Keyed Washer/spacer

[savarin]

I need to make one of these

50mm outside dia, 12mm inside dia, 4mm thick, the tab 5mm across, all in stainless steel.
It has to be very flat on both sides with no warping.
The only way I can think of is to cut a key way and braze the tab in then smooth it out.
But.... I dont trust my brazing skills with stainless.
Any other ways I could do this?

 

[DSaul]

Brazing stainless is easy with a high silver content rod (45% or higher) and the matching flux. It flows at a lower temp than brass and adheres well to stainless steel. Unfortunately your local welding store probably doesn't carry it and will look at you like they never heard of such a thing. It is a common thing in the bicycle frame building world and can be obtained from Cycle Design here http://cycledesignusa.com/wp/?page_id=55

 

[Wreck™Wreck]

Depending on the ID and OD tolerances, surface finish and concentricity requirements, abrasive waterjet, laser at the loose end and EDM at the tight end, a round broach/punch would also work well but would be limited to one shape and sized part. If the allowable radius in the corners is less then say .25 MM then punching/broaching and EDM are your only choices. Flat and parallel surfaces are the easy part as a surface grinder will make short work of that.

If you are not concerned with the surface finish a 2 axis mill, (or manual using a rotary table) will easily make such an internal feature using a 1.5MM endmill leaving a .75MM radius in the corners which may be removed easily by hand with a file afterwards or removed with an undercut during the mill operation, an undercut is common practice where an inside corner radius is not allowed. A laser or WEDM will still leave a small radius in the corner so an undercut is the easist method.

Like so

 

[savarin]

Hmmm, edm, never thought of that, looks like I will have to repair my lash up edm and have a go at that, I dont have a mill so thats out.
I'm allowed a little leeway on the hole dimensions as it has to slide up and down the shaft approx .25mm max.
If I make the tab a little wider than 5mm I can file it back to size.
Thanks

 

[Wreck™Wreck]

Hmmm, edm, never thought of that, looks like I will have to repair my lash up edm and have a go at that, I dont have a mill so thats out.
I'm allowed a little leeway on the hole dimensions as it has to slide up and down the shaft approx .25mm max.
If I make the tab a little wider than 5mm I can file it back to size.
Thanks

Wire or Sinker EDM?
A sinker of sufficient accuracy using equally well made electrodes will produce such a feature with nearly zero inside corner radii, at great expense of course. If you are required to produce thousands of parts at loose tolerances a broach or punch would yield the most bang for the buck I suspect.

A 12MM round broach with a slot ground to the key width would be easily accomplished by a manufacturer of broaches and multiple parts would then be broached in a stack, assuming a pull broach of course as a push tool would be entirely too long given the dimensions.
Good Luck

 

[Bob Korves]

I'm interested in these internally toothed washers as well and looking for ideas on how to make smaller ones. My app. is for cloning Aloris BXA tool holders. The real advantage of the Aloris over the copycats is that the Aloris has a toothed washer and slotted stud for the height adjustment. It is like the older bicycle axles, which used the same idea. It allows adjusting jam nuts one at a time without using two wrenches and making possible turning just one nut at a time and not upsetting the adjustment. This is really the major advantage of the Aloris over the clones, their quality is just a bonus. Also need to slot the stud, but I have a way to do that by drilling and tapping a block for the work and then milling away access for slotting. These washers are essentially not available in stock sizes unless you want to buy thousands, too bad. If you have ever adjusted bicycle wheel bearings without these washers between the nuts, or used a clone tool holder, you know what I am talking about. I need to make about 20 washers. Edit: My best idea so far is to make a punch and die and borrow access to an arbor press, or do them on my 20 ton press.

Aloris sells them as a kit, p/n bxa-ha. Enco has them at $13.86 each, more than the price of clone tool holders complete... The idea is to learn something new, make something nice, and SAVE MONEY!
http://www.use-enco.com/1/1/33997-bxa-ha-aloris-quick-change-tool-post-holder-accessories.html

 

[Wreck™Wreck]

I'm interested in these internally toothed washers as well and looking for ideas on how to make smaller ones. My app. is for cloning Aloris BXA tool holders. The real advantage of the Aloris over the copycats is that the Aloris has a toothed washer and slotted stud for the height adjustment. It is like the older bicycle axles, which used the same idea. It allows adjusting jam nuts one at a time without using two wrenches and making possible turning just one nut at a time and not upsetting the adjustment. This is really the major advantage of the Aloris over the clones, their quality is just a bonus. Also need to slot the stud, but I have a way to do that by drilling and tapping a block for the work and then milling away access for slotting. These washers are essentially not available in stock sizes unless you want to buy thousands, too bad. If you have ever adjusted bicycle wheel bearings without these washers between the nuts, or used a clone tool holder, you know what I am talking about. I need to make about 20 washers. Edit: My best idea so far is to make a punch and die and borrow access to an arbor press, or do them on my 20 ton press.

Aloris sells them as a kit, p/n bxa-ha. Enco has them at $13.86 each, more than the price of clone tool holders complete... The idea is to learn something new, make something nice, and SAVE MONEY

As noted, buy thousands as this will be the least of your costs when manufacturing a dovetail toolpost, it will pale in contrast to the mill and lathe operations, heat treating and whatever surface treatment that you intend to employ, black oxide, flash chrome, TIN Etc. One thousand threaded plastic ball knobs for the handles will cost more then 1000 of these washers.
One is unlikely to produce a simple product at a lower cost then that which may be produced by a firm that makes similar products and has had the equipment, infrastructure and experience in place for decades.

As to what Aloris charges for them OEM replacement parts are always highly marked up, if your venture succeeds you will appreciate this, you will be selling a complete tool for $49.99 and when a customer needs one of your OEM replacement parts you sell them a $0.09 washer for $4.99 thereby covering the costs of of having staff at the phones at all times.

 

[derf]

I would entertain the thought of making a cylinder a coupla inches long, broach it for a keyway, and then silver braze a key in place the whole length. Chuck it up and slice it off.

 

[Bob Korves]

As noted, buy thousands as this will be the least of your costs when manufacturing a dovetail toolpost, it will pale in contrast to the mill and lathe operations, heat treating and whatever surface treatment that you intend to employ, black oxide, flash chrome, TIN Etc. One thousand threaded plastic ball knobs for the handles will cost more then 1000 of these washers.
One is unlikely to produce a simple product at a lower cost then that which may be produced by a firm that makes similar products and has had the equipment, infrastructure and experience in place for decades.

As to what Aloris charges for them OEM replacement parts are always highly marked up, if your venture succeeds you will appreciate this, you will be selling a complete tool for $49.99 and when a customer needs one of your OEM replacement parts you sell them a $0.09 washer for $4.99 thereby covering the costs of of having staff at the phones at all times.

Uh, WreckWreck, this is HOBBY machinist and I am one. As noted in my post, I am in need of about 20 of these washers for the holders I have and the ones I will be making. I do not need anything else, I have all the materials I need to make an additional SIX tool holders to fit my Phase II toolpost set. 12 of the washers will be for clone holders I already have that were built without the tab washers. I do understand that you are a pro and have a different view of things, my "venture" is only to please myself...

 

[savarin]

I only need one of these, its to prevent the pressure nut from unscrewing on the clutch when the azimuth is moved manually on my telescope.
I have to re-build my simplistic sinker edm that I built to remove broken taps. (very successfully)
Ive found some edm electrodes at 18mm dia x 100mm long for $20 so I'm hoping I can turn them down to 12mm and mill the 5mm groove. If this all works its another tool that may have even more uses.
I've only used copper electrodes to date so this is a new direction.
The advantage of being a hobbyist is loads of time (if swmbo allows it) can be languished on a project to finish it without having to worry about earning a profit. I only realised the other week that this project has been going on for just over a year.