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Surface grinding aluminum

matt_d77

Aluminum
Joined
Jul 23, 2009
Location
Midwest usa
Does anyone know of a more affordable solution to MagnaLock-MagnaVise when surface grinding non magnetic materials? I know the obvious vacuum chuck and blocking techniques. Thanks!
 
We looked into this for a product:
Laag
JR

That's at least a few decades old tech, crystal - optic makers have been using uv curing adhesives both permanently and not so permanently for ages. Lot faster and less thermal stress than waiting for the heat bonding rosin types to harden.
 
Apologies if this already falls under your "known blocking" techniques, but a lot of people don't have or are not familiar with the plain old fashioned hold-down combs, which are surprisingly effective. Often even with relatively small contact area. Work really well with a full bite on a straight edge.

smt_rotab8.jpg


smt_rotab9.jpg


John W, hold that part flat without distortion on your mill and do it 10x faster including fixturing :) (Part is about 18 - 19" long, for size reference)

smt
 
Apologies if this already falls under your "known blocking" techniques, but a lot of people don't have or are not familiar with the plain old fashioned hold-down combs, which are surprisingly effective. Often even with relatively small contact area. Work really well with a full bite on a straight edge.

smt_rotab8.jpg


smt_rotab9.jpg


John W, hold that part flat without distortion on your and do it 10x faster including fixturing :) (Part is about 18 - 19" long, for size reference)

smt

Yeah but you can hold it down with double stick tape on the mill. That way you don't have to grind aluminum.
 
I can get a mirror finish and dead nuts accuracy on a mill. And do it 100 times faster than can be done on a surface grinder.

Whatever works.

Grinding aluminum with the right setup you can easily hold parts flat and parallel to .0001 in a 10" x 10" part or even a larger piece if you are really good and have a great grinder. You can't do that on a mill. Parts can also be ground after Hard anodizing with amazing results.
 
Is that a D-8 with thru the wheel coolant?

Ray-

D1030. But it only has a 10 x 24" chuck on it. Yes on thru wheel coolant. (+ normal flood)

Yeah but you can hold it down with double stick tape on the mill. That way you don't have to grind aluminum.

Point taken. Might have to try that sometime, but usually would have to remove the vise and a rotab or DH that is usually mounted on either mill. Then set back up and tram again. So if a surface grinder is available, it is often faster overall, here anyway. Plus it runs while I do the next part on a mill, or some other op. (all manual machines here, non cnc)

smt
 
Grinding aluminum with the right setup you can easily hold parts flat and parallel to .0001 in a 10" x 10" part or even a larger piece if you are really good and have a great grinder. You can't do that on a mill. Parts can also be ground after Hard anodizing with amazing results.

No, you can do that on a mill too as long as your cutter is at least as wide as the part. Bonus is you can take off a lot of material if you have to and get a perfect finish.
 
No, you can do that on a mill too as long as your cutter is at least as wide as the part. Bonus is you can take off a lot of material if you have to and get a perfect finish.

Ever since Bush and those evil Republicans ruined this country I haven't even tried milling a part that flat and couldn't afford a cutter that big. I am guessing that with some "Hope and Change" I can quit grinding, start milling and get the same results that every one deserves. Thank you John for giving me the renewed confidence in my milling potential. I had just gotten in a rut of low expectations. Anyone need an Okamoto grinder?
 
what you guys do about clogging up that wheel? Don't you ever fall into a situation where you grind a few passes and then clog up the wheel, have to dress it and only then may you continue?
 
I often use a combination of grinding and milling to get really tight tolerances on parts with shoulders that need to be cut or stepped features that can't be easily ground. I mill then grind one side so it is dead flat then mill the fixture so it is parallel to the machines travel. The ground face is mounted to the fixture and then I finish cut the part on the second side in the mill. This extra grinding step takes out any twist or flatness error from clamping during the previous operations. Grinding is done with the part floating on ground blocks to avoid adding deflection from holding and other blocks to keep the part from moving. The blocks around the perimeter are set with a shim to leave about a .002 clearance around the perimeter of the part I am grinding. I use a rather open wheel with about a 15% coolant ratio for 6061 but I can use lower for 7075. There are many different opinions on grinding this is just the method I developed. In my first shop we had 6 Okamotos running 24/7 just grinding aluminum. We had some really smart guys in grinding.
 
Well, coolant should help.

I do most my grinding dry because the same grinder is continually alternating between tool steel and graphite (graphite dust + coolant = one grand mess) :angry: and a guy who worked here years ago taught me a trick for that occasional bit of aluminum that needs to be dusted off... brush on a coat of oil. I have a little stopper bottle with a built-in brush, and I keep it filled with way lube, which does a good job of staying in place as the wheel approaches it. The stopper bottle keeps the oil clean when not in use so one doesn't put hard particles in the path of the wheel where they'll embed themselves and leave lines.

Dennis
 








 
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