New 540C-7XL pics dissected,
 

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

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

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

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! ;)

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?

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

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.

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?

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

You must have spent a lot of money on those developer kits... I got a Dewalt 36v battery on Ebay (10 M1 cells) for $101 shipped that will become 5s2p :027:.

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.

Yah, i bought mine way back in July when the first came out, i have been watching them since fall 2005... the kits i bought were $100 each, i bought two of course @ 6 cells a kit.

I made the pack into 2 cells together in parallel, then 5 of those in series. Now with this BL system i am attempting to direct solder the cells, which is not recommended. They say the only outcome is reduced cycle life because of the heat of the iron. But i have a good way of very quickly soldering and then rapidly cooling it down.

We will see.

Do you balance your cells at all?

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 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

I think I will do that at a later time, when i am done making my new chassis. And then i know where the pinion has to be. I think i will make a crater from a drill bit, it seems that will work better, and better balancing...

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...

Well, the only way to know for YOU, is if you buy them, now they aren't cheap, but they are not as expensive as LiPo's. The voltage issue is irrelevant though, i mean they are a different type battery altogether. I personally, LOVE them. I would never go back to Li-Po.

You ask about the holy grail of battery tech........


Europositron technology

This company is based out of Finland, and received a Frost & Sullivan award for 2005, for good reason, well VERY good reason. They say 1-2 years market. :)

Energy Density/Volume: 2100 Wh/litre

Energy Density/Weight: 1330 Wh/kg (Standard LiPo: 140Wh/kg)

Cycle Life: 3000+ cycles

Minimum Working Temperature: - 40C

Maximum Working Temperature: +70C

Life: 10-30 years

Discharge Rate: Adjustable

I justify the lower capacity/higher weight of the A123 cells when compared to LiPo by comparing them to NiMh - more power, more runtime, higher voltage, faster charging, etc. for less weight. I'm pretty much converting everything over to A123 cells - Rustler is getting a new, A123-specific chassis, Revo will have batt mounts made to hold them, and the Savage will also get batt mounts. What really draws me to these cells is that they physically can't puff up - I had to send my Maxamps 4s3p pack of 2100HV cells back for a replacement when one of the parallel groups puffed up for no apparent reason (with the use of a Dimension Engineering CellShield LVC and a balancer on every charge). My only LiPo-powered cars will be my 18t (still need a Mamba and LiPo pack), Dark Impact (have 2 Lipo packs for it), and my X-Terminator (getting the replacement Maxamps pack).

MM, believe me, I'm not trying to downplay your choice! Comparing them to NiMH, there are advantages. I think the trouble I have with them is the size. They are kinda difficult to stack in a space-saving way. Makes for an oddball package IMO. I could see maybe running these in my Jato at 3s1p. But to run them in my Revo, I'd have to 2p to get any amount of runtime out of them (I like at least 15 minutes) and then 6s for the voltage. That's 12 rather large cells.

Now, if they had a solid 4 or 5Ah, then runtime would be higher and would only need 1p for most applications. The cells would of course be larger, but the footprint would be less than two of the current sized ones together. If only the M1 cells were flat, it would be a no-brainer!

Believe me, I'd like to covert to one super battery chemistry for everything. Maybe the Europositron technology stuff might be what I'm waiting for. My Hyper8 buggy is still sitting around because I can't decide whether to go for lipos or not.

Aren't you the one who's running one NiMh pack on top of the other in your Revo? :005:. These cells are slightly taller, but that wouldn't do much to the COG of your Revo since they're lighter.

:p

Yeah, only because I had sized the batt-tray for a 5s2p pack of the TrueRC 8Ah packs, but then decided against it. So, I remade a few of the 3300 packs I already had laying around until I could find something else. That "until I found something else" was longer than I anticipated. Believe me, it's not my ideal choice!

Besides, the M1 cells are quite a bit bigger really; ~4mm wider and ~20mm longer than NiMH cells. They are actually roughly the same size (a little smaller) than my emoli cells and those are a pain to stack in an economical way! I dunno. Maybe if a pack fell into my lap I might try to finagle them in there. I think it would be clunky though...

Oh for sure, i would love a prismatic A123 cell that would safe a lot of space!, The volumetric density is quite low, the gravimetric is high however. They feel very light when you pick them up, for their size that is...

YES, the Europositron battery technology has an energy density 12 times higher than A123 cells, and 10 times more than LiPo!
You would only need a batt the size of one A123 M1 cell to get 15 minutes runtime, HAHAHA, that day will be beautiful!