HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Feb 08, 2005, 01:47 AM
Registered User
los altos, california
Joined Jan 2005
14 Posts
Can someone help me figure this out?

HiMaxx HB 3630-800 direct drive
Kv (RPM/volt)= 813
Rm (milliOhms) = 85
max amps = 55

HiMaxx HA 2825-5543 4.3-1 geared
Kv (RPM/volt)=5500
max amps 25-30
Rm (milliOhms) = 11

How can I maximize performance with these motors?
I have 2- 3 cell 2,600ma lipos and a 60 amp esc,
How big of a plane will these motors push?

thanks for the help

Rob
Cloudracer is offline Find More Posts by Cloudracer
Reply With Quote
Sign up now
to remove ads between posts
Old Feb 08, 2005, 06:01 AM
Registered User
vintage1's Avatar
East Anglia, UK
Joined Sep 2002
29,689 Posts
I had to guess at idle current,and power dissipation capavbility, but its a hunky motor so 100W is possible as far as heat goes... but here is the direct drive estimations of best voltage cuurent and RPM, and a quick check on what 14 cells would do for you.

I keyed in 10v as well to simulate 3s LIPO on the DD one, and it looks like about 32A is best for it, and a shade under 6000 RPM. Its not terribly efficient at that voltage though. Only 70% or so. Does better at higher volts, RPM and less current as you can see.

300W out makes it a nice sort .25 to .40 glow equiavlent.

Motocalc predcst from the numbers a 12x10 prop on 3s LIPO will pull the right current, and do 43oz of thrust and a pitch speed ofabout 50mph.

Ideal for a 40 style trainer I'd say.
vintage1 is offline Find More Posts by vintage1
Reply With Quote
Old Feb 08, 2005, 06:23 AM
Registered User
vintage1's Avatar
East Anglia, UK
Joined Sep 2002
29,689 Posts
And now for the smaller high KV motor.

Well, according to data I could find. its actually more powerful!
I downrated its heat capability to 50W, and that gives best power at 12v and a staggering 45A and 65,000 RPM!!! over 510W out and 560W in.

I find this somewhat hard to believe.

On 3s LIPO the calcs reckon 50A is possible, although I'd feel safer with 35-40A. That's still 350-400W input.

On 2s LIPO I'd say 45A or so. is the limit.

Going over to Motocalc. on 3s LIPO a 9x5 prop gves the right sort of draw on a 4.3 box, or an 8x8 if you want real 100mph speed

On 2s LIPO 10x10, 11x7, to 12x5 seems about right. For a 300W sort of input power.

All these results prediacted on the assumption that the idle current figures I could find are correct, and that I am guessing right about heating, and the motors are in fact as good as the published specs.

In prcatice, I'd say try these sorts of props and packs, and use a tacho and whattmeter, and carefully check the motor temps on the bench, before committng the air.


I hope that someone who owns these motors will confim or refute this with real world data.
vintage1 is offline Find More Posts by vintage1
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Can anyone help me figure this out... av8ersteve Batteries and Chargers 3 Aug 10, 2005 07:36 AM
Can someone help me price this? Pookee Electric Plane Talk 1 Dec 19, 2004 01:50 PM
Can someone help me price this? <please delete> Pookee Aircraft - Electric - Airplanes (FS/W) 0 Dec 19, 2004 01:31 PM
can someone help me identify this plane? torcgolf Thermal 5 Aug 27, 2004 12:29 PM
Can someone help me figure amp draw on...... shelby Electric Plane Talk 1 May 20, 2001 11:00 PM