Thread: Diy Brushless Spindle
31-10-2011 #41worth it though... when im designing something with production in mind i can spend hours just looking at the same drawing to see if it can be stream lined or knock some of the pain out of production and make it look posh etc etc etc....
Went to play with the lathe at lunch and was greeted with it in this state... Bloody hairy arsed fitters. Spent lunch cleaning and setting the tailstock up as it was miles out...never got to do any cutting!
I havedesigned and made a brushless spindle as well but my design is a big biggerthan most (overkill really) it has a FAG angular contact double row on thebottom and FAG standard bearing on the top with a 20mm shank ER16 collet chuckfrom ebay.
I waswondering what people use for the power supply as I fund that my 15Amp batterycharger doesn’t provide enough power.
The picture shows a drill chuck but that is being held by the ER16 chuck because i did not have the right size collet
Nowhere near as big as mine :)
What motor did you use...what power? Doesn't it accept more than 12v (assuming the battery charger you're using is 12v)?
A toroidal transformer (eBay) plus rectifier and some good low ESR caps would do nicely, but you might find it needs to be a bit large. Another option is a switching power supply ... which isn't cheap either unless you use old ATX (computer) power supplies. If it's 12V then just use one, if not you can put them in series - but check that they're isolated first to prevent fireworks.
My next spindle is going to have 2 or 3 motors 3kW motors on the same shaft, ER-20 up to 27000rpm (ish) and oil cooled. That's the only way I can work out to get the required rpm range and torque without rewinding (which I might need to do anyway). Wye/delta switching plus something else to get more torque options). Bought the motors a couple of days ago. Going to use FEA to model the friction due to oil cooling and optimise it ... then proceed.
Anyway, the relevant bit for you is I'm going to use 2 (or 4, depends) ATX PSUs in series, to get about 1kw input power, with a 3Ah Lipo battery placed in parallel, to take care of current peaks, as close as possible to the ESC (to minimise impedance). Will also replace the electrolytic capacitors on the ESC (which will be incorporated into the oil cooling) to an array of low impedance ones as that will make the ESC run a lot cooler.
Hope you're not milling with that chuck, or spinning it as fast as that motor might go.
Last edited by Jonathan; 06-11-2011 at 05:50 PM.
06-11-2011 #45I fund that my 15Amp batterycharger doesn’t provide enough power.
i bought somthing like this for mine, iv not tripped it out once so far
My next spindle is going to have 2 or 3 motors 3kW motors on the same shaft, ER-20 up to 27000rpm (ish)
i only ever cut alli and plastics and iv never needed any more than 360W... my top speed is only 1500mm though wich i guess is not worth getting out of bed for in "Jonathan world " :lol:
It's for my friend from school who I will be helping (well, letting him use my router - he doesn't need help) build a smaller rigid machine to be used mainly for cutting aluminium and occasionally steel (hopefully)...knowing him probably titanium too. Anyway, the reason for that much power and the whole coil switching thing is to be able to get lots of torque at low rpm, which is useful for drilling/facing among other things. I don't expect to use anywhere near the full rated power of the motors.
Top speed 1500, mm/min? Is that rapid speed or top speed you use when cutting?
06-11-2011 #47Top speed 1500, mm/min? Is that rapid speed or top speed you use when cutting?
It's for my friend from school who I will be helping (well, letting him use my router - he doesn't need help) build a smaller rigid machine to be used mainly for cutting aluminium and occasionally steel (hopefully)...knowing him probably titanium too.
The motor is a Thumper 5055, 10.8-29.6V, 1280 watts and 580 KV
Yes the motor does accept more voltage but the charger was the only thing that I had on hand. My Grandpa has an ex-school lab transformer that is 12v,100A which once rectified should provide more than enough power . I just need to find theright sort of low ESR caps, could you recommend any?
Do you think that if I up the current that the motor will be more powerfulor will I also need to up the voltage and use a different supply?
My spindle ESC also gets quite hot after running for more than about 15 mins as well, but nothing excessive. The spindle however gets very hot after beingrun for about 25 mins, I think that I will need to devise some sort of watercooling but I am going to try bigger and more fins and a fan first. The projec tis also my Product design coursework at collage so a big thank you for all your advice
Thank you blackburn mark for the ebay power supply I needed something like that for my audio set up and at that price you can't go wrong so I have ordered one
Last edited by Joe; 14-11-2011 at 04:17 PM.
Bought a turning tool last week and did some turning of my second piece at lunch....much better results.
Got to buy a boring tool now as some ijit used it and has knackered it. Getting there slowly...
Now thats more like it
your already on your second peice of alli ???? owch :rofl: no pressure then
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