New 540C-7XL pics dissected, - RC-Monster Forums

zeropointbug · **New 540C-7XL pics dissected, -** 11.28.2006, 02:22 PM

Hi everyone,

Here are some pics of my new and FIRST brushless system, for my 1/8 emaxx truggy conversion.

The pic with the two brushed motors are dual DeWalt 820 size motors (massive torque), both 300 watt each for 600 watts, of which weights in at over 1 kg! The 7XL replacing it is 400g, up from the standard 370g. 7XL. The new can is about the same size as one 820 motor, and looks like it has about 8 TIMES the copper in it. Heck, the thing IS one solid block of copper.
Enjoy!

Zeropointbug

neweuser · 11.28.2006, 03:19 PM

Looks like you have the newer version of the Quark! Nice!

zeropointbug · 11.28.2006, 03:23 PM

Yah, is there anything different in the new version, BESIDES the fruit-cake color wires... i so wanted the white wires. Oh well.

neweuser · 11.28.2006, 03:28 PM

Quote:

Originally Posted by zeropointbug

Yah, is there anything different in the new version, BESIDES the fruit-cake color wires... i so wanted the white wires. Oh well.

I have not heard anything on the newer versions, just that the wires are different. you can always call sky and technology and get more info, I heard the guys there are great!:027:

Yeah, fruitcake wires!!!! LOL

zeropointbug · 11.28.2006, 03:45 PM

Yah, once you get one of these motors you can really tell they are not the best quality.

And guess what, when taking it apart, I thought i had the right hex wrench to take out the little set screw on the end bell, i ended up turning the set screw ALL the in and OUT of the thread of the bell. SCARY, it took 1/2 hour poking and turning and fiddling with it to get back up and into the thread. I thought i was going to damage the coil! Anyways i got it out! ;)

MetalMan · 11.28.2006, 05:56 PM

While you have it apart, you may want to consider grinding a flat spot onto the shaft if you have a Dremel or similar tool. You pinions will thank you :027:

Looks like you also have some A123 M1 cells. Did you get the developer kit?

neweuser · 11.28.2006, 05:58 PM

Quote:

Originally Posted by MetalMan

While you have it apart, you may want to consider grinding a flat spot onto the shaft if you have a Dremel or similar tool. You pinions will thank you

Doing that with the motor open though, would it not increase a chance of shavings getting into the motor?

zeropointbug · 11.28.2006, 06:04 PM

Yeah! A123 cells are GREAT! They have fantastic power, it seems like its 100% right until they dump too! They simply suddenly slow right down. And charging! It's great, i have a 5s2p pack (developer kits) that i charge on a lab quality BK Precision power supply with all programmable features and CCCV; anyways charged 5s2p in 25 minutes, and they still room temperature, try doing that with LiPo's....

About the 5mm shaft, i forgot to ask about that, what are other people doing about that. I THOUGHT they came with a flat spot on shaft? Will it simply spin and ruin the pinion/shaft if you don't?

BrianG · 11.28.2006, 06:40 PM

Quote:

Originally Posted by zeropointbug

Yeah! A123 cells are GREAT! They have fantastic power, it seems like its 100% right until they dump too! They simply suddenly slow right down. And charging! It's great, i have a 5s2p pack (developer kits) that i charge on a lab quality BK Precision power supply with all programmable features and CCCV;

Do you balance your cells at all?

zeropointbug · 11.28.2006, 06:50 PM

I do yes, after 10 or so runs through them, i just tap each cell in the pack and do a precise 100% charge. But here is the kicker, they are only ever off by like .02 volts at the most.

DO invest in these batteries, for a given runtime, you need less A123 cells because they are more efficient than LiPo's and they give you 100% performance right until you they dump.

mtucker · 11.28.2006, 07:23 PM

I do the plastic bag trick like Metalman when I put a flat spot on the shaft.
Slide your pinion on and see about where the pinion set screw is going to go and then mark that place on the shaft with a felt marker. Cut a small hole in a plastic bag and slide it over the shaft. It only takes a few seconds with the Dremel cutting tool to make a flat spot on the shaft.

You pinion will likely wind up spinning on the shaft if you don't.

Matt

BrianG · 11.28.2006, 07:32 PM

Quote:

Originally Posted by zeropointbug

I do yes, after 10 or so runs through them, i just tap each cell in the pack and do a precise 100% charge. But here is the kicker, they are only ever off by like .02 volts at the most.

DO invest in these batteries, for a given runtime, you need less A123 cells because they are more efficient than LiPo's and they give you 100% performance right until you they dump.

I guess I should have phrased the question: How do you balance them? Or what do you use?

I'm still not totally sold on those A123 cells yet. Even though they have high discharge rates, the runtime isn't great unless you parallel them. And then, the voltage isn't quite as high normal lipos. I guess I'm still waiting for the Holy Grail of batteries to arrive...

MetalMan · 11.28.2006, 06:03 PM

You would take the rotor out of the motor first (make sure not to damage the windings in the process!). I like to stick the shaft through a plastic bag before grinding the flat spot to reduce the amount of metal shavings that get onto the magnet.

neweuser · 11.28.2006, 06:15 PM

Just take your dremmel and make one, pretty easy actually. 5s2p in 25min????????????????? WOW!

zeropointbug · 11.28.2006, 06:20 PM

Yah! I know! It's so convenient/sweet/kickass/everything you could ever want in a battery, moment. That is when they charged up. They are so durable in every way.

I don't have a dremel, i have wanted to get one for a long time though. It just seems to me though that a dremel wouldn't do a nice job.