Telescope Counterweight

angelfj1

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This will be my first real project with my Enco 9x20 lathe. I need to make a number of counter weights for a telescope. See photo below for an example of a commercially available counterweight.
Counterweight1.JPG

The weights need to be stainless steel and approximately 10 lbs each. After looking at the scale of the telescope mount, it looks like 6-inch diameter SS round stock would work and look good. The weights need to have a central hole to slide on a 2-inch SS shaft. There also needs to be a radial hole drilled and tapped for a locking pin. I'm not sure why the one in the photo has what looks like a brass sleeve. Perhaps this is to prevent marring the shaft.

I am motivated to do this on my own because the commercially available counter weights are very expensive, approx. $150 - $200 each.

I did the math and a 1-inch thick, 6-inch diameter round with a 2-inch diameter hole weighs approx. 7.3 lbs, so a 1.4 inch 'slice' would weigh close to 10 lb.

Questions:

Can my little lathe handle this material?

I guess I would start with a length of 6-inch round SS stock and then use a parting tool to cut off 1.4 inch slices?

What would be the bast way to hold a 1 foot piece in the lathe?

Or, is it better to rough cut these slices on a band saw and then finish/machine each piece.

Is it best to bore the 2-inch hole completely through the stock first and then cut the slices?

Finally, any suggestions for a reasonable cost source. I was a bit shocked at the prices I have found for on line, anywhere from $50 - $75 per inch based on 6-inch diameter 304.

Counterweight1.JPG
 
I'd definitely cut it with the bandsaw first. There's a thread on slab cutting going on right now.
http://www.hobby-machinist.com/showthread.php/12007-How-To-Cut-a-Chunk-of-Steel

Just get the cutting speed right. Good thing that free-machining SST doesn't need to be slower that regular steel. 135, 150 SFM will do. On the lathe, about 100 RPM for 6" diameter should work for HSS, faster for carbide.
 
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