Thompson Grinder Restoration: Grinding the Table & Magnetic Chuck True

Thompson Grinder Restoration: Grinding the Table & Magnetic Chuck True
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[@Paul-FrancisB]

Hi Keith, I wouldn't have been able to resist cleaning up the bozo marks either, the chuck looks so much better without, and will save you having to explain they were "before my time" in the future 😁

[@peterhobson3262]

Definitely getting the chuck as close to perfect as can reasonably be done will result in better results when grinding in the future.

[@deathk26]

I'm curious if that mag chuck is strong enough to have the divots transfer through what you're grinding (ie. leave a minute blemish). Glad he ground them out regardless. Pretty unsightly if nothing else.

[@jdmjesus6103]

I'd say it's purely cosmetic but that's OK, it's a restoration after all. A lot of the work is for cosmetic reasons, it's all part of the job.

[@windrk_6754]

Just a home shop hobby guy, but w/ my little 6x12, used/worn, from an auction, the first time I ground the chuck & left a big area untouched, near the front center, once a large area was nicely cleaned up - I told myself, I'll leave that for the next time I touch it up.. I got really good results, and subsequently, had better technique, & confidence, the second time I ground the chuck, just a couple more tenths.. I also, before dressing the chuck, did some test grinding to make sure I was comfortable with how things were working. Thanks, Keith, for another great video, that's an amazing machine!

[@TomokosEnterprize]

Most of these machne coolants that are water soluable are based with good old pine oil from, pine trees. Great stuff The anti freeze is a great idea. We can't all see flash rusting so we need to stay aware that it has an eye out for us. Well bud, That is a great looking project well worth the time and resorses to do. Well done laddy ! Yup, I am older than you about a schonche Take care and see you soon bud.

[@rickpalechuk4411]

Your priority list = lots of content for us 😁👍😁👍

[@GameBacardi]

Quality over quantity

[@paulputnam2305]

Awesome job on the grinder. The one in the shop where I work is manual feed so my arm got tired watching this video. Ha ha I told my wife I wanted to “kiss her to clean her up.” Now I’m single. Ever since you showed what scraping was all about, I started looking at the manual machines in the shop. I was surprised that most have the cool telltale signs of scraping. Thanks for sharing your awesome life with us.

[@WestHamBubbleBoy]

Good video, Keith. I have three surface grinders in my workshop, and all are British made. The largest is the 12ft long Churchill built in Manchester in 1931. It has an 18" wheel and is used for all my really big projects. It also has an 8ft electro magnetic chuck and a coolant unit with a magnetic separator. For your information. Churchill was originally an American company that under licence built their machines in England. We continued to build your machines until the end of the First World War, when Churchill relocated to England permanently. Churchill then became The Churchill Machine Tool Co, which is still in business today. Next is the Bridgeport built in 1938 in Stratford. It has a 12" wheel and 3ft electro magnetic chuck. Sadly, the machine is out of commission. I purchased it in 1989. "Sold as seen spares or repair" for £200. It was meant to be a working project only i never had the time. The smaller and last of my grinders is the Jones & Shipman, built in Leicester in 1941 and has a 9.5" wheel. It has a 2ft electro magnetic chuck. The coolant unit has a magnetic seperator, but that was added later as it did not come with the machine. Compared to yours, mine is just a baby, but baby or not, it has a valuable history. From the latter part of World War Two (1941-1945), my machine was used to grind parts used in the making of the Rolls Royce V12 Merlin engine. These engines powered the early Spitfire models. They powered all of the Hawker Hurricane series and the Mosquito too. The Mustang and Lancaster bombers also used the same engines, but neither of these names are mentioned in the document correspondence i have where parts were manufactured. The company is still in production but is now part of the 'Hardinge Group.' Both of my working machines have their own diamond dressing stones similar to yours, although the dresser on the Jones & Shipman needs new diamonds. For both of my machines, I use copper slip for the same reason you used it on yours. Both of my machines have splash guards like yours only mine are not segregated which brings me to my question. At the rear of your machine your splash guard is split into 3 parts, and yet one part is missing. Do you intend to make another, or will you allow coolant to splash over the side?

[@Hoaxer51]

That has to be the longest question in the history of this channel. Lol I’m just kidding, I hope you have at least a little bit of a sense of humor to go along with my attempt at being funny. I really do enjoy the history of these old machines, where they’re made, where they’ve been, what have they made, it’s hard to imagine the whole history of all these finely made old beasts, so thanks for sharing yours. Have a good one!

[@johnwilcox4078]

I worked as a scraper at Midwestern Machinery in Minneapolis, Mn. in the early 80's. They bought, sold, and rebuilt used machine tools of all kinds. They bought a monster Churchill planer all the way from England. It's base and table were nearly 20' long! It took two low boy trailers to haul it from the port of NYC due to weight restrictions. When we pulled the table off, the ways were still in decent shape. A guy found a large British 1942 coin cleaning out the chip tray!

[@joernsaermark]

Hi Keith. I have some advice for you regarding the surface on the chuck. Im sure your wheel is perfect for the job, but one thing people often forget when grinding with these vertical stone grinders, is to dress the wheel before doing the last 2 fine passes. What I always do, is leave 0.01mm (sorry for the metric, Im european), then I dress the wheel, and do 2 passes taking 0.005mm each pass, and then let the machine spark out until there are no more sparks at all. I dont know if your grinder is able to adjust the stone wheel speed, but if it is, then another tip is to lower the speed before the last two passes, and dress the stone at that lower speed. Often if the stone is spinning to fast, tiny ballance fluctuations will leave a "spotted" surface even if you ballance and dress the stone. So finishing of as described, im sure you will get a close to mirror finnish on everything you grind :) Great video, and lovely machine. Once you propperly get the hang of it, you wont find a better surface grinder than that :) Cheers

[@dannyl2598]

It's like a new machine now, but made with all of the old school quality that you can't get anymore. Nice job Keith.

[@noblsht]

always thumbs up. I always like that. You put out a lot of videos the more the better so always interesting. I don't come from that background. I'm a construction worker but machine shop work is pretty interesting.

[@DAKOTANSHELBY]

I see the Steam Stoker Engine on the floor next to the surface grinder partially covered. Maybe it's next in the cue???? Thanks for another great video.

[@garybrenner6236]

Don't hold your breath!

[@johnwilcox4078]

Well done Keith, the machine produces a beautiful finish, and I like the built-in wheel dresser. This brings to mind my years at the DoAll plant in Savage, Mn. as a scraper hand, where surface grinders and band saws were produced. Each grinder underwent the same procedure, done by one man in my department, grinding the table top and both sides of the magnetic chuck. Then a test cut was performed. We tried to maintain.0002" on our grinders, the largest size we made was 10"×30". If it was needed, the table was pulled off, and I would touch up the saddle and/or table ways with a hand scraper, then he would try a test cut again, a sometimes tedious procedure to get it right. I'm interested to see how she does on accuracy!

[@bogartaspen]

Keith: You might try balancing the wheel. It should help with your grind finish. Great job on your rebuild!!

[@djfaber]

Was thinking this as well, the slight scalloping could be out of balance wheel (not by a lot, just enough)

[@mhansl]

I can't get over how, on the screen, that machine looks just-off-the-skid-brand-spankin-new. Nice job.

[@petegraham1458]

That’s a very nice addition to the fleet of machines in your workshop ! You did a nice job of restoring it to be accurate and reliable. Well done.

[@angelarichards3588]

Hiya Keith. 5 thou is a mega cut on such a presice machine, 5 tenths of a thou is still a big cut but getting closer to the machines capabilities. Beautiful tool though , I'm very jealous 😊

[@sferg9582]

A guy in our shop was going to grind the chuck and started by removing the back rail and then dressed the wheel. Everything was going well up to a certain place on the surface that wasn't grinding. Turned out there was a diamond particle embedded in the chuck and every time he made a pass over that spot, it would dress the wheel back.

[@paulkinzer7661]

Another series I've been watching from the beginning. What a difference! Beautiful.

[@bruceintas]

Fantastic, Bravo. I am a Carpenter in Tasmania & I enjoy watching metalworking.

[@TomokosEnterprize]

Onward Keith. I remember doing this in school. It made me feel kind of important that I was chosen to do it.

[@tomoakhill8825]

Adam Booth, Kurtis Allen, Leo Goolden, Dave Engles, and Keith all machine wood or metal, and do it to a high level of perfection. All five of them would remove the "bozo marks". I have seen each of them take time to remove harmless imperfections, even ones that can _not_ be seen because other parts will cover them up. It is this compulsion that makes these channels worth watching. I love seeing them perfect items they are working on. (abom79, Cutting Edge Engineering Australia, Sampson Boat Co, Engles Coach Shop).

[@lesgaal4017]

Hi Keith on my grinder coolant tank is similar in design in the front section i put some old microwave magnets in the bottom. It works well to catch all metal filling.

[@carlbyington5185]

The tank is like the locks in Panama for ships.... different levels.

[@johncloar1692]

Nice Job the chuck looks great! Thanks for the video Keith.

[@truckguy6666]

What a nice machine! But then again I could say that many many times walking thru your shop.

[@d6c10k4]

I'm interested in your take on step-over amount when grinding. I worked as a toolmaker for many years and we almost always used a small stepover, the thinking is it creates less heat, and less heat distortion. Also, with a small step-over, as the wheel wears there is still quite a bit of unused wheel face that is unworn and keeps the depth of cut consistent. Recently I had the tables on a 12" jointer reground at a shop that does machine tool rebuilding. He set them up on his huge gantry grinder. ( you could park a small car on the table) He said he had quite a bit of trouble with the thin castings swelling from heat but looking at the grind pattern you could tell he was stepping over about an inch per pass. Didn't make sense to me. The other theory with a large set-over is you can get uneven wheel wear across the face of the wheel, creating a very slightly uneven surface.

[@Bob_Adkins]

High production shops push for speed, and as you know, there's a tradeoff. In my old shop, we would hog off metal with high feed and stepover, but then re-dress the wheel and gently dust off the last half thousandth. Keeping a strong coolant flush made the wheels last surprisingly well.

[@charlieromeo7663]

I noticed a bit of z-axis movement while the table was traversing the x axis. Is that normal for these machines? When I grind on my Jones and Shipman 6x18 grinder I avoid that. I think balancing the wheel will make a big difference once Keith finds some for this machine.

[@edsmachine93]

Keith that Thompson Grinder is a nice machine. Really nice and smooth. Great job on your scraping. Really shows in the in the quality of the grind finish. I think it was worth all of the work you put into this machine.👍👍💯 Have a great day.

[@Sowhat-u6f]

I always enjoy these videos. The anti-seize is probably a good idea. It may been a good idea as well to spray it on the bottom of the mag chuck and not just the deck.

[@bosshimsaidhetried8499]

Watching from home Keith, the cross feed seems to be moving a bit too far and fast. You said your stroke was maxed out. May help finish if you can let the cross feed stop before stroking

[@ccrider5398]

Good luck on building your collection of wheels for your surface grinder. The right wheel can really make a difference specific to the material being ground. I hadn't heard of putting the anti-seize between the table and the chuck, but it sounds like a good idea. Keep up the good work.

[@JaapGrootveld]

The copper in the antisees has a thickness. It's about the least suitable thing you can use for it.

[@joeblan9426]

Great job! I believe I would of set my table stops a little wider if possible though. Always enjoy your videos Keith.

[@loydsa]

What a wonderful beast that grinder is 🙂 Great to see it running and the never seize tip is very valuable

[@annacalise8336]

What a nice machine Keith, I can't wait to see the next video! I would've taken those marks out of that chuck too, when you started the grind on the table I was surprised at that heavy cut too but I already knew you weren't trying to do that lol, as always thank you for the great content my friend and I'll be looking forward to the next one!

[@TheUncleRuckus]

Nice thing is you could always redress the mag chuck later when you get some different grinding wheels. 👍👍

[@mdouglaswray]

Wonderful to see this step completed! That is one heck of a grinder. Thanks Keith!

[@iTeerRex]

I was thinking of grease, but anti seize is probably better. I was also think to cold bluing all the pits on the bottom side. Just as a preventive measures. But it’s looking great.

[@mousemade1]

Hi Keith, another great vid, thanks for posting.

[@tropifiori]

A beautiful machine. I need to find someone who has a similar one to grind my lathe bed with

[@jossmaxwell00]

Fascinating watch Keith. Thanks for showing the workings of these engineering machine's.👍👍👍

[@samuelaho4046]

I use basically the same vintage Thompson grinder every day😄

[@KennyP88]

That was so much fun watching, brought back many hours of memories on a surface grinder. ❤

[@nathanbrickles6387]

When I was in the production factory we found that that coolant really wasn't the best for grinding because it would cause the wheel to load up...the stuff that worked the best is the stuff that looked and smelled like antifreeze...because that's what it actually was when reading the ingredients list...down side to it you gotta give everything a good dose of wd40 when your done

[@prillewitz]

We had such a machine at school for fine machinery works, I was an electrician so I never got to work with it. The sparks coming from that machine always drew my attention.

[@timothybryan5113]

It’s set up like a septic tank, except that it recirculates

[@jamesdavis8021]

Trim E-206 is the only coolant I use.Lard oil ,like Mobilmet S-122,will discolor and pit precision surfaces.

[@RDJ-v5j]

Cool piece of machinery. Great restore.

[@walterplummer3808]

Good morning Keith! Have a great weekend. Thanks for the videos.

[@adeeponionbrah]

A beautiful surface grinder restored. Nice work!

[@CraigLYoung]

Thanks for sharing 👍

[@truckguy6666]

As a tradesman myself, I was once called out by a homeowner who noticed I said "heighth" and ever since I have not been able to not notice immediately when I, or someone else says it. I have noticed it is very prevalent in tradesman. I can only speculate that it has something to do with saying fractional dimensions for many years. Eighth, sixteenth, 64th, depth, etc...

[@flockshot1967]

Rock on.

[@elsdp-4560]

Thank you for sharing.👍

[@davidc6510]

Another great video Keith. Thanks for sharing.

[@melshea2519]

Happy Friday Keith 😊

[@johnyoungquist6540]

magnificent grinder Great size, Looks e new!

[@martineastburn3679]

What I found out was grey were medium grind. Best GP is white that fractures and cools. I have Grey, White, Red, Green. Red is Ruby and eats nicely. Green is for Carbide or exotic steels. I have some that are OGE ground for edges. Light cuts on them they are ruby. I have two dry vacuum's that draw grit and metal and has enough force to steal 1/2" steel being cutoff. I found some in the hundreds of pounds of grit and iron when I got mine. 3-Phase 380v 3 motors. I have some books (new) if you need their titles.

[@bulletproofpepper2]

Thanks for sharing.

[@SciPunk215]

Very nice

[@railfan439]

Keith: Check with Steve Summers, Adam Booth, Mike Wiggins and Keith Fenner. I seem to remember someone getting in a big supply of grinding wheels, most of which they couldn't use. Can't hurt to make some phone calls. Thanks for the video. See you at the Bar-Z. Jon

[@snowtiggr]

Another good show, I noticed the stocker engine on the floor, any progress planned on it.

[@garybrenner6236]

Don;t hold your breath!

[@randymusselman4504]

Keith, Your Thompson is a Hoss! It’s a beast of a machine. Nothing beats mass for low vibration and precision. Did you mention this before, what is the chuck, working size? 10x24? The pattern or inlay you see in the working face of the chuck, it’s crevasse free in order to direct grind and not get embedded grit stuck in it? I’m not sure how these chucks are made. Wonderful addition to your shop! Thank you for sharing! Randy

[@wilsonlaidlaw]

Keith, Would applying the power to the chuck affect its dimensions at all, even by tenths of a thou, so that it might be best to grind with power applied?

[@Paul-FrancisB]

Hi Wilson, that's a really good point particularly with electrically powered vs mechanical mag chucks that I assume will warm up and "grow" a little bit when powered, although that bed would be a massive heat sink 🙂

[@alan-sk7ky]

Yes it will I was waiting for Keith to say he was going to lick it over once he has it powered but he didn't. Also is good practice when putting a mag on a grinder once its settled in place with clamping set up finger tight but not tightened to energise chuck then nip the clamping up.

[@ddblairco]

thank you Keith

[@markedis5902]

During my apprenticeship, I learned that you should start the wheel and then the coolant so you don’t soak the wheel. Also you dress the wheel every time before you start and again if you see sparks because you’ve taken too big of a cut.

[@someguy2741]

I am surprised you didnt coat the coolant tank with a white epoxy to aid with cleaning.

[@timf6916]

Good job

[@macgyver1978]

I'd very much like to see a shot of the coolant tank during use.

[@markedis5902]

To get rid of the pattern on the finished surface try a diamond mounted on the magchuck. It will dress the wheel to the part not to the top of the machine

[@Bob_Adkins]

As long as both are rigid, it makes no difference, but the chuck is always rigid.

[@charleshodge6202]

No sooner than I had asked that question, there sat the "Stoker Motor" right beside the Thompson Grinder>

[@6NBERLS]

Most excellent.

[@Sundancer268]

Why not use a silicone grease between the chuck and table to prevent rust from forming? I would think over time the rust would cause a jacking effect on the chuck causing misalignment.

[@glenc90240]

Seems to me, grinding patterns come from wheel balance or bearings, (when there is a good grind on the wheel, and proper wheel for material being ground).

[@larrycleeton]

Is it typical to have the wheel/arbor move in/out while still over the part instead of having more horizontal travel so the head moves before getting back over the part?

[@TimMiller-ie8lz]

I see that too the wheel is moving when it is grinding !!!! It should move over at the end of each grind not when it is grinding !!! It is putting a side load on the wheel !!!!! I hope that this help you !!!!

[@narcism2672]

​@@TimMiller-ie8lz Also it let some parts not grinded at the end of each longitudinal stroke.

[@alan-sk7ky]

You didn't energise the chuck when you were flatting out the topside Keith, is there a reason?

[@someguy2741]

Is there a way to cut the outer ends of the bed? It seems that you might want to bolt down things that are longer and might stick past the machined area. That being said. I dont use these sorts of machines so maybe that situation doesnt happen on this size of machine. Excellent content.

[@charleshodge6202]

Keith, I often wonder if the "Stoker Motor" is ever coming back to your shop to be finished?

[@garybrenner6236]

Don't hold your breath!

[@johnparichuk8367]

My curiosity has got the better of me. I notice the stoker engine sitting on the floor next to the grinder. Do you have any updates on this engine?

[@miguelangelsimonfernandez5498]

copper and steel in a detergent coolant medium, not a good galvanic idea, but I may be wrong

[@someguy2741]

Would there be a benefit to put down a layer of wax or oil on the bed before putting the magnetic chuck. I was thinking the underside of the chuck could be waxed or at least fill and protect the rust... or convert it and rustoleum rust reformer it. Lol. I suspect I am probably suggesting things that would help it survive 200+ years assuming zero maintenance but probably wouldnt matter in the near term. ... and then you sprayed on the anti-seize. Lol. Alrighty then. Keep up the good work!

[@someguy2741]

When you sprayed on the anti-seize would you not want to let it settle for a day or two? Maybe run the machine before grinding it in? The antiseize is one a few thou but it might throw it out if you put one end super thick.

[@steveNCB7754]

What's your take on the 'old chestnut' I remember from my first career in engineering, when I left school here in the UK (so 1970's/1980's)? This is about the potential danger when operating a surface (or other) grinder, that uses a liquid coolant. The theory goes that, whilst operating, the coolant soaks into the wheel and as a result is uniformly distributed within the wheel's matrix. Then, when the wheel is inevitably shut down, even if left to spin a while before doing so, any remaining coolant liquid in the wheel will gradually migrate downwards under gravity, to then accumulate at the bottom of the wheel. The implied danger, is that when that surface grinder is next turned on, the wheel is technically out of balance, running the risk that the wheel might actually explode, due to that out-of-balance moment. In the company I worked at back then, divisions which operated night shift working, didn't actually turn their grinders off, as one shift changed to another. In those that only ran a day shift, the grinders were turned off, but it was the job of the maintenance staff covering the night shifts, to come in and safely start those grinders again, such that they were already running when the day shift began.

[@alan-sk7ky]

More likely I think the grinders were kept running to keep the machines 'warm' and tolerances within the machines consistent (what sort of product were they working on?). As for the out of balance issues, I don't know to work out how much G the periphery of a grinding wheel is subject to, easily in to the hundred+ at least, which I'm sure would prevent capillary action withing the wheel matrix. A stopped wheel sitting in a coolant puddle on the other hand is a different matter.

[@steveNCB7754]

I'm sure you are right about keeping things at working temperature. In the divisions with night shifts; one was making pumps and compressors, the other made hydraulic systems (pumps, valves, etc.). My division had surface grinders, but only used intermittently for production and, of course, all divisions also had Tool Rooms with similarly infrequently used machines. @@alan-sk7ky

[@bchrisl1491]

Gotta get this lawnmower blades sharp!

[@Bob_Adkins]

Handy for excavator teeth too!

[@sferg9582]

Is there any way to get the Y-axis to move before taking the next pass in the X-axis? Seems really sluggish. I wouldn't like having the wheel traversing at an angle the way it was. I mean it works, but maybe something can be done.

[@markedis5902]

You’d get a lot less sparks and a better cut if you angled the coolant onto the wheel instead of the steel

[@LyallPearce]

Just wondering what happened to the stoker engine.... :)

[@justinl.3587]

At the start of the video, it looked like your way oil tank was empty. Did you fill it or pull a usual Keith move and forget? You mentioned how the head was sticking at the bottom, I wonder why? 😅

[@ErikBongers]

Those strips of metal on that table, the ones that are ground flat and that the magnetic chuck rests on, are those consumables? They seem to be welded on. Are these sometimes replaced when they get too thin? Or does that rarely happen?

[@grntitan1]

Pretty sure the table is one cast iron piece. Those “strips” you speak of appear to be T slots.

[@joebledsoe257]

Is that a Philmont Scout Camp belt I see on your pants?

[@markloving11]

Aren’t you supposed to grind the top face in with the magnet on?

[@TimMiller-ie8lz]

Hello Keith it looks like your wheel is moving over when it is grinding this is not good !!! It will put a side load on the wheel when grinding ... The wheel should move over at the end of the part you are grinding ... Not when grinding I like all your work and I hope this help you !!!

[@garybrenner6236]

When is the Stoker Engine coming up?

[@georgejaros2781]

What happened to the stoker machine for the locomotive?

[@garybrenner6236]

Don't hold your breath!

[@miguelangelsimonfernandez5498]

will you not burn out the diamond if you spin the wheel it too fast while dressing?

[@pforbom1844]

When the chuck is energized does it change shape?

[@alan-sk7ky]

Yes.

[@tomswindler64]

Nice 😎😎😎👍👍👍

[@bobjohnson6743]

You should have turned turned the magnet on for the finished grind.

[@Craneman4100w]

Second and second biggest fan.

[@railroad9000]

I noticed the stoker engine casting in the background. How is that coming along?

[@garybrenner6236]

Don't hold your breath!

[@W4BIN]

While upside down I would have connected the DC power for grinding the bottom. Ron W4BIN

[@jamesriordan3494]

🙌

[@johnhenderson1760]

So, what does the coolant emulsion additive do?

[@ellieprice363]

Basically it’s a water soluble synthetic oil that keeps the work cool (very important), flushes away the metal particles from the chuck and prevents rusting. All the manufacturers will claim their fluid is the best but any reputable brand will work.

[@anthonyraffin1034]

How do you account for stone wear on a surface grinder? You dress the stone, creating your zero point and start grinding. Now the stone is wearing, why isn't the workpiece tapered?

[@alan-sk7ky]

That is where the skill comes into play 🙂