Horizontal Grinder Building - Thinking it through...

Great advice. I am using shoulder bolts, what appear to be consistent spacers, and I have drilled and tapped both on my mini-mill after tramming.
The only other thing I can think to do is to fly-cut the plate to ensure it is flat.
 
I would definitely fly cut the face unless it's cast mic6 tooling plate and already flat. But do it in the same setup as your hole making.

The easiest way to do that is generally drill a couple low precision holes that match you mill T slots, counter bore/sink so the bolts sit below flush, then mount to your table. Put the holes where they won't interfere with your design and bingo you can mill 5 sides, drill and tap without moving or changing clamps.

Assuming your mill has sufficient travel.
 
edit: Kuraki posted fly cutting is good while I was typing up my response. Kuraki certainly has more machining experience than I do. I did drill/tap my holes with milling machine.

I don't think fly cutting is needed at all for aluminum plate. BTW, where did you find a single plate that wide? 10" is about the widest I could find and had to splice two of them together.

While you do need to take care to be sure the wheels are square with plate, it's not tenth of a thou critical. If it looks square with a 1-2-3 block by axle it should be plenty good. Tracking on my horizontal grinder seems to be good. I can switch for forward to reverse without belt moving much at all. Might have to touch tracking wheel, but that depends on the belt. All belts don't track the same.
 
Ken is right I don't think it's necessary but since you're using shoulder bolts and have the capability it's more a way to reduce variables than anything.

ETA: If you wanted to get really crazy, since the load on the axles is radial, you could design in a single point bored counter bore into the threaded holes, say .25" deep, that would add to their stability in remaining perpindicular to the plate. You could also do this INSTEAD of fly cutting, since the individual pocket faces would be (ideally) bored down to the same plane. This is typically how I design a tooling plate for fixtures at work to avoid having to have big plates blanchard ground flat.
 
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Brock Cutlery said:
Great advice. I am using shoulder bolts, what appear to be consistent spacers, and I have drilled and tapped both on my mini-mill after tramming.
The only other thing I can think to do is to fly-cut the plate to ensure it is flat.
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Check the plates stock flatness on both sides before machining.
The tracking arm pivot/plate top will be your starting point for wheel height. You will want some type of wide, thin shim between those two surfaces and a thicker(3/16"?), wide single shim on top since it's not being pinched between two stationary pieces.
 
Are those UHMW wheels? that material is susceptible to moisture and is not suitable for the application imo. you would be better off using acetal/delrin
 
kuraki said:
I would definitely fly cut the face unless it's cast mic6 tooling plate and already flat. But do it in the same setup as your hole making.

The easiest way to do that is generally drill a couple low precision holes that match you mill T slots, counter bore/sink so the bolts sit below flush, then mount to your table. Put the holes where they won't interfere with your design and bingo you can mill 5 sides, drill and tap without moving or changing clamps.

Assuming your mill has sufficient travel.
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This is turning out to be very timely advice, from all you guys. I sure appreciate it. I am sure others do too.

My mill travel is brief. My clamping tools are pretty pitiful currently too, but I am rectifying that.
I need a bigger mill for this stuff. Mine is working, but I could see where it could be much easier to do with something even a little bigger.
 
This is turning out to be very timely advice, from all you guys. I sure appreciate it. I am sure others do too.

My mill travel is brief. My clamping tools are pretty pitiful currently too, but I am rectifying that.
I need a bigger mill for this stuff. Mine is working, but I could see where it could be much easier to do with something even a little bigger.[/QUOTE] What is your plan for the motor mount? Are you recessing the 4 1/2" pocket for the face mount and drilling oversize for the shaft or boring the 4 1/2 all the way through? I can see grit being an issue if you drill an oversize hole. It will eventually cause issues with motor bearings if you have no way to blow it out.
 
Yes, those are 4" UHMW material. I had the material on hand, got 5 ft of it for $30 or so shipped one time when I needed just a tad. I figured it'd give a cheap way to test my ideas on the horizontal grinder. Once they go bad, I'll get a better material for them. Delrin or acetal are pretty darn expensive - aluminum is less.
 
Ken H> said:
BTW, where did you find a single plate that wide? 10" is about the widest I could find and had to splice two of them together.
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Most aluminum suppliers should be able to get you a plate up to 4 or 5 feet wide. Check out Midwest Steel and Aluminum. They have some of the best prices I've found, especially for custom cuts.
 
Midwest is where I got my pieces.

mike-E said:
What is your plan for the motor mount? Are you recessing the 4 1/2" pocket for the face mount and drilling oversize for the shaft or boring the 4 1/2 all the way through? I can see grit being an issue if you drill an oversize hole. It will eventually cause issues with motor bearings if you have no way to blow it out.
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I'm cutting a 6.5 (slightly larger) hole in the Al plate, then cutting a 3/8ths steel plate to fit over that with the motor mount there. I don't know that I have the means to cut the 4.5 inch hole to mount the motor flush, so I may be drilling the center hole only, then 4 mounting screw holes. If need be I'll have to dismount it occasionally to clean out. :\ I hadn't thought of that, so thanks for that tip!
I may use this temporarily and order one properly cut from a shop.
 
That is exactly how I would do it in order to get more interface with the shaft and drive wheel. I would try to get that 4 1/2" hole through the plate though. Otherwise your only making contact on the thin ring. I was thinking about it and you could put that plate on a hinge and use it to track the grinder if you're not happy with tracking from the kmg arm.
Edit: you have a mini mill right? You can mill that 4 1/2" hole easily.
 
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Ken H> said:
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While you do need to take care to be sure the wheels are square with plate, it's not tenth of a thou critical. If it looks square with a 1-2-3 block by axle it should be plenty good. Tracking on my horizontal grinder seems to be good. I can switch for forward to reverse without belt moving much at all. Might have to touch tracking wheel, but that depends on the belt. All belts don't track the same.
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Fact is that it is critical ............. especially if you want same tracking in reverse.....I use on my new grinder M8 x 0.5 threaded bolt for tracking .......Look at this video clip and see how much I turn that bolt to show how tracking works ..........Of course , that bolt acts through the lever but see how little I turn that screw and reaction of belt ...
PS .Tracking wheel have almost invisible crown to the eye ..

 
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Your grinder looks like it tracks nicely - good job.

Both my grinders track just fine in reverse - Note, I did say "tenths" of a thousandth. You should be able to check with a square to see if wheels are close enough to square. No way you can "see" tenth's of thou.
 
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Natlek said:
Fact is that it is critical ............. especially if you want same tracking in reverse.....I use on my new grinder M8 x 0.5 threaded bolt for tracking .......Look at this video clip and see how much I turn that bolt to show how tracking works ..........Of course , that bolt acts through the lever but see how little I turn that screw and reaction of belt ...
PS .Tracking wheel have almost invisible crown to the eye ..

Click to expand...

Why would you need reverse tracking on a horizontal grinder?
 
mike-E said:
That is exactly how I would do it in order to get more interface with the shaft and drive wheel. I would try to get that 4 1/2" hole through the plate though. Otherwise your only making contact on the thin ring. I was thinking about it and you could put that plate on a hinge and use it to track the grinder if you're not happy with tracking from the kmg arm.
Edit: you have a mini mill right? You can mill that 4 1/2" hole easily.
Click to expand...

I don't know how to cut a circle without CNC. Rotary table? I don't have one
 
Brock Cutlery said:
I don't know how to cut a circle without CNC. Rotary table? I don't have one
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Use a bi-metal hole saw.

If you need a really precise hole, follow with a boring head.

You could also rough it out with a jig saw and follow with a boring head.

Alternatively, you could get a hole cutter. Either one that goes in a chuck, or something like a roto-zip with a circle cutting jig. Aluminum cuts pretty easy.
 
knife to a gunfight said:
Use a bi-metal hole saw.

If you need a really precise hole, follow with a boring head.

You could also rough it out with a jig saw and follow with a boring head.

Alternatively, you could get a hole cutter. Either one that goes in a chuck, or something like a roto-zip with a circle cutting jig. Aluminum cuts pretty easy.
Click to expand...

Thanks for the education Drew. The boring head is a cool tool. I think I can get that Aluminum cut based on one of the above.
Any ideas how I might cut that 4.5 hole in the steel plate?
I know I can rough it out by drilling a series of holes around. Then mill smooth?

I found a few vids on boring heads and other methods. This one isn't maybe ideal, but looks like it will work for this one job.

BTW, your grinder design looks pretty great. I would have bought that to start with if it were available.
You thinking of making it a production thing?

 
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