My Clock Build Project Thread

Once you have the tooth shape on the pallet fork working as it should, I would recommend hardening it. In particular, this sort of drop pallet is what was originally called a dead-beat escapement, because it doesn't cause the seconds hand to back up at all on each tick and tock. This was a common design on jeweler's regulator movements back in the deeps of time. I have a Gilbert jeweler's regulator with an escape wheel and pallet shaped very similarly to what you are making here. On that clock, the pallet is dead hard.

Rick "looks like fun!" Denney
 
Yes, after I get it to tick tock, I plan on hardening it. That's why I used 4140.

I've never heat treated anything before. Will a Bernzomatic propane torch get it hot enough? Quench in oil? Water?
 
devils4ever said:
Yes, after I get it to tick tock, I plan on hardening it. That's why I used 4140.

I've never heat treated anything before. Will a Bernzomatic propane torch get it hot enough? Quench in oil? Water?
Click to expand...
Use MAP gas...not propane. Map gas gets hotter and burns a bit cleaner.

Then....

You mentioned gears...not cycloidal gears but were going for involute instead.

May I ask why?

Involute tend to have the flat tops instead of the pointed tops to them. Which since the teeth are going to be small I would thing that work hardened cycloidal gears would be the best thing.

I'm asking because I'm studying the same thing and so far I'm with ya on a lot of this. The brass is outrageously priced at the moment....and if you have aluminum you can anodize them or electroplate them with nickel and get a fantastic finish on everything.

Is it going to be a 4 wheel or 5 wheel train?
 
I am following this build with a lot of interest. way to go so far!

4140 needs to be yellow hot to harden sufficiently to make it worthwhile. Butane/propane torches don't cut it. Map gas is still available in Canada, but I cannot say in your area. You can get a propane/air or a propane/oxygen torch to heat up things just fine. Given the costs and technologies today I'd stay away from acetylene, ad it gets expensive for occasional use. oh and HHO torches don't make enough BTUs for your application.
 
Eddyde said:
Unfortunately Map gas is no longer produced.
Click to expand...
It's been a while since I bought any...

When they stop making it....it was great stuff. I used it all the time to solder plumbing joints. You could even use the high temp sticks instead of regular silver solder with it. That stuff would get the copper glowing pretty easily.
 
I'm going with involute gears for a couple of reasons.

First, I have involute gear cutters.

Second, they are readily available in many pitches/modules.

Third, I've read that there is no real benefit to cycloidal gears. I think it is just tradition to use cycloidal.

Fourth, I think the spacing is more critical on cycloidal gears where involute gears will work if the spacing is not exact.

But, this build is starting as a prototype. So, I may change my mind on this.

Great wheel (bottom) is 96T, center wheel is 96T, third wheel (top) is 90T. All pinions as 12T. For the hour hand: 48T wheel driving a 12T pinion. This drives a 45T wheel driving a 15T pinion. I may change these ratios since I don't have a 24 division plate for my dividing head which is needed for 96T gears. I can make 104T gears and 13T pinions with standard dividing plates. However, I'm thinking I can make a 24 division dividing plate with my rotary table though.

Schematic of gear train:
gear_train2_transparent_edit.jpg
 
You must log in or register to reply here.
Back
Top