Silver Steel

A long time ago I bought John Wilding´s book on how to make a Weight Driven 8 Day Clock. In discussing gear cutting he describes a gear cutter. I tried to make such a disc type profile cutter. You create the edge profile, introduce radial slots and then saw parallel to the circumference to create a lot which is then collapsed by walloping it one. You can try to get away without the relief or using his idea you slot the disc and you cut a slot (with a piercing saw) parallel to circumference for a part of the tooth and wallop it with a brass object to create relief on the cutter by collapsing the circumference partly into the space left by the slot..

I thought I would try it.

Piercing saws and silver steel don´t get on. Is silver steel delivered in some highly annealed state? Sometimes the steel cuts, sometimes not, either it is work hardened or just delivered that way.

Any insights please?

Dick.

Hi Dick,

The silver steel (Stubs) bar I have used to make module gear cutters has not been difficult to machine. It was annealed when I got it, it is harder than mild steel so you have to reduce the speed. I have also made a gear cutter from gauge plate, more or less the same way as I did when using silver steel.
Where did you get your silver steel? You might try a different supplier and see if that makes a difference.

Thor

I've had no problems using piercing saws for cutting silver steel rods and gauge plate. Be sure to use good quality blades.

The more accepted way to make cutters is to mount the disc eccentrically on a mandrel to create the form relief.

This is a photo from a thread I posted a while back. Then you mill out between the lobes to create the cutting edges.

No need to use a piercing saw or bash the steel.

Thanks for the suggestions and the illustrated guides. I´ll try the eccentric approach. I was a bit wary of using this approach with my small lathe. I´m trying to make a 0.6 mod cycloidal cutter so the cutting tool is small.

As to the silver steel, it machined okay, just the piercing saw blades I have seemed not to take kindly to it.

The secret with silver steel or O1 steel cutters is in the heat treatment. Don't get it too hot on the initial heating, Let it soak at temp for quite a few minutes before taking it to the bright cherry red. Dunk into oil for O1 and water if it is W1 Stubbs Silver steel. With the tempering, it wants to be at about 150 c for like 20 mins, dunk into boiling water, then back into the 150 c again and then let cool slowly. This process works very well. Keep in mind that the Carbon steel cutter has about 1/2 the surface speed of HSS cutters also, and perform best when they are water coolant flood cooled.

Neil

How much relief does a cutter actually need if cutting brass?

The relief is giving "back clearance" to avoid the part of the tool behind the cutting edge rubbing - about 5 degrees is usual. For brass it is "front rake" that you don't need much of, or any, to avoid digging in.

By the way, the tool in that photo is made of gauge plate, effectively flat silver steel, and I think i might have roughed out most of the sectors with a hacksaw before milling the edges.

Have you got piercing saw blades, or have you got ordinary fret saw blades, the latter will cut brass and aluminium, but with any steel, if you don't break the blade, you'll strip the teeth off. When cutting, let the saw do the work, don't push it.

Ian S C

I've come across the ends of silver steel rods being hard, presumeably after being cut to length by grinding .

I have in the past made cutters as John Haine

Roy

I believe the reason silver steel is sold in 13" lengths is because the cutting to length process hardens the ends, the extra inch allows half an inch off each end to be disposed of and you still have a full 12" of useable material.

Mike

Edited By Mike Poole on 09/01/2018 17:07:43

Iv'e just had to cut some parts out of 1/32" gauge plate with a piercing saw. It was a nightmare. I tried 4 different makes of blade including Bergeon and a couple of types of "platinum" jewelers blade for cutting hard material.

They performed pretty much the same - worked fine for 1/2" of cut then started getting blunt. If they cut an inch before breaking I was lucky.

I used over 30 blades to cut out 28 small parts and it took all weekend. I've got a load more of these to cut out and I'm not lucking forward to it.

There has to be a better way.

Steve It sounds to me that you are forcing the saw. I have cut several long case clock hands out of 1/32 gauge plate

with very little trouble. I find I work better sitting down and relax. Also I try to cut towards me so that I can see the line I'm cutting to

Roy

Hi Roy, could you tell me which size blades you use for 1/32?

And how you hold/support the piece?

Thanks, Steve

Are you taking long , slow strokes with the piercing saw, using the full length of the blade? Saw blades are the same as other tooling, you need to take it slow and steady on tougher materials such as silver steel. If you "over-rev" the saw with frantic short strokes at high speed, the teeth will not last long.

For 1/32" plate you need a very fine blade, and possibly tilt the saw forward to give a longer face to cut, have a bit of candle, and rub this on the blade often to lubricate it.

Ian S C

Steve My blades are about 32 ttpi use the finest you can get. As Ian says lubricate often and take it easy. For support I use a piece of 1/2 inch plywood with a V cut in the side nearest to me, and hold the work with thumb and first finger of left hand. Same as we used to use for fretwork if you can remember that. I personally find piercing saw work to be very therapeutic once I get into the rhythm

I also endorse what Hopper says

Roy