If she stays in till the 26th of may, her birthday will be on the same day as mine!

Congrats to both of you!

Yes, Joe. Congrats on the upcoming family member! For your gearing question - on 6 cells, you should see about 2 mph increase in speed by adding a tooth to your pinion. Obviously, more voltage will add speed as well (1 cell will add almost 5mph at that gearing).

Thanks for the well wishes, guys. :)
And thank you for the information on the gearing, Mike.

That goes for me as well.... :)

Another minor update today.

I started creating the battery trays for the buggy.

I'll tell ya - it's tough to make pretty stuff with a Dremel and a reciprocating saw :)

Wish I knew someone with a machine shop that was just waiting around for me to give them stuff to do for free :)

Anyways, I have a new picture up at rcpics.net.

http://www.rcpics.net/member/Batfish

Update on the family :)

My wife and new daughter are doing great :)
She's just over a week old now.

Thank you all again for the well-wishes!

Awesome
 

Good to hear everyone is doing well - my wife has 1 1/2 weeks left and she wants it out NOW - lol..

Concratulations to you and your family!

Latest Run
 

I finally got my battery trays in some type of order and was able to get everything together for a run tonight for the first time in a couple weeks.
I used two 6-cell GP3300 packs (unmatched) wired in parallel. The BEC on the Warrior was enabled and I did not use a receiver pack.
My observations:
Speed - the speed was good for my back yard. I'm pretty sure it was as quick as my stock E-Maxx on 12 GP3300 cells. I'm hoping to get to my local track and try my 8-cell packs some time this week.
Cogging - very minimal. I'm definitely happy with how it worked this time around.
Brakes - I noticed mid-way through the run that I had no brakes again. I ended up breaking one of the pickets on our picket fence! (Don't tell my wife :) ) I had set the brake exp on my M8 to 100% last time out and I'm wondering if I need to start the radio at 0% and increase it after the car is already on. Does that make sense?
Runtime - on the two 6-cell packs (peaked about a half hour or so before I started running) I got at least 10 solid minutes of running. It was probably more like 15 or so, but I didn't time it.
Heat - here's where I may have a concern. Both the motor and speed control got hotter than I expected them to. I had left my IR temp gun in the garage, so I was just touching them. The motor was definitely hot to the touch and the speed control would have burned my fingertip if I had left it there for more than a second. When I was done I brought the buggy into the garage and checked the temp. After having a couple minutes to cool down in the 50-degree weather, the motor showed 140 degrees and the ESC was at 145. On only 6 cells should either be getting that hot? The batteries were actually cooler than either the controller or the motor. I'm sure this is because they are decent cells and they were wired in parallel, but both packs were comfortably warm and nowhere near hot.

Anyway, that's my latest report. Comments? Feedback?

Thank you.

The heat is due to the amps you are drawing. On six cells, in order to make the power, the system has to draw high amps. If you cut the gearing in half and used the cells in series, the truck would run cooler AND have more power. The cells were wired in parallel, so they shared the amp draw, which no doubt minimized the temps. For the brakes, when you lost them, were they gone for the rest of the run, or did they disappear and reappear? This may be a result of the heat as well, but it is somewhat baffling.

Okay, so I'll get better temps with 8-cell packs? Good :)
Temps have to stay safe for at least 15 minutes of racing.
Speaking of heat, what's the "safe" upper-range for the 8L and the Warrior 9918?

As for the brakes, I didn't even try to use them for the first 5 minutes. The brakes did not work at all when I tried to use them. It wasn't that I lost them, they just didn't work when I tried. I would push the throttle to full reverse, the buggy would cruise to a stop, then reverse would kick in. No brakes. As long as the weather is good tomorrow, I'll try what I was thinking with setting the radio to 0% before turning the buggy on, then increasing brake exp on the radio and see if it works.

I have new information regarding the brake problem.

Using my IR temp gun I've determined that the Warrior stops braking when it reaches 120 degrees.

Here's some information as to how I arrived at that conclusion.

Batteries: I ruled out the possibility of bad batteries by running these configurations - (1) 6-cell GP3300 sport pack, (2) 6-cell GP3300 sport packs in parallel, (1) 8-cell IB3600 pack in an MEC solderless power tube, (1) 6-cell GP3300 side-by-side matched pack. In other words, I've tried 7 different battery combinations with 5 different pack configurations, 3 different pack assemblies, 3 different pack manufacturers, 2 different cell types, and both matched and un-matched cells. I think that rules out that the batteries may be a problem.

Motor: The Feigao 8L was at different temps each time I noticed the brakes failing. 100, 113, 98, 128, 130, etc...

Radio: I had my M8 set at 75% brake exp the entire time and did not change it either while the buggy was on or while it was off. There was no change in the radio configuration between the times the brakes worked and the times they did not.

Speed Control: The Warrior 9918 was measured for temp by pointing my IR temp monitor at the heatsink. Brakes worked fine at the following temperatures: 65, 88, 91, 98, 112, 116, 118. Brakes did not work at all at the following temperatures: 122, 125, 130, 134, 140.

To test this, I drove my buggy in my back yard at at least 1/2 throttle (as fast as I could in my small yard, at least). I would drive for maybe 20'-100' or so and try to apply the brakes. I measured temps when the brakes were working; each time the temp was 118 or lower. I also measured temps when the brakes were failing; each time the temp was 122 or higher. When I took the measurement of 125, I stopped the buggy and let the ESC cool to 116, then drove forward about 15' and applied the brakes; the brakes worked. I then drove about 100' and tried the brakes; they did not work and the ESC measured 122 degrees.

Lastly, my Warrior has the first two digits on the sticker blacked out with what looks like magic marker. So it's *blackspot*18. Is this indicative of something? I was under the assumption it was just one of those mis-labelled controllers I read about in another post, so Mike may have just blacked out the 70 so customers wouldn't think they were ripped off. If that isn't the case, please let me know.

So my new question is: What do I do next?

Thank you.

That is very interesting info, Joe. I will try to contact BK and see if they have some comment on this. There must be a component that is overheating and causing the failure and I will try to see what it could be. In the meantime, I would try a fan over the controller heatsink to keep it cool.
There were quite a few mislabeled controllers, and I sincerely doubt the sticker is any more than a coincidence. If your controller has 4 caps and two boards, it is the 9918 controller with the wrong sticker.

Thanks, Mike. Let me know what you find out.

I have a few 12v CPU fans around. I'll set one up on the controller and see if that helps keep the temp below 120. The fan won't spin very fast since I only run 6 or 8 cells, but it's something to try.

My concern at this point (aside from the obvious) is that the controller gets to 120 in less than 5 minutes running in my back yard. It's got no chance of keeping brakes during a 15 minute race at that rate. I'm hopeful the fan will help while you find out from BK what's going on.

What is your gear ratio?
I ran my MBX-5 with a 13T pinion and a 46T spur and fried my controller in 10 minutes. This gear ratio is way too high. I temped my controller at over 200 degrees F. I fried two FETs and who knows what else. The motor was also damaged in the experiment. Luckily it didn't cost that much to repair...

I am setting up my MBX-5 with a gear ratio closer to a monster truck. I'm going to start really low and work my way up.
My first try will be a 13T pinion and a 65T spur.

Hope this helps.