Let's design the perfect tool rest

[Mark Baldwin III]

Alright. Along with rebuilding my General grinder, it needs new tool rests. I could buy some, but that would be too easy. I want to see what kind of ideas are kicking around out there, combine a few and see if we can come up with a perfect tool rest, or something close to perfect.
I suppose there are some basic criteria that need to be met: machined tool surface, adjustable angle, ease of use.
But there's some open areas: mounted to the grinder or the table? specific width? And I'm sure there's other ideas.
Here's a picture of the grinder housing that I'm building. It has lugs for the guides. The original guide was not adjustable for angle. I'll be able to do all the machine work required, looks like simple mill/lathe operations.

[James Scheffler]

There is a home-made tool rest pictured in Leonard Lee's sharpening book. Not surprisingly, it looks a lot like the metal one that Lee Valley sells. The tool surface is wood or plywood, not machined metal.

Jim S.

[Jim Matthews]

That's a purty casting. Something like a donkey's ear from my shooting board would fill the bill.
(A ramp with a ledge along the bottom to hold the tool in place.)

If you have sufficient clearance, you could fit rather long handle tools, that way.

I use a powered sanding belt grinder, when this becomes necessary. I like to stash it out of the way, so I would vote for a mobile base block.

Hey, JS - you've got the lights on already?

[john brenton]

I know I need to come up with something thinner. I have a few short tools that just won't reach the wheel.

[Mark Baldwin III]

James, I can see using a wooden rest but there is an argument against it. I'm not going to flat out reject the idea, though (that's not the purpose of the thread). My argument against a wooden rest is wear, water, and imbedded dust. They would probably work fine, and be definitely be easier for a woodworker to make (for metal work I'm lucky enough to have access to a mill and lathe).
Old Street Tools has an article about grinders that I've read a few times, and is part of the reason I want to include a regular grinder in my tool maintenance. They also make the argument there against using aluminum for a tool rest because it will allow embedded dust. I had considered aluminum prior to that, but turned my sights towards steel.
John-How wide do you think is too wide? That's certainly something to be considered as well.

[James Taglienti]

Jus curious how embedded dust affects grinding...

[Mark Baldwin III]

Jus curious how embedded dust affects grinding...

Looks. Anal retentiveness. Scratches. I doubt there's a functional effect. But, like I said, all options are open for now.

[Derek Cohen]

Jus curious how embedded dust affects grinding...

Me too. I have used a Veritas grinder rest on one of my setups for a good many years and never noticed grit embedded in the aluminium. If it did the blade would not slide as smoothly across the surface. Never found this to be an issue. Furthermore, scratches are a non-issue since the blade rests on the side that ends up being ground. The back of the blade is never going to be at risk.

I have a second aluminium rest on my Tormek, and this, similarly, is not affected.


Regards from Perth


Derek

[george wilson]

The best tool rest should be cast iron,or hardened steel. You don't want embedded grit making it difficult to make those minute adjustments on the tool you're grinding. The tool needs to slide easily and smoothly on the tool rest.

[jamie shard]

Just as an additional data point -- I have the lee valley tool rest and I have had embedded grit. This was after doing extensive grinding of two lawnmower blades, with the blade angled up off of the surface of the rest. Some grit did embed and could be felt "grabbing" the next plane iron I ground. It was easy enough to find and scrape out the particle. I can see if someone was doing very high quality grinding/polishing how an aluminum rest might be enough of a problem. For me, it's not an issue.

[David Weaver]

I like the simple two-piece cast rests that come on the baldor grinder (if you get the one with the cast rests).

They're not much additional to the price, they're easy to adjust and they're large enough that I've not had an issue grinding large blades on them.

At the same time, they're small enough so you can grind short chisels and other such things on them. I don't like huge rests that preclude you from grinding short or small tools.

[george wilson]

Aluminum,anodized or not,isn't suitable for avoiding embedded grit.

[Jessica Pierce-LaRose]

What about a two piece rest, out of round steel rod? You have a horizontal piece of steel rod fixed close to the wheel, and then a little bit further back, you have another piece that you can adjust up or down to change the effective angle of a blade lying across these two rods. You could have a couple of attachment points, so you could place the second rod closer to the first, making an effectively shorter rest for smaller chisels. Get fancy by having stops for the adjustable rod in the rear to stop the height at preset angles.

[Dale Cruea]

My rest is made of wood.
Keep it kind of dry, clean it once in a while and a coat of wax now and again.

For me a tool rest only needs to be stable.
The rest is eye hand coordination.

[Jim Matthews]

That's clever.

The tool rides at the tangent contact point on either rod - defining a line.
You could have a pair of perforated blocks to set a fixed grinding angle on your most commonly sharpened tools.