Elegent Scroll Frame Skeleton Clock

[Kim]

Hmm... more good input.

I may end up skipping the heat treatment on the springs.  I made them from W-1 so that I could heat treat them. But maybe that wasn't necessary...

Kim

[Dave Otto]

Hey Kim.
Nice work on the assembly.
I'm not sure how good of a spring W-1 would make after heat treatment, typically just a high carbon steel is used. Something along the lines of 1095 steel. The tool steel may be too brittle at any temper.
I think that I wound not try to heat treat the springs and if they are working for you just leave then as is. Which is what I think you are leaning toward anyway.

Dave
 

[cnr6400]

  Looking great Kim!

[Kim]

Thanks Dave and CNR! 

I'm not sure how good of a spring W-1 would make after heat treatment, typically just a high carbon steel is used. Something along the lines of 1095 steel. The tool steel may be too brittle at any temper.
I think that I wound not try to heat treat the springs and if they are working for you just leave then as is. Which is what I think you are leaning toward anyway.

Thanks for the input, Dave.  Yeah, makes sense.  And yes, I've decided not to do any heat treating of the springs.  If they give me trouble, I can remake them in some other material.  This seems to be working fine for now though!

Kim

[Roger B]

Excellent work on the springs      Cutting off a 1/32 thick section looks a little tricky 

[bent]

That makes sense, Crueby and Dave, and argues for "if it ain't broke don't fix it", i.e. don't bother with heat treating.  I'd think of hardening the spring only at the tip that engages with the pawl, to minimize wear?  Still, partial hardening of the spring might not be a good idea either...and would it really wear less if the pawl is also hardened...hmmm.

[crueby]

That makes sense, Crueby and Dave, and argues for "if it ain't broke don't fix it", i.e. don't bother with heat treating.  I'd think of hardening the spring only at the tip that engages with the pawl, to minimize wear?  Still, partial hardening of the spring might not be a good idea either...and would it really wear less if the pawl is also hardened...hmmm.

Hmmm, good question!  On the escapement mechanism, the toothed wheel, usually brass, is not hardened, but the arm that engages it is usually a polished hardened and steel. That arm is engaging/sliding on the teeth at least once a second usually (depending on the pendulum length and tick period), so a LOT of potential wear there. For the spring/pawl, its often only wound once a week, and has very little travel on the surfaces, so they can get away without hardening.

[Kim]

The final items to make for the fusee assembly are the slip washer and the bearings.

I started with the slip washer.  This was shaped on the lathe from a slice of 303 stainless round bar, then the keyhole slot was milled in it:


Then I made a 0-80 threaded hole in the great wheel to hold the slip washer in place.  As you can see here, the slip washer slips into a notch on the fusee arbor to hold the great wheel in place.   The slip washer, in turn, is screwed into the great wheel to keep it from sliding out of place.   This allows the great wheel to turn freely on the arbor without sliding out of place.  Very clever!


Here are the pieces that make up the fusee assembly.


Finally, I made the bushings for the fusee arbor.  I reamed these to size so that they are a nice fit around the arbor.  Here you can see the notch on the right side of the arbor that the slip washer fits into.


Here’s the whole thing reassembled and fitted into the frame.  This required a little adjusting of the width on the fusee arbor.  I had made exactly the width to fit between the plates and bushings, knowing that I’d have to shave a bit off.  John Wilding says you need a little wiggle on all your arbors.  They should NOT be too snug between the pivots. They need to have some play so they will run freely.


And finally, a family shot of everything that’s done so far.  That’s a lot of work for not much change. But I’m pleased regardless!


Thanks for looking in,
Kim

[Krypto]

That stainless clock is looking really good already!  Nice change from brass and you don't need to worry about tarnish.

[crueby]

That whole winding assembly is beautiful,  very clean!   

[cnr6400]

  Looking great Kim!

[kvom]

Impressive 

[RReid]

There is a lot of work hidden in that assembly, and the result is truly beautiful. Triple kudos, Kim!

[Dave Otto]

Hi Kim, the family shot is very impressive! The all stainless parts sure gives it a different look.

Did you make the bushing also from stainless? I would think that some sort of bearing material would be in order here. Maybe I don't understand the relationship of these parts, but it seem to me that there would be quite a bit of load on the bushings due to the spring? Probably whit some good lube they will be fine, I would worry about galling and the bushings becoming one with the shaft/s.

Dave

[Kim]

Thanks everyone!

Did you make the bushing also from stainless? I would think that some sort of bearing material would be in order here. Maybe I don't understand the relationship of these parts, but it seem to me that there would be quite a bit of load on the bushings due to the spring? Probably whit some good lube they will be fine, I would worry about galling and the bushings becoming one with the shaft/s.

No, the bushings are made from W-1 tool steel, and I plan to harden them once I'm sure I have them tuned and polished.  The bearing surface is tapered in from both sides so that there is only a small area of contact with the shaft.  My thinking is that by hardening them, they will wear better and should not gall with the shafts.  The two shafts I've done so far are both stainless.  But the remainder of the shafts will be done with Pivot Steel or hardened W-1.  Not sure yet.

In the original design, John Wilding just uses the bare brass for the arbors to run in.  I'm hoping that hardened W-1 will make a decent bearing surface.  If not, I can remove it and make it with something else.  I did consider putting brass or bronze bushings in, but I kinda wanted to stay with the color scheme, so opted for W-1.

Does that seem problematic?  I'm always open to input. 

Kim