Surface Grinder Initial Tooling

Hello Benster, can you take your 4140 stock and grind it on your mag chuck directly and eliminate a bunch of potential sources of error?

Please be aware that annealed steel is much harder on a surface grinder wheel than hardened stock is. Theory has it that it 'grabs' the grit more often out of the matrix, rather than wearing down the AO particles.

Best of good fortune! :D
 
I haven't mounted the mag chuck yet due to the corrosion issues. I might give it a shot tomorrow.
 
Mounted the mag chuck, got it ground in. Took a roughing pass to remove all the corrosion, let the chuck cool, then redressed the wheel. Took another thou off in several passes until the whole thing was getting skimmed. Then, put a piece on it to test grind, only to realize the mag chuck "doesn't work". The on/off lever seems to do nothing, and the magnet is very strong on the right side, and very weak on the left. My current options are to buy a new Shars 8x18 mag chuck, or wait until a used one of decent size pops up on ebay.
 
One of the youtubers, 'this old tony' I think, rebult his magnetic chuck. It can be done. If you are game, I can look at my viewing history and see if Ii can find it for you.
 
I tried to disassemble it. Drilled out the plastic that was poured in the bottom fasteners, then was unable to separate the halves. I think they epoxied the top and bottom together. I bought a "new" used magnetic chuck off ebay, a 6" x 18". Should be here next week, but it'll be another week after that before I have time to install it and play around.
 
So Bester, how is your SG project going?
 
The new magnetic chuck I bought was good quality. I believe its older American made. I wasn't able to find a brand. I dressed the wheel and ground the chuck in. I ground a test piece about 6" long and using my surface plate and a half thou test indicator I wasn't able to measure any variance. I don't currently have a tenths indicator. The only project I've used it on was to grind some rifle parts to fit in the receiver. I achieved a very good surface finish and fit. I'm able to hit my target dimension within two tenths, but I'm currently limited by my z dial as it is incremented by two tenths so I have to eyeball one tenth. I need to setup a dial indicator on the head. Besides the rifle parts I haven't used it much. Many of my current project ideas involved spindles or round components so I was thinking of using my Taig lathe on the grinder to OD grind between centers. Could add a second counter shaft to slow the rpms.

I also want to try my hand at making some tooling like a mini tooling plate and some angle plates.
 
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