outrunner'd e-revo

[sikeston34m]

The outrunner's coils and armature don't make direct contact with the rotating can. What heat doesn't get swept away by the air flow, migrates to the motor plate.

I wonder if adding some thermal paste between the two motor plates, then focus on cooling the motor plate would help?

I think there's probably room, if some creativity were used.

[kevin23]

I'm all about modifying.
If only you saw my old tnx pro that I was racing,I went and changed the tank to a mgt,I made my own sway bars for it,used the traxxas flywheel setup and used the revo slipper and spur gear because the stock gear was sooo weak anyway,

you talking about putting the heatsink compound between the motor and the motor plate?I will try that,I think I could pretty easily add some fans as you have on the maxx.
I have to wait and see where all the electronics go first

[sikeston34m]

Originally Posted by kevin23

I'm all about modifying.
If only you saw my old tnx pro that I was racing,I went and changed the tank to a mgt,I made my own sway bars for it,used the traxxas flywheel setup and used the revo slipper and spur gear because the stock gear was sooo weak anyway,

you talking about putting the heatsink compound between the motor and the motor plate?I will try that,I think I could pretty easily add some fans as you have on the maxx.
I have to wait and see where all the electronics go first

Yes, between the motor and the motor plate, but that motor plate then slide onto a post and mounts to another plate. There are several spots there that would benefit from the thermal paste.

I would add some to the post, then also where the two plates touch. Aluminum is such a heat sink.

The fans that I used are 25mm square. I power them with the CC BEC also. Remember it can carry like 10 amps. You could probably power a 100 of those small fans with one.

[kevin23]

here are a couple pics of the lastest setup,2 4s 5000 in parallel.
hoping for 30 min runtime on the track,should be plenty seeing as how the 2
2s packs in series gave me between 15-20 min.
all up weight is less than stock e-revo with 2 8.4v 5000mah nimh batt's

[kevin23]

I raced at the rc pro series florida series race #2 today with the revo.
I qualified 2,less than 1 sec from tq.
during the 20 min a-main,for some unknown reason the batteries came unhooked 3 times
the first time it happened I was leading the race,after the 3rd time it happened,i was multiple laps down,but fought my way back to 2nd and that's where I finished.
I am very pleased with the truck and the axi motor.I finally have the motor temps under control now,20-40 is how it's geared after the 20 min main,that was real wet after the thunderstorm delayed the race the motor was 140,esc 100,batt's were ambiet temp
That is with about 2-3 pounds of clay added to the truck
I think I will try a 21 pinion,that may be where i end up gearing on a track that is not deep like the track today after the rain.

[sikeston34m]

Originally Posted by kevin23

I raced at the rc pro series florida series race #2 today with the revo.
I qualified 2,less than 1 sec from tq.
during the 20 min a-main,for some unknown reason the batteries came unhooked 3 times
the first time it happened I was leading the race,after the 3rd time it happened,i was multiple laps down,but fought my way back to 2nd and that's where I finished.
I am very pleased with the truck and the axi motor.I finally have the motor temps under control now,20-40 is how it's geared after the 20 min main,that was real wet after the thunderstorm delayed the race the motor was 140,esc 100,batt's were ambiet temp
That is with about 2-3 pounds of clay added to the truck
I think I will try a 21 pinion,that may be where i end up gearing on a track that is not deep like the track today after the rain.

Congrats Kevin,

I would tighten up those Deans connectors for sure. You would have taken 1st if that hadn't happened. Bend the little spring thingie on the Deans with a pair of needle nose pliers to tighten them up.

I never tried 20/40 gearing. Sounds like it works pretty good.

How much runtime are you getting on the new batteries? 4S2P 5000mah 20C right?

[kevin23]

yep,I ran it pretty hard on the track for 20 min,when I came off the track,one batt had unplugged,not sure how long I was running on just the one batt.
but I checked voltage in both packs.
one pack(the unplugged one) was 3.9 volts each cell
the still plugged in pack was 3.5 volts each cell
Still had more runtime in it,surprised me because of the extra load on the system with the wet track and the added weight.
I think the chassis is flexing,pulling the connectors.That is the only explanation I can come up with.
The deans are still hard to unplug,it unplugged after landing off of a big double jump 2 of the 3 times.

stepping down the pinion gears helped alot more than I would have thought.batt temps come way down,motor dropped 30 degrees or so,speed control dropped about 20 degrees.Runtime went way up,after the 5 min qualifiers on 22/40 I used 1500-1600 mah each pack, that would have me running 12-15 min per charge,which is what I was getting.
I ran 20 min in high load situation with lots of battery left I think

[kevin23]

The response from the other racers was astounding!
Everyone seemed to really like it,had 2 guys asking me about the truck in detail where they want to do the same to their truck

[lincpimp]

Very small zipties can be used to hold the deans plugs together, although you have to heve a side cutter handy to unplug them...

Bending the tabs will help the plugs fit tighter, and a little slack in the wiring will help too.

[kevin23]

I will be using zip ties now,I still cant believe they came unplugged as hard as they are to pull apart.

[secondgear]

This looks like something I would like to do to my e-revo.
The leg work you guys have done to figure out what works will help a lot of people who would like to try this.

I am curious, though, about the largest size pinion that you could fit on the motor shaft and still have it clear the inside of the aluminum motor mount. What have you found?

What top speed are you seeing with this setup?

What gearing are you running right now? It's a little unclear about which gearing causes the motor to heat up, etc...

Thanks for the help.

Karl

[kevin23]

I am currently runnning 20/40 mod 1 gearing.
the motor runs great temp wise at that gearing.
After the 15min main today the motor was 150,esc 110,batt's 100 degrees
with the 22/40 gearing this setup run the motor 180 degrees.

The largest pinion i have used is the 22,not sure how much bigger you could go.
top speed on the track,125ft straight is about 30-35mph,lots of bottom end grunt and awesome acceleration though,just not the blazing top speed

[secondgear]

Do you think that a pinion larger than 22 teeth could fit onto the shaft in the e-revo mount? How much clearance do you have with the 22 tooth?

How hard are you running the truck to get to the 150 and 180 degree temps? Are those temps in Celsius or Fahrenheit?

I've ordered the motor, I'm just debating the gearing.

Karl

[kevin23]

fahrenheit,running the truck real hard,lots of hard accel through a relatively small clay offroad track(120'x80').
most all the turns are pretty tight,really pulls the power out of the batt's and creates heat.
I ran the rc pro race at a different track that is larger with a little higher overall speed and the motor temp was 20 degrees cooler after the main last week to this week's race.
I guess it depends on how you are running the truck,I do think that a 22 is going to be the highest you should run with this setup,imo

[secondgear]

Sounds good with a 22t.

Puts the top speed somewhere around 33mph which is more than enough for how I run.
I can always gear down if I plan on racing in a small track or something like that.

Karl