Fingers crossed it'll cut ally

[routercnc]

Hi Mark,

Those brushless motors look like the type I use in my model aircraft. I was wondering how you are controlling them, and what power source you are going to use. Looking at your stats for the big motor:

2800rpm for 12v is a 233Kv motor. This will obviously give you 8633rpm at 37v no load.

1700W is achieved at 45A for 37v. Do you have a 37v supply, and more to the point, can it give out 45A at the same time? The 12v 60A supply we have at work is the size of a suitcase, and probably cost us a bit, so I'm interested in the bench supply you have in mind. If you have simply read the motor spec, then you might like to know that on aircraft, when run from Lipo cells (37v) these motors run at about 45A on average (depending upon prop and throttle), and last for 8 - 9 minutes before a recharge is required. If your bench supply can't give this kind of current, then your actual power will be down (plus not so efficient), and you may have to back off on the ali cuts. But then maybe you have a cunning plan for all this . . .

I assume you are using a speed controller to run the brushless from. What amp rating are you running on that, and are you using a servo simulator to control the speed on a dial?

If you can get this all to work, then you're right about the noise, very quiet. I did consider this route myself, but the above put me off. Keen to see more . . .

[irving2008]

5 of those cheap 50v supplies from ebay in parallel will give 43v-56v @ 50A for £12 each, not bad for £60...

[blackburn mark]

Irving,,, you seem to have it all worked out,
if i have any dastardly electrical plans im hoping youll stop me from blowing myself up :)

[blackburn mark]

im using a servo tester with an 80A speed controller

i bought the motor as a 250kv at 2000w but a review i read has it at more like 1700w

i have two server power supplies at 12v 45A each... im hoping to stick with 12v to keep
the speed down for ally

i can use the smaller motor at 12v for up to 10000rpm

im also hoping to replace a 3.17mm shaft in a 4000kv helli motor with a 3.18mm shafted
engraving bit... not sure how practical this will be as ill have to strip the motor every time the bit wears out... worth a try if im desprate to do some really fine work
this one should run up to 48000rpm on 12v (i think) it will be interesting to see
how the bearings hold up

feel free to critiqe... im sure youll know more about these rc motors than i do