Planetary speed increaser

[Tjark]

Jeroen, I have watched your work on the side line and wondered how easy you went from idea to a practical useful tool.
Very nice work, hoping you can use this tool for a long time without troubles.

  Tjark.

[dieselpilot]

Very good. If you're happy with the surface finish it offers, you've succeeded. I think you would see a significant improvement with good bearings and reduced spindle runout. I suggest mounting a very sharp carbide tipped boring bar in the vise and writing a program to true the collet taper in the beraings. I did this when the second shaft in my spindle had too much runout. I had to replace the shaft due to a crash that bent my original spindle shaft. The runout and fit of collets has been excellent. That planetary gear looks a little light, though time will tell.

What is the resolution of your PC Mill 50 after conversion?

Greg

[Coopertje]

Thank you Tjark, once you have the right idea in the head its just a matter of making swarf. Makes a difference that it is not a very complicated device to make.

Greg, I am quite happy with the finish, looks good with a additional finish pass between 0.1 and 0.2mm.  I expect that this will the MKI model and will build a MKII version with improvements on spindle bearings, most likely some quality ER-11 collets (the collets used  in this one I picked up one day on a show and they are not in a perfect state). I am quite sure that the bearing is responsible for the run out, I was very careful when setting the spindle in the independent 4-jaw. I have thought the same as you suggested, mount a small milling spindle (or what you suggest a small boring bar) in the vise and grind / turn the collect holder true when mounted in the machine.

The PC Mill 55 has a standard step resolution of 0.005mm. Since I use the original drives (designed an interface board to translated between the differential Emco drives and the standard TTL logic on a break-out board) this resolution is not changed. The spindle pitch is 10mm and in Mach I have 2000 pulses per rev. -> 10mm/2000p= 0.005mm/p

Regards Jeroen

[Roger B]

Looks good to me  and does what you expected    Excellent job 

The collets you have look to me like DIN 6343 dead length collets rather than ER 11. The ER (extended range) collets are tapered and split from both ends.

[Coopertje]

Thank you Roger. You are very right, the collets used are not ER-11. What I meant was if I make anotherone, the MKII version,  I will use ER-11 collets from a good quality to improve total runout of the spindel.

Regards Jeroen