Diy Brushless Spindle

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worth 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....

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Certainly is I find it usefull for visualising what somethign is going to look like. Gives you an idea whether it's going to work or not. Also use it at work to draw 3D (without having to get the DO involved) pics of what I'm quoting. Just starting to build up a library of standard parts. Slow progress tho as it has to be done in lunchtimes etc and I'm still trying to get into it....

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!

Hi Guys
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
Attachment 4816
Joe

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.

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I fund that my 15Amp batterycharger doesn’t provide enough power.

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http://www.ebay.co.uk/itm/12V-30A-36...item231493182c

i bought somthing like this for mine, iv not tripped it out once so far :smile:

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My next spindle is going to have 2 or 3 motors 3kW motors on the same shaft, ER-20 up to 27000rpm (ish)

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:eek: on your router ?... i cant imagine a router making use of so much power, youve got me thinking cutting wood at high speed must soak up the spindle watts :eek:

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:

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Originally Posted by blackburn mark

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http://www.ebay.co.uk/itm/12V-30A-36...item231493182c

i bought somthing like this for mine, iv not tripped it out once so far :smile:

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Not bad, but a fiver down the car boot should get you a computer power supply which will deliver at least that. Just put a resistor on the +5V rail (google it) to keep it on and stable.

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Originally Posted by blackburn mark

:eek: on your router ?... i cant imagine a router making use of so much power, youve got me thinking cutting wood at high speed must soak up the spindle watts :eek:]

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Wood does with a good size cutter, but that's not the reason as I hardly ever cut wood an no DIY router is rigid enough to use that much power. Why use plywood when you can use 3/4" aluminium :smile:
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?

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Top speed 1500, mm/min? Is that rapid speed or top speed you use when cutting?

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owch!!! you buggar! kick a man while he is down lol ..... errrr... thats rapid, i am "slowly" coming around to the idea that a little more speed might help (what did it cost you for your drivers ???? and would i need to swap my 57BYGH76-401A steppers current 2.8A ???)

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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.

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youve got to do a log on that jonathan!! :)

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:smile: . 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 :smile:

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 :smile:

your already on your second peice of alli ???? owch :rofl: no pressure then :eek:

The second piece is for the cap, I've rough (rough bring the operative word!!) turned the first piece but should really have bought a longer piece of Ali...so I'm going to turn a shoulder in the end of the first piece to more accurately hold it in the jaws (so I can then finish machine out the jaw marks) then finish machine, bore it for the bearings and part off ( couldn't get the parting off tool near enough without hitting the jaws before)...

Well that's the cunning plan anyway ;-)

What's the easiest way to accurately drill the holes for mounting the motor without any sort of indexing head/table anyone?

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What's the easiest way to accurately drill the holes for mounting the motor without any sort of indexing head/table anyone?

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errrr? i did a bit of a hatchet job on my first one (not having cnc at that point)
scribed a line with a centre finder square... dot punched my first two holes then used my vernier calipers (one tip in the dot) and scribed a circumfrence from both dots trail and error style :)

it got me there (just)

make sure you mark and drill the face that is going to sit on your motor just in case your drill wanders.... i find it really easy to forget stuff like that :redface:

Well I was thinking of either buying one of these http://www.rdgtools.co.uk/acatalog/PROTRACTORS_ETC.html or drawing the bit in CAD, printing it out and sticking it on and centre punching the holes before drilling on the pillar drill, think I'll go the first way as the second seems a bit crude!!

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Originally Posted by njhussey

Well I was thinking of either buying one of these http://www.rdgtools.co.uk/acatalog/PROTRACTORS_ETC.html or drawing the bit in CAD, printing it out and sticking it on and centre punching the holes before drilling on the pillar drill, think I'll go the first way as the second seems a bit crude!!

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No need to buy those... as Mark said all you need is dividers. Scribe a circle, or lightly touch the lathe tool to it whilst in the lathe to make a circle then use dividers to divide that circle equally - centre punch then a quick swing on the pillar drill. Equally nothing wrong with printing out a template and sticking it on - printers are pretty accurate.

If you've got access to a milling machine then just put it in the vice, center drill (or spot drill) in mill and mark out the holes with that. Zero the X/Y dials in the center, noting in what direction you zeroed them so you can compensate for the backlash by always turning to that point in the same direction. Move it the correct distance using CAD program or simple trig to find the distances.

There's many more ways to do it sufficiently accurately without buying anything.

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Originally Posted by Jonathan

No need to buy those... as Mark said all you need is dividers.

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Hmmm... Dont have any but do have vernier calipers so might try that

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Scribe a circle, or lightly touch the lathe tool to it whilst in the lathe to make a circle then use dividers to divide that circle equally - centre punch then a quick swing on the pillar drill. Equally nothing wrong with printing out a template and sticking it on - printers are pretty accurate.

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Might have a go at one of those ways on some scrap bar..,

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If you've got access to a milling machine then just put it in the vice, center drill (or spot drill) in mill and mark out the holes with that. Zero the X/Y dials in the center, noting in what direction you zeroed them so you can compensate for the backlash by always turning to that point in the same direction. Move it the correct distance using CAD program or simple trig to find the distances.

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We have an old Bridgeport milling machine at work, not sure if it works though, will ask the guys tomorrow.

Cheers chaps, given me plenty to think about...

Well I've ordered the ER16 collet from fleabay http://www.ebay.co.uk/itm/ws/eBayISA...EOIBSA:GB:1123 and have had a go a boring the bearing housing. However my boring tool (went for the 10mm brazed tip boring bar http://www.rdgtools.co.uk/acatalog/B...ring_Bars.html) needs alot of grinding to get it to not rub...might see if I can grind one from scratch as we have a few lengths of tool steel lying around...still got probably 3 weeks to do it in before my ER16 collet arrives on these shores :smile: Thinking of which my bearings should be here from the US within the next week :tongue:

Collet arrived today :-) ...but still waiting for my bearings :-( Going into work early tomorrow to do a bit more (been doing 12 hr days at work recently so not had a chance to get more done tut) on the spindle and maybe even my machine!!

Neil,

Great work so far on the spindle, I'm anxiously watching how it turns out. I'm building a similar spindle, however, I'm thinking of incorporating a v-belt pulley drive so if I want to change the speed/torque I can have that option. Does complicate things a little more.

My intent is primarily to machine aluminum and hard plastics. I'm designing for 500-4000 RPM with hefty torque to use with 3-12mm end mills.

Anybody have an idea if these type motors will deliver decent torque at 500 RPM?

Adam

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Originally Posted by Villacherman

Anybody have an idea if these type motors will deliver decent torque at 500 RPM?

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Not unless you either rewind the motor to get a lower kv, or use belts, which you are doing. Still 500rpm is pushing it with one belt reduction. I think you'd need two. My brushless motor spindle is a big 12 pole motor, so it's quite slow - but still 6000rpm on the full 50V. Eleven to one reduction isn't happening with one belt, but 3:1 to get max 2000rpm would probably be fine with that motor. You would only get about a quarter of the power out of that motor, but a quarter of 6kW or so is still plenty!

Well bought the motor today, got a 320kV one http://www.giantcod.co.uk/xyh5065-32...-p-404606.html so hope to have that early next week! Still waiting for my bearings from the US, been over a month now :-(

Still will give me a chance to finish off the bearing housing!

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My intent is primarily to machine aluminum and hard plastics. I'm designing for 500-4000 RPM with hefty torque to use with 3-12mm end mills.

Anybody have an idea if these type motors will deliver decent torque at 500 RPM?

Adam

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i dont cut with a 12mm endmill however i do cut a lot of acetal/delrin and a bit of alli with the larger of these spindles(250kv) 2.5mm to 6mm + fly cuting without any major problems, i personally believe you would struggle to make use of any more low speed power/tourque without having your gantry shake rattle n roll :eek:

thats asuming your going to run it on a router ?

i just had a look at where you live to see if it was worth nipping over to you so you could try one :lol: san francisco !!! thats a looooooong way LOL :smile: sorry man

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Well bought the motor today, got a 320kV one http://www.giantcod.co.uk/xyh5065-32...-p-404606.html so hope to have that early next week! Still waiting for my bearings from the US, been over a month now :-(

Still will give me a chance to finish off the bearing housing!

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that looks a much better choice motor than i made for my C8 spindle... i think mine is 980kv

Well got the motor today :smile:
Attachment 5009
Flipping bearings still have not arrived....think they've bneen lost in transit as now 5 weeks...:thumbdown: still the seller said they'd expedite another shipment...

Mark,

did you put a groove in the ER collet shaft for the circlip or not?

Mark,

Well I will be over in your timezone in December for a couple weeks visiting wife's family, I suspect Newcastle isn't all that close to you all, however.

Thanks for the input, yes it will be a gantry router type design. I have a minimill that I'm making parts on and that's relatively low RPMs (up to 2000).

What RPM do you use the flycutter at?

Neil- maybe me bringing the bearings over and sending them through you post system would be faster! Any other parts hard to get there? Belleville washers?

Adam

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Originally Posted by Villacherman

Neil- maybe me bringing the bearings over and sending them through you post system would be faster! Any other parts hard to get there? Belleville washers?

Adam

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It can't be any slower Adam!!! Thing is I want these as they are 22mm OD which is better as the motor mounting bolt holes are 3mm dia on a 30mm PCD which only leaves 2.5mm wall thickness.

Belleville washers are ok, I've found a couple of suppliers and Mark kindly said he'd give me enough if I was struggling!

Gonna crack on with the bearing housing now and wait for the bearings...

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did you put a groove in the ER collet shaft for the circlip or not?

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no.... my thoughts where that the tight fit (bearings n housing) would hold it all in place, iv had no problems so far using the double row a/c... i did have an issue with one my C8 spindle bearings (cheap skate bearings/bad fit on the shaft) resonating the inner race around the shaft at certain speeds so i used a bit of epoxy on that and its been ok so far.... now i think about it i guess the bellville washers become redundant once the glue has set and when the bearings wear i might get some slop ... it may need some further thought

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What RPM do you use the flycutter at?

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hi adam... iv not measured rpm's for a while however im pretty sure i skim acetal at 1500rpm and aluminium at less (maybe 1000rpm) thats with a 30mm radius fly cutter

with aluminium i have to be pretty careful (light cuts) or i get resonance patterns but im pretty certain thats my gantry sides and not my spindle

i should really do a test to see how low i can take the rpm and still cut with the fly cutter but iv never seen the need as iv allways got by at those speeds

Dissassembled the motor, worryingly there was no locktite on the grub screw holding the body onto the shaft....needless to say there will be when it goes on the collet :naughty:

Am ashamed to say :redface: that for the first housing I'm cheating and getting someone else to machine the housing as they have offered to do it for nothing (our local machinist we use at work) in between jobs they are currently doing...which is very nice of them. I'll use the other bits I've started to do a smaller high speed spindle for engraving

At some stage I'll re-wind it as the winding is poor and also the potting/epoxying of the magnets wasn't too clever either as some was proud and was rubbing on the armature. Still you get what you pay for so I shouldn't be too surprised I guess...

Attachment 5016

Neil,

Does the rewinding take much effort? That's to change the v/RPM?

I'm waiting to see how things go with yours to start mine, looking forward to it! :)

Adam

Adam, I don't know how much effort it will take. I'll do it to tidy up the winding (see photos) as it's not very neat but will not bother at first as I want to get the spindle up and running first!

You'll find lots of info on rewinding this type of motor on the rcgroups forum. If it works fine I wouldn't worry ... but if you want to change the number of turns to get optimal kv then it's got to be the way to go.

I wouldn't say you've got what you paid for when you paid more than the going rate for that motor:

http://www.hobbyking.com/hobbyking/s...idProduct=4913

I've not had any from hobbyking with poor magnet potting...but I've only bought about 10 and not the one you got.

Jonathan - Yeah you save yourself about £5 but have to wait 2 - 3 weeks, I bought mine on Thursday night and it was delivered to my works (no Sat deliveries) Monday am, you won't get that with Hobbyking :wink: One of these days I'll pluck up the courage and order something from there :tup:

Turnigy motors are good motors, I've had a few in my planks and only had a couple of issues (loose magnets and noisy bearings.)

Single AC bearings finally arrived today, this is the second lot as the first lot never made it...

Run out of time to do the spindle this side of Xmas as off visiting relatives after the end of this week till the New Year!

Neil,

Sorry, I'm on lunch at work so I didn't have time to look through the thread... you are putting one bearing in front and one in back (of the housing which is out front of the motor), correct? What type of fit are looking for on 1) the shaft and 2) in the housing. Press fit I'm assuming, but roughly how much force?

I'm assuming this will cause some pre-load on the bearings... and with more interference on the fit, the more preload on the bearing.

Have a good holiday... anything I should not miss up in Newcastle? I'll be there for a couple weeks...

Adam

Hi Adam, not been on here for a while as work was mad (trying to get a quote out and clear my desk) last week, 57 hour week...

I've tried the bearings on the ER16 collet shaft and they are disappointingly a loose sliding fit...will be a light press fit (heat housing first and slide the back bearing in) in the housing with Bellville washers pretensioning the inner races. Will have to locktite one bearing to the shaft and I guess leave the other a loose fit to keep the pretension? If the bearing starts skidding on the shaft (like Mark's did) then I'll have to locktite that too I guess.

I don't know Newcastle or the surrounding area, never been to that part of the country yet, so can't help you on what not to miss I'm afraid!!

Hope everyone has a Merry Christmas & a Happy New Year!

Hey guys how is this thread progressing?

I'm working on one with two brushless motors, ATC and water/oil cooling. It will be a while until I post the build log, but my prototype for the ATC works. Having difficultly sourcing disc springs/Belleville washers though...

http://www.leespring.com/uk_index.asp?CountryCode=011

Jonathan, I found these people http://www.bellevillesprings.com/bel...e-washers.html and was quoted 100 off D18842 for £15 (min order charge else would have been £10.33) with P&P £5.50.

Progress as far as I'm concerned has ground to a halt at the moment as our lathe at work is poorly at the moment...

DIY spindle porn...

http://www.dieselrc.com/projects/cncspindle/

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Originally Posted by HankMcSpank

DIY spindle porn...

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very posh !

a lot of work in one of those :eek: