Thread: An idea for a contact grinder.

Originally Posted by Voidmonster

I'm still pondering what to do with the linear actuator that this one used for raising & lowering the treadmill. I'm kinda pondering rigging it up to raise and lower the table on my drill press. It's otherwise a huge hassle!

I kept everything. The frame was pretty beefy steel tube, the tread belt looks potentially useful for... Something. The rollers have good bearings in them. There was even a little metal grab bar that'd be awful nice to have in a street brawl, should that ever come up. Heavy and rubber coated!

Oh man, I LOVE the idea of using the actuator on the drill press. Mine's still sitting here looking for a new use too. I had the same thought about the tread belt too.

Watch out for label makers. Anyone with a smidge of OCD can disappear down that rabbit hole for days.

Originally Posted by Cangooner

Oh man, I LOVE the idea of using the actuator on the drill press. Mine's still sitting here looking for a new use too. I had the same thought about the tread belt too.

It's especially tempting on mine, which doesn't even have a crank to raise and lower it. It's just a cast iron plate that weighs about 30 pounds that has a brake to keep it in place when you position it on the mast of the drill press.

Then I added a 15 pound milling vise onto it. So it'd be really nice to be able to raise and lower that without all the weird crab dancing.

Originally Posted by DZEC

Watch out for label makers. Anyone with a smidge of OCD can disappear down that rabbit hole for days.

I've been living with my OCD long enough I can mostly keep it under control... It was just realizing I had two extremely similar looking jars of liquid and one of them I actively want to put very hot things into and the other one I should definitely never put very hot things into... It seemed like a good idea to make sure I knew which was which.

Honestly, the smell would probably have been enough. There's no mistaking the smell of solvent from canola oil that's quenched 3-4 red hot lumps of steel. Well. Except that the whole garage kind of smells like the quenching for a day or two.

OH MY!

I’ve now definitively answered my long-ago question: can I grind a razor from stock to finished razor using my drill press and a drum sander?

The answer is: Yes. You can also whittle redwood replicas of the works of Rodin with a penknife.

The better question is: do I want to?

And the answer to that one is NOOOooooooOOoooOoOOOoOoooooooOooo...oOOOoooo....oo .

That said, I got about 85% of the way through the pre-heat treat grinding before the cut-down sanding belt disintegrated too much to use.





At the max speed of my drill press, that took about 2 hours on an 80 grit ‘belt’.

If I didn’t get sunburned while doing it, I definitely got swarf-burned from all the sparks. To grind flat like that, on a drum sander, required somewhat regularly having at least one arm in the spray of newly liberated metal.

(I wore a face shield and respirator and did the grinding outside).

So, I am now fully ready to build a real contact grinder. Just as soon as I have access to the waterjet again, and once John has settled on a design.

I’m working on it, so much more to this than I ever imagined, doesn’t help that I know next to nothing about metal fabrication, all my experience begins and ends with wood. I think if for whatever reason your motor quits on you we can just swap the motor mount for the dc motor you have to whatever motor you move to without effecting the rest of the frame. I based the cutout in the frame to accommodate any motor with a diameter up to 6.625”.

Speaking of which what does the mounting area look like on your motor?

The razor is looking good, you did way more than I would have attempted with what you’re using.

Originally Posted by jfk742

I’m working on it, so much more to this than I ever imagined, doesn’t help that I know next to nothing about metal fabrication, all my experience begins and ends with wood. I think if for whatever reason your motor quits on you we can just swap the motor mount for the dc motor you have to whatever motor you move to without effecting the rest of the frame. I based the cutout in the frame to accommodate any motor with a diameter up to 6.625”.

Speaking of which what does the mounting area look like on your motor?

The razor is looking good, you did way more than I would have attempted with what you’re using.

This is the motor (I’ve taken measurements so I can build a CAD model, but I haven’t built it yet).



The mounting plate:



And the pulley wheel:



Since I want to enclose the motor and also step-down the speed with a pulley wheel, I’ll slightly modify the cut for mine so that instead of mounting the motor, it mounts a pulley and drive wheel.

Gonna stow the motor under the table so there’s room to duct out the motor and keep dust out.

It’s worth noting, I’ve got a fair bit of square steel tubing that could be used in this design to help with rigidity. Hooray for treadmill parts!

Duh.

Measurements.













Originally, the key on the pulley wheel was a fair bit longer than the wheel itself, which was definitely going to make enclosing that end of the motor annoying, so I ground it flush with the wheel. (I think the original is visible in some of those pics)