- Mar 31, 2016
Hi Randall With those extra 4 holes I am able to tune the disc in to a local radio station, bit of a result hey !! I wish.
I have not done the math on all the combinations, but on the surface 60 to 1 sounds so much more practical then 40 to 1.The dividing head ratio is 60 to 1 so each full turn of the handle is 6 degrees, 10 turns of the handle gives me 60 degrees for the sides of the nut.
As you can see from the first pic my 6mm lathe tools are still my only small parallels. In fact other than my V blocks, my only parallels.
All went well and I ended up with the barrel ready for boring to the final size. Next project some parallels!! and a camera.
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I thought I would show the tools I have had to start this project with.
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I have not shown the lathe or the milling machine that has a vice and a clamping set, or the taps and dies and drills and bits of beer cans I cut up for shims!!
I had 5 pieces of 6mm by 6mm tool steel 3 of them you can see here the others have been cut up, and that was it.
You can make one now if you want one.Hi Thank you all for your comments, they are as always very encouraging and inspirational. I am not sure over all whether 60:1 or 40:1 is better, 60:1 you have to turn the handle more but 60 seems to divide into 360 better. I think the big deciding factor that really sways the decision for me is that I didn't have a 40 tooth spur gear!!!
A far cry from the good old days. During my apprenticeship in the early 60's we often used square HSS tool bits as parallel bars quite often, they were pretty reliable up to .0005". Of course for greater accuracy we did use toolmakers parallel bars .wayne,be careful. Those ground HSS cutters are not accurate to use as parallels. If you measured them(which you may have already done),you will find out that they can be several thousandths different in size. Even the small ones can be quite different in their sizes.