can you guys explan why electric motors seems to be the way to go instead of nitro for crawlers?

Nitros, usually don't have enough torque at low RPM's to rock crawl very well. You can still do some crawling with them, but they mainly use momentum or wheel speed to get over stuff.

Since nitros have to rev up alot more to make enough power, they will quickly burn up clutch's while crawling. They also need airflow to cool them down, so they don't do very well at low speeds for a long time. And they have a tendancy to load up with fuel if they are idling for extended periods of time. You need to rev them up ever once in a while to clean them out and keep them running smoothly.

You can still make a nitro crawler, but IMO its hard and more expensive to go that route.

Also, it can be very difficult to incorporate reverse into a nitro drivetrain.

Agreed... Nitros don't make good crawlers compared to electric. The guys at my LHS are all hardcore rock crawlers and belong to that Rock Crawling Organization (USRCC I think?) and go to the events religiously. They are all electrics.

Clear as crystal!
Thanks guys!

If I had the money, I would try putting a big thumper (4-stroke) motor on a monstertruck. I think that would be a cool project to do anyway. That should take care of the low end power, but you would still have problems with burning clutches though.

the clutch is a big problem, if you stop on a big hill and then try to go again you will roll, not good also you would have to shift in to reverse, also not good, there is lots of play in nitros which is not good for the precision driving required in rock crawling, also it was mentiond before but overheating is a huge problem, even if you can gear it down low enough to have it in the power band at slow speeds you have to have a huge fan or fans running, which means more battery needed, so if you look at the big picture you have a fan, 3 servos, (1 for reverse, 2 for steering), a battery to power all that, a huge tranny to gear it down so low, a motor, a fuel tank, and you can only run it for a tank and then you have to cool it. so electric is the wy to go for many reasons, also gas is loud, messy, and annoying. there is trouble with comps already if you add nitros there wont be anywhere left to have comps.

it could be done nicely with an x-factor, if you come up with some way to gear it way down(like topping out at 12mph) then the power would amaze, specially if it was a four stroke, also, ever watch a temp gauge on a nitro running low rpm, they drop, when not over half throotle(with proper gearing youd never need more) the temps will drop even moving very slowly, i cool my t-maxx down when it gets to hot by driving very slowly and letting it idle(sounds like crawling to me) would it be a challenge, yeah, would it cost alot, yeah probably, would it be the sickest looking and sounding thing to hit crawling, quite possible...

your not in power band if it is cooling down, motor rpms and car speed are two different things.

the speed was relating to the fact of no aircooling, but my point is that geared down right you could crawl without needing full power, and a computer fan will run on 2 sub c cell easy and would be plenty so either way im just saying it could be done very succesfully.

Make NO mistakes about it, NITRO CRAWLING won't be for everyone, and it's gonna take, time, thought, and perseverance in the face of all the "naysayers," but giving up is NOT an option!

Personally I can't wait to crawl against one.

Can't wait to destroy it on a competition course.

Well I cant wait eather Dez. Just one question what is your final ratio of your truck?

Steve,

The final drive on my supper is 43 to 1 w/ my current gearing.

Dez

electric motors have gobs of toque on veary low rpm as a nitro would not have.Also a nitro has clutch shoes which will burn up due to the stress on them.[sm=cool.gif]

To overcome this problem on our engine dyno at work, a steel clutch system was used--problem solved. I can't take credit for it as I had nothing to do with it, but as far as I can tell the steel clutch works like a charm. I'll get more info when I get back to the office next week. The other main concern with nitro crawlers is heat. The problem is also the same on our dyno. Two (I believe) inecpensive brushless cooling fans (look like computer fans to me) solved that problem. That's just some food for thought. Even with those two issued addressed, I don't think (and have never said) a nitro crawler could compete with an electric crawler. I'm not sure why it keeps coming back to that. It would nice if we could keep this civil since it appears this topic is here to stay on this forum.

Dez The final drive on my supper is 43 to 1 w/ my current gearing.

43:1 is a ok gear ratio but I am looking at a ratio in the naborhood of 114:1 for the nitro crawler, also an electric crawler could benefit from a lower ratio so the electric guys could run a standard motor.

MattHiggins: To overcome this problem on our engine dyno at work, a steel clutch system was used--problem solved.

I have used steel clutches, they are not new, I got the idea to use them and the clutch from RC Heli's. They work great. I tested one in a T-Maxx and worked great.

Steve

I didn't mean to imply we invented the steel clutch.