weight limits w/ the 540 motors?

[BigSki]

I'm just wondering how much weight is 'too much' for these motors? I realize that reduction gearing helps a lot but I'm starting to wonder if my large scale Willys is just pushing the limits of what these motors can handle.

I'm about at 96:1 overall gearing ( including axle gears) and the rig weighs at least 15 lbs, probably more! I use a 5000 3s LiPo and FX-r for electronics. After running the rig for an hour or more the motor just gets really warm, I've had it thermally shut down the ESC once. I've already fried a 45T Tekin machine wound motor and now I have one of my HH 35T Torque Masters, I don't want to cook it. It's geared the way it is because with the weight of the rig I wanted slow speed for realistic crawling and braking control while descending.

[ickabob]

Originally Posted by BigSki

I'm just wondering how much weight is 'too much' for these motors? I realize that reduction gearing helps a lot but I'm starting to wonder if my large scale Willys is just pushing the limits of what these motors can handle.

I'm about at 96:1 overall gearing ( including axle gears) and the rig weighs at least 15 lbs, probably more! I use a 5000 3s LiPo and FX-r for electronics. After running the rig for an hour or more the motor just gets really warm, I've had it thermally shut down the ESC once. I've already fried a 45T Tekin machine wound motor and now I have one of my HH 35T Torque Masters, I don't want to cook it. It's geared the way it is because with the weight of the rig I wanted slow speed for realistic crawling and braking control while descending.

Wow, How does that FX-R do on a 3 cell?

[WIDELOAD]

Not sure about weight limits. As long as its not getting hot (over 160*f/70*c) and isnt over-geared (which it isn't) it should be fine.

Only thing i can think of is its either A) gotten shit into it and damaged a wind, causing a short OR 2. was on it's last legs and then decided just to shit itself.

Can you pull down the dead motor and see if you can spot anything out of the ordinary. Or post up some pics of the internals of the dead one and someone might be able to spot what has caused it to shit its daks.

Originally Posted by ickabob

Wow, How does that FX-R do on a 3 cell?

Read the instructions that come with it. If you run a 35t or higher you can use 3s and it will be fine.

[JohnRobHolmes]

It is a combination of gearing, voltage, wheelspeed, traction, and vehicle weight. Plus your driving style plays a huge part in it. The only way to reduce the motor temps is to use a more efficient motor, increase the cooling of the motor (through increased airflow or surface area), or of course reduce the load. I would suggest you keep the endbell temp under 150f for such long outings, and don't dunk it into water when it is hot! I assume you probably got a motor with 5mm web and standup brushes, which is about the coolest running 35t you can have.

If the motor just doesn't cut it, you will need to get a bigger motor or force some extra cooling on it. Sounds like you have found the limits of the machine wound motors and the fXR at least.

[BigSki]

Thanks for the input John. What is the next size up in the electric motor world? I was eyeballing a big azz motor hanging off of a 3 speed Bruiser housing but I have no idea of the # of windings or amp draw or anything like that, it's just a huge silver can motor. Maybe a PCU fan or a Traxxas fan might be worth a try as well.

[EeePee]

550 is the next step up, it's just a little longer. Like the Traxxas motors, or a Trinity Monster Maxx. Traxxas also has a 750 size, in their Summit. That might be what came in the Tamiya Bruiser, also.