1/8 Buggy w/ a Outrunner Motor

[crazyjr]

By Jhautz: guess I run it in Inrunner mode (very good crazyjr, you called it on that one)
z:

Just a suggestion based on the rpm limits, I know that the outrunners run like a 4 stroke (on a different rpm scale) but these are a little different. I'm thinking about trying these on my local track

I wouldn't expect it to be as strong as some of the more commonly used motors. According to tower hobbies site this thing only weighs 5.6 oz.. My M.M. 5700 is closer to 6.5 oz. If 5.6 is correct, and it has enough power for on the track that would be great!:027:

[jhautz]

I did get a little more testing done this week with the outrunner. I ran 2 more packs with it and 2 more packs with the Neu 1515/2.5D. All in all it ran pretty well on the outrunner, but it didn't quite have the snap and responsiveness of the neu. The spool up made it feel a little sluggish on the bottom end. I think I am going to wind up sticking with the Neu and the Quark 80B as the final setup.

I forgot my eagletree but using my Watts Up meter I saw amp spikes of around 120A on the Outrunner motor and around 112A on the Neu. I'm kinda surprised that the outrunner was drawing more considering how much bigger the neu motor is.

I also made a few changes to the setup to accommodate the Quark. I made an ESC mount/heatsink out of aluminum L stock and put a haetsink on the side with a small fan. Seems to work fine, but when is 40 degrees outside anything stays cool. We'll see this summer I guess.

Anyway... Heres a few photos of its final (for now) form.

[BrianG]

Pretty sweet!

You must have been anticipating using some rather large pinion/spur combos judging by the length of the adjustment slots on the motor mount!

[jhautz]

It was actually a mistake part that was left over from my XLB project. :rolleyes: The XLB Runs a 65T spur so It needed a little longer mount. I was able to salvage it and make it work for this application. Your right, Its way longer than I need, but I already had it. I just needed to drill a couple screw holes into it for mounting and I was done. So I took the lazy route rather than starting from scratch again.

[coolhandcountry]

Cool. How was the torque of the out runner to the neu though?

[jhautz]

Originally Posted by coolhandcountry

Cool. How was the torque of the out runner to the neu though?

The torque was fine, but on the bottom end it took so long to spool up it felt like there wanst enough snap. It felt like a nitro where when I punched the throttle from a standstill or slow roll it kinda felt like it bogged down and didnt really take off like I expect from brushless.

I tryed a few different pinion sizes and it didnt seem to make much difference in the end all it did was effect the top speed, not really much difference in the bottom end.

Mid range was just a powerfull feeling as the neu, if not even more. so no issues there. Starscreams clutch system hess using in his 8ight migh be a potential solution. Although, it actually feels like there is a clutch on it.

[Sylvester]

Very nice work jhautz! Looks like it can whip the crap out of a nitro ! Than again almost any bl will do that. ;)

[Mike.L]

yeah it looks nice!

[MetalMan]

Do you think using a different size outrunner might affect the "snap"?

[jhautz]

possibly.... But this is the only size that I found that is 40K rpm capable. All the others are like 10K rpm motors.

[BrianG]

The fact that they made is capable of 40k rpm, yet is actually quite small physically may have something to do with the performance. Kinda like trying to use an S size motor on something large - it will work (and be hot), but will struggle a bit and suck some serious current to do it.

I wonder if using a typical 10k outrunner and gearing appropriately will work much better?

[Sylvester]

It could possibly work better, but, how are you gonna gear and get the voltage to run near that 10K... Somthing maybe leroy should try;)

[BrianG]

It would probably be better for a direct drive type of system. For instance; a typical outrunner KV is 600. Using a 4s pack gets it to 8800 rpm. Use a buggy diff connected directly to the motor shaft. With that 3.3:1 ratio and using typical 5.65" tires, top speed would be about 48mph.

[Sylvester]

Didnt think of that... lol