Making a Micro T the RCM way

[Metallover]

Got some testing done. This thing is a beast. I took it down to some smooth road. It crashed under my friends car, almost under a running lawn mower, and in front of a moving van. This thing too 5 or 6 crashes at full speed and I didn't even break a part. It's heavy, and I expected to break something, but never did.

Holy crap. It looks over 40. really. I think I go out of range though, so I need to work on that. Yeah, I didn't get a video. Sorry. I might be able to get one by the end of the week.

I think there's a rock in one of the motors so I'll have to take it apart and clean er out. I'll do both while I'm at it. The mount needs some work too.


And, I think this estimate is pretty cose

Differential Ratio: 1
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 1
Pinion Tooth Count: 1
Total Voltage: 7.4
Motor KV: 1500
Tire Diameter (inches): 1
Tire Ballooning (inches): .25
Motor Current Draw: 0
Motor Coil Resistance: 0
Spur/Pinion Ratio: 1 : 1
Total Ratio: 1 : 1
Tire Circumference (inches): 4.71 inches (119.69 mm)
Rollout: 4.71:1
Total Motor Speed: 11100 RPM
Vehicle Speed: 49.53 mph (79.57 km/h)
Effective KV Value: 1500
KT constant: 0.9 oz-in/A

[Metallover]

I decided to continue the perpetual project today. I got the motors off, and I saw one of my wires was disconnected. Maybe that's what was causing the cogging... Insted of trying to repair the motor, I think I'll go ahead and rewind it. By what I've read, I should be able to get a higher turn for less kv and more power due to tigher packing. I really need the low kv because the thing is so overgeared...

I am considering buying some magnet wire over at gobrushless.com, but I don't know hou much I need or what gauge to get. Can anyone chime in here?

If you know a good tutorial for winding an outrunner, let me know.

Also, rewinding the motors might cause a differnt kv for each motor. It's a risk I'll have to take I guess..

And here are some pics of the motor

[BL_RV0]

Contact MTXMUGEN on here or aim.

[Metallover]

I've been chatting with ron_van_sommeren and jdetray on RCU and they gave me a ton of good imformation - http://www.rcuniverse.com/forum/m_17...tm.htm#9200941

My heart is pretty much set on getting some wire locally, probably 22 gauge, and terminating in a star config. That should give me hopefully around 1000-1500kv. That's a solid 20mph on 2s lipo which should be very controllable. Also the power and efficiency should be way up lenghthening runtimes and hopefully improving startup.

Next time I take it trip into town I'll stop by radio shack or similar and pick up some magnet wire. I was going to go with gobrushless.com, but I figured it would be easier and faster to buy locally..

[BL_RV0]

I'd gear for 30ish if I were you, you'll get quite the torque geared for 20...

[Metallover]

I went and got some magnet wire. After I replace the dryer vent hose I'll attack rewinding the motor. I'll get some pics up too.

No clue how much speed I'll get. It depends on the kv I end up getting, and I have no clue what that'll be.

[BL_RV0]

How much was the wire?
Dryer vent hoses... Oh I remember those....

[Metallover]

The wire was about $6.59. I got three rolls. 40' of 22g, 75' of 26g, and 200' of 30g. I will have lots of the smaller wire if I need to have more turns.

[Metallover]

An hour and a half down. One stator clean. First 6 teeth took about 15 minutes. Next two teeth took about 45 minutes. Last tooth took 45 minutes and some serious concentration and anger management. There was some sort of epoxy or glue on the one tooth. That stator suffered a little damage, but I think it'll be ok.

I'll start winding probably tomorrow with the 26awg wire. Turns out 26awg is probably the exact size the original windings used. I hope to be around the 1000-1200kv range.

Here are some pics















And I found I was geared for 75mph with the old 2300kv.

[Thomas]

Just found this thread. Nice setup! Is the receiver an integral part of the motor mount?

[Metallover]

Originally Posted by Thomas

Just found this thread. Nice setup! Is the receiver an integral part of the motor mount?

Nope, just strapped onto it. I am replacing the motor mount and possible the chassis too because the motor mount was too weak. I'll have to find something else to make the motor mount of out.

[redshift]

Originally Posted by Metallover

An hour and a half down. One stator clean. First 6 teeth took about 15 minutes. Next two teeth took about 45 minutes. Last tooth took 45 minutes and some serious concentration and anger management. There was some sort of epoxy or glue on the one tooth. That stator suffered a little damage, but I think it'll be ok.

I'll start winding probably tomorrow with the 26awg wire. Turns out 26awg is probably the exact size the original windings used. I hope to be around the 1000-1200kv range.

And I found I was geared for 75mph with the old 2300kv.

Gives ya a whole new respect for the woman who probably has to do about 40 of these per hour.. when you really think about what's involved, $8 seems all but impossible. If these were made in the US (haha) they would be ten times that much.

That takes some real patience. One of my most memorable nightmare projects was lacing my own wheels for my mountain bike. That was over 20 years ago... you guys just have one carbon spoke now- it's a lost art!

Very cool project and I hope you get those motors REAL close in kv!

Steering trim might not fix more than about 2% variance.

Good luck little China girl...

[Metallover]

I have even more respect now, after I tried to wind it. Half hour wasted in 3 attempts. I'll read up some more and give it another shot tomorrow. If you can wind a brushless motor,,, That's impressive.

[Bondonutz]

Originally Posted by redshift

Good luck little China girl...

Seriously, I thought I had incrediable pateince. I don't think I'd have it for winding those tiny motors with my big fat fingers. Keep up the great work and good luck to you Riley

[lincpimp]

Ever finish your winding?