Astroflight Cobalt 40's

[mikep]

Anyone had any experience with these motors (with / without planetary gearbox)? Are they reliable - anyone seen the tech / performance specs for them etc.? Any gotchas?? Their website is pretty unhelpful! Am thinking of dusting off the grinder and building a mini-DisConstructor, and these motors look interesting!

[Kenny]

Astroflight Cobalt 40s

just looked on your website bloody hell you had 2 lems for drive and a lem for disc bet that one hell of a powerful bot

[ewan]

Astroflight Cobalt 40s

Astros are brill motors if used correctly, two for a weapon would be brill (Geoff Smith will know more about that ). They are also great as drive motors with the gearsets that you can buy, (also... Geoff! well Karoline & co will also know). Problem is battery drain with so many brill motors though...

[typhoon_driver]

Astroflight Cobalt 40s

not a big fan of them. We used one in typhoon cadet in san fran. Burnt out in its first match. The resins inside the motor had melted and then the motor seized completely.

They are good motors but remember that to produce 1hp from such a small package you need a large amount of cooling because it doesnt have enough mass to do it effectively itself.

We got just as good performance from a normal drill motor (18v on 24v)

[geoff]

Astroflight Cobalt 40s

Ok, I heard someone was taking my name in vain!!

Mike,
Astroflight 40s..So were do you want to start?
I could write a dissertation on he pros and cons of this motor, we have 6 (soon to be 10) of these things spread across our feathers.
The 15:1 planetary g/box (model 940P)is a truly superb traction motor check outhttp://www.pillowtorque.com/tech.htmhttp://www.pillowtorque.com/tech.htm for an example of an extreme featherweight drive train. Also take a look at http://www.pillowtorque.com/pillow_fight.htmhttp://www.pillowtorque.com/pillow_fight.htm for a twin motor application using the model 40 motor without the g/box as a spinner drive.
The 940P is a very rugged drive unit but requires mounting properly using the four M4 tapped holes in the face of the gearbox and for best results the motor supported too.
The 12mm output shaft, although quite capable of having a wheel mounted directly to this shaft there is a possible issue with long term repeated shock loads weakening the front bearing. We have found that this can be avoided by using a separate axle for wheel support driven by a belt/chain from a pully/sprocket mounted on the gearbox. (see Pillow Torque) Mounted like this they are entirely reliable, we have had the same units in Pillow Torque for the better part of 2 years completing over 125 fights (mostly at 100% duty) plus many hours of testing and only now are we replacing the motor brushes and repacking the gearbox with new grease. Other than that they have had no maintenance whatsoever. As Gary points out that due to the silly amounts of power they can deliver they do produce a lot of heat, which at first seems quite worrying but we have learned that these motors are quite happy to run at 100 C all day!BUT and its a BIG BUT if you are using the motor alone as a weapons drive, then gear ratio is CRITICAL. These motors run at around 16,300RPM @ 24V We have found that a reduction ratio of a MINIMUM of 3:1 is required to prevent the heat build-up eventually melting the whole thing (ask Ewan what happens to them at 2:1!!) I would prefer a ratio of 4-4.5:1 for peace of mind.
If you want dimensions for the 940P they are herehttp://www.teamwhyachi.com/misc/A40P.pdfhttp://www.teamwhyachi.com/misc/A40P.pdfthe full spec. of the motor alone is here http://www.robotcombat.com/marketplace_astroflight.htmlhttp://www.robotcombat.com/marketplace_astroflight.html You may also want to check out these alternative gear boxes http://www.teamwhyachi.com/Twa40.htmhttp://www.teamwhyachi.com/Twa40.htm
Both Team Whyachi and Robot combat are good sources of the motors and will happily ship to the UK .

If you want any further info e-mail me teamscorpion@aol.com and Ill try to help.

Regards,
Geoff.

[stu]

Astroflight Cobalt 40s

Thats what took so long to hear from Geoff about Astros.
He did a bloody essay.

Mr Stu

[geoff]

Astroflight Cobalt 40s

What do you mean essay...thats the SHORT version!!

[mikep]

Astroflight Cobalt 40s

Many thanks for feedback - all very helpful. Gary - one question after your meltdown...was the motor repairable?

[typhoon_driver]

Astroflight Cobalt 40s

eh definately no!

The motor turned fine immediatly after we removed it but once it had cooled, the resins inside hardened again and the motor was non repairable. An expensive mistake!

I would possibly advise a heatsink and or fan beside one if you are going to run one.

Personally I would never use them again, too easy to nacker.

[grant_ploughbot]

Astroflight Cobalt 40s

Did you throw the motor gary? if not, i wouldnt mind it?

[typhoon_driver]

Astroflight Cobalt 40s

Grant we didnt throw it. I am afraid its not for sale. Just one of those little tinkets we will be keeping to remind us of our combat days.

[grant_ploughbot]

Astroflight Cobalt 40s

Are you sure :sad: u got the whole robot to remind you :sad: lol. No probs though.

Just a notice, if anybody has burned out/broken astros that you are about to throw, keep a holof them, i may be intrested in them for replacement parts.

[james...venom]

Astroflight Cobalt 40s

just out of interest does anybody know what speed an astro 40 with the 1.7 : 1 gearbox run on 14.4v would be? cheers

[storm]

Astroflight Cobalt 40s

You just being lazy James ?

http://www.astroflight.comwww.astroflight.com tells you speed/volt = 682rpm/v

So 682 x 14.4v = 9820rpm

Put that through a 1.7:1 gear box and you get

9829 / 1.7 = 5776rpm (unloaded speed).

Hardly rocket science - I thought you knew how to build robots ;o) ?

Ed
http://www.teamstorm.comhttp://www.teamstorm.com

[geoff]

Astroflight Cobalt 40s

Mee Oww!! :wink: