Jamie James

iTrader: (4)

I have a Caster EX1R with a 44T spur.

I have just picked up a new motor esc combo. I got the Hobbywing 80A esc and 2000kv motor. Have not even run these yet.

I have had 2 DNF's at the last 2 race days due too electrical failures.

Last time out I was running the exact same set up as above and with less than 1 min to go in the first qualifier the system died on me. The corner marshal said he saw a little white smoke, when I got back to the pits the motor was WAY too hot to touch for even a second.

I was running a 13T pinion. Track is a good sized outdoor 1/8 track.

Was I over geared or under geared?

My friend has the same motor / esc and buggy, but he is running a 46T spur.he just dropped to a 12T pinion from a 13T.

So if he's running a 12/46 set up, should I be running something like 11/44 on mine??

Here is the motor

badassrevo

iTrader: (12)

You need a temp gun.

You shoud be running a 44/13 maybe your ESC problem was causing the motor to run hot.

Jamie James

iTrader: (4)

I have a temp gun

Last time out, both the motor and esc were brand new.

So, do you think my friend is under geared then dropping down to a 12T pinion with his 46T spur?

I'm just trying to get a good starter range as far as gearing goes. I've had two DNFs already this year.

Cain

iTrader: (294)

How long was your race? what Temps did you run in? Track conditions? Driving style?

could be a few things causing you to kill electronics, some for example:

- Bad electronics, yup, it happens
- Bad setup
- Electronics can't handle load being placed on them

This one is a bit more tricky as your friend has no issues, but, something to keep in mind is that a variety of things can add extra strain on your setup than what your buddy is seeing. First off, how is your gear mesh? are you running it too tight? Tight mesh and you can put extra strain on electronics. Any binding in the drivetrain, etc?

Undergeared can put a strain on the system too. Using the logic from the Late Big Jim, one of the premier motor guys prior to his passing, I always gear my car to top out towards the end of the longest straight, within reason, and check temps. I keep my temps in my safe range ( I personally like anything under 150 degrees) as well as keep my ESC around 100 degrees. Start there.

If you have a radio that can do it, having a temp sensor onboard is a handy too if it can relay the info back to the remote.

When I ran 1/8 scale until Nomadio closed its RC department, it was the radio I had to have as it would display voltage date on the battery pack so I could see how it was doing, and I could get a temp reading back to based on whereever I put the sensor, usually around the motor.

The DX3S can do this for the temps, and I recommend using this so you can see what is going on. This is what I use, and prior to getting out of 1/8 electric temporarily, always had the temp sensor on the motor.

Jamie James

iTrader: (4)

Thanks for the reply, here is what I can tell you.

Quals were 5min, outside temps were comfortable, hot but not too hot. track cond was good, a little loose in the morn. I was taking it easy that day because I had a failure last race and was using brand new stuff, easy on the throttle, gentle on the brakes.

Set up was good, putting power to the ground, not much spin. Using Turnigy 5200mah 30C lipos. Hobbywing 80A esc , 2000ish kv motor

Mesh is good. Buggy rolls freely with and without motor installed.

I know being under geared can be as bad as being over geared. I'm just trying to get suggestions for a good starting point.

adrictan

iTrader: (10)

A 12/13t should be fine. If u have a spare motor, you can try it out to see if the temp reaches that high. Since u said nothing is binding, the differentials shouldn't be the problem. Did u measure the temp on the ESC? If it's within the tolerable level, the problem should be the motor itself.

Cain

iTrader: (294)

Usually when you don't have any starting info, guys will go with the 40mph starting point based on the calculator that can be found online.

Jamie James

iTrader: (4)

Link??

adrictan

iTrader: (10)

here:

http://scriptasylum.com/rc_speed/_top_speed.html

Jamie James

iTrader: (4)

If what i entered is correct, running a 13/44 pinion / spur set up will net me 35.4 mph.

The chart is telling me that an 11T pinion is need for a 1:1 roll out.

hakmazter

What motor is it?

If it is a Caster 2045 that is purple, throw it as far away from you as you can.

If it is a fiagio, do the same thing, just not quite as hard. Otherwise, there is a heatsink fin that we have at casterracingusa and I think the part number is

JR-0133

http://casterracingusa.com/product.p...5&cat=0&page=6

Cain

iTrader: (294)

With your gearing you were using, where were you topping out down the longest straight?

Jamie James

iTrader: (4)

Original post edited with motor pictures. The local Caster dealer says it's the new Caster/Hobbywing motor.

I think I was topping out right around half way. Problem is, I won't get a chance to do any practice runs until the day of the race. I'm going to run 4-5 laps and bring it in for my friend to check temps, if everything is ok, I'll do another 4-5 and check again and regear if I need to.

I have a Tekin 2050 on the way. If it gets here in time I will prob just run that instead.

Might as well put one here too.

hakmazter

That is the new hobbywing motor. It should be fine.