How to lay out the winding arbor holes on a new dial?

[Keith Doster]

I'm working on a large two-sided Seth Thomas clock that mounts perpendicular to the wall. It would have been used on a train station platform or in a school hallway. I acquired the movement and hands several years ago, and a very talented friend created a custom case for it. Now to make the dials. I am having some thin sheet steel cut to fit the case and intend to use paper dials on the steel. One side of the movement has the two winding arbors. What would be the best way to drill accurate holes for the winding arbors? I don't want to have to do this twice. The steel sheet/dial is square, so that will probably simplify things somewhat. Any advice would be appreciated. A video might be even more appreciated! I'm sure this isn't as complicated as I envision it to be. Thanks!!

 

[shutterbug]

Make yourself a preacher. But an easier way might be to use the front plate of the movement as a stencil. You'd just have to find the center of the dial for the initial positioning of the center hole.

 

[Keith Doster]

Make yourself a preacher. But an easier way might be to use the front plate of the movement as a stencil. You'd just have to find the center of the dial for the initial positioning of the center hole.

Using the front plate sounds like a great idea. I knew there had to be some, relatively easy way to do this. That is a big help. Finding the center for the minute arbor shouldn't be a big deal.

 

[bruce linde]

Make sure you use one of these bits to ensure round holes: Step Drill Bits - Amazon.com

 

[Uhralt]

You can also take a sheet of paper or thin cardboard with the dimensions of you dials. Punch a hole in the middle with a diameter of the hour cannon. Put that sheet on the front of the clock with the hour cannon inside the hole. Mark the position of the winding arbors. Now you have a template for drilling your holes.

Uhralt

 

[Keith Doster]

Make sure you use one of these bits to ensure round holes: Step Drill Bits - Amazon.com

Yes, Bruce! Got one! They are so useful. How many things do we use now and wonder how we got along without them? Like the internet!

 

[Keith Doster]

You can also take a sheet of paper or thin cardboard with the dimensions of you dials. Punch a hole in the middle with a diameter of the hour cannon. Put that sheet on the front of the clock with the hour cannon inside the hole. Mark the position of the winding arbors. Now you have a template for drilling your holes.

Uhralt

I had to read it a couple of times to understand what you were suggesting, but that is also an excellent idea. I may need to post some pictures of this process when I get around to it. Thanks for the advice!

 

[Willie X]

A large machinist compass (not a drafting compass) and a vernier caliper can get you there in just a few steps.

Using the front plate is by far the easiest but to do this effectively you have to have a bare front plate. Something that may not be practical.

Willie X

 

[JimmyOz]

I think using the back plate would work and no need for much dismantling. Put a X from corner to corner on your sheet, drill a hole the same size as the hands arbour pivot and put a stiff wire through the plate pivot hole and through the sheet, now mark the winding arbour holes, making sure the plate is 90 degrees to the edge of the sheet. This is saying the sheet is square though.

 

[JimmyOz]

Okay I just read the OP post again it is a 2 sided movement, however it may still work?

 

[Keith Doster]

JimmyOz, thankfully, the other side of the clock has no winding arbors, just a center hole for the minute arbor. No seconds bit. Piece of cake!

 

[Mike Phelan]

I've always used Uhralt's way with a thin card.