy apparently had a process to normalize his carbon steel semi frames after they were arched properly.
I worked with a mechanic one who I witnessed straightened a pump-axle with a torch. It was straightened from barely visible to where you would need a lathe with instruments or laser-rig to measure it
Stainless Steel Strain Relief Cord Grips. You can search and find the size you need. If you have hanging lines for controls must have. I use them on my saw mill power cables the go to the saw head on my woodmizer. I always learn something from you videos. Hope someone has already suggested the strain relief cable ties.
It was "The end of November, and I'd been walking around the uninstalled vehicle lift in my shop since 2014... I fixed that problem too Eric. Thanks for the informative bender vid
The way the old union carbide oxyfuel handbook describes it is that when you heat a small region of steel, it becomes soft and malleable, and also expands in volume. But it's restrained by the harder, less malleable,cooler metal around it. It has to go somewhere, so the metal is squeezed and deformed in a direction perpendicular to the surface. The metal gets thicker there. Then when it cools, the hot metal shrinks back to its original volume. So take a rod with a bend in it. Heat a spot opposite the bend red hot. That little volume expands, but the rest of the rod restrains it, so the hot soft metal squeezes upwards. When it cools, that spot shrinks to its original volume and pulls the rod back towards being straight.
Polishing the Opal. I like that. I hope you don't mind if I start using that. Cause I'm gonna. And I will tell where I heard it. Thank you Scott for all that you share with us. Keep up the good work!!
For your hoist cable issue there is a drop cable strain relief product that is available/designed for the exact issue you have. That would be the best however they are not cheap and also would require disconnecting all wires to the hoist to install. As a cheap doable option you can use approximately 10” of fine cable often called Aircraft cable, attach one end to the hoist body and the other end attached to the drop cable making sure the aircraft cable is now bearing the weight of the cable and controller. How you attach to the drop cable you will have to come up with a way that grabs the cable without crushing or damaging the cable outer or inside wires. A couple of gear clamps and Pex type tubing around the drop cable is one thought. Nice job on the beam, heat shrinking is a real talent to see it happen in front of your eyes.
Great content. I have done many heat straightening jobs and the the key is to go wider on the heat-affected zone than you think. When that cold steel stretches, it is not just at a narrow zone, it is a component of depth/width of the flange (for your I-Beam) and the the degree of bend. It creates more of an arc than a single-point bend. I'd start with the smaller adjustments out to 12"-18" of the apex of that bend and work your way in, judging by the the I-beam size. That, of course, depends on the alloy of steel, which is probably not easily determined. It is easier to use heat to stretch than it is to contract, though.
For the hoist, just put a short piece of wire, somewhere 4 to 6 inches, in to make the white wire a tad longer. You can just use the same type of connectors or put on a new plug an crimp it on with a but connector. That should give it enough relief to not pull out again. Also possibly just squeze down a bit on the connector to make it slightly tighter.
On the topic of your hoist, the cranes in the shop at work that arent wireless, they have a special cable that has steel wire rope on both sides, that holds the remote, so there is never any tension on the wire itself. Might be able to do something similar with thin steel rope to your hoist. Although I tend to prefer hand hoists, no magic pixies to apease in those 😅
I really like the idea of cooling the steel down quickly, so you can avoid the blue brittle stage. However, when you were toasting that area and it turned orange, it likely ran above 1200F which is a big No-No for structural steel. New grains begin to develop and that particular area sbecomes significantly weaker than its surrounding area. The best practice would be to use a 1150F temp stick and do several small heats to slowly correct that bend over 6-8 passes. I'm not sure of the imapct of having large grains right next to a heat affected zone, but I would keep that beam in compression. I love watching yoru videos. I wish my dad was as patient and eloquent when describing how he did things.
On your crane, use some small cable or chain to hang your pendant from that is a little shorter than the cord. That way if you pull on the pendant the cable or chain is taking the strain instead of the cord. We have a bunch of cranes where I work and that’s how we set them up.
Zip ties on the inside of the case,(zip ties around the wire inside the case). Then when the case is put back together the zip ties inside on the wire insulation will be the strain relief. It works very well as strain relief
Sir, I loved the opal reference. Yeah, me too sometimes over do things in search of perfection. Another say I adapted for that matter:"Good enuff for the girls I go out with". Works every time. And I too inagined You pulling out an old tombstone buzz box- something that way. I try to learn stick and go with that. Good enuff… Merry Christmas!!
For the white wire, I’d suggest replacing the connector since they tend to wear out. 3M makes some excellent options. I’ve soldered those connectors and used heat shrink tubing in the past, but I’m not sure there’s enough space for that approach in this case.
Hoist solution: just like you once posted a video of raising/ lowering your mag 77 by the cord without it bearing on the connection itself. Redistribute the load, find a way to put the weight on the cord, not the connection. I'd probably weld a bracket to the hoist case and secure the cord to it. Thanks for sharing your craft!
Well, the very simple and easy fix for that White wire connector is to just use a set of pliers, and crimp it closed a bit. It will create a tighter friction fit, and not come loose as easily. Pretty easy "Non-Electrician" fix, if you ask me!! 🤣😂😉 Keep up the great work!
Hoist. Release the clamp. Strip back the cable jacket farther giving you more slack. Reattach the cable strain relief farther down. Loop and bind the control cord and hang to release tension while doing this.
I wonder what it's to be used for. I had an 11meter I beam to which I welded about 1.5meter heavy right angle steel at right angles about a foot from each end. This enabled me to sit the beam atop two poles ( set into the ground ) and then bolt into them through these two downriggers. This forms the entrance of my openspan 11x 6 meter implement shed.
Throw a sash chain (or facsimile) loop around the case of the hoist loosely. Then put a knot in the cable around the chain. The chain takes the cable load and there is enough slack in the connection to move some without being pulled apart.
Female spade connectors will spread apart and not grip the male spade connector as tightly as it should. Using a needle nose pliers down the center of the female spade connector will tighten it up so it grips the male spade connector with more force and be far less likely to pull lose.
Lightly crimp the terminal end spring arms. It will need 'encouragement' to be placed back into position. But once there should stay friction locked into position.
For your jib crane there are a few different options there are standard cord grips that have a tapered plastic insert and a nut to grip the cord or there are woven cable grips similar to Chinese finger cuff toys. 13:28
A better wire choice for welding would have been E71T-1 flux core with gas. (aka dual shield) Usually used is .045. Change feed roll, liner, and contact tip. Much better structural wire. Basically 7018 in a mig wire. Also, can you put a plate across the splice? Would be perfect application for using a magnetic drill. Keep up the good work....!!
Just lightly pinch each edge of the blade connector on the end of the white wire. Not enough to close the gaps.. just a handshake squeeze. I repaired professionally. This is all you need.
Hola, interesante video; soy técnico electrónico y trabajo reparando ascensores, por lo que conozco los problemas de conexiones de partes con movimiento y vibraciones; parece que ese cable está muy justo y tirante, por lo que será el primero en desconectarse, cuando eso haya pasado varias veces el terminal hembra tipo pala se va abriendo y la conexión empeora. La solución más rápida es dejar la entrada de cable mas dentro del polipasto para que haya más cable sobrante en el interior, poniendo unas nuevas abrazaderas; se pueden doblarlas pestañas del terminal con unos alicates o cambiar el terminal hembra de conexión por uno nuevo. Existen terminales de seguridad con una pestaña siendo necesario hacer un pequeño agujero en el terminal macho; obviamente antes de cualquier intervención es necesario haber desconectado la corriente y esperar a que el condensador se descargue.
You can crimp down the female blade connector with a pliers to make it bite more. I’d also use a cushion clamp on the power cord and attach it to a housing screw/bolt in order to secure it up.
Concerning your white wire just take your pliers and squeeze that connector a little bit to make it fit tighter on the lug. Or if you want to Make a permanent fix cut the connector off and solder the wire to the lug. Great video keep em coming!
If you can just crush the spade connector a little where it slides on to tighten up the friction fit. As others said prob change it out to a longer wire to take the tugging off.
You could try putting a kellems strain relief on the cord. It will keep it from being pulled down and making the wire unplug or a cheaper way you could slide the wires through the strain relief farther so you have plenty of slack on the wires and put a couple zip ties on the top side of the strain relief so the wires can't be pulled down
I have a friend that can do that. He just uses air cooling, does other things during that time. No beam is straight from the mill, in most applications they are good enough. But some times they have to be straight within less than 1/8 of an inch. So you take a torch and straighten it.
@johnadolph4094, more of your vast knowledge put to good use fella! @Scott, regarding your overhead winch - just put a cable-tie in the inside part (inside the housing) of the anti-strain boot and it will stop the pull-out. And do yourself a favour and squash the male blade connector with a pair of plyers, to give it a bit more grip tension, so its not as loose. kind regards Spen
Regarding the white wire unplugging on the hoist - Drill a small hole through the connectors, with it plugged, and then "twist tie" it with a short piece of copper wire.
Simple fix to the crane. Cut loose connector off and replace with a new tight one. Then a thick zip strip where power cord feeds inside housing and zip strip right outside the housing. Like a rubber grommet without the rubber or grommet 🤔🙄 Retired Veteran here making quick or possibly long term fix to complete the mission. Have a good one 👍
Great video as usual! I'm always impressed, and comforted watching your content. I'm just a bit younger than you and remember a time when people got their hands dirty a lot more often! I wonder if simply extending that white white a few inches would allow for that control cable to swing around, and not pull that blade connector loose?
For the lift, Looks like making the white wire a little longer and snugging up the spade terminal with pliers. For the beam, Probably a good idea to gusset that butt joint weld with some strapping on the both sides of the web and top and bottom of the flange. Especially since it will likely be the center of the span and highest stress area
Fit a tiny chain onto the crane and attach the cable to it with some slack on the top. In this way You pull the chain to move the crane and not the cable.
Just put couple strands of thin copper wire like a wedge over the plug. You could ever hammer the wire thinner to get the gauge you need then plug wire back in and bam it should be good to go. Those plug’s are useful but can be a pain in the but I find wedging a thin piece between that loose connection makes a big difference
You probably got that thing straightened to within the allowable steel mill tolerances, which are pretty loose. My bigger concern is welding two beam sections together. I'm a structural engineer, not a welder--but I know you need to consider a lot of stuff like pre-heating the steel in order to get a weld you'd stake your life on..
if you had some big pieces of chanel you can tack that on the opposite side as your welding and itll help keep it from drawing on you so much. i used to do that and it worked for me .
You can squeeze those crimps with pliers just a bit to give them a better grip. Probably have to get the plastic insulator off first. Or put a new crimp on. You can get one of those mesh strain reliefs and install pretty easily. Just unhook the wire, replace the fitting that goes through the hole, and put the wire back in. Pay attention to the wire and hole diameter when you buy it, there are different sizes. You can get them from supplyhouse, or I'm sure somewhere local.
Scott, I’ve been a carpenter, welder, concrete man, electrician, plumber, excavator,heating and cooling , amongst everything else it takes to be a General Contractor. You, my friend, are a joy and a breath of fresh air!!keep up the good work!!👍🙏
That old man taught you and now you’re the old man teaching me, thank you
Rule of thumb heat 2 contract 3 , and if you weld something and it pulls to much grind a little at the end half of the weld it will heat and release .Practice .
When I was a young man, my uncle was trying to teach me how to sight a wall while performing plumb and line of a building. He was running the braces on a particular wall while I was sighting it. As I was being wishy washy about whether the wall was straight or not, his patience ran thin and he shouted- "if it looks straight, it is straight!
At that moment, learned what straight was. I never questioned my ability to know straight again...Well, until my eyesight was not young any more.
Thanks for another insightful video.
I mean, you can get really really damn straight by eye sight alone with the right positioning and set up. How else is it possible for snipers to be so accurate?
@@LagMasterSamwith a scope and a spotter
With humility , gratitude , and a willingness to learn , I'm now successfully , a retired welder . Looking back , some days were brutal . But , boy , I got to do some cool things ! Like being on fire on a daily basis . Who else can claim that ? Been after this stuff for forty years . Thankfully , I got a lot of sage advise along the way . Never considered myself an expert , because no matter how much you know about welding , you only begin to realize how much more there is , - that you have no idea about ! To those who yearn to be a welder , I would offer this ... If you come into a shop , -or an approach to a problem , thinking you have all the answers , those who know , I mean really know , will just smile , sit back , and watch you fail ! Never hurts to ask for other's opinions . Welding is TRUTH . This isn't a " Fake it until you make it " situation , because that doesn't fly . Try your best , and swallow your pride if you need to correct your mistakes . I'm cleaning up my language here , as any Weld Shop survivor will surely recognize . Verbal brutality is as common as grinding dust . You best be prepared for it ! But as long as you're being razzed you're probably OK. If you're NOT being razzed you might have something to worry about . Carpenters who aspire to become welders face challenges . Cutting a 2X4 , is only an inch and a half by three and a half in their world . Getting back to truth here . And the saw dust probably won't start your pants leg on fire ! But I digress . Heat Sraightening : Hope this helps . Everybody knows that when steel is heated , it expands . What many don't realize is that if heated past a critical point where it turns cherry-red , as it cools , it shrinks just a tiny bit more than it expanded ! It's more of an art than a science , but if you picture an inverted catenary arch , heating and subsequent cooling in this area on beams or tubing can pull distorted structural members back into straight . Guessing the SPAN of said arch is the trick . Best thing though is if you over do it , you can pull it back from the opposite side . Cooling with wet rags , quenching , or even better , as Scott correctly demonstrated , a mist blaster of some sort will shock cool the material and enhance desired shrink . Maybe a little more distance along the flange ... ? Scott , not sure what you're planning to do with that beam , but sometimes it's good to have an engineer look at it , especially if that weld is critical in any way . A forty foot beam isn't exactly tiny . Structural weld failures can get people killed . PLEASE look up AWS D1.1 !!! Just as with Electrical and Plumbing , there are prescribed CODES to strictly be followed . @AMS had a very good point about " Fish-Plates " , and is a worthy , IMPORTANT topic for another discussion . ( A way to reinforce a weld joint . ) Sticking metal together is great fun , and it's a good start . But what you don't know can get you .
50 +years on industrial equipment, welding with stick, tig and Meg over the years, you do great work and Straighten the beam is amazing
Well done on many fronts: straightening the beam; making an informative movie; showing us your workshop; keeping your dialogue simple and enjoyable.
I loved the opal story. So aplicable to many things in life.
Yes, indeed it is.
@@regsparkes6507 Me too, I do all the things but ive been a jeweler for 40 yrs, and I always tell my associates "God hates perfection"
I've welded many beams for constructing commerciela buildings over the past 50 yrs. Depending on the load, we almost always welded "fish-plates" on the sides of the beam's web to strengthen the joint.
2nd that!
Same
Flitch plates.
Scabs
Good morning, I love watching your videos. I work with my hands and mind everyday also, sometimes with my hands more than my mind. Add a short piece of wire to that white wire to take the strain from it. As someone who works with steel on a regular basis it always amazes me how far the tiniest bit of heat will move a steal. Have a blessed day.
I think EC is one of the most entertaining and educational channel on RUclips.
You’ll think the subject matter won’t interest you till you’re hooked watching it.
Thank you!
Your memory is soooo much better than mine.. I love your work and determination.
As I will always say, "It's good enough for who it's for" Great Job!
Scott, try a steel mesh style strain relief with the cable connector. Should be able to thread in or with the lock nut go into your motor housing. You definitely need more relief for your motor control drop. Love the channel. 👍👍
Kellems grip if you want to search it
Cut the end of of the wire and crimp a new end with a 3 inch extension. Let it loop on the inside, install a new spade connector, and zip tie the loop in a position that won't pull out.
If you don't want to extend the wire, use a pair of pliers to squeeze the terminal closed, then force it onto its spot. Then zip tie it to something more secure. Those connectors tend to spread with cycles of heat and time, you can pinch them, or replace them to make a better connection.
It looks to me like someone cut that white wire and put a new spade on it, therefor that white wire is about and inch too short. Agree, add a couple inches of wire with a new spade.
And give the capacitor time to drain before you start working. I was once doing exactly as you said when I got a suprise poke while on a ladder from a hoist that I had just unplugged and locked out. I about went over backwards.
Oh how many if us can relate to polishing the opal. My grandfather layed hardwood floors by hand nailing and taught me that when i’m tempted to hit it one more time… don’t !
The crane controller needs to hang from a cable, something like 1/8” braided cable, swaged, eyelets, to isolate the electrical wires from the pulling around of the hoist, the electric wire gets a little “relief “ up by the hoist, slight bend or loop, then the wires don’t get jerked loose
I used to re-camber the beams on flatbed trailers all the time. Back when I lived in a steel town that produced a lot of sheet and tin. The coils were very concentrated loads and would sway back the trailers. I'd remove the bulkhead and turn them upside down with the front and rear sitting on RR ties. I used a #20 rosebud. The faster you apply the heat, the better it works.
The way it works is, when heated fast it tries to expand, but it can't expand lengthwise because it is constrained by the cold metal. So it distorts the only way it can, by becoming thicker in section. So when it cools being that you have displaced the steel, it loses length. You do it to the flange in enough places and that flange becomes shorter. I've done it with brand new beams when building trailers also. Back in the day, some of the guys would want to run kind of heavy, and they wanted to use heavy beams with a big arch. They would load out about 2 truckloads on one truck and they didn't want to look swaybacked and heavy. Damn, I miss the America that once was.
It’s been a while since I was paid to weld. But I would have put in a root pass with 6010 (6011? Yeah it’s been a minute) rod and capped it with a few 7018 passes.
I’ve also witnessed by dad straightening out I Beams that were warped like that by Laing down welds in a particular pattern to draw the steel back to straight. Never knew how he did it but it was frickin magic to see.
Keep up the good work!
MIG is a poor choice for structural work. Stick or flux core would have been better. being on the west coast, he is in an earthquake zone so 7018 all the way or dual shield are probably the code for a beam splice.
Guessing you are a 60+ yr old welder. Mig is often used in structural today. Especially flux core with cover gas.
@@peetky8645 Beat me to it. I'n not a pro welder but I wouldn't trust my life to a MIG butt weld. Stick all the way with a gusset plate reinforcing the joint
@@4110mahindra MIG is a short circuit process, hence the bacon noise. MIG is never used in structural welding because of limited penetration and a discontinuous arc. Duals Shield Process is not MIG, it is FCAWg. Stick, FCAWg and FCAWs are the only code structural processes in the USA.
@@rubencantu5067 Great idea. A nice fish plate on both sides would be prudent since the weld is MIG....
Have used flame straightening quite a few times in the ski industry. To straighten bent tiller bars on the snow groomers (16 foot - 8 inch diameter rotating at 1200 rpm), correct lift tower lean ( 38 inch diameter 40 foot tall out of plum by a foot) and the most challenging was straightening a 14 foot diameter bullwheel while in horizontal position on a ski lift (not in tension). Always amazing to me what a little heat can do!
Very cool. I work for a steel bridge girder fabricator. We use similar techniques for heat-curving or straightening steel girders. I no longer work in production, but I've spent hours heating at strategic locations along the girder to reach design tolerances. Nice job in the winter!!
Just your average day Shrinking and welding a 40 foot I Beam in the average workshop ...... Thx for sharing this story and journey ....
Flame and water can be so cool.
There is a great story from George Philpott who worked in the Eveleigh Railway Workshops, in Sydney, building trains back in the days of steam.
"In Carriageworks we had one bloke called Chutney. You might have an accident and the under-frame would be twisted and bent. Chutney would come along and have a look at it, and he'd say to the fellers, 'Put heat here, put water there,' and you would see the whole metal under-frame twisting back into shape. These people are gone, and there's no one left to show anyone how to do it." - Railways, Relics, and Romance: The Eveleigh Railway Workshops, Sydney, New South Wales
We are still around son, I'm one of those few who continually pass on this kind of knowledge by way of practice.
Don't think there's no-one anymore! 👍
I'm not a welder!! Apparently my short term memory stinks. I always learn something from your videos when I actually get a chance to watch videos. Thank you. I am good at what I do and I will keep doing what I do. Good night and thanks.
Just love "hanging out" in the shop watching new and outside the "normal box" projects on a rainy day! Excited to see what that new beams task will be!!!!!!
for some strain relief on that cable; lift the cable up into the head of the crane more and place a wire clamp around it (think breaker box cable clamp or cable u-bolt), so all weight below it is held by the clamp/housing and wire above it is essentially just floating.
Another great video from EC.
When metal is locally heated up to, say, red hot two things happen to the hot spot: the compressive strength decreases and the hot spot tries to expand. Put these two together and the hot spot fails in compression so that when the hot spot metal cools it is smaller and pulls hard on all the metal around it. Careful use of this fact allows bending or straightening of any metal object.
You know what your talking about.
I had a super skilled stainless steel (s/s) pipe weldor show me the use of a wet rag to prevent s/s pipe from warping in 1986. S/s is bad to warp b/c the chrome grains are so close together...heat from the weld is slow to move. The opposite is copper and aluminum. In these two the, grains (pores) are open... hence...they are used in electrical wires.
Carbon steel (c/s) A-36 (plate, structural) A-105 (seamed pipe)...the mild steel group...the pores are inbetween the s/s & the copper/alum non ferrous group. In c/s when the heat, then the wet rag is applied on the correct side...is very accommodating to move and so holding dimensions are very doable.
I wrote..."the wet rag is applied on the correct side"... the waters job is to remove the heat that causes warping. This means...apply the wet rag...opposite to where the heat is.
If water spills on the welded portion...the warping will be...encouraged.
This water/wet rag takes practice. It is very satisfying.
All the best, Pete 🙂
Isn't there a corresponding trick of throwing a fire blanket over a weld immediately to hold the heat in to insure even cooling?
Love your work! G'day from Australia 🇦🇺
Pretty sure - I'll never actually do what he does. But he's fascinating to watch. Here's the thing.... Here's the value in listening to Scot..... His work wisdom, his work ethic, his commitment to getting it right, not going for perfect when good will work. It's not often you meet a man - you wish you knew much longer and as a close friend. Keep up the good videos.
Scott, since the hoist is pulled by the chain and the wiring, it's probable that the neutral wire is cut a bit short (likely from replacing the spade terminal at some time). If it were me, I would make up a short 3 inch extension, with spade terminals on both ends (1 male, one female) and install that on to the neutral wire (white wire), wrapping it with either heat shrink tubing or electrical tape at those new connections. You can get those spade terminals as a locking terminal if the male connector has a hole in it, that work really really well in a tension or vibration environment.
The trick with the old sandblaster for a cooling gun is absolute gold. I'm stealing that one from you and Jon! Thank you for the knowledge sharing! Even us old dogs can learn new tricks!
Good enough for the job at hand ; thanks as always from old New Orleans 😇
Merry Christmas and Happy New Year
I still think that process is as close to magic as you can get as an engineer/craftsman, and I say that as a retired toolmaker and design engineer. The time lapse footage was especially interesting.
Bridge Clamps are the best!
Good job straighting the I- beam , heating in triangle and cooling is a good way , and the air / water mist is a idea I have not done yet but will next time .
Welding a bead will also draw the metal smaller , that is done on mobile home frames on top to put some up bend in the frame so when the structural load is on it the it will be some where near straight .
I had to straighten a heavy equipment trailer I was building , that got pulled out of flat from cutting out a and welding in a bottom plate to make room for the axles , the welding drawed the the beam down at rear of the trailer , did not see this until we turned the frame right side up and seen what had happened and did it nearly the same way to fix the problem , a old black smith told us how to heat and cool it .
Got it nearly straight said that was good enough , loaded many big pieces of heavy equipment on that trailer for decades and it never bent , but always put blocks under the tail of the trailer when loading that takes that over the axle bending force out of loading.
Must have been strong enough a the first time we load the 9 ton back hoe we did not use blocks under the tail and it actually lifted the wheels of the single axle dump truck off the ground 30 feet from the back of the trailer when backhoe drove on , always used blocks after that , even had a third air pusher axle added later to haul a 21 ton JD 750 track loader .
Great tip about the old sand blaster. Thanks for sharing.
I lifted a trailer tail that was sagged 6" from the hind wheels back to the rear-end. I learned this method from an old welder that used to re-arch semi trailer frames.
I stretched a chain on the top of the frame end to end, and kept it in tension with a bottle jack. That tension is important because it prevents the steel from moving when it is heated. I heated wedge-shaped portions of the frame 3" wide at the top, down across the width of the frame. Because the steel couldn't expand and bend the frame further due to the chain tension, the heated steel actually thickened. I quenched the heated wedge from red heat to cool. Three successive wedges of heat, spread along the bent portion of the frame lifted the tail 6 inches. I did that to both sides of the trailer and it looked good as new. Plumb, strait, square and level.
Trailers are mild steel, so I wasn't concerned about heat treatment that might have occurred if the steel had been carbon steel.My old welder guy apparently had a process to normalize his carbon steel semi frames after they were arched properly.
I worked with a mechanic one who I witnessed straightened a pump-axle with a torch. It was straightened from barely visible to where you would need a lathe with instruments or laser-rig to measure it
That's impressive.
Stainless Steel Strain Relief Cord Grips. You can search and find the size you need. If you have hanging lines for controls must have. I use them on my saw mill power cables the go to the saw head on my woodmizer. I always learn something from you videos. Hope someone has already suggested the strain relief cable ties.
GOOD TO SEE YOU WORKING INSIDE YOUR SHOP, GOOD WINTER WORK, THANK YOU.
Good effort as always, Scott.
Hi, Kenny, from Scotland!
It was "The end of November, and I'd been walking around the uninstalled vehicle lift in my shop since 2014... I fixed that problem too Eric.
Thanks for the informative bender vid
The way the old union carbide oxyfuel handbook describes it is that when you heat a small region of steel, it becomes soft and malleable, and also expands in volume. But it's restrained by the harder, less malleable,cooler metal around it. It has to go somewhere, so the metal is squeezed and deformed in a direction perpendicular to the surface. The metal gets thicker there. Then when it cools, the hot metal shrinks back to its original volume.
So take a rod with a bend in it. Heat a spot opposite the bend red hot. That little volume expands, but the rest of the rod restrains it, so the hot soft metal squeezes upwards. When it cools, that spot shrinks to its original volume and pulls the rod back towards being straight.
You Sir are the fabric of America
Polishing the Opal. I like that. I hope you don't mind if I start using that. Cause I'm gonna. And I will tell where I heard it. Thank you Scott for all that you share with us. Keep up the good work!!
I've over-polished an "opal" a few times, it's something that must be learned and can't be taught.
For your hoist cable issue there is a drop cable strain relief product that is available/designed for the exact issue you have. That would be the best however they are not cheap and also would require disconnecting all wires to the hoist to install. As a cheap doable option you can use approximately 10” of fine cable often called Aircraft cable, attach one end to the hoist body and the other end attached to the drop cable making sure the aircraft cable is now bearing the weight of the cable and controller. How you attach to the drop cable you will have to come up with a way that grabs the cable without crushing or damaging the cable outer or inside wires. A couple of gear clamps and Pex type tubing around the drop cable is one thought.
Nice job on the beam, heat shrinking is a real talent to see it happen in front of your eyes.
Great content. I have done many heat straightening jobs and the the key is to go wider on the heat-affected zone than you think. When that cold steel stretches, it is not just at a narrow zone, it is a component of depth/width of the flange (for your I-Beam) and the the degree of bend. It creates more of an arc than a single-point bend. I'd start with the smaller adjustments out to 12"-18" of the apex of that bend and work your way in, judging by the the I-beam size. That, of course, depends on the alloy of steel, which is probably not easily determined. It is easier to use heat to stretch than it is to contract, though.
For the hoist, just put a short piece of wire, somewhere 4 to 6 inches, in to make the white wire a tad longer. You can just use the same type of connectors or put on a new plug an crimp it on with a but connector. That should give it enough relief to not pull out again.
Also possibly just squeze down a bit on the connector to make it slightly tighter.
On the topic of your hoist, the cranes in the shop at work that arent wireless, they have a special cable that has steel wire rope on both sides, that holds the remote, so there is never any tension on the wire itself. Might be able to do something similar with thin steel rope to your hoist.
Although I tend to prefer hand hoists, no magic pixies to apease in those 😅
Looks good from the street.
I really like the idea of cooling the steel down quickly, so you can avoid the blue brittle stage. However, when you were toasting that area and it turned orange, it likely ran above 1200F which is a big No-No for structural steel. New grains begin to develop and that particular area sbecomes significantly weaker than its surrounding area. The best practice would be to use a 1150F temp stick and do several small heats to slowly correct that bend over 6-8 passes. I'm not sure of the imapct of having large grains right next to a heat affected zone, but I would keep that beam in compression. I love watching yoru videos. I wish my dad was as patient and eloquent when describing how he did things.
On your crane, use some small cable or chain to hang your pendant from that is a little shorter than the cord. That way if you pull on the pendant the cable or chain is taking the strain instead of the cord. We have a bunch of cranes where I work and that’s how we set them up.
good idea
Zip ties on the inside of the case,(zip ties around the wire inside the case).
Then when the case is put back together the zip ties inside on the wire insulation will be the strain relief. It works very well as strain relief
Sir, I loved the opal reference. Yeah, me too sometimes over do things in search of perfection. Another say I adapted for that matter:"Good enuff for the girls I go out with".
Works every time. And I too inagined You pulling out an old tombstone buzz box- something that way. I try to learn stick and go with that. Good enuff…
Merry Christmas!!
For the white wire, I’d suggest replacing the connector since they tend to wear out. 3M makes some excellent options. I’ve soldered those connectors and used heat shrink tubing in the past, but I’m not sure there’s enough space for that approach in this case.
Hoist solution: just like you once posted a video of raising/ lowering your mag 77 by the cord without it bearing on the connection itself. Redistribute the load, find a way to put the weight on the cord, not the connection. I'd probably weld a bracket to the hoist case and secure the cord to it. Thanks for sharing your craft!
Well, the very simple and easy fix for that White wire connector is to just use a set of pliers, and crimp it closed a bit. It will create a tighter friction fit, and not come loose as easily. Pretty easy "Non-Electrician" fix, if you ask me!! 🤣😂😉 Keep up the great work!
I'd try crimping that wire connector in the hoist so it has a bit more friction holding it together. Looked a little wobbly from the video.
Hoist. Release the clamp. Strip back the cable jacket farther giving you more slack. Reattach the cable strain relief farther down. Loop and bind the control cord and hang to release tension while doing this.
I wonder what it's to be used for. I had an 11meter I beam to which I welded about 1.5meter heavy right angle steel at right angles about a foot from each end. This enabled me to sit the beam atop two poles ( set into the ground ) and then bolt into them through these two downriggers. This forms the entrance of my openspan 11x 6 meter implement shed.
Throw a sash chain (or facsimile) loop around the case of the hoist loosely. Then put a knot in the cable around the chain. The chain takes the cable load and there is enough slack in the connection to move some without being pulled apart.
You should carefully crimp the 2 edges of the white connector which contact the blade to provide a little more friction
thank youbGod bless you!
So good! Thank you Scott
Female spade connectors will spread apart and not grip the male spade connector as tightly as it should. Using a needle nose pliers down the center of the female spade connector will tighten it up so it grips the male spade connector with more force and be far less likely to pull lose.
External strain relief, small chain attached to upper hook or re work the internal strain relief to be tighter.
Lightly crimp the terminal end spring arms. It will need 'encouragement' to be placed back into position. But once there should stay friction locked into position.
For your jib crane there are a few different options there are standard cord grips that have a tapered plastic insert and a nut to grip the cord or there are woven cable grips similar to Chinese finger cuff toys. 13:28
A better wire choice for welding would have been E71T-1 flux core with gas. (aka dual shield) Usually used is .045. Change feed roll, liner, and contact tip. Much better structural wire. Basically 7018 in a mig wire. Also, can you put a plate across the splice? Would be perfect application for using a magnetic drill. Keep up the good work....!!
"Stop polishing the opal"... in my business, we had an analogous saying: "Better" is the enemy of "good enough." Well done!
Just lightly pinch each edge of the blade connector on the end of the white wire. Not enough to close the gaps.. just a handshake squeeze.
I repaired professionally. This is all you need.
Hola, interesante video; soy técnico electrónico y trabajo reparando ascensores, por lo que conozco los problemas de conexiones de partes con movimiento y vibraciones; parece que ese cable está muy justo y tirante, por lo que será el primero en desconectarse, cuando eso haya pasado varias veces el terminal hembra tipo pala se va abriendo y la conexión empeora. La solución más rápida es dejar la entrada de cable mas dentro del polipasto para que haya más cable sobrante en el interior, poniendo unas nuevas abrazaderas; se pueden doblarlas pestañas del terminal con unos alicates o cambiar el terminal hembra de conexión por uno nuevo. Existen terminales de seguridad con una pestaña siendo necesario hacer un pequeño agujero en el terminal macho; obviamente antes de cualquier intervención es necesario haber desconectado la corriente y esperar a que el condensador se descargue.
You can crimp down the female blade connector with a pliers to make it bite more.
I’d also use a cushion clamp on the power cord and attach it to a housing screw/bolt in order to secure it up.
Great video today. Great thoughts on the opal.
Concerning your white wire just take your pliers and squeeze that connector a little bit to make it fit tighter on the lug. Or if you want to Make a permanent fix cut the connector off and solder the wire to the lug. Great video keep em coming!
Just try squishing the connector on the Hoist when they become loose I just use my Leatherman to squish them down a little to make them tight
If you can just crush the spade connector a little where it slides on to tighten up the friction fit. As others said prob change it out to a longer wire to take the tugging off.
You could try putting a kellems strain relief on the cord. It will keep it from being pulled down and making the wire unplug or a cheaper way you could slide the wires through the strain relief farther so you have plenty of slack on the wires and put a couple zip ties on the top side of the strain relief so the wires can't be pulled down
I have a friend that can do that. He just uses air cooling, does other things during that time. No beam is straight from the mill, in most applications they are good enough. But some times they have to be straight within less than 1/8 of an inch. So you take a torch and straighten it.
Yes, please show us where you are going to install this beam!! Thank You..KUTGW
@johnadolph4094, more of your vast knowledge put to good use fella!
@Scott, regarding your overhead winch - just put a cable-tie in the inside part (inside the housing) of the anti-strain boot and it will stop the pull-out. And do yourself a favour and squash the male blade connector with a pair of plyers, to give it a bit more grip tension, so its not as loose.
kind regards
Spen
I was going to suggest squishing the blade n that too. would help the pulling on it.
Regarding the white wire unplugging on the hoist - Drill a small hole through the connectors, with it plugged, and then "twist tie" it with a short piece of copper wire.
Simple fix to the crane. Cut loose connector off and replace with a new tight one. Then a thick zip strip where power cord feeds inside housing and zip strip right outside the housing. Like a rubber grommet without the rubber or grommet 🤔🙄 Retired Veteran here making quick or possibly long term fix to complete the mission. Have a good one 👍
There is a book Lincoln Arc Welding Procedure Handbook you should have in your arsenal! It has a excellent section on flame straightening and bending.
Great video as usual! I'm always impressed, and comforted watching your content. I'm just a bit younger than you and remember a time when people got their hands dirty a lot more often! I wonder if simply extending that white white a few inches would allow for that control cable to swing around, and not pull that blade connector loose?
For the lift, Looks like making the white wire a little longer and snugging up the spade terminal with pliers.
For the beam, Probably a good idea to gusset that butt joint weld with some strapping on the both sides of the web and top and bottom of the flange. Especially since it will likely be the center of the span and highest stress area
Fit a tiny chain onto the crane and attach the cable to it with some slack on the top. In this way You pull the chain to move the crane and not the cable.
Concerning the white wire in the hoist: I wouldn't change anything, otherwise the next time the crane breaks you won't know what the cause is. 😆
Just put couple strands of thin copper wire like a wedge over the plug. You could ever hammer the wire thinner to get the gauge you need then plug wire back in and bam it should be good to go. Those plug’s are useful but can be a pain in the but I find wedging a thin piece between that loose connection makes a big difference
You probably got that thing straightened to within the allowable steel mill tolerances, which are pretty loose. My bigger concern is welding two beam sections together. I'm a structural engineer, not a welder--but I know you need to consider a lot of stuff like pre-heating the steel in order to get a weld you'd stake your life on..
Preheating is not required unless the thickness is over an 1 1/2 or the steel temp is under 70 degrees depending on what coad you are working under
@@russelltreat4572 Thanks!! Good to know.
Great job. Thank you 😊
if you had some big pieces of chanel you can tack that on the opposite side as your welding and itll help keep it from drawing on you so much. i used to do that and it worked for me .
You can squeeze those crimps with pliers just a bit to give them a better grip. Probably have to get the plastic insulator off first. Or put a new crimp on.
You can get one of those mesh strain reliefs and install pretty easily. Just unhook the wire, replace the fitting that goes through the hole, and put the wire back in. Pay attention to the wire and hole diameter when you buy it, there are different sizes. You can get them from supplyhouse, or I'm sure somewhere local.
Simply amazing
Squeeze in the tabs on that spade connector a little and it will grip more.
That was awesome.
Can you extend the length of the white wire and add a loop so it’s not taking stress during flexing?
thxs for sharing...
install a small cable as a new strain relief, thats what I would do on similar cranes I used to work on