Author Topic: Brushless DC Motor Spindle by c raynerd  (Read 26598 times)

Online tonybraz

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Re: Brushless DC Motor Spindle by c raynerd
« Reply #25 on: January 16, 2013, 01:46:29 PM »
Hi Chris I saw your post on MYCNC as well. I use a 20  Amp Pro Peak power supply, this is a bench power supply for my Bantam BC6 charger. It runs at 13.5volts ,10 amps this is using a 6mm diameter cutter with a cut of 1mm in ali. motor does get warm but have inproved spindle bearings still using orginal motor, hope this helps. If anymore questions just ask.

Tony

Offline Swarfing

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Re: Brushless DC Motor Spindle by c raynerd
« Reply #26 on: January 16, 2013, 03:40:56 PM »
A Ham radio supply would work well, most will tune up from that voltage as well.
Once in hole stop digging.

Offline andyf

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Re: Brushless DC Motor Spindle by c raynerd
« Reply #27 on: January 16, 2013, 06:44:38 PM »
Chris, I don't know if you are a member of the RSGB, but my copy of Radcom has just arrived with an article in it about using computer PSUs. It mentions a Dell 7000245 as used inside Dell servers, "rated at 900W and has been seen on Ebay for under 40 including postage". Apparently it has a main regulated output of 12v at 77A.

I imagine that 0.9kW might be enough to keep your spindle running!

Andy
Sale, Cheshire
I've cut the end off it twice, but it's still too short

Online John Rudd

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Re: Brushless DC Motor Spindle by c raynerd
« Reply #28 on: January 17, 2013, 04:21:43 AM »
Chris,

Over on RCGroups there's info on modding server power supplies that may help you.......

http://www.rcgroups.com/forums/showthread.php?t=1292514

It stretches to 5 pages so there's a lot of info
eccentric millionaire financed by 'er indoors
Location:  Backworth Newcastle

Skype: chippiejnr

Offline j_e_f_f_williams

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Re: Brushless DC Motor Spindle by c raynerd
« Reply #29 on: January 17, 2013, 01:16:06 PM »
I lucked out at a yard sale and found one of these:
http://www.ebay.com/itm/LORAIN-FLOTROL-A100F25-HIGH-FREQUENCY-RECTIFIER-100A-/360548962643?pt=LH_DefaultDomain_0&hash=item53f2649153

Still has the $20.00 written on it in marker from the sale.  supplies 15 or 24VDC in the config I have at up to 100A!  (Don't short the leads and always power it off everywhere when touching wires!)

They were used by Bell (phone company) to charge battery banks in the central offices.  They may not be common but it's another direction for big power if you can find the right sale or salvage place.  I use it to power lots of things wanting 12VDC as 15 seems to be close enough in most cases and I havn't had the amp meter go over 50 yet.

Jeff

Offline raynerd

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Brushless DC Motor Spindle by c raynerd
« Reply #30 on: January 17, 2013, 03:30:50 PM »
Hi guys, thanks for the suggestions. I think iirc my atx can supply on 8a @12v. I say can, I should say could...of course I've killed it now!!

Those big server supplies look like a good choice, as do all the other recommendations made! Just gotta keep an eye on fleabay for something at the right price. Chris

Offline raynerd

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Brushless DC Motor Spindle by c raynerd
« Reply #31 on: January 17, 2013, 03:32:19 PM »
Tonybraz - does your motor ever stall with the 20a supply?

Online tonybraz

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Re: Brushless DC Motor Spindle by c raynerd
« Reply #32 on: January 17, 2013, 04:35:06 PM »
Hi Chris, no I have not had the motor stall ,it has broken a couple of cutters when they become clogged.

Tony

Offline Swarfing

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Re: Brushless DC Motor Spindle by c raynerd
« Reply #33 on: January 17, 2013, 06:14:39 PM »
Chris be careful with server power supplies. A lot of the leads and things are for measuring temp, drain etc. this makes them a bit more of a problem to get running. You also have the issue that some of them do a lot more than 12v so make sure you find specs first before purchase. You would be better off looking for a high powered PC supply instead, you can get these around the 1000w range.

I have servers at work that use supplies that run at 60v to the MB. They also use a lot of -v lines too which is great if you want to tie lines together to get the voltage you want? they also share single negative rails on most modern supplies also.
Once in hole stop digging.

Offline around

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Re: Brushless DC Motor Spindle by c raynerd
« Reply #34 on: January 18, 2013, 07:31:16 PM »
Chris,

Off-the-shelf Mach3/EMC2 brushless motor controllers.

http://www.logicnc.com/rcnc.html

Cheers,

Adrian

Offline MetalMagus

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Re: Brushless DC Motor Spindle by c raynerd
« Reply #35 on: January 22, 2013, 05:36:23 PM »
Hi,
I have used these server power supplies for powering my r/c helicopter battery charger. 12 volts DC @ 47 amps. They can be linked together to give 24V or more. Lots of info on how to modify them on rc groups. Around 12.50 each with postage.

http://www.ebay.co.uk/itm/ESP135-HP-ProLiant-DL380-G4-DL385-G1-575W-Hot-Plug-Power-Supply-Unit-321632-501-/251014979830?pt=UK_Computing_Servers&hash=item3a71a8a0f6

Cheers

Sean

Offline raynerd

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Brushless DC Motor Spindle by c raynerd
« Reply #36 on: January 22, 2013, 06:40:48 PM »
Cheers guys. Sean, that seems like an unbeatable price!

Offline raynerd

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Re: Brushless DC Motor Spindle by c raynerd
« Reply #37 on: February 16, 2013, 06:13:10 PM »
 :ddb: :ddb:
I've been busy with work over the last 3 weeks and had little time for projects, but when Sean posted his message above and answered a few of my questions over on pm, I went ahead and for 8, purchased a supply. It has has sat on my bench until today when Rob asked the question, am I going to hand cut my wheel crossing outs. I hadn't considered CNC as my spindle has simply not been upto the task of cutting metal with the motor just stalling.

Anyway..the results are about to be posted on my Parslow clock build thread but I can safely say that this beefy power supply has turned my little do brushless motor into a PROPER useful cutting spindle!!

Thanks for those who have posted. Pictures when I get time.

Chris