Seeking Recommendation on a Bench Grinder with Specific Features.

[Tom Bender]

Not familiar with this material but here's an out of the box idea. What happens if you try to hand plane this stuff? If that works maybe you can shear it to the correct thickness (with a very sharp blade) and result in no waste and a pretty good surface.

No, a hand plane won't work, you'll have to make a shear with a good sized lever and a serious blade and a die to hold the stock.

[stephen thomas]

Per my earlier notes, tonight i played around with cutting a 1.5" dia piece of ultem 1000.
Also per my earlier notes, alignment is critical, deflection the enemy.
Using a 1/64" x 4" saw, using a set up that was on one of the vertical mills, i kept generating cones while gradually iterating the dividing head spindle a few (arc) minutes at a time to ameliorate the deflection.
This yielded improvement, but did not ever yield satisfactory (flat) results.

Next, i mounted a 1/32" x 4" saw, cut straight in, and then rotated. (As opposed to dialing in gradually while constantly rotating)
This looks promising, except it revealed a slight front-to-back lean between the work spindle and the tool spindle.
Basically, i have a good idea of what should be done, but don't really have the time to dedicate to doing it on a machine that nods. It may surprise some just how much time can get eaten up dialing all the axes in for a sensitive project to levels that are unnecessary for run of the mill but still close, work.

Saw plates/stabilizers to limit the blade rim projection to just over 3/4" (to cut to center of 1.5") would make a really big difference over the 1-1/4" projecting now. Or going down to a 3" saw and a slightly smaller arbor.

At the same time, since initially i envisioned this as live tooling on a lathe, (saw blade on a lathe) i began to wonder "what if" a parting blade were simply ground to 1/32" and set up on that machine. Way, way easier to dial in. But it will have to wait a few days again.

I do not think that abrasives at the speed you envision will be any less subject to deflection.
But of course would be interested to see what your experiments yield.

How do you currently cut the discs?
How much oversize?
How do you flatten them uniformly after parting them off?

smt

It also occurred to me that if it were my project, i might just get a small bandsaw (14", e.g.) and hollow grind a blade for it, down to say .020 cutting thickness, then set up the dedicated saw with coolant, perfect tracking, minimal strain, and a carriage with micrometer stop. However, my interest does not extend that far.

[Ray Selinger]

A band saw uses guides for their thin blades. I use graphite impregnated phenol board for my old Beaver band saw. Old saw mills used litne vitea pucks (some pretty bad spelling) on the saw blades on the big pony saws. This kept the blade from defection. The saw blades were slid back and forth for each slab, so the guides held them in line.

[Wes Grass]

Wes, hi, you and another poster mentioned the same thing, something about a smoother blade for a bandsaw. The little nine-inch band saw I have cuts this stuff beautifully, but the surface is very rough. Are there other blades I might try? I'm cuirrently using a metal-cutting blade with 18 TPI.

sm

I think I'd try flipping the blade 'inside-out' so the teeth are trailing, and pinch it between a couple stones until there's still just a hint of set.

Or, if you've got a vise with smooth hard jaws, you might be able to squeeze the set out. It's always going to spring back a bit, so you'll still have some clearance. Although I think there will always be a bit of a 'corner' left to generate a rough surface. But it might save a lot of stoning.