Saturday, April 16, 2016

 Gary Fields 2016 ©

I would like to give a little background on this movement I am working on. I was contacted by a gentleman from the NAWCC forum, who wanted this clock to have some of Mark Butterworth's Butter bearings™ installed. In our back and forth, I determined that I could do the bearings up to the minute arbor. This would entail the winding arbor, second and third wheels, and the minute arbor wheel, a total of eight bearings. 

He also told me about IGUS self-lubricating plastic bearings, and wanted to see what I thought of them. I put in a request to a representative of the company, and was sent a 10 mm. diameter rod, 100 mm. long, and two other sleeve type bearings of which would not be applicable for what I am doing.

The 10 mm. rod was the smallest of which they had to offer. My plan is to reduce the diameter down to 1.79 mm.  I know, a lot of waste, but that is the size I need for the upper three wheels and possibly the pin lever also. I am using this size because I would install brass or bronze bushings of that size if this is unsuccessful. A backup plan, if you will!

Having installed Butter bearings™ before, I have been impressed with the results of how much they improve a clock's running, if done properly. The drawback for me is aesthetic. The bearings do jut out from the clock plates by a few millimeters, and I have always desired to use some form of retainer and/or housing to encase them in. Since I am retired, and have time on my hands (no pun intended), this is a perfect opportunity for me to try out what I have desired to do.

Pictured below is some of the work I have been at for the last 3 or 4 days. Trying this, trying that, measuring and re-measuring until I could be happy with the results. The winding arbor was reduced in size on the back of the movement, so it would fit the bearing intended for it. My first two attempts at creating a housing will go to the brass scrap pile, but I was pleased with the third attempt that I did today.

Using some harder brass from a drift punch, I turned down the outside diameter to .500 of an inch.

Checking the centering of the piece to my tailstock drill.

Center drilled then drilled with a #12 drill bit.

Next, the hole was enlarged with my homemade boring tool, to a diameter of .274". Here, the 903 Butter bearing™ has been press fit and checked for depth.

Bearing was removed, a blue marker used for layout dye coats the end of the retainer cap, measured and marked for three hole locations to mount to the mainspring retainer on the back of the movement.

First hole drilled

All three now drilled.

Retainer cap was parted off the stock at .068" thickness. Burrs removed with a reamer.

Retainer cap superglued to original  bar stock and first screw hole counter sunk for the screw head.. I did not notice at first, but I was off center just a tiny bit as you can see above. I didn't catch it until I counter sunk the screw head holes, and had one just a little closer to the edge than the others, but not enough to cause a problem. I'll use the odd one as a locator for the twelve o'clock position when I mount the retainer cap on the back.

Counter sinks completed.

After initial polishing of the brass. Bearing next to the steel spacer will go into the retainer cap.

Bearing in retainer cap, one screw for the retainer towards rear of photo.

Retainer screw is at 12:00 position. No slot has been filed yet.

Now that I have some of my machining steps down a little better, this will be located and installed on the mainspring retainer, which is mounted on the back of the movement. Next will be the front retainer cap and bearing for the winding arbor, a bigger task than what you would think it would be. Thanks for looking!

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