Diy Brushless Spindle

[njhussey]

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 Thinking of which my bearings should be here from the US within the next week

[njhussey]

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!!

[Villacherman]

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

[Jonathan]

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

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!

[njhussey]

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!

[blackburn mark]

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

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

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 sorry man

[blackburn mark]

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!

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

[njhussey]

Well got the motor today

Flipping bearings still have not arrived....think they've bneen lost in transit as now 5 weeks... 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?

[Villacherman]

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

[njhussey]

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

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...