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View Full Version : AWD 2.4 GHz, what breaks, wears out?


lornecherry
2010.12.29, 06:02 AM
Most of our event/party fleet will be new MR -03s. However I recently discovered that we have three AWD cars and although they seem a touch more complex, we'd like to make them part of our fleet.

First, let me say that these will be throttled-limited to about 50-70% and the bodies are completely protected by a bumper system that absorbs almost any shock. It also prevents the front wheels from getting hit at all (think of those go-kart bumpers that wrap the entire kart and you get the idea.) In short, we've gone to a lot of trouble to keep the cars/chassis/bodies from being damaged, even when driven into the side of another car or the track rails (which also deflect the car and absorb shock)

So, my question is: What breaks or wears out on these things? (there's no H-plate thankfully). After about 1,000 laps on the test track, the only potential problems I can foresee is with the part of the differential that receives the dogbone may eventually give out.

If you've driven these cars extensively, let me know what wears out, or what needs replacing. From what I've seen so far, the cars handle very well and I have no need to do anything other than bearings? (the stock differentials seem fine on our track ...these cars go where they are pointed). - Lorne

Tjay
2010.12.29, 08:49 AM
What normally breaks on the car:
-dog bone or swing shaft
-knuckles
-toe bar

What wears out the most (1500+ laps):
-Gears: front/rear center shaft spur & diff gears (inside and outside)
-motor brush (just replace the motor with eco motor if kyosho still sells that. If not, go with PN80 turn)

If you have a wrap-around bumper protecting the wheels, chassis and running 50-70% of its stock speed, then I dont think you or the driver will break anything. Also if you put the car together to where it's smooth enough and has no binding or grinding noise, you may even exceed the 1500 laps mark. I know when we did an oval race for one hour with my modified awd, I wasn't able to break anything and the only thing I had to replace was my worn down tires. This was with stock plastic knuckles and stock plastic swing shaft and probably did 600+ laps with it.

ChiMiniRc
2010.12.29, 08:52 AM
In short, we've gone to a lot of trouble to keep the cars/chassis/bodies from being damaged, even when driven into the side of another car or the track rails (which also deflect the car and absorb shock)


If you can, please share pictures of your bumber design. I promote our mini-z club and local hobby shops by doing events that draw large amounts of kids. Something like this would help alot :)

lornecherry
2010.12.30, 12:09 AM
...thanks Tjay, it appears from what you say, that the AWD cars are reasonably robust and no more prone to wear and tear than the other Mini-Zs.
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ChiMiniRc, our BPS (bumper protection system) consists of three parts: 1) an ABS flexible plastic bumper that is "spring loaded" to absorb shock; 2) a Velcro under-body wrap that holds the body tight to the chassis and prevents broken body clips; 3) a specialized 3M clear coating (used by sign makers to protect graphics on hockey boards) this coating is placed on the bumpers to prevent paint transfer and make the bumpers wipe-clean. (Hard to see it the photos). We use the same coating on the track rails to keep them looking new, as Mini-Zs love to shed their paint.
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Much of this has been developed through trial and error in our school programs that I ran way back in 04-05.
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You have to use the correct type of Velcro, thickness of plastic and 3M Urethane coating to make it all work well.

Adhering the Velcro to the body (so that it stays put and does not peel off) is also a bit of an art; after trying many adhesives, we settled on the new rubber-additive CA (regular CA is too brittle and very few glues work well on the glass-coat outside body). You must also dab on CA accelerator to the body, being careful not to get it on areas not covered by Velcro, as it dissolves/softens the body paint.
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The body system is rather ugly; we added vinyl numbering to the sides to make it more appealing and try to match the color of the bumper to the car.
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For beginners, the BPS also deflects the cars straight off the rails in a predictable trajectory; no more stuck cars on the rails or damage from wheel caught against the rail. With no "corners" on the bumper or front end, cars tend to get hung-up on the track or other cars a lot less, and are also prone to less flipping.
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In our experience, most Mini-Z damage is from body-to-body collisions with other cars, or from being hit on the front wheels when the steering servo is on. This system completely prevents that. If you can get around the "go-kart" look it would also work well for racers (especially the Velcro under-wrap that prevents the body from coming off its clips when hit hard.) - Lorne

http://img89.imageshack.us/img89/8226/bps007.jpg (http://img89.imageshack.us/i/bps007.jpg/) Uploaded with ImageShack.us (http://imageshack.us)

http://img194.imageshack.us/img194/1310/bps006.jpg (http://img194.imageshack.us/i/bps006.jpg/) Uploaded with ImageShack.us (http://imageshack.us)

http://img602.imageshack.us/img602/8854/bps003.jpg (http://img602.imageshack.us/i/bps003.jpg/)

http://img602.imageshack.us/img602/8854/bps003.jpg (http://img602.imageshack.us/i/bps003.jpg/) Uploaded with ImageShack.us (http://imageshack.us)

http://img502.imageshack.us/img502/5241/bps001g.jpg (http://img502.imageshack.us/i/bps001g.jpg/) Uploaded with ImageShack.us (http://imageshack.us)

wildthing
2010.12.30, 09:15 AM
got more photos of your rentals... I really appreciate it and picked-up a few tricks of trade that I can implement on my rentals too.

I specially like the bumper that will surely protect the front clip and body and the velcro "body clip"... because right now, we only use duct tape to strap the body to the chassis... after breaking the "ears" that holds the body clip. These "upgrades" are really best for rentals.

Now I just have to look for the 3M clear coat that you use.... :)