Using RC Brushless motors as spindle

[Jonathan]

It's alive!

Heated the angular contact bearing in oven, cooled the shaft and it dropped straight on.
Bit of a fiddle to get the rest together, but it went ok.

I've run it up to 3100rpm (24v) and it sounds fine. Slight noise from the bearing but I don't think that's significant.

I also measured the runout and it's less than 0.01mm.

Will post some more pics in a minute.


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[blackburn mark]

It's alive!

Heated the angular contact bearing in oven, cooled the shaft and it dropped straight on.
Bit of a fiddle to get the rest together, but it went ok.

I've run it up to 3100rpm (24v) and it sounds fine. Slight noise from the bearing but I don't think that's significant.

I also measured the runout and it's less than 0.01mm.

Will post some pics in a minute.

Nice one jonathan !!!! iv waited a long time to see this beast
it should have enough power to make a walnut wip out of your Y axis :)

[Jonathan]

Nice one jonathan !!!! iv waited a long time to see this beast
it should have enough power to make a walnut wip out of your Y axis :)

That makes two of us.
Make a walnut what?! But yeah, running it off two 12v 92Ah batteries for the moment. Not got a power supply which would supply anything like enough for this. Idling at 3100rpm it consumes 94w. 45w ish at 1500 rpm... that implies almost 200w just to spin the thing at full speed let alone cutting!

[blackburn mark]

looks great, i love how simple these thing are :)

Make a walnut what?!

walnut whip ! .... shit joke.... sorry :)

94w

owch, but as M250cnc phil said to me not to long ago"give your bearing a chance to run in at low (ish) speed before you start flapping about heat" or "drag" in your case

im getting on fine using 350w 12v on my 1700w motor, i dont think you will need to throw 6000w at yours if your using it on your router

[Jonathan]

owch, but as M250cnc phil said to me not to long ago"give your bearing a chance to run in at low (ish) speed before you start flapping about heat" or "drag" in your case

im getting on fine using 350w 12v on my 1700w motor, i dont think you will need to throw 6000w at yours if your using it on your router

I did the mount today, not the neatest of things I've made with the rotary table but it works:




Spinning...nice effect:


I ran the motor in for about 5 mins on 12v, soon got bored of that (I'll leave it running properly tomorrow). So I tried carefully grasping the motor body with some kitchen roll to protect my fingers - couldn't stall it, not even close . It merely drew 550w and about 53 amps. I'll have to think of a safer way of testing the power at higher voltages.

I think I'll stick with the batteries for now unless anyone can point me to a 50v PSU that can deliver a LOT of current. Maybe a few of those switching PSUs people have been using for steppers on eBay...

[M250cnc]

I did the mount today, not the neatest of things I've made with the rotary table but it works:

(Picture tomorrow)

I was under the impression your mill was under cnc control why the RT ?

I ran the motor in for about 5 mins on 12v, soon got bored of that (I'll leave it running properly tomorrow).

Its a temperature thing if it doesn't get hot just keep increasing the speed in increments.

It merely drew 550w and about 53 amps. I'll have to think of a safer way of testing the power at higher voltages.

I think I'll stick with the batteries for now unless anyone can point me to a 50v PSU that can deliver a LOT of current. Maybe a few of those switching PSUs people have been using for steppers on eBay...

Sounds like mum & dad are gonna have a big leccy bill coming.

Phil

[Jonathan]

I was under the impression your mill was under cnc control why the RT ?

I took the steppers off the milling machine and put them on the router. Didn't want to put them back just for one part. Rotary table was also the most accurate way I could make the hole for the spindle, not having a boring head.

Its a temperature thing if it doesn't get hot just keep increasing the speed in increments.

That's good, the bearing didn't get hot at all. ESC warmed up a little but that's all. I'll leave it running on 3100rpm for a while today and see what happens.

Sounds like mum & dad are gonna have a big leccy bill coming.

Hmm, didn't think of that - and nor have they :naughty:
The batteries I'm using to power it were going to be charged from my wind turbine. If only I had space to mount it...

I measured the runout again now it's mounted properly. I put a 10mm cutter in and measured 0.03mm about 10mm from the collet. If I put the DTI on the collet chuck itself it reads 0.01mm.