RC Brushless spindle

[volcano]

Hi, tnx for replay,
I want to cut a little of everything (alu, pom, mdf , some glass etching), (Glass isn`t obligatory - i can do it with my dremel tool @ 20000+ rpm). So... first alu , than acetal and mdf.
I know that`s hard to do with one motor, but hope it isn`t impossible.
Now as i`m not "bound" to previous motor specs, i would like to go "around" and start with psu i`ve got already- 12V30A. Read here that similar psu-s are already used - not for max motor efficiency , but still, for something useful.
I`ve heard that 24v cause hot motor ( and i have 24v@4-6A, only)
So if i go with this cheap psu what can i drive with it?
Some other suggestions?
Cheers!
P.S. They say that i can keep this 270kV. Any use of that thing (if it works- i have not tested it yet as i don`t have esc and servo tester yet)?

[njhussey]

The problem is with 12V and 270kV you'll only have max 3240 RPM which is from a practical point of view too low for Ali, Plastic and MDF, well technically it's not but the feeds will be very slow. With 24V yes you will have to think about cooling the motor (a couple of 12V PC Radiator fans in series mounted round the motor would do it) if you're doing long runs but you get better speed. I ran my spindle off 2 HP Server PSU's wired together to give 24V (and over 1000 Watts) and it was fine, but I didn't do many long runs and didn't use it in anger as I have a 2.2kW water cooled spindle which is fantastic! If I made one again I'd put water cooling in the bearing holder body as they do start to run hot after a while.

One suggestion is to make the spindle unit (don't over engineer it) and have the motor drive it by belt, if you make an adjustable motor mounting plate (or different ones you can swap over) then you can use different kV motors depending on what you want to cut, so larger lower kV motor for cutting Ali, MDF and Plastic and high kV smaller motor for engraving glass etc...

[volcano]

Thanks for your advices, as always. This means a lot for me in my future building. One thing is to just read topics... and completely different thing is when someone experienced push you in wright direction :-), as you all know.

It`s done. I order this:
http://www.ebay.com/itm/N5055-1450W-...QGNF7nYDNiv2jQ
The 270kv one, will wait for now (if it works, anyway). I`ll build belt driven spindle later, i hope.
For now, i want to build direct drive spindle, to be my first. :-)
I found those bearings:
http://www.ebay.com/itm/1Pcs-708AC-7...QAAOSwpP9Y7IHm
Are they good, or to go with cheapest ceramic skate bearings? ...or steel ones?
I asked this because i already gone on cheapest route ( motor, collet shank...esc...).
I need this answer as quick as possible ( because of shipping time )
Hope you`ll understand.
Cheers!

[volcano]

While waiting for motor,chuck,esc... to arrive, i`m thinking about hooking this spindle to arduino (grbl1.1 with pwm variable spindle controll).
Can this item be "in between" esc and arduino? Check it here please:
http://www.ebay.com/itm/Pulse-Signal...EAAOSw1S9We2se
If this can be used it would be great. By the way...if anyone here control esc with arduino with grbl, let me know, how, please?

[volcano]

Where are you folks? I started to feel that i wrote here for myself pleasure only!
Anyway, new build idea...
I think i`ll add 1 of those bearings in spindle nose and then add skate ones after.

I think that this will eliminate axial force on ("next in row") radial skate bearings.

P.S. I must construct proper housing for this combo.
Cheers!

[volcano]

Hi,
New motor came, but again bad news. Motor came damaged due poor packaging.

Can this be repaired? How to balance it?

Good news is that C8 ER11A 100L Collet Straight Shank Chuck Holder finally arrived,
and it`s good quality. I also ordered dial test indicator to help me in my future spindle build,
and other project... very handy tool.
Cheers!

P.S. This topic is watched (by the counter info) but it`s been a while since no one write here.
Please help me with all my doubts and questions above.
P.P.S. Those bearings from above... can they handle spindle rpm?

[Clive S]

Hi,
New motor came, but again bad news. Motor came damaged due poor packaging.

Can this be repaired? How to balance it?

Good news is that C8 ER11A 100L Collet Straight Shank Chuck Holder finally arrived,
and it`s good quality. I also ordered dial test indicator to help me in my future spindle build,
and other project... very handy tool.
Cheers!

P.S. This topic is watched (by the counter info) but it`s been a while since no one write here.
Please help me with all my doubts and questions above.
P.P.S. Those bearings from above... can they handle spindle rpm?

I read most topics and help where I can but I have never played with this sort of thing in this situation so I am at a loss.

Can you return the motor as it looks shot (no pun intended)? I have no idea if the bearings are suitable, I have used that type but at low speeds. Good luck with the build.

[njhussey]

Hi,
New motor came, but again bad news. Motor came damaged due poor packaging.

Can this be repaired? How to balance it?

Good news is that C8 ER11A 100L Collet Straight Shank Chuck Holder finally arrived,
and it`s good quality. I also ordered dial test indicator to help me in my future spindle build,
and other project... very handy tool.
Cheers!

P.S. This topic is watched (by the counter info) but it`s been a while since no one write here.
Please help me with all my doubts and questions above.
P.P.S. Those bearings from above... can they handle spindle rpm?

Without doing a google on a bearing site I cant tell you if they're suitable. However whatever bearings you use will need a preload on them to stop them from skidding. The best bearings to use (apart from a double row AC bearing) are magneto (single AC bearings) bearings and preload them with something like bellville washers.

Sent from my HUAWEI VNS-L31 using Tapatalk

[routercnc]

Hi,
New motor came, but again bad news. Motor came damaged due poor packaging.

Can this be repaired? How to balance it?

Good news is that C8 ER11A 100L Collet Straight Shank Chuck Holder finally arrived,
and it`s good quality. I also ordered dial test indicator to help me in my future spindle build,
and other project... very handy tool.
Cheers!

P.S. This topic is watched (by the counter info) but it`s been a while since no one write here.
Please help me with all my doubts and questions above.
P.P.S. Those bearings from above... can they handle spindle rpm?

The reason you don't have many replies is that it's been a while since anyone has posted on building their own spindles from brushless motors.
Most of the regulars on here bought a water cooled Chinese 1.5 or 2.2 kW spindle a long time ago because they work really well and are good value. They are highly recommended.
No-one on here is holding out on you and not answering, we just don't know how to help. Sorry but I've never used Arduino, grbl, etc.

[volcano]

Can you return the motor as it looks shot (no pun intended)? I have no idea if the bearings are suitable, I have used that type but at low speeds. Good luck with the build.

I`ve got a 2/3 refund without returning it, so it`s my 2nd defective junk motor in collection.
So i`ll try one more time...( i think that you have the same joke about "3rd luck" )
I checked few companies for this type of bearings. All of them are low speed indeed, so no go.
Finally, thanks for your wishes.
Cheers!
@ routercnc,
Thanks for your replay and kind words, too.