making rubber washers

[CCWKen]

Sounds like a good spot for an O-Ring.

[Mcgyver]

Mc Gyver,
I'm a little slow on the uptake this morning. Can you explain further? Is the black or the yellow the workpiece? Is the tool tapered and sharpened on the od?

sure, the black is the workpiece, its about a 3/4" thick piece of rubber (made a new brake shoe for the sunnen hone). The tool is thin wall tubing with a bevel on the end, visible in the photos. The yellow is the handle of the tool, used to rotate it....thats the action, cutting like a circular knife, NOT punching. Think of how easily rubber cuts with a razor knife, same idea....It walks right through rubber. You can see the slug it cut in the first phone still stuck in the end of the cutter. Its a nice nesting set, but you could easily make individual ones much to shorter if you're only going through a thin piece, it would not need to be hardened imo.

Its a simple tool that works well but the key is it does so by rotating not punching. Same idea as a paper drill.

For the two concentric circles for a washer? No need to over complicate things. Cut the OD so you have a rubber blank. If eyeball alignment for the ID isn't good enough, Make a simple guide that has a bore the OD of the blank you just cut, and not quite as deep as the blank so you can hold on to the rubber to stop it rotating. In the guide, have a hole that fits the next cutter you make the washer's ID with

[J Tiers]

Those are standard lab cutters for making holes through rubber stoppers, typically for tubing, etc. Chemical equipment suppliers should have them.

[DICKEYBIRD]

Sounds like a good spot for an O-Ring.

You Texans are always findin' the easy way...where's the HSM fun in that?

[hermetic]

generally cut mine from rubber tubing. Put a piece of round bar same as the ID in the lathe, push the tubing right over it, and cut washers with a razor blade or stanley knife at low rpm. Works like magic!

[CCWKen]

You Texans are always findin' the easy way...where's the HSM fun in that?

You guys would have the OP buying $500 in tools and material to make a silly gasket.

[CCWKen]

generally cut mine from rubber tubing. Put a piece of round bar same as the ID in the lathe, push the tubing right over it, and cut washers with a razor blade or stanley knife at low rpm. Works like magic!

Yep, that works great. I made a tool holder that uses just the Stanley razor blades. I used it a lot for cutting down 2" tape into 1/4 - 1" tape for painting jobs. It also works well for uses like yours--I've made the seals in A/C maintenance valves and hoses.

[Arcane]

McGyver : I built something similar for "punching" out the center of cotton buffs. I took an Osborne style punch with the correct "id" and turned the the outside down to about 20 thou wall. Mounted it in a dedicated drill press ... 400 rpm. Cuts a 3/4 inch high density buff like butter and ejects the plugs out of the open side. Worth while... we've put a few thousand through it in the last year.

Quite a few years ago a friend showed me that same method of modifying a hole punch and it certainly works great. He uses his to cut thicker gaskets that using a hammer on a punch tends to make the hole "tear' through but the rotary cutter leaves the edges looking very smooth. Indeed, well worth while.

loose nut, I'd also suggest making two punches for the ID and OD and if eyeballing concentricity doesn't come close enough just make one punch a nice close sliding fit inside the other and a little bit longer. Cut the OD first and then slide the other punch into the first punch which will center it on the rubber slug still inside it.

[wdtom44]

Today, 08:53 AM #16 CCWKen CCWKen is offline
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Sounds like a good spot for an O-Ring.

Yep, O ring.

[Glug]

A few ideas..

For this lightweight task, two brass tubes, held concentric with either a bushing or even epoxy. They can be easily sharpened, and either pressed through or spun in a drill press/mill.

The work could be held against a block of wood (or similar) using an overlay template (though I think a sharp thin tube should cut right through). If you make two templates, and a way to reference-locate them against your clamped block, you could make the concentric holes in two operations and avoid making a combined tool.

It might help to glue the rubber to the block. Maybe rubber cement would hold but also peel off? If the rubber is too pliable, freeze it.

[lakeside53]

Here's mine. Rusty scrap, 10 minutes. For Baldor grinder felt washers. Only $7 each from Baldor + stupid freight, but would have taken a week or two. PhotoSuckit is being slow today... the image will eventually show up, but here the link.

http://s238.photobucket.com/user/lakeside53/media/felt%20punch_zpsdmoxwdok.jpg.html?sort=4&o=1

[CCWKen]

That's a good looking 10-minute die!

The first time I checked your post, the picture wasn't there so I click on the link. Wow! That's the last time I'll click on a PB link. They start showing me a video of someone's birthday in a couple of window panes. Then on top of that, they want me to allow Flash Player. WTH! The only reason for that must be tracking and stealing my machine time for more ads.

[J Tiers]

It is indeed good looking.

An example of what can be done quickly with a machine having some power and rigidity..... Not gonna get that done in a hurry with an Atlas 618, or a 9 x 20 import.

[loose nut]

Sounds like a good spot for an O-Ring.

Can't, I'm making a scale model and it needs to at least look historically accurate.

loose nut, I'd also suggest making two punches for the ID and OD and if eyeballing concentricity doesn't come close enough just make one punch a nice close sliding fit inside the other and a little bit longer. Cut the OD first and then slide the other punch into the first punch which will center it on the rubber slug still inside it.

I could do that but I now think I will switch to a more ridged material and just turn them. The rubber will compress to much and cause the mechanism to jam up. 1/32" nylon or something like it would work if I can find some.

The original had hard leather washers about .2 to.25" thick. I would just use that but in 1/32" the leather is just to soft.

[loose nut]

Sounds like a good spot for an O-Ring.

Can't, I'm making a scale model and it needs to at least look historically accurate.

loose nut, I'd also suggest making two punches for the ID and OD and if eyeballing concentricity doesn't come close enough just make one punch a nice close sliding fit inside the other and a little bit longer. Cut the OD first and then slide the other punch into the first punch which will center it on the rubber slug still inside it.

I could do that but I now think I will switch to a more ridged material and just turn them. The rubber will compress to much and cause the mechanism to jam up. 1/32" nylon or something like it would work if I can find some.

The original had hard leather washers about .2 to.25" thick. I would just use that but in 1/32" the leather is just to soft. I may go to a local gasket manufacturer and beg some scraps of 1/32" thick "Klingersil". that will do the job.