Successful 700mx rewind

[Inkslinginmofo77]

Well I am totally new to the rewinding. I like to understand everything so I decided to rewind my motor after seeing the mag wire lookin crispy and motor was running hot. I am a tattoo artist and build my own machines so was already familiar with coil wrapping. However I took the stock .3 28 gauge wire and used 24 gauge wire. The original setup had 9 strands at 6 wraps. I did the delta style with 4 strands of the 24 gauge 155*c rated black mag wire and it didn't catch on fire. The motor runs cooler too. I was wondering if I can get someone with mathematical experience with this stuff to tell me what my outcome specs may be. The stock motor was a BL700MX 510kv, .3 28 g wire wrapped 6 times and it's 12 tooth stator with 10 mags, I wrapped 4 strands of 24g. Wire 6 times around each stator tooth and running the delta config. Anyone who could do the math and let me know my rough KV rating and any other specs would be appreciated

[fusionsx00]

All you need to input is the original turns and original kv and this will tell you
http://lambertus.info/?kv-rechner-(w...-umrechnen),13

My guess is 765kv

More turns equals lower kv, less turns equals higher kv

[prototype3a]

Sounds like you increased the copper content just slightly with the same turns so it should be a little more efficient and the same kv as before.

That is assuming it was delta before.

9 strands of 28awg is 0.724003914mm^2 of copper
4 strands of 24awg is 0.818859555mm^2 of copper

[Inkslinginmofo77]

Yes it was a delta before. I've only ran it without blades. Next is hovering and hope to got my $4000 heli don't catch on fire! Lol

[Inkslinginmofo77]

That link is in German

[fusionsx00]

My phone translates it and so does my desktops google chrome.

Also i misread , i thought you did less turns.


Did you test for shorts before putting the motor back together and test the motor on the bench(spool up no load) ?

[Inkslinginmofo77]

I noticed I have a vibe now. The heli runs smoother now but my Skookum vibe log tells me I have a lateral vibe from my motor. It is on the same vibe frequency as the motor. Is there a way to balance the can or maybe something that is common when rewinding that cause vibes that weren't there before? I made sure there is no up down play on the can. Is that okay? And in doing so it narrowed the gap between the lip of the can and the motor mount. Maybe a mm. It was a hair bit more before. Would that caise vibes?

[fusionsx00]

Yeah, you can balance the can. Did you change the bearings and shaft?

This video will give you a good idea how to, just take off the pinion and let it spin under no load. And use the sk vibe analizer. You can add tape and use CA to make it permanent.

Also this way will let you know for sure its the motor, since it will be the only thing spinnning

In depth video how to balance brushless motors using a vibration meter and tape - Ontaerial (25 min 35 sec)

[Inkslinginmofo77]

I will give that a go. Thanx so much