Clock bushing

[mclark3617]

Well ive read all your advise and watched the courses but in the end i had to use the tools i had available to bush my Seth Thomas clock plate, i will describe how i did it.

I used a Bridgeport mill, i bit overkill but like i said i had to use the tools i had.

I assembled the two plates and used a guage pin to pick up the hole, the hole that needed bushing was slotted so the pin located at the original center and having both plates helped keep everything inline, i used an indicator to picked up the hole location.

I then used an endmill to locate the hole and give me a round starting hole

I then drilled it out to .002 under the bushing diameter

Then pressed in the bushing using a prescision vise so it would press in square to the plate. The pin hole also closed in .002 but ill keep it like that and measure the pivot after i clean and polish it then open it up the required amount

[chris mabbott]

Great post with equally good clear photos…
Thank you for presenting this technique, it will be a great help to me when I eventually hit the two clocks I have waiting in line lol

Love the Bridgeport …

[david pierce]

McLarke,
I do believe you nailed it. In fact, you can make the entire clock if you want to; fantastic!
david

[bernie weishapl]

Great post and really nice pictures. You definitely could build your own clock.

[mclark3617]

I have fixed many a bad hole in many different ways,,but never on such a small scale, it would be nice to have the tools to do this in my home, but for now ill just take it to work. There is always more than one way to do something, and you can usually get the job done with the tools you have you just have to be alittle creative. And yes i could put the plate on a CMM, Coordinate Measureing Machine, and reverse engineer all the hole locations and make a plate…maybe one of these days.

[Bob Tascione]

Good job and thread Mclark!
Thanks for posting this for us.
Bob

[david pierce]

McLark,
There is nothing wrong with the tool you used on that job. If I had the room and the electrical service I would get one too. Unfortunately my machine shop is in a small upstairs spare bedroom. The largest of my mills weighs 750 pounds and I did not know if the floor was going to hold it or not. As it turned out it did but I am not going to push my luck. My largest engine lathe has a 9″ swing, weighs 250 pounds and is in the same room but against the other wall. Incidently, the Bergeon Bushing machine is something you could build yourself if you wanted to. it is similar to a bench hand tapping machine with some side supports.
david

[mclark3617]

I noticed that about the bergon machine and was gonna look for a similar tool mabey at harbor freight and modify it. But for now with the amount i do, taking it to work seems to work fine,,,i need to get some small boring bars though.

[khoward279]

I make small boring bars the old fashion way I guess here’s how. I get hss or carbide drill blanks and hand grind the cutting edge for a lathe or my boring head and the work great. Good luck.

[mclark3617]

I always hand ground two flute endmills… never thought about using a drill,, seems all the twist would make it difficult

[david pierce]

I have ground out boreing bars before from end mills and also made T-Slot cutters from end mills. Off the shelf commercially available boreing bars are too large for watch work so the extremely small ones will have to be made in the shop. I like the idea of making them from drill bits but I have never tried it before. I used to make a lot of that kind of stuff with a full size tool and cutter grinder but all I have now is a single lip cutter grinder similar to a Deckel. If I can find some time I will try it. Great idea.
david

[daryn]

Round section high speed steel of various grades is available very cheaply these days, the last lot I bought was from msc 1/8″at 36p each (I guess less than half a U.S. Dollar
Is great for small boring bars, I’ve also ground back normal tool steel gravers for hand held boring jobs

[khoward279]

Normally i purchase drill blanks ( HSS or Carbide ) with no flutes so it makes grinding them so much easier. I also order 1/8″ or 3/16 cermented carbide c-6 grade lathe tool and they also work great.

[Author]

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