Here are the several ways that lathe mfgs. designed protection for your lathe's gears & lead screws. Did you know that I have almost 900 shop videos for your viewing pleasure? Please subscribe.
A tip for saving the old style break-away (frangible?) lead screw bearings from breaking in a lathe crash: I mount mine with nylon hex head screws. They are strong enough to stand up to reasonable cut depths, but will still shear in a crash, saving the bearing. Carelessness and inexperience have resulted in two crashes in my shop, and the nylon screws saved the day. Last time I looked, the bearings go for about $50 on eBay. Thanks Lyle for the great videos! I would like to see one on adjusting the Craftsman lead screw clutch.
20:10 - I never knew what that was for, certainly explains a lot on how it was built. My machine is also in pristine condition... the original owner purchased it in August 1961, and owned it all his life. After he died, his children didn't know what it was and while working for his son we were talking about machining one day. He brought me there and asked if I would be interested in buying it for $300. I don't think I ever ran to the bank that fast in my life.
I remember when I was in Tech School, after HS we had just got a new bench digital VOM in the shop. The instructor was thrilled ... Within 2 days one of my fellow students smoked it like I have never seen an instrument destroyed in 40 years of being a electronic technician. The instructor was ex military, nicest politest gentlemen I have ever meet. He took the cover off looked inside and said three words....'' this is skrewed''...he just walked off went to his office and stayed there for an hour... And no one bothered him.....
Well understand Keith , he was a smart kid, more intelligent than myself, I went to school with him since the 1st grade.He went on to be a Instrument tech , Got a Bachelor Degree in Computer Science. The instructor or anyone else was never able to simulate or figure out why the VOM, a B&K with them old big red LEDS, sent a cloud of smoke up 10 foot high. He and his lab partner were on a training bench just like everyone else, most of us were using Simpson 260's, low V and I . I have trained technicians myself out of tech schools on the job. That is when you learn to respect what MrPete, my instructor, experience and go through . If it were not for them their patience and caring I and many others would be living in a " leaky camper down by the river "
A friend of mine ruined a cutting tool on the lathe in school. Our metal work teacher walked up and looked at it and said 'it's as good as raped' and walked off. There's no restriction on bad language in schools in Ireland
Mr Pete, When I was in my first year HS machine trades, I was doing turning towards the chuck on the lathe with the power feed on. I had a 123 block [I was so proud of just making it that week had to carry it around I guess] in my top apron flap pocket, and as I was leaning over the lathe it got wedged between the live carriage handle and the locked crossfeed handle. I was caught there off guard a bit and "SNAP" went the shear pin!
This video was a good idea; I too noticed the confusion in the comments of the carriage stop series, this is a good answer to those questions. I had to smile when Mr. Pete talked about his videos on fixing the gear box on that Logan Lathe; that's how I discovered him. I had bought a lathe with a badly damaged gearbox and while searching online for repair help I came across that video. Got hooked on Tubalcain videos then and have been here since.
I also have an 820 that is currently having it's gearbox "rebuilt" by me. I watched MrPete's videos on the topic quite some time back and have an order into McMaster for the gears. The P.O. let the handle shaft come out the one end and it chewed 4 gears. MrPete, Given the nature of the 820 gearbox, would you personally use an alternative material gear instead of the typical steel spurs ? As it stands, I am needing a 40t & 22t for one handle, and 2 sets of the 32/16t combo. Current Logan pricing totals $610 for those and after a rather unpleasant conversation with Scott L. regarding his practices, I decided after all these years to just do them myself. ($177 from McMaster + my time) Todd
Although I don't own a lathe, I enjoy your articles. My connection to a machine shop was limited to classes I took several years ago in order to make some parts I needed. The main one was a one-piece flywheel I designed for my factory turbocharged 1965 Corvair Corsa. GM designed the flywheel as a three piece assembly held together by rivets. Whenever the rivets failed - and they eventually would - it allowed the flywheel to move off-center, away from proper alignment, causing the aluminum starter nose to break the next time the starter was used. Then it wouldn't start again until repaired. Solution: Replace the flywheel with a one piece unit and eliminate the problem forever. And it worked perfectly. Other viewers have probably already responded in the manner I'm about to suggest, but in case they haven't... Through your illustrations and descriptions, I think it would be a rather simple task for anyone with an unprotected lathe to make and add such protection via a shearpin or clutch located at the head end of the lead screw. Per your comments, I would suggest trying the smallest, i.e. weakest, shearpin that works; I believe you stated that 3/32" aluminum was used. If that proved too weak for ordinary usage, gradually increase the size but do not exceed 3/16" under any condition. Other arrangements such as adding a clutch should work as well. Again, use the weakest setting that allows normal usage without continuously interrupting operation. Do you agree?
Mr. Peterson, as I've said before, I love your videos and always learn something from them. I have an Atlas, Jet and Clausing-Colchester, and never knew anything about a clutch or shear pin on any of them. Several years ago I crashed my Jet, and stripped out the feed gear. Parts are no longer made for it, but support at Jet told me where to find a replacement gear and I got it up and running again. At 64 years of age, I hope to never stop learning, and hope you keep your videos going for a long time. Thank you again for the service you provide! In past correspondence I told you that you remind me of my Junior High and High school shop teachers. They made going to school worthwhile, and watching your videos is liking stepping back in time!!
Shortly after my dad purchased his 13" Sheldon Lathe (used) in 1977, he stripped the bakelite gear in a mild crash (by overdriving the lead screw trying single point threading, IIRC). I remember it quite vividly, because I was making my Pinewood Derby car, and it was missing one of the axles (really, just a short brad), so I went to my dad. He mentioned he could make one, but he was waiting for a part for his lathe... it dawned on him shortly after that he didn't need the powerfeed to trim a 20p nail down (we selected the nail based on the head size). He let me set the cross-slide on the lathe and 10 minutes later, we had a new axle for my pinewood derby car which looked identical to the stock part. From then on, I was hooked on machines. I was about 9 or 10 years old at the time... two weeks later, I watched him replace the bakelite gear. I used that lathe quite a bit until we sold it in 1991.
Thank you for being a great RUclips teacher for doing a Thorough explanation in all your videos! I had metal shop 4 years back in the mid 70s and my teacher was horrible at teaching and more interested in telling jokes... I have used aluminum cotter pins as sheer pin replacement and they work great!
Oh crap - I've got a 1950 Sheldon 13 inch with brass or bronze gears in the reversing mechanism where you showed the fiber ones. - and my lead screw has a steel roll pin attaching it to the gearbox. So, no protection at all. Looks like I'd better try out some aluminum rod for a shear pin. Great info as usual. Thanks for sharing.
Mr Pete , I own 2 Sheldon lathes a 10" built in 1952 and a 11" built in 1977 the 11" has a reeves drive . The gear train that transmit the power from the spindle to the quick change gear box have a mix of gear materials , micarta , Aluminum and cast iron , when I purchased the 10" lathe I contacted National Acme to purchase a spare micarta gear . I was asked if I had one and I responded yes and they told me that I would never need to replace that gear as the mix was done to keep noise down not to act as a safety . the out put shaft on the quick change has a Aluminum taper pin . I have owned the 10" for 33 years now and the micarta gear is still in good shape . When I worked in a tool shop I used a 17" Sheldon daily another fine machine . Hats off for National Acme for being honest as that gear at that time (1984 ) cost $56.00. Keep making these videos .Jeff
Super useful. Alas I did crash my Myford ML7 a small UK lathe (3.5 inch, 20 inch between centres), v belt, no clutch. On the one I have (3/4 inch lead screw) there is, as far as I know, no shear pins or fragile bearing housing. One moment I was happily machining a part, focused on the cut, not watching the carriage approach the stop. Then there was a bang, then no power feed & part of the half nut fell. I felt terrible like I had killed the goose that lays golden eggs.
Excellent video. Great reminder on how attention to the small things can often save expensive equipment from complete failure. When I purchased my 15" engine lathe I had to repair unexpected damage to the lead screw. On this machine both the lead and drive screws are connected to their respective portions of the gearbox with collars. Both were double pinned, but the pins are likely composed of steel. To make matters worse, the safety stop bar below the screws was missing. It's scheduled for replacement but now that you reminded me I'm going to swap out the taper shear pins as well. Its always a pleasure listening to your words of wisdom!
Yep... Sheldons are very good lathes. My Sheldon has a clutch and V-belt drive. It has a "fiber" (PHENOLIC) gear at that location... I never knew why... now I know! I bought my Sheldon in a very abused state. It had about 21 thou of bed wear near the head stock, like someone was grinding on it. It was worn in many places. I had the bed re-ground and replaced the bronze bearings on the change gear box. I put a bronze bearing also on the tail stock ram. The back gear had four teeth broken off (presumably from a crash with back gear engaged). I welded-up new teeth with "high-nickel" AC rods and ground them to shape with a die grinder and a sheet-metal template... all the while in the head stock! I was not about to disassemble that head stock. It has worked fine for years. Good enough is good enough (sometimes). I am now restoring a MONARCH model 61 (16 x 108" capacity) I bought at auction in excellent condition. It takes up about 1/5 of my 1000 sq ft shop!
Fibre gears are pretty useful . On my myford I have them and on the Wong fu mini lathe as I've replaced all the gears on it with steel gears . I just 3D printed a gear and it works brilliantly on the mini lathe . Thanks for posting
Mr. Pete, I'm sure you can find some room in the basement for a nice Sheldon lathe. It's a shame to have someone knowledgeable like yourself who worked extensively with Sheldon lathes and not be able to pass on the experiences. My Sheldon and I sure would appreciate a Sheldon Lathe series :)
They are still around but everyone seems to want a South Bend and overlook the Sheldons. Admittedly there are almost no parts available for them including the composite Formica gears you mentioned. I had to make mine out of brass as the last one I sourced was $230 each.
To adjust the clutch in the craftsman there is a collar that is threaded. To tighten the collar you will need a spammer wrench. You turn the collar clockwise to tighten. I guess I was being dense about it, but I looked at it for days before I figured it out.
When I was teaching machine shop we had several Powermatic Logan lathes. One of my little dears decided it would be a good idea to place both gear change levers in the far left set of pin holes. Turning the machine on resulted in the immediate fracturing of a change gear inside of the box. It was a fairly expensive and very time consuming repair, forcing me to completely dismantle the box to replace a single gear no bigger than a quarter. I was of course fit to be tied! After that I made it a point to make sure that students knew not to place the levers in the same side of the box together. In some respects you hate to tell the kids that doing something will result in destruction of the machine, most kids don't want to do harm, however some do.
Thanks for the vid Mrpete. I'm not a machinist at all but I am a welder by trade and I watch your vids and others just because I too deal with metal of all sorts and having just a cursory knowledge of machining gives me a advantage when working out a problem. In other words I don't come off like a idiot when talking to the machine shop lol Anyway, thanks for the time you put into teaching some of us knuckle heads a few things. 😀
I have a Sheldon 11-44 bought in 1952 and is in good to great condition. A bit dirty but in use 3 seasons of the year. Been light hobby use since purchase. MotoWanderer - I do have documents - part lists... for a number of models.
Mr Pete, I think I’ve seen someone make a modification to his small lathe, he made his own sheer pin clutch on his feed screw. Because the original support at the end of the feed screw was broken. So it’s possible to make the alteration and add that feature to lathe that doesn’t have any protection. But you need to cut the feed screw at the proper point and machine it to add that sheer pin feature or clutch/sheer pin assembly. And it does work !
I suspect the change from leadscrew shear pin to slipping clutch was because some operators replaced a failed soft pin with something handy and far too strong, like a nail. I would be interested to see how the leadscrew clutch works. Thanks for yet another thorough and intersting video. Clearly you can never have enough lathes! Bob.
I imagine that the spindle clutch comes in very handy when cutting screws. Is that so? Perhaps what is needed for that is a half-nut clutch? Today's video was full of great lessons. Thanks so much.
Random extra bit of info. I noticed a comment somewhere that Colchester "Student" lathes run the nut off the crossfeed screw at both ends for a little extra protection. Why did I notice? Because during a momentary loss of concentration I engaged the crossfeed on my Logan 200 when it was feeding out and at the end of its travel, and busted the miter gear bearing post (didn't help the gear much, either). I was so distressed about breaking my little lathe that I almost threw up. I still consider turning the inboard threads off the crossfeed screw to keep that from ever happening again. Love your stuff, Mr. Pete. This kind of education is one place the interwebs live up to their potential.
Very interesting Mr Pete. Thanks for the in depth look. I guess with the exception of the flat belts, none of these protect from someone manually winding the carriage into the chuck which is something I would probably do!. I'm not too bright!
For the shear pin you might like to try an aircraft rivet. Made of aluminium alloy. The Number would be something like AN470AD-3-16 This would get you an rivet with a dome head and 3/32 thick and 1 inch long. Adjust the last number as required for correct length. They have a higher shear resistance then pure aluminium, thanks for the videos Gregg
anther great video Mr Pete thank for sharing your knowledge on crashing a lathe I was wondering if you could do video on your thoughts on lathe level and how a home Shop could do it
Pleased to learn that my Craftsman lathe has the clutch! I inherited it from my father. Bought a Chinese tool holder for it. I spend more time on my wood lathe and watching Tubalcain on RUclips, though.
Very interesting, thank you Mr Pete ! My ancient Standard Modern (12") has a shear pin on the lead screw, and a shear key on an external gear. I'm not sure why it has double protection, and hopefully I will never need to replace either piece
I want to make a power cut carriage stop now, a stop button fitted to a movable clamp on the bed that cuts power to the motor when touched. Seems like a decent solution for the smaller or older lathes out there, mine is 100 years old this year so it lacks basically any safety features.
When I was in high school we got a new trade school, 1973 I was in welding shop but we made racks for machine shop they were still setting up the south bend 13 lathes I heard the machine shop teacher tell my mine that the 13 south bends were idiot proof ! When they closed down the shop classes in 2002 , lack of interest I bought one of the sb13s and a 300 amp Lincoln tig welder they were sitting outside uncovered ! At the auction I payed 600 for the lathe 350 for the Lincoln.
I've used a lathes only a few times in my career, so when I read the title of this vid I envisioned the twisted metal of a wrecked truck hauling a lathe... Hahahaha different sort of crash altogether!
Thanks, Mr. Pete. Really interesting and useful review of the different design approaches taken. It would seem that the shear pin is the cheapest and most idiot proof. I don't see why you couldn't add it to any lathe's lead screw as added protection. A coupling with 2 aluminum pins holding it to the two parts of the lead screw shaft after you cut it. Would be very worthwhile considering that parts (gears, etc.) are sometimes impossible to find if the worst happens. Our basement systems are usually old and have suffered for lack of maintenance and maintenance by previous owners. Doesn't seem to make good sense to rely just on an old stiff belt, a maybe frozen clutch, or other design feature that may no longer be working.
Recently got a 1940's era 6" craftsman (Atlas I believe) 109 and thought of you immediately because the compound shows the machine has been crashed a few times, but ... the compound is still functional.
Very informative video Mr Pete. Now you have me thinking how I can retrofit a clutch on my Atlas TH54 Heavy 10 that does not have one. Perhaps a simple shear pin type. I think it would involve parting the lead screw. Yikes! One of my night mares is that I somehow crash the lathe, break gears and have to locate, purchase and replace replace the broken gears.
I am a newby at this. Self taught until I discovered Mr Pete, Boy have you taught me a great deal!!!! I have a Craftsman 12. My question is I have always cut from right to left, All you videos you go left to right. When you mentioned about the thrust bearing on the end of the screw made me wonder if I need to change?
We set up a back up alarm from a fork lift on a push button. If set properly it beeps for 60 seconds before the carriage hits the stop. You can hear it anywhere in the building. We have a lablond lathe.
We set that up because we had to knurl 44 rods for one of our processing machines. Took about an hour per rod. Couldn't take standing at the machine for that long but didn't leave the room for safety. Also helped myself and my coworker would take turns.
Seems to me that a fella might do a fair amount of business making a casting and pouring copies of that Craftsman/Atlas lead screw bearing out of aluminum!
I Cant talk about other VFD but the Invertek optidrive one I have will kill the power if it senses an over load. I can vouch for that as when I had a senior moment and turned the carriage handle the wrong way and crashed the tool into the work piece the VFD shut the power off. The Lathe also has a clutch on the lead screw and drive bar
Some may not know this but if you want to support this channel and can not monetarily do that, by watching at least 31 seconds of the intro ad videos before hitting the " skip video " button, that adds to the revenue for mrpete222.
I replaced drive with a nylon gear to protect mine in case of crash,,the quick change gear box gears are steel where side gears are zmak,,so they should strip before gear box gears,, and the nylon gear I added between them will strip first,,as well as I changed it from 40 teeth to 20 to slow feed rate to .0021,,,giving a fine finish,, l have to multiply chart by 2 for treading and lose first row on chart,,,that's a very course tread anyway..
One point about the Atlas clutch is that is really is not good to get oil on the clutch. You won’t be able t do the lightest cut or threading without the clutch slipping.
Quite interesting. I have a Clausing 5900 12" I know now the kind of sheer pin to use. I thought they were steel taper pin. Someone even told me to replace it with a on old drill. It is not a good advice to do that. Thanks.
Interesting video. I have a Sheldon EXL listed as a 10" but some call it an 11". Anyway the parts manual I have is not identical to my lathe and it shows there are two fiber gears. Mine has steel (cast) gears and they are not replacements for the fiber ones BTW. These have part numbers cast into them so I know they are real Sheldon gears. I have no plans on crashing this machine (who does???) however if it were to happen I am wondering if I could replace the taper pin on my lead screw with another material to prevent damage??? Thanks
20:40 - I wonder about the Atlas book statement about the breakaway lead screw tail support breaking if you crashed into the tailstock? If the carriage was driving to the right, wouldn't the load be pushing to the left - against the gearbox instead of the tail support?
On the lead screw tail bracket, instead of a break apart design, could instead replace the mounting bolts to a soft material, aluminum, and let them act like a shear pin? Seems like it would accomplish the same task, but not destroy the bracket.
I have a Clausing 5912 lathe which is pretty much the exact same as yours. Clausing still has the shear pins available by the dozen. When I first got the lathe I considered swapping them for something else, but soon changed my mind as this would sure protect much more costly parts. I have sheared them twice and both times were when I was trying to make too heavy a cut on Stainless Steel.
Now I know why the bearing support on my Atlas has been repaired by welding. Unless there are special Zamak rods this must mean that you can weld it with pot metal rods for gas welding.
When you turned the compound on the lathe in the garage, I saw a bolt drop down on the side. I'm not sure if you knew that or not??? Just trying to save a later problem for you.
Do you know if there is an adapter to fit a keyless chuck J6 taper to a craftsman drill press with J33 spindle? Thanks for great videos. Started watching you several years ago. Thanks
I see a potential problem with that leadscrew clutch. If you should ever "activate" it while single point threading, you would lose your indexing and have to try to pick up the thread as though you had removed the part from the chuck and replaced it. Possibly doing whatever it takes to make that clutch slip would be a bigger problem while threading than losing the indexing.
At or around 25:49 you can see that lever sticking out of the head stock right above the threading rod clutch, what does that lever do? I have the exact lathe and am in the process of taking it apart it is full of thick nasty hardend grease and i will be pai ting it its original color but other than that its a little surface rusted but cannot seem to see what that lever does it engages the big gear inside but doesnt spin the outside shaft. The book mine came with got wet to
That looked like an aircraft rivet--and they're made from 2117 alloy. That would explain why the hardware store aluminum rod, likely 5052 (or softer), sheared easily.
Lyle, do you think the shear pin on the Logan lathe was a stock item or did someone cut the lead screw and make the collar ? My 1942 model 200 has had a gearbox added some time in its life. Since it has neither shear pin nor clutch on the carriage I would like to add some protection for my next Ah S___t Moment . ( which I hope never to repeat ) . Great video , I always lean something from them . Thanks again
i am not going to read all your comments to see if somebody saw a same thing i did on your logan 820 you did not put the compound nut back on that T bolt and as you were turning the compound the bolt fell down in to the cross slid so now its all jammed up . the bolt more then likely is a 5/16 x 18 that would have a 1/2 head but in the lathe world they like to go a size bigger so 9/16 head and thinner i have a clausing 4804 that i have been putting back together in been in parts for the last 20 years about done with it but i was missing one of them nuts so i took a 3/8 x 16 bolt put it in the lathe and faced it drilled an F hole in it and tapped it to 5/16 x 18 cut it off and faced that side and there was my nut no turning a log in to a tooth pick or 9/16 th hex stock that's what i love about machining your imagination is your limitation
Наука
A tip for saving the old style break-away (frangible?) lead screw bearings from breaking in a lathe crash: I mount mine with nylon hex head screws. They are strong enough to stand up to reasonable cut depths, but will still shear in a crash, saving the bearing. Carelessness and inexperience have resulted in two crashes in my shop, and the nylon screws saved the day. Last time I looked, the bearings go for about $50 on eBay.
Thanks Lyle for the great videos! I would like to see one on adjusting the Craftsman lead screw clutch.
20:10 - I never knew what that was for, certainly explains a lot on how it was built. My machine is also in pristine condition... the original owner purchased it in August 1961, and owned it all his life. After he died, his children didn't know what it was and while working for his son we were talking about machining one day. He brought me there and asked if I would be interested in buying it for $300. I don't think I ever ran to the bank that fast in my life.
Right place---Right time
I remember when I was in Tech School, after HS we had just got a new bench digital VOM in the shop.
The instructor was thrilled ...
Within 2 days one of my fellow students smoked it like I have never seen an instrument destroyed in 40 years of being a electronic technician. The instructor was ex military, nicest politest gentlemen I have ever meet. He took the cover off looked inside and said three words....'' this is skrewed''...he just walked off went to his office and stayed there for an hour...
And no one bothered him.....
Been there--DONE THAT!!
This really made me laugh! Some people really just have a knack for just destroying things without even trying.
Well understand Keith , he was a smart kid, more intelligent than myself, I went to school with him since the 1st grade.He went on to be a Instrument tech , Got a Bachelor Degree in Computer Science. The instructor or anyone else was never able to simulate or figure out why the VOM, a B&K with them old big red LEDS, sent a cloud of smoke up 10 foot high. He and his lab partner were on a training bench just like everyone else, most of us were using Simpson 260's, low V and I . I have trained technicians myself out of tech schools on the job. That is when you learn to respect what MrPete, my instructor, experience and go through .
If it were not for them their patience and caring I and many others would be living in a
" leaky camper down by the river "
A friend of mine ruined a cutting tool on the lathe in school. Our metal work teacher walked up and looked at it and said 'it's as good as raped' and walked off. There's no restriction on bad language in schools in Ireland
Thanks for watching
Mr Pete, When I was in my first year HS machine trades, I was doing turning towards the chuck on the lathe with the power feed on. I had a 123 block [I was so proud of just making it that week had to carry it around I guess] in my top apron flap pocket, and as I was leaning over the lathe it got wedged between the live carriage handle and the locked crossfeed handle. I was caught there off guard a bit and "SNAP" went the shear pin!
Freak accident
This video was a good idea; I too noticed the confusion in the comments of the carriage stop series, this is a good answer to those questions.
I had to smile when Mr. Pete talked about his videos on fixing the gear box on that Logan Lathe; that's how I discovered him. I had bought a lathe with a badly damaged gearbox and while searching online for repair help I came across that video. Got hooked on Tubalcain videos then and have been here since.
Glad you found me
I also have an 820 that is currently having it's gearbox "rebuilt" by me. I watched MrPete's videos on the topic quite some time back and have an order into McMaster for the gears. The P.O. let the handle shaft come out the one end and it chewed 4 gears.
MrPete, Given the nature of the 820 gearbox, would you personally use an alternative material gear instead of the typical steel spurs ? As it stands, I am needing a 40t & 22t for one handle, and 2 sets of the 32/16t combo. Current Logan pricing totals $610 for those and after a rather unpleasant conversation with Scott L. regarding his practices, I decided after all these years to just do them myself. ($177 from McMaster + my time)
Todd
Although I don't own a lathe, I enjoy your articles.
My connection to a machine shop was limited to classes I took several years ago in order to make some parts I needed. The main one was a one-piece flywheel I designed for my factory turbocharged 1965 Corvair Corsa.
GM designed the flywheel as a three piece assembly held together by rivets. Whenever the rivets failed - and they eventually would - it allowed the flywheel to move off-center, away from proper alignment, causing the aluminum starter nose to break the next time the starter was used. Then it wouldn't start again until repaired.
Solution: Replace the flywheel with a one piece unit and eliminate the problem forever. And it worked perfectly.
Other viewers have probably already responded in the manner I'm about to suggest, but in case they haven't...
Through your illustrations and descriptions, I think it would be a rather simple task for anyone with an unprotected lathe to make and add such protection via a shearpin or clutch located at the head end of the lead screw.
Per your comments, I would suggest trying the smallest, i.e. weakest, shearpin that works; I believe you stated that 3/32" aluminum was used. If that proved too weak for ordinary usage, gradually increase the size but do not exceed 3/16" under any condition.
Other arrangements such as adding a clutch should work as well. Again, use the weakest setting that allows normal usage without continuously interrupting operation.
Do you agree?
Mr. Peterson, as I've said before, I love your videos and always learn something from them. I have an Atlas, Jet and Clausing-Colchester, and never knew anything about a clutch or shear pin on any of them. Several years ago I crashed my Jet, and stripped out the feed gear. Parts are no longer made for it, but support at Jet told me where to find a replacement gear and I got it up and running again.
At 64 years of age, I hope to never stop learning, and hope you keep your videos going for a long time. Thank you again for the service you provide! In past correspondence I told you that you remind me of my Junior High and High school shop teachers. They made going to school worthwhile, and watching your videos is liking stepping back in time!!
Shortly after my dad purchased his 13" Sheldon Lathe (used) in 1977, he stripped the bakelite gear in a mild crash (by overdriving the lead screw trying single point threading, IIRC). I remember it quite vividly, because I was making my Pinewood Derby car, and it was missing one of the axles (really, just a short brad), so I went to my dad. He mentioned he could make one, but he was waiting for a part for his lathe... it dawned on him shortly after that he didn't need the powerfeed to trim a 20p nail down (we selected the nail based on the head size). He let me set the cross-slide on the lathe and 10 minutes later, we had a new axle for my pinewood derby car which looked identical to the stock part. From then on, I was hooked on machines. I was about 9 or 10 years old at the time... two weeks later, I watched him replace the bakelite gear. I used that lathe quite a bit until we sold it in 1991.
good story-Thanks for watching
Thank you Mr. P. Just remember what we say in the Government...we declare that "No horse is too dead beat.
Always a pleasure to watch and much appreciated.... TM
Thank you for being a great RUclips teacher for doing a Thorough explanation in all your videos! I had metal shop 4 years back in the mid 70s and my teacher was horrible at teaching and more interested in telling jokes... I have used aluminum cotter pins as sheer pin replacement and they work great!
Sorry to hear that you had a terrible teacher.
Thanks for the explanation. I have been wondering about this every since you made the stop.
Oh crap - I've got a 1950 Sheldon 13 inch with brass or bronze gears in the reversing mechanism where you showed the fiber ones. - and my lead screw has a steel roll pin attaching it to the gearbox. So, no protection at all. Looks like I'd better try out some aluminum rod for a shear pin. Great info as usual. Thanks for sharing.
Thanks for watching
Mr Pete , I own 2 Sheldon lathes a 10" built in 1952 and a 11" built in 1977 the 11" has a reeves drive . The gear train that transmit the power from the spindle to the quick change gear box have a mix of gear materials , micarta , Aluminum and cast iron , when I purchased the 10" lathe I contacted National Acme to purchase a spare micarta gear .
I was asked if I had one and I responded yes and they told me that I would never need to replace that gear as the mix was done to keep noise down not to act as a safety . the out put shaft on the quick change has a Aluminum taper pin .
I have owned the 10" for 33 years now and the micarta gear is still in good shape .
When I worked in a tool shop I used a 17" Sheldon daily another fine machine .
Hats off for National Acme for being honest as that gear at that time (1984 ) cost $56.00.
Keep making these videos .Jeff
Thanks for watching--good story
Thank You .If you were my shop teacher I would have spent less time as an apprentice.
No wonder I had trouble finding a used lathe.....you have all of them! lol Another informative video.
Thanks for watching out for us Mr. Pete!
Excellent walk through of the many methods used for protection. Thanks for sharing.
Super useful. Alas I did crash my Myford ML7 a small UK lathe (3.5 inch, 20 inch between centres), v belt, no clutch. On the one I have (3/4 inch lead screw) there is, as far as I know, no shear pins or fragile bearing housing. One moment I was happily machining a part, focused on the cut, not watching the carriage approach the stop. Then there was a bang, then no power feed & part of the half nut fell. I felt terrible like I had killed the goose that lays golden eggs.
Excellent video. Great reminder on how attention to the small things can often save expensive equipment from complete failure. When I purchased my 15" engine lathe I had to repair unexpected damage to the lead screw. On this machine both the lead and drive screws are connected to their respective portions of the gearbox with collars. Both were double pinned, but the pins are likely composed of steel. To make matters worse, the safety stop bar below the screws was missing. It's scheduled for replacement but now that you reminded me I'm going to swap out the taper shear pins as well. Its always a pleasure listening to your words of wisdom!
Thanks for watching
I don't own a lathe but sure appreciated the video and information. Thank you!
Great video to start off my Sunday. Thanks, Mr. Pete.
Thanks for watching
My 6900 had a durn nail in it when I got it. I'm still bringing her up to snuff, so this is really timely. THANK YOU!!
Excellent study of this topic!
Yep... Sheldons are very good lathes. My Sheldon has a clutch and V-belt drive. It has a "fiber" (PHENOLIC) gear at that location... I never knew why... now I know! I bought my Sheldon in a very abused state. It had about 21 thou of bed wear near the head stock, like someone was grinding on it. It was worn in many places. I had the bed re-ground and replaced the bronze bearings on the change gear box. I put a bronze bearing also on the tail stock ram. The back gear had four teeth broken off (presumably from a crash with back gear engaged). I welded-up new teeth with "high-nickel" AC rods and ground them to shape with a die grinder and a sheet-metal template... all the while in the head stock! I was not about to disassemble that head stock. It has worked fine for years. Good enough is good enough (sometimes). I am now restoring a MONARCH model 61 (16 x 108" capacity) I bought at auction in excellent condition. It takes up about 1/5 of my 1000 sq ft shop!
Sounds like a great repair job on that Sheldon
Thank you for this video. I do have an Atlas 6" so I will be very careful with it. It was a gift from a friend. Greg
Fibre gears are pretty useful . On my myford I have them and on the Wong fu mini lathe as I've replaced all the gears on it with steel gears . I just 3D printed a gear and it works brilliantly on the mini lathe . Thanks for posting
You have an unlimited supply--with that 3d printer
this video answered a lot of questions i didn't realize i had until you answered them.
Thanks for watching
Very interesting - and especially valuable info if one is a new lathe owner and operator, this is must know info for first timers especially.
Another very interesting video, Thanks Mr Pete.
WE LOVE Your Videos! - Best Shop Teacher on the Net!!
Thanks for watching
I'd love to see more about setting that clutch, and how its constructed and works
Mr. Pete, I'm sure you can find some room in the basement for a nice Sheldon lathe. It's a shame to have someone knowledgeable like yourself who worked extensively with Sheldon lathes and not be able to pass on the experiences. My Sheldon and I sure would appreciate a Sheldon Lathe series :)
Great lathes--I never see them anymore
They are still around but everyone seems to want a South Bend and overlook the Sheldons. Admittedly there are almost no parts available for them including the composite Formica gears you mentioned. I had to make mine out of brass as the last one I sourced was $230 each.
if interested - I have some documents on Sheldon lathes.
To adjust the clutch in the craftsman there is a collar that is threaded. To tighten the collar you will need a spammer wrench. You turn the collar clockwise to tighten. I guess I was being dense about it, but I looked at it for days before I figured it out.
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When I was teaching machine shop we had several Powermatic Logan lathes. One of my little dears decided it would be a good idea to place both gear change levers in the far left set of pin holes. Turning the machine on resulted in the immediate fracturing of a change gear inside of the box. It was a fairly expensive and very time consuming repair, forcing me to completely dismantle the box to replace a single gear no bigger than a quarter. I was of course fit to be tied! After that I made it a point to make sure that students knew not to place the levers in the same side of the box together. In some respects you hate to tell the kids that doing something will result in destruction of the machine, most kids don't want to do harm, however some do.
Yes--I did NOT want to give them ideas!
Thanks for the vid Mrpete. I'm not a machinist at all but I am a welder by trade and I watch your vids and others just because I too deal with metal of all sorts and having just a cursory knowledge of machining gives me a advantage when working out a problem. In other words I don't come off like a idiot when talking to the machine shop lol
Anyway, thanks for the time you put into teaching some of us knuckle heads a few things. 😀
Well done, terrific video.
I have a Sheldon 11-44 bought in 1952 and is in good to great condition. A bit dirty but in use 3 seasons of the year. Been light hobby use since purchase. MotoWanderer - I do have documents - part lists... for a number of models.
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Excellent video, thanks for sharing. Peter
Thanks ! Mr Pete I learned alot
Excellent video mrpete. A lot of very useful info' there. Thanks for sharing. regards from the UK
Thanks for watching
Mr Pete,
I think I’ve seen someone make a modification to his small lathe, he made his own sheer pin clutch on his feed screw. Because the original support at the end of the feed screw was broken. So it’s possible to make the alteration and add that feature to lathe that doesn’t have any protection. But you need to cut the feed screw at the proper point and machine it to add that sheer pin feature or clutch/sheer pin assembly. And it does work !
Thanks for sharing this information.
I suspect the change from leadscrew shear pin to slipping clutch was because some operators replaced a failed soft pin with something handy and far too strong, like a nail. I would be interested to see how the leadscrew clutch works. Thanks for yet another thorough and intersting video. Clearly you can never have enough lathes! Bob.
Thanks for watching
I imagine that the spindle clutch comes in very handy when cutting screws. Is that so? Perhaps what is needed for that is a half-nut clutch? Today's video was full of great lessons. Thanks so much.
Random extra bit of info. I noticed a comment somewhere that Colchester "Student" lathes run the nut off the crossfeed screw at both ends for a little extra protection.
Why did I notice? Because during a momentary loss of concentration I engaged the crossfeed on my Logan 200 when it was feeding out and at the end of its travel, and busted the miter gear bearing post (didn't help the gear much, either). I was so distressed about breaking my little lathe that I almost threw up. I still consider turning the inboard threads off the crossfeed screw to keep that from ever happening again.
Love your stuff, Mr. Pete. This kind of education is one place the interwebs live up to their potential.
Thanks for watching
Very interesting video once again.
thank you sir ,I love your video's .they are very very informative.
Thanks for watching
This video was a "shear" delight!
Very interesting Mr Pete. Thanks for the in depth look. I guess with the exception of the flat belts, none of these protect from someone manually winding the carriage into the chuck which is something I would probably do!. I'm not too bright!
GREAT VIDEO !!!
I think that the term for castings that are designed to fail (e.g., the Atlas lead screw bearing) is "frangible". Many thanks for another fine video.
Thanks-I need to remember that word
THANK YOU...for sharing.
Thanks for watching & your faithful interest
thank you so much - now I know -- atlas old lathe - crashed it once and smashed the compound - love my lathe - more carefull now
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Thanks for sharing sir...
For the shear pin you might like to try an aircraft rivet. Made of aluminium alloy. The Number would be something like
AN470AD-3-16 This would get you an rivet with a dome head and 3/32 thick and 1 inch long. Adjust the last number as required for correct length.
They have a higher shear resistance then pure aluminium,
thanks for the videos
Gregg
anther great video Mr Pete thank for sharing your knowledge on crashing a lathe I was wondering if you could do video on your thoughts on lathe level and how a home Shop could do it
i have the exact same sheldon lathe 11" as seen on the magazine :)
Pleased to learn that my Craftsman lathe has the clutch! I inherited it from my father. Bought a Chinese tool holder for it. I spend more time on my wood lathe and watching Tubalcain on RUclips, though.
Very interesting, thank you Mr Pete ! My ancient Standard Modern (12") has a shear pin on the lead screw, and a shear key on an external gear. I'm not sure why it has double protection, and hopefully I will never need to replace either piece
I want to make a power cut carriage stop now, a stop button fitted to a movable clamp on the bed that cuts power to the motor when touched. Seems like a decent solution for the smaller or older lathes out there, mine is 100 years old this year so it lacks basically any safety features.
interesting stuff!! thank you!!!
Atlas is also very clever to design its rear lead screw support much thinner so it will break before anything else.
When I was in high school we got a new trade school, 1973 I was in welding shop but we made racks for machine shop they were still setting up the south bend 13 lathes I heard the machine shop teacher tell my mine that the 13 south bends were idiot proof ! When they closed down the shop classes in 2002 , lack of interest I bought one of the sb13s and a 300 amp Lincoln tig welder they were sitting outside uncovered ! At the auction I payed 600 for the lathe 350 for the Lincoln.
I've used a lathes only a few times in my career, so when I read the title of this vid I envisioned the twisted metal of a wrecked truck hauling a lathe... Hahahaha different sort of crash altogether!
Thanks, Mr. Pete. Really interesting and useful review of the different design approaches taken. It would seem that the shear pin is the cheapest and most idiot proof. I don't see why you couldn't add it to any lathe's lead screw as added protection. A coupling with 2 aluminum pins holding it to the two parts of the lead screw shaft after you cut it. Would be very worthwhile considering that parts (gears, etc.) are sometimes impossible to find if the worst happens. Our basement systems are usually old and have suffered for lack of maintenance and maintenance by previous owners. Doesn't seem to make good sense to rely just on an old stiff belt, a maybe frozen clutch, or other design feature that may no longer be working.
Thank You!
Recently got a 1940's era 6" craftsman (Atlas I believe) 109 and thought of you immediately because the compound shows the machine has been crashed a few times, but ... the compound is still functional.
Thanks for watching
thank you Pete!
Thanks for watching
I remember in shop class when someone would crash a SHELDON lathe, the teacher would yell BAZINGA.
I teach a shop class, and seems like the philosophy has changed a lot, we don't do the "sink or swim" strategy any more lol
Thats for sure
Well, now I know. Thank you.
Very informative video Mr Pete. Now you have me thinking how I can retrofit a clutch on my Atlas TH54 Heavy 10 that does not have one. Perhaps a simple shear pin type. I think it would involve parting the lead screw. Yikes! One of my night mares is that I somehow crash the lathe, break gears and have to locate, purchase and replace replace the broken gears.
I am a newby at this. Self taught until I discovered Mr Pete, Boy have you taught me a great deal!!!!
I have a Craftsman 12. My question is I have always cut from right to left, All you videos you go left to right.
When you mentioned about the thrust bearing on the end of the screw made me wonder if I need to change?
I machine from right to left 98% of the time
We set up a back up alarm from a fork lift on a push button. If set properly it beeps for 60 seconds before the carriage hits the stop. You can hear it anywhere in the building. We have a lablond lathe.
Great idea
We set that up because we had to knurl 44 rods for one of our processing machines. Took about an hour per rod. Couldn't take standing at the machine for that long but didn't leave the room for safety. Also helped myself and my coworker would take turns.
Seems to me that a fella might do a fair amount of business making a casting and pouring copies of that Craftsman/Atlas lead screw bearing out of aluminum!
I Cant talk about other VFD but the Invertek optidrive one I have will kill the power if it senses an over load. I can vouch for that as when I had a senior moment and turned the carriage handle the wrong way and crashed the tool into the work piece the VFD shut the power off.
The Lathe also has a clutch on the lead screw and drive bar
It would make a good video series on how to make a clutch for the other lathe.
no entendí nada pero me fascinó la máquina!!
fyi on the later model chraftsmann lathe the internal pheonolic washers can be replaced still avaliable through saers under three dollars each
Some may not know this but if you want to support this channel and can not monetarily do that, by watching at least 31 seconds of the intro ad videos before hitting the " skip video " button, that adds to the revenue for mrpete222.
THANKS!
What happens after the bushing shears? ...its then going to want to pull from the gearbox.....what will take place there?
I replaced drive with a nylon gear to protect mine in case of crash,,the quick change gear box gears are steel where side gears are zmak,,so they should strip before gear box gears,, and the nylon gear I added between them will strip first,,as well as I changed it from 40 teeth to 20 to slow feed rate to .0021,,,giving a fine finish,, l have to multiply chart by 2 for treading and lose first row on chart,,,that's a very course tread anyway..
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One point about the Atlas clutch is that is really is not good to get oil on the clutch. You won’t be able t do the lightest cut or threading without the clutch slipping.
Quite interesting. I have a Clausing 5900 12" I know now the kind of sheer pin to use. I thought they were steel taper pin. Someone even told me to replace it with a on old drill. It is not a good advice to do that.
Thanks.
Thanks for watching--great lathe that 5900
Interesting video. I have a Sheldon EXL listed as a 10" but some call it an 11". Anyway the parts manual I have is not identical to my lathe and it shows there are two fiber gears. Mine has steel (cast) gears and they are not replacements for the fiber ones BTW. These have part numbers cast into them so I know they are real Sheldon gears. I have no plans on crashing this machine (who does???) however if it were to happen I am wondering if I could replace the taper pin on my lead screw with another material to prevent damage???
Thanks
I have a Sheldon m and just today I removed the leadscrew and it has a shear pin. I am in the process of rebuilding it.
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20:40 - I wonder about the Atlas book statement about the breakaway lead screw tail support breaking if you crashed into the tailstock? If the carriage was driving to the right, wouldn't the load be pushing to the left - against the gearbox instead of the tail support?
Someone suggested that for the South Bend 9 that you "nip" the bolt that holds the change wheel bracket to the lathe in lieu of a shear pin ?
On the lead screw tail bracket, instead of a break apart design, could instead replace the mounting bolts to a soft material, aluminum, and let them act like a shear pin? Seems like it would accomplish the same task, but not destroy the bracket.
I have a Clausing 5912 lathe which is pretty much the exact same as yours. Clausing still has the shear pins available by the dozen. When I first got the lathe I considered swapping them for something else, but soon changed my mind as this would sure protect much more costly parts. I have sheared them twice and both times were when I was trying to make too heavy a cut on Stainless Steel.
Great fuse!
Now I know why the bearing support on my Atlas has been repaired by welding. Unless there are special Zamak rods this must mean that you can weld it with pot metal rods for gas welding.
445supermag The bearing support was also broken on my atlas and someone made there own(did a good job) now I understand why. Thanks
When you turned the compound on the lathe in the garage, I saw a bolt drop down on the side. I'm not sure if you knew that or not??? Just trying to save a later problem for you.
Do you know if there is an adapter to fit a keyless chuck J6 taper to a craftsman drill press with J33 spindle? Thanks for great videos. Started watching you several years ago.
Thanks
Do not know
I see a potential problem with that leadscrew clutch. If you should ever "activate" it while single point threading, you would lose your indexing and have to try to pick up the thread as though you had removed the part from the chuck and replaced it. Possibly doing whatever it takes to make that clutch slip would be a bigger problem while threading than losing the indexing.
Will not work--you can't select the right pitch either
At or around 25:49 you can see that lever sticking out of the head stock right above the threading rod clutch, what does that lever do? I have the exact lathe and am in the process of taking it apart it is full of thick nasty hardend grease and i will be pai ting it its original color but other than that its a little surface rusted but cannot seem to see what that lever does it engages the big gear inside but doesnt spin the outside shaft. The book mine came with got wet to
That looked like an aircraft rivet--and they're made from 2117 alloy. That would explain why the hardware store aluminum rod, likely 5052 (or softer), sheared easily.
I think you are right
I'm pretty sure it's an AN426-AD-3-n rivet, where 'n' is the length in 16ths of an inch.
Lyle, do you think the shear pin on the Logan lathe was a stock item or did someone cut the lead screw and make the collar ? My 1942 model 200 has had a gearbox added some time in its life. Since it has neither shear pin nor clutch on the carriage I would like to add some protection for my next Ah S___t Moment . ( which I hope never to repeat ) . Great video , I always lean something from them . Thanks again
Thanks for watching--do not have an answer
i am not going to read all your comments to see if somebody saw a same thing i did on your logan 820 you did not put the compound nut back on that T bolt and as you were turning the compound the bolt fell down in to the cross slid so now its all jammed up . the bolt more then likely is a 5/16 x 18 that would have a 1/2 head but in the lathe world they like to go a size bigger so 9/16 head and thinner i have a clausing 4804 that i have been putting back together in been in parts for the last 20 years about done with it but i was missing one of them nuts so i took a 3/8 x 16 bolt put it in the lathe and faced it drilled an F hole in it and tapped it to 5/16 x 18 cut it off and faced that side and there was my nut no turning a log in to a tooth pick or 9/16 th hex stock that's what i love about machining your imagination is your limitation
The plastic gear was probably micarta or something similar. The kid that broke one should have learned how to make a new one. Nasty dust though.
Thanks for watching
Hi Mr.
What causes the bandsaw blade(horizontal) to cut the metal inclined .
My Regards