Toolmaking Mounting a Magnetic Chuck Part 2
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- Опубликовано: 14 апр 2016
- In this video we show some of the detailed operations to mount and true a magnetic chuck on the surface grinder. Stay until the end as we do some fussy measurements on the five block test parts. We discuss wheel grades and techniques for grinding the magnetic chuck.
I am continually blown away by how much you and the other guys know and your attention to detail. I think there should be a "Machinist Hall of Fame"! Your pool of knowledge is priceless. Thank you Tom
I really appreciate the lack of crass and crude language on this channel, very respectable
OMG .. that gauge! Great detail and great show.
+Shadon HKW Hey Stan, I've got a question for you and/or Tom...So, am I correct in thinking that 20 millionths of an inch is equal to 2 one hundred-thousandths of an inch? That is what my decimal place arithmetic tells me, but I never hear it said that way. Is that just because it's a mouthful, or is there another reason? Thanks and I hope you all have a great weekend...Aloha, Chuck
+Knolltop Farms I've wondered the same thing, just always assumed it was difficult/confusing to say.
+Knolltop Farms Precisely my question. I would have said two 100,000ths by default. Why is that Tom? Tens of millionths seems like saying it's 20 to three (o'clock) instead of 2:40. Also we have near certainty that Tom is warm blooded.
+Shadon HKW do you recall when you rebuilt your grinder you discovered that you had a 1/10th increase in chuck height when moving the table side to side due to the oil being taken up onto the ways?
Might this account for what seems to be hollows in the middle of so many mag chucks on surface grinders?
As always, precision eventually come from attention to detail. I have the greatest respect for people working in production using methods based on high levels of automation, but you and others in this group are building a knowledge base that is priceless. When it comes to making the machines that provide efficient production there is still someone at some point who is willing and able to "fuss" with them to get them out the door.
4:40 At the rifle range where we shoot Anschutz target .22 rifles for competition, during practice nights the sound of a 4mm allen key hitting the floor is by far the most recognizable sound there is. Followed by getting out of position to pick it up off the floor.
Excellent, Tom. Good to see my rants on the effect of thermal expansion on precision measurement unimpeachably confirmed. Them millionths stack up, whether a micrometer in a warm hand or straight railroad track in hot weather.
Another great video Tom. Surface grinding seems to be one of those subjects that is getting harder and harder to find good information on. Thanks for your efforts and dedication to teach some of us newbies a thing or two that we might not have otherwise had the opportunity to learn.
Great video. Getting ready to do go through the same exercise on a electro mag chuck and this will really help me. Thanks..
Wowwwww Tom! I I love so much when you go in this type Of technical détail and precision. As i read the comments you lift passion and a lot Of interest about precision ans measurement. You are such a Great teacher! Good job Tom !
Great video! Thanks for taking the time to show all the important bits and go into such detail.
As always very informative and that indicator is jaw dropping accurate!
You have some very high precision tools there. Thanks for the great video.
Cool demo of heat expansion. Makes a lot more sense when you can see the results.
I'd have to vote this as your best grinding video yet Tom. Extremely informative and very much appreciated. First time I'd ever seen those temperature tapes as well. Yourself, Stan, Chuck, Don at Suburban and a few others have vastly increased my knowledge about surface grinding so far.
I've got a Mitutoyo branded millimess indicator that's good to the nearest 20 millionths that I thought was pretty good until now. And while it's got the Mit. name on it I'm positive it was built for them by Mahr. It's not even close to being in the same ball park as what you have tho. But your certainly right, getting them set on the zero mark can be more than a bit frustrating at times.
I realize its long ago the temp tape are sold for fish aquariums - pet shop item
Nice demo on the process so far.
Great stuff, talk about attention to detail. Thanks, Harvey
OMG, you make TOT look like a carpenter! (no disrespect TOT, just playin'), Subscribed!
always enjoy the new videos Tom ty for sharing
Very nice video, Tom! I'm learning...
Of course I knew about heat expansion, but I just saw it for the first time "live". Very cool and thank you for showing it.
Yes Randy "way wear". Tom always getting so fantastically serious! I was thinking even thicker film of way lube on one side than the other. Great video Tom
Great video Tom, Its always interesting to see what simply touching, holding the object your measuring or the measuring device itself can have an effect. Matt C.
Tom, you are human, thats a good thing. It keeps me watching. Thank you for the hours of time put into these videos. They are so relevant for shop work they could be training videos for future generations. They may even be used by Mars colonists as this century continues. On Mars people will have to obtain skills from someone or source and it may be you. I know, sounds futuristic, but so was a trip to the moon in July 1969..
Hi Metal,
Lots of folks serving their virtual apprenticeships right now. Thanks for the comment.
Cheers,
Tom
Exactly the knowledge I needed. Thanks Tom.
I can't pat my head and rub my tummy at the same time, so I don't think I'll invest in a surface grinder :)
Great video again, Tom!
Oh how nice! As soon as you started grinding the blocks and talking about very accurately measuring and comparing them I thought "Well that would be a PERFECT example of when to use a CEJ Mikrokator (comparator)!" And what a nice surprise just a short time later :)
+Daniel S Hey Daniel,
Its a really nice unit. Its so very crisp and snappy. You Swedes are some clever cats. Thanks for the comment.
Cheers,
Tom
And it _was_ neat to see the size/temperature demonstration.
Nice buddy, I'm glad I don't have that gage you do I would probably need to be committed. I get mine to 50 millionths or better I'm happy. The block test is the way most manufacturers recommend you test your chuck which I never knew until I did my big wet grinder 18x24 they showed that in the manual. We were taught to use Crisco never understood why I use cool mist and I love those blue Norton sg wheels they hold the edge better than the white. It's awesome to see this stuff demonstrated brings back the mold shop memories!
+Jerod Bias (JayRod75) Hey Jerod,
I have heard the crisco thing but never tried it. I'm a WD-40 man. The SG wheels are pretty good. I have some Norton Quantum 5NQ ceramic wheels waiting to be tried. Not enough hours in a day to play with all the fun stuff. Thanks for the comment.
Cheers,
Tom
amazing to be able measure with such precision
Great video. Thanks for sharing.
Interesting device. Scary accurate. I had to google it and figure out the Abramson movement.
Thanks for showing the test block grow. I was hoping you would do that.
Love anything grinding. Thanks tom
oh my.... that indicator is cool ..... great video, thanks .
Tom,
Thanks for the video, I recently purchased a Boyer Schultz 3A from a friend and will be going through this soon as I set it up. Want to rebuild the hydraulics also. The friend suggested grinding the mounting base then the bottom of the chuck then the top of the magnet, not sure if it will make a difference. He works for your friends at Advanced Grinding btw.
Great video Tom, it was interesting during the 5 block cuts, the blocks closest to you appeared to have a louder/larger spark trail along with a startled grunt/groan from you....your testing showed that as the center block was low which is why the change when you got to the outside......
+outsidescrewball What he said.... :-)
+outsidescrewball Hey Chuck,
The groan was like Howie going whaaaat? It startled me when those blocks seemed to cut heavier. The center block was tall not short. It was sitting in a hole in the chuck Chuck. Thanks for the comment.
Cheers,
Tom
very detailed and I learned a lot , thanks
Nice job Tom. Breaking out the big gun metrology equipment...
Now that is precise .. Right on tom , Thumbs up man !!
good video thanks Tom
That gauge is just amazing! I would love to see you take one of those blocks or something and take like one stroke with a file and see how much material does it remove, than with a scraper. I think that would be interesting to see.
+Garage workshop Stay tuned. I have an even better idea. Thanks for the comment.
Cheers,
Tom
It's interesting to watch the reflection of the shop lights in the surface of the chuck as you are grinding the five blocks. From that it appears that there are some low spots near the front.
Watched a different Video, he said to make sure the magnet is ON for this. You did good, had to come back and check..
He also talked about the temp of the coolant. Same deal as temp of the spindle being stable. Had not thought about that, but every tiny thing matters.
Those clamps are works of art!
The video has been up for a month so I guess it's old news and a long time resolved, but I'd guess the chuck was getting heat in it to keep coming up hollow like that. It doesn't take much! It would be interesting to hear the end result.
Hey Pete,
Well thanks for the nice words about my quickie clamps. I didn't impress myself very much with them. Yes it took a while to get the chuck nice.
Best,
Tom
We used to have a bit of coolant dripping on it. Good vid, thanks
The temp strips are neat, but i like to see temps from more than one spot so my neat trick of the day is: PC temp units. You buy those and stick em in the old DVD CD hole in a PC tower, they come with (in my case at least) 6 points to read your temps and some even have controllers for fans.
Happened to have one from an old PC. Now it reads the temps on my mill, plan to get another for my lathe and my welder.
The fact that the LCD is backlit is a bonus, you can even set temp alerts on mine.
+aserta Hey Aserta,
That is cool idea......... Thanks for the comment.
Cheers,
Tom
keep up the good work. with the middle one being hi could one say there is wear in middle of the bed ways as you did not use the full travale to do # 3?
Tom, I know this is an old video. I don't know if you even read the comments from it anymore. I'm trying to learn some things about machining, in particular, precision grinding. Could you do a video about wheels? In particular how hardness and grit interact with each other and how dressing different hardness of different grits with different types of dressings effect accuracy and surface finish. I think this would be a very interesting video and it falls right into your scientific wheelhouse.
Thanks,
Chuck
glad I found this one I just bought my first surface Grinder a Boyar-Schultz Challenger Im having to do just this.
Hi Cliff,
Good deal. Hermann Schmidt has a technical article on their website about mounting mag chucks that is pretty good as well. Thanks for the comment.
Cheers,
Tom
Great video. Thanks for posting. The 5 point test is a pretty cool idea. However, it wouldn’t have found the hole you were showing around 20:42 in the video. Right? Or is it only intended to measure the flatness after you’ve ground it down ‘flat’?
+Pet Rock's Garage Hey Pet,
I first run an indicator all around the chuck to look for holes and hills. When I'm satisfied its seems flat then I go to the five block test. The indicator drive is really boring to watch even for a nerd like me. Thanks for the comment.
Cheers,
Tom
Cool video Tom thanks for sharing, great ending ;-).
.Me
we have a little puller for our surface grinder mandrels that only has a hex on the end rather than a handle I like to just screw it in till the stud touches and tap it sideways. pops right off.
+Max Maruszewski Hey Max,
They should come off really easy if the taper is in good shape and clean. Thanks for the comment.
Cheers,
Tom
I enjoy your scientific approach to machining Tom!! Is this your highest resolution indicator in your shop? What is the next step up from there with measurements?? Id love to know.
+dannymaciejewski Hi Danny,
Well we can go light bands next. Actually really accessible even for the home shop. Optical flats, gage blocks and a light source. There are some really sensitive electronic indicators around as well. Thanks for the comment.
Cheers,
Tom
Very cool! When you were roughing the chuck how much did you take off and how much during finish passes?Thanks for doing what you do.
+SlowEarl1 Hey Earl,
Roughing was maybe one to two tenths. Final fussy finishing was 25 millionths with spark out passes. Thanks for the comment.
Cheers,
Tom
Fantastic video Tom. Keep up the great work. Learned a lot. Thank you !!!
Thanks for the lesson Tom!Now that I have a couple grinders, I can pretend that I know what I'm doing!!
Thanks, Tom
+Osama Osama Hi Osama,
Thanks for the comment.
Cheers,
Tom
cool.
If I may be so bold to suggest you tag the equipment you use, in the description; it will help people find the awesome content you have ;)
+John Galt Hi John,
I do put tags on my videos. I should probably put more stuff in the description as well. Thanks for the comment.
Cheers,
Tom
This came about because Stan was talking about your using a Mikrokator. I searched and searched with no luck. Thanks again for the cool, informative content!
Interesting to watch, how precise you can go in the shop. Is the next step a temprature controlled room?
+Rob Gerrits That would be sweet! I'll wager he's got access to one at work if he moves their time machine over next to the Tokamak. :)
+Rob Gerrits Hi Rob,
Its kind of all relative. If your parts machines and gages are all at the same temperature they you can do pretty good. The heat from the operator is the thing that is hard to judge and control. If you handle something its hard to tell that its a few degrees hotter than the gages. Thanks for the comment.
Cheers,
Tom
😂😂😂😂😂
You scared people with that gage.
Thanks for the fun, Tom.
John
Tom, you have the patience of a saint!!!! However, given all the external factors (ambient temperature etc) what is your position on 'ABSOLUTE'? Kindest regards from Bonnie Scotland and thank for sharing your vast knowledge young man. Joe.
+Joe McIntyre Hi Joe,
You are only as good as your standards. If you have good length standards that are at the same material as your work and at the same temp then you should be able to do pretty well. For the really fine stuff it can be a statistical game of uncertainty. Thanks for the comment.
Cheers,
Tom
Tom, Great Vid Thank you. I have a question, When traversing the Surface Grinder bed side to side and then Advancing your work piece "Bed" in &/or out for the next pass. Does it matter in relation to the Spindle/Stones rotation to the feed direction? .. Kind of like conventional Milling too Climb Milling. Does this matter in a Surface Grinder &/or could it provide a better surface finish when Grinding in one side to side action? It seem like you where grinding on both side to side actions. .... Love that Gauge, Guess you could use chopsticks to move small pieces around and still have thermal isolation.
+Charles E. Malone Hi Charles,
I have not seen a big finish difference in long feed direction for fine work. In heavy roughing you can feel the rotation assist the table motion. I generally advance the cross at each end point of the long traverse. I'm and equal opportunity grinder. Thanks for the comment.
Cheers,
Tom
+oxtoolco Thanks Tom for the insight. "equal opportunity grinder "Laugh""
Hi TomLove the five block test. Makes a lot of sense. Can you please tell us what brand name your balancer was and where we might be able to get them. Looking at Sopkos on ebay but no luck.
+Tom Vitagliano Hi Tom,
My wheel balancer is made by Taft Peirce. I got it with the machine. They are pretty easy to make in the average shop. Study some of the designs and you will get the idea. Thanks for the comment.
Cheers,
Tom
Great show Tom. What brand straight grinding wheel do you like/are using.
+Eric Commarato Hey Eric,
This was a Norton SG wheel .McMaster sells them. Thanks for the comment.
Cheers,
Tom
+oxtoolco thanks Tom!
Hi mate. That is a wonderful gauge you have got there. I wonder if you can get those angle blocks out and show us the one second one. I was wondering, you knew that you had a dip in the front of the magnet, why did you not put an extra block there? It would be handy to see if you had removed that dip adequately, not?
+Marcel Timmers Hey Marcel,
That sounds like an excellent idea. Thanks for the comment.
Cheers,
Tom
The block test is great for a newer grinder, but how would you test for wear on the ways of an older grinder? I would imagine something like a long parallel (upright), which would then be compared to a surface plate. (My second time watching this video now that I have a surface grinder)
Could you do a video explaining the process of surface grinding a angle plate... Were grinding angle plates at school and where having a hell of a time getting all the sides to come out perpendicular...
+Joey Broadston Hi Joey,
An angle plate is a bit of a challenge because there are so many right angles. You need a good reference to work off like a squaring block or good large vee block. You also need to be able to check your progress. You will have a hard time if you can't see where you are. Thanks for the comment.
Cheers,
Tom
Hi did you ever do a video on tilting the grinding wheel
Hey Tom, great video and I loved the part where you illustrate the fine resolution of the human eye in seeing the shallow dip in your mag chuck(did someone say Chuck?). I also have a question for you, am I correct in thinking that 20 millionths of an inch is equal to 2 one hundred-thousandths of an inch? It sounds stupid as I ask it, because that's what my decimal place mathematical learnin' tells me, but I never hear it said that way in Metrology. Is that just because it's a mouthful, or is there another reason?
Thanks and I hope you all have a great weekend. Aloha...Chuck
+Knolltop Farms Hey Chuck,
Hundred thousandths is kind of a mouthful to say. There are preferred units in most engineering fields. It funny as each discipline has its favorites. For example machinists like millimeters and many of the Physicists I work with prefer centimeters. They are pretty good at switching units around. Everything is fine as long as you state the units. Thanks for the comment.
Cheers,
Tom
if I hold my hands on it too long, the thing will start to grow. lol you're so funny Tom
Tom did you end up grinding the fence in another vid?
Just gotta love the "degree" of accuracy! When yer hot, yer... lol Cheers.
Nice one Tom, Cliff
+Clifford Fender Hey Cliff,
Thanks for stopping by.
Best,
Tom
For those of us in the home shop, what kind of accuracy could we expect from our surface grinder in our garage? I've got a Harig 612 and I can't find any stated specs on how accurate it should grind.
Is the reason the center block came out larger because it was in the center mass of the magnet which may be cooler than the outside edge's ?
Wow Tom that's cool. Well I'm crazy enough, I don't need anymore help with a millionth gage. LOL. Great video, thanks
What would be the thinnest you think you could grind something? How would you go about holding it if it was something like a brass shim?
+SuperSecretSquirell Hey Secret,
I would probably pot it to a block using something like Crystalbond. With care you could probably get down to a half thou if everything was nice and flat to start. Thanks for the comment.
Cheers,
Tom
That would be cool to see. *wink wink, nudge nudge* ;)
Your sick, and I love it. Millionths and I was on the edge of my seat. My wife says I'm addicted to tool porn, thank's for delivering.
"welcome to the party pal"
I think number three was lower because you went back and forth much quicker then on the outside blocks, making it hotter while grinding. I noticed that allready while you were grinding, and thought you had to wait a little longer after each pass on block three in order to match the grinding pace on the outer blocks. cheers.
+Flip de boer Yes, I can see the logic in that. I wonder if a full sweep of the chuck had been made the timing would have been nearly the same.
+Flip de boer Good observation! Would definitely account for some of that error.
+Flip de boer Hey Flip,
Number three was longer not shorter than the rest. If it got hot I would have taken more off not less. I ended up regrinding the chuck and sure enough there was a hole around .0001 near the center. 25 microns for our European viewers. Thanks for the comment.
Cheers,
Tom
when i came to think of it, I was fearing this answer from you. It's so damn hard to make a smart comment on this channel..cheers.
+Flip de boer Hey Flip,
Don't ever be afraid of commenting. I only bash the trolls. Thanks for the comment.
Cheers,
Tom
Holding .00002 will we see a line of Ox tool gage blocks? :-)
+bcbloc02 20 millionths is not close to the flatness of a gage block.
What an idea !
The Handscraper
Looks like to me if Tom can hit size within 20 millionths those blocks he ground would qualify grade B for a gage block. While there are sets with much tighter tolerances it looks from the standards there are ones with much worse too.
+bcbloc02 Gauge blocks are more than just accurate. They have to be flat enough and smooth enough to wring, something I'm not sure he could do.
Is that big building you show all the time, - your shop?
+Blackaboe ya if you go back he got a shop video witch explains and give you a good overview
Great-Great video thanks Tom
How did you know I was screaming hold that in your hand for a minute I wanna see it grow"?Haha.
Physics teachers should use that gage to show thermal expansion. Great teaching aid.
no auto feed on that grinder?
Ok dumb question, but isn't the wheel diameter ever so slightly less once you get to the end of a pass i.e. Once you get to the edge of the table closest to you? I guess you minimize this by taking very light cuts and taking large stepover but is it a concern? P.s. I know diddly about this...or did you already guess :-) great video thanks. I am seeing the price of machines plummet around here so I am on the hunt for a small SG so I am really enjoying these videos and Phil Kerner and Don Bailey.
+scott black I've always wondered about that. I guess it's not enough to matter.
+scott black Hi Scott,
Yes you loose wheel diameter but at a very slow rate during finishing. Wheel wear basically means you always come up short of what you dial in. On the fine finishing passes I was taking a quarter of a tenth doc. Heat is the real demon and causes most of the grinding problems. In the example of the chuck it grows up toward the wheel causing overcut and a pissed off grinder hand. Thanks for the comment.
Cheers,
Tom
The ends justify the means?
Won't grinding the magnets provide enough of a mechanical shock to demagnetize them? Or are these not the super high-powered rare-earth magnets that do that?
+Phoxtane you don't grind the magnet. The magnet is inside the chuck. You only grind the pole pieces. The pole pieces conduct the magnetism to your work piece. They make pole piece riser blocks to use on magnetic chucks too. Pole pieces are like electrical wires, but for magnetic flux. If the pole pieces were actually the magnet then flipping the lever would not turn the chuck off.
Awesome indicator and show! I would hate to guess what that thing cost............We have a clapped out Chevalier 12x24 with turcite ways at work, Its a POS if you need to do anything even slightly fussy you have to grind the chuck but its hydraulic with easy to set stops so you can sit back and watch LOL I'm surprised your Taft Pierce doesn't have Y axis auto feed?The crappiest grinder I ever ran had that?
+gentharris Sorry to reply to my own post but after grinding the chuck set up an indicator mounted to the wheel guard or whatever is handy about 2" away in x&y from the wheel contactand probing the chuck will tell you a LOT about the condition of the machine prepare to be spprised
+gentharris Hey Richard,
I go over the chuck with an indicator before I do the blocks. Its difficult to tell truly what condition the chuck is in. First off its hard to retain 50 millionths on a mag base indicator moving the machine around to cover the chuck. It give you a pretty good picture but not what it will actually grind when everything is moving. My guard is cast aluminum so I have to reach back to the column to hang the mag base. I may add a steel plate to the guard as that is a great spot to snap the indicator to. Thanks for the comment.
Cheers,
Tom
Antimony expands when cooled, that's pretty damn nifty.
+Justin Bell Can you tell me the another molecule that expands when cooled? :)
+Knolltop Farms
DHMO is pretty good at it.
LOL!!! You almost had me Googling "DHMO" in my search bar, you rascal...I should have known I'd be reaping what I sowed, thanks for the great laughs! Have a good weekend...Aloha, Chuck
Must have had a tremor over there on the coast and horsed up a measurement?
Fussy stuff... :-)
Colin
I'd like to see you run those numbers written in sharpie under the comparator!
+Jason Nixon Good question, just how thick is a sharpie mark?
Bravo Maestro. One millionth of an inch is 25 microns. Now, my puzzlement is this: it is an abrasive process. So every pass you make, the wheel has to get smaller. Question is how much. Of course the wheel is much harder than the metal. So it will wear down much slower than the metal. You block test seems to show that the ends are within say 30 microns in Y and X. Is there some kind of guide as to which hardness of wheel you should use for a given amount of accuracy?
Your math is off by 1000. One thousandth of an inch, 0.001" = 25 micron (0.001 in X 25.4 mm/in). A tenth of a thou. is 2.5 micron. A millionth of an inch is 0.254 microns or 254 nanometers (wavelength of UV light)
You are quite right. I do not speak Imperial well at all. Sorry. My question still remains.
+Juan Rivero Hi Juan,
The blocks are soft steel. In general for soft steel you use a harder wheel and hard steel you use a softer grade. There is wheel wear to be accounted for. Getting it all to come together at the same time for a particular part or setup is what takes years of making door stops to figure out. Thanks for the comment.
Cheers,
Tom
Thanks for the reply. I would have thought exactly the opposite applied. I figured there is a lot more to grinding than meets the untutored eye.
31:48 all grow with heat. Except water
Yes, think he was talking about just metals, but a good point. Had not thought about that. Thanks
Looking at Phase diagram, as Liquid water moves towards the Vapor State, does it get bigger. Still a liquid, yes and but moving towards that transition line to a vapor from either lower pressure or higher temperature. Not sure, but something to think about.
Water is bigger as a solid vs liquid. as it changes state. not sure. Damn the things I have to think about.
had a co worker once who would hold apart for inspection and gages would read off because of his hands would make the parts very warm.
Hi Tom !
That last 2-3 mill. is what we over here calls ... "mosquitofucking" (= dirty word for "hair-splitting")
Anyway some nice instructual video - thx for sharing.
+Keld Sørensen I don't believe RCH can beat that....
+Keld Sørensen Hey Keld,
I like your translation better. Thanks for the comment.
Cheers,
Tom
Nice video! but what happened to the meatloaf series? I am hungry :(
+Eugen N Hi Eugen,
Everybody get tired of meatloaf at some point. Thanks for the comment.
Cheers,
Tom
20 millionths :o)
I got curious about the thermal expansion comment. Antimony does expand (11 µm/(m·K) (at 25 °C)), but you can produce materials that have near-zero thermal expansion (ZTE) by combining materials with positive and negative coefficients of expansion. This paper gives an example of a single material that has near ZTE: www.nature.com/nature/journal/v425/n6959/abs/nature02011.html
Hi Mike,
Thanks for the link. I was thinking about antimony alloys that expand on cooling. Thanks for setting the record straight and thanks for the comment.
Cheers,
Tom
Tom wasn't eating paste in grade school... he was at the pencil sharpener working out feeds and speeds.