Speed Increaser

Edited By Roderick Jenkins on 18/06/2011 14:49:21

Edited By Pat on 18/06/2011 15:41:42

Edited By Roderick Jenkins on 19/06/2011 17:15:05

Hi Rod

How's your build of the speed increaser coming along?

I am trying to draw up plans to build one along the lines John S suggested. HPC do a 72 tooth ring gear with a 60mm OD and Dick Stephens suggested a 16 tooth sun gear should be ok giving a ratio of 5.5:1.

The intention is to drive it with a KX3 so the top speed could be excess of 20,000 RPM. This gives me concerns about the oilite bush getting enough oil to stop it burning up! I am thinking of using 3 planets to take the strain off the sun gear. Just working out the machining sequence.

Cheers Michael

Michael,

It's put to one side for the moment. My thoughts are following Michael's comment above and using my Arrand spindle which is good for 8000rpm.

Keep us informed of progress.

best wishes

Rod

Hi Michael

I have seen the thread you mentioned but couldn't find it on a revisit. I was put off by the bulk of the design. But your mention of it has triggered the thought of use the body of the bearing housing as a pulley which will run at spindle speed, take an elastic band out to an outrigger shaft with small and large pulley then another elastic band back to to the new spindle so long as I can get a ratio 4:1 I will get my target speed of 20,000 rpm. Probably want a gaurd for the elastic bands cause i'll bet they'll sting if they snap and hit you!

Hi Rod

if the above will work I think it will be the way to go, the gears for my other design were going to cost £76 I've probably got the materials in my scrap box

Cheers Michael.

My design got shelved as the price of the high speed 400 Hz spindles are now really affordable and the plus side is they are so quiet.

Even at 4:1 increase you still have to run the mill flat out and get all attendant noise and vibration with it.

I'm running a 24,000 rev spindle at half speed and the noise of the cutter in the material is the greatest noise.

So far the longest it has run cutting a job was an engraving of the Mother in law which took 11 hours to cut, mind you she is a rather large lady.........

A bit of lateral thinking - I made a toolpost drill/mill by fitting the planetary gearbox out of a broken portable drill into a steel housing.

If you took the internals out of such a gearbox and fitted them the other way around...

Note these gearboxes are two-stage, so you could just use one stage.

Neil