Wasn't this project for a 22,000 RPM spindle?

20,000 it was  but 1475 would have been fine for a start, especially as that was what the pulleys in stock would give

Hood

Sorry to be dense, but I'm not following this at all. How do you engrave at 1,475 RPM   

Sorry to be dense, but I'm not following this at all. How do you engrave at 1,475 RPM   

easy, you put a zero at the end of that should be 14750
Hood

So where does the 3,000 RPM fit into the puzzle  . . .  3,000 at the motor and 14,750 at the spindle? Is that what you have?

My spindle on the Beaver Mill has 3800rpm top speed the way I have it connected. The gearing in the speeder I made is 3.75 times so that gives me the 14250 (14750 was another typo ). I have been testing out at 3000 rpm spindle speed so output was 11250.

Hood

Hood,

Are those gears you found ground? Otherwise don't think it would be a good idea to spin them at the speeds you like...

Daniel

They are very nice quality anti backlash gears from an old Bullard lathes encoder/switch housing. They are possibly a bit on the light side but time will tell Not sure what speed they would originally have done, will have to put them back in order and see if I think they will do.

Hood

Wow  I did not realize you were trying to drive the high speed engraver off the main mill spindle. Almost 4:1 speed increase with a single belt is pretty optimistic.  Going the other way is a whole different animal. If you are now thinking about using gears, you would be well advised to seek out a planetary set. Consider yourself so advised 

In my setup, I am shooting for 40k to 50k rpm, but I'm starting with a pre-balanced 30,000 RPM tool motor.  In any case, good luck and please keep posting your results. This is interesting to follow.

Wow   I did not realize you were trying to drive the high speed engraver off the main mill spindle. Almost 4:1 speed increase with a single belt is pretty optimistic.  Going the other way is a whole different animal. If you are now thinking about using gears, you would be well advised to seek out a planetary set. Consider yourself so advised 

Ok I will take that onboard Now what about this idea, this was actually my first but it ended up going by the wayside. I have some small Alpha in line planetary gearboxes that are meant for servo reduction. I was planning on driving it arse for tit and then I discovered the Input (which would be the output) relied on being clamped to the motor shaft. No probs I thought, housing, angular contacts and job done. I then looked up the spec and it says 6000rpm input speed so I decided against it. I am thinking it may be worth a shot, have a couple of angular contacts and would be simple to make up a housing and shaft. If the box screws up its no big deal as I got 2 of them for £12
So what do you think?

In my setup, I am shooting for 40k to 50k rpm, but I'm starting with a pre-balanced 30,000 RPM tool motor.

Thats quite a bit faster than I need, tool I have is rated to 20,000rpm in stainless I think so anywhere between 15 and 20K would suit me.

In any case, good luck and please keep posting your results. This is interesting to follow.

Interesting as in funny watching me screw up?

Hood