Noob needs help
 

I'm searching the Castle Forums here looking for some guidelines for setting up my MMM in Castle Link. I'm coming up dry though. Maybe it's the words up searching for, particularly the "motor timing" setting on the "basic" tab.

As you probably already know, you get several choices.

Highest (20)
High (15)
Normal (10*)
Low (5)
Lowest (0) Best for Bashing it says.

Normal is what it auto detected for me and my setup. MMM 4s (two 2s in Series) a Tekno 1515 1Y. I thought there was 0 degrees of timing on these brushless motors. Or am I getting my terms confused here?

When I first got my truck setup I had the absolute worst glitching I've ever seen. I switched out the bone head traxxas radio/rx and am currently using a HPI FM tx/rx from a RTR Baja buggy. It works much better and will suffice until my Futaba 3pm gets in from Tower.

Anyway, I am seeing some serious hesitation from my truck under full throttle, either from a stand still or running WOT across a large soccer field. I'm not sure where to start the trouble shooting.

For one thing, I really have to scratch my head over the fact that the MMM comes with 6.5mm bullet connectors on one side to handle all that juice being pulled from the motor, and then on the battery side I have some tiny solder joint on a fraction of the bottom diameter of the 10ga wire on traxxas connector. See photo:


http://img382.imageshack.us/img382/5...nectorsgo2.jpg

I just can't believe that there's enough contact area there to get the job done. If there was, it would stand to reason that surely the 4mm connectors that come with the MM would have sufficed, right? I mean, if that crap solder connection is good enough for 16v and 110amps, then why ship MMM with 6.5mm bullets?

I'm running Max Amps 2s2p 8k's and we all know how the packs need a 25% buffer over what your system requires. But I should have that covered up in spades. 1515 1Y is 110amp max. Max Amps 2s2p 20c 8k's, should, by definition, be 160 amps.

I'd really like some opinions on these issues.

I know what the search button is for, too. :lol:

Thanks

IMO the reason CC uses 10 awg wire is because they use aluminum wire not the best conductor, if they used copper stranded wire they would be able to get away with 14-12 awg, and I dont think they need 6.5mm connectors especially if you are running more than 4s you could use 5.5 mms and be fine...you cant fit 10 awg wire in a 4mm connector unless you remove some strands, and another factor to look at is the "C" rating this is the amount x your capicity will be your possible output depending on your motors demand

I was using exaggeration to make my point. The point was the contrast between the large bullet connector with it's large surface area contact connection. Contrasting against the Traxxas connection where the solder joint is less than half the diameter of the wire and only touching the few outside strands at that.

Short of spending even more money on a data logger, I'll have to assume what the C rating is.

Neu recommends low timing on their motors, 10 deg max I think.

it has been widely talked about on this forum and others that the Maxamps packs are overrated thier 20c packs are more like 10-15c

Thanks, I appreciate good advice. And that is what the MMM auto detected it as. I'll trying moving it lower.

On the castle website or in one of their manuals (I forget which) it says the esc autodetects the optimum timing for the motor connected, and the adjustment in the castlelink adjusts the timing around that detected optimum - I dont think what your choosing are degree values wrt zero.

why not switch the traxxas connectors out for a few runs, see if that helps... simple and pretty easy, a 5 minute job. solder on some large bullets (5.5+) and see how that goes...

Do the joints get warm? thats usually a pretty good indication of their adequacy... only if everything else is cool though, by which I mean if your overdrawing your batteries, then they will be warm, and some heat will be drawn away by the wires, which will warm up the connectors anyway (and this isn't good, hotter = more resistance = more power loss = more current draw = even hotter). If your pack and wires a cool, but the connector and joint is warm, it means its like a bottleneck and you need high current handling connectors.

Good idea. When I bought my MMM I went ahead and got a couple of extra bags of the CC Bullets. I planned on putting them on the battery side of the ESC today. Unfortunately, I don't have enough connectors to do each connector on the "series adapter" that makes the two 2 cells a 4 cell. Might run up to Radio Shack to look at their bullet connectors to do the series cable and the connectors on each lipo.



I was taking temps of everything and it came up like this after some WOT runs up and back on the large soccer field:

Motor ~130f
ESC ~115f though it's hard to get a reading with that fan on top
batteries 90f
wire from batteries 102f
connectors on battery 105f
connectors at each point on harness about the same 105f
connector at the esc 110f
didn't get the temp of the connectors from esc to motor (6.5mm bullets)

That's all normal, right? I have no frame of reference.

Thanks!

Switched everything over to 6.5 bullet connectors and the problem persisted. Go WOT and the truck will stutter and the front end looks like it's being pulled down. I checked the Castle Link again and saw that the "Starup Power" setting was set to "Medium" for "High Quality" batteries. As we all already know and azjc keeps pointing out, Max Amps batteries are over rated. I'm recharging at the moment, but I'll try this setting at "Low" and see how it goes.

yeah im not really sure what start power does, I can't notice any difference between high and low, all my cars will just flip from a standstill if I want them to lol...

Start power helps higher pole count motors get started. Now, with the new firmware that cc came out with recently, this setting does not really need to be changed.

You are most likely hitting the lvc at full throttle. What do you have it set for? 12v? You can set it much lower for testing purposes, but only on a fully charged pack, and do not go full throttle more than a few times. Sounds like under load the battery voltage is sagging low enough to trip the lvc, causing the power loss you noted. If it still happens after you disable the lvc, then I would say to reprogram the MMM to your radio. You may need to reset all of the values in the radio to zero/centered, and then reprogram the mm to the radio. You may be going full throttle and the mmm is not seeing the full travel of the radio, and going into failsafe mode.

What are you talking about? You can't solder to aluminum. We have NEVER used aluminum wire on ANY product.


All of our wire is 100% oxygen free copper (OFC), 101% IACS.

Try setting "timing" a little lower, and set "punch control" a little lower.

I agree with you on the connectors -- we ship those big 6.5mm connectors because that much current needs a big connector. Some of our 1515/1Y setups draw as much as 125A continuous at full speed.

You can also try gearing down, current draw is directly related to gear ratio -- so if you want tot try limiting current, the easiest way is by changing gear ratio.