Diy Brushless Spindle

[blackburn mark]

Question to you guys is how well do the DC motors handle heat when running at different RPM's?

I’v had no issues with motor heat... i could confidently push my spindles much harder if I needed to.
Where i do have concerns is the ESP (speed controller) they do get hot... iv not blown one yet but i bought a spare because i thought i might with the amount of heat they push out (no problems though so far) at £20 (ish) its silly not to have a spare.

with a 12v 350w power supply the majority of my spindles are vastly under the “claimed” potential and iv not once thought I needed more power/torque… im sure our honorable speed freak friend Jonathan would want more speed n torque (you would need the extra speed if you wish to cut wood…I’m cutting plastic 90% of the time, I don’t cut any wood at all)

if your cutting wood and alli/plastics its worth weighing up if making two spindles is easier than dealing with pulleys on one ?

[njhussey]

Most model ESCs are mounted where there us some airflow (the ones I have in my planes all have air ducts directing air onto them and the one on my Trex 500 heli is on the side so in the downdraught) so I'll be putting a 24V fan by mine for cooling.



Belleville washers arrived today but just back in from a weekend away so will be tomorrow before I complete the spindle now :)

[Jonathan]

Most model ESCs are mounted where there us some airflow (the ones I have in my planes all have air ducts directing air onto them and the one on my Trex 500 heli is on the side so in the downdraught) so I'll be putting a 24V fan by mine for cooling.

A fan does make a big difference to the ESC (not ESP! ) temperature - I put fans on the ESC(s) in my model car for the same reason. A lot of model car ESCs include fans now since the airflow tends to be poor in that application.
Bit off topic, but is that a genuine T-rex or did you get a cheap copy? I got the latter, but can't say I've used it much yet as I always seem to have other things to do...

How much did all those springs cost?

[njhussey]

It's a genuine Trex 700 nitro, don't think HK do a copy....yet ;)

The main reason I've not got further with this project is I've probably spent 2.5k on helis in the last 18 months to the exclusion of everything else!

They cost £15 + the dreaded and P&P so I think approx £25 in total...still got about 130 left :)

[njhussey]

Bit off topic, but is that a genuine T-rex or did you get a cheap copy?

Just realised I'd said I had a Trex 500 in my text....yeah it's a genuine one...my Avatar is the 700...I did buy a HK450 but it's a bit like buying a router made from MDF with unsupported rails lol

[njhussey]

Assembled the spindle last night...well tried to anyway! Found that the Belleville washers don't compress much so you have to be careful how many you use otherwise you load the bearings too much.

Went to assemble it and put the motor bell back on and was putting the last bolt in when I noticed that it was a bit stiff. I bought a pack of 5 off SS 40mm long M4 bolts and on the first assembly used 4 and then obviously used the spare bolt when doing the final assembly. Took the offending bolt out and noticed that the first thread was damaged so I've only gone and flipping cross threaded 1/3 of one of the motor mounting holes grrrrrrr.......got to find my tap now and see if I can re-tap it and clean things up. Failing that I'll drill the cross threaded bits out and just use the rest of the thread with lots of threadlock!!

Will get it up and running tonight and power it from my Trex 500 for a test as I've not got the power supply and ESC for it yet.

[njhussey]

Had the spindle running tonight, coupled it up to my Trex 500 esc...it works!!!



http://www.youtube.com/watch?v=3yaSp...e_gdata_player

[njhussey]

Mark, you've got some smaller spindles haven't you? How have you done them? I want to make a smaller powered one but one that runs much quicker to cut balsa, but on looking the smallest shank of an ER11 collet holder is 8mm and I don't want to be messing around turning the shank down to 5 or 4mm if I can help it!

[Jonathan]

How have you done them?

Look for motor with 1/8" shaft, buy 1/8" shank cutter, replace shaft with cutter...

[njhussey]

Look for motor with 1/8" shaft, buy 1/8" shank cutter, replace shaft with cutter...

Cheers Jonathan, I looked at that but I was looking to do one if possible where I can change the tool without having to remove it from the motor. I was having a look to see if there was anything out there like a pin vice that could be used but thought I'd float the question.

I've got a Proxxon E50 that I was originally going to use but thought I'd go back down the brushless motor route.