rock racer build need help

[Detour]

I have a hot racing rock racer chassis and the ax-10 battery tray does not fit and will not fit anywhere where are some places to find a tray.

Also where is the best shock angle for 90 degree plus with other axle flat
straight rear axle.

[dentonmac]

Originally Posted by Detour

I have a hot racing rock racer chassis and the ax-10 battery tray does not fit and will not fit anywhere where are some places to find a tray.

Also where is the best shock angle for 90 degree plus with other axle flat
straight rear axle.

Yeah, you don't want to use the battery tray in the stock location. It puts too much weight sprung (on the chassis) and high up (raises center of gravity). Look for an axle servo battery mount. To put as much of electronics weight low on the front.

Shock angle - If you are referring to 90 deg of articulation, there is no reason to ever need that much. It will just take away from performance. I run just a little more than tire height before the opposite axle starts to lift.

I see you are from Knoxville (Tenn I assume). I am as well, I'd be happy to meet up and talk it over and of course crawl some.

[Detour]

all right but I have no idea what battery to use I have a bta steering kit also. and I actually live in Louisville right next to the pellissippi and Alcoa highway I have multiple courses in my dads yard that sits on a hill\ mountain

[Detour]

this is what I have so far had to go to work so done till Saturday

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[MRCrackhead]

Not many people running this chassis, so you're not getting much help here.

Despite that, you're making some good progress.

Not sure if the chassis will allow, but a lot of guys prefer to run the transmission turned around 180 degrees.

It seems to help counteract torque-twist produced by a shaft driven vehicle.

Also, not sure if that behind the axle setup you have could be flipped so everything is on the passenger side of the axle. Opposite of what you have.

That will also help climbing performance since the right front tire is the first to pick off the ground due to torque twist.

Getting that heavy servo on the passenger side will help keep that tire down when things get steep....

[Detour]

Thanks and I can probably flip the transmission I just have to fab it up and why would should I put my servo on the other side I am going to run my Lipo there whenever I decide to get one because I have no idea about them.


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[chevotafun]

Maybe try getting a front diff plate that would allow you to run your servo and battery on the front diff

you would need to run a smaller battery tho

[Detour]

The plate now runs the whole axle so I can probably just drill holes if I need

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[MRCrackhead]

Originally Posted by Detour

Thanks and I can probably flip the transmission I just have to fab it up and why would should I put my servo on the other side I am going to run my Lipo there whenever I decide to get one because I have no idea about them.


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It's not mandatory to put the servo there. Just a suggestion.

When you pick a battery you can see how much it weighs.

My servo is 74 grams.

Battery is only 45 grams.

[Detour]

okay I just did my first run and I found a few problems one is that my body torques to much with the top going to the left and yes I see where my right front picks up. I don't want to switch the servo so what else can I do. to be honest I don't know what yall meant when you said turn the transmission.

[MRCrackhead]

Originally Posted by Detour

okay I just did my first run and I found a few problems one is that my body torques to much with the top going to the left and yes I see where my right front picks up. I don't want to switch the servo so what else can I do. to be honest I don't know what yall meant when you said turn the transmission.

If you look at nearly every other build on this site you'll see what I mean.

Turn the transmission around. Back to front, front to back.

Your motor will be on the other side of the car, spur gear towards the front.

My guess is the skid plate is symmetrical, except for the holes drilled through it to bolt the transmission down.

Turn the whole skid plate around and you'll have the motor on the passenger side of the vehicle.

Some more pictures would help a lot...

[Detour]

Okay but doesn't that make it go backwards

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[Detour]

I am so new to modifying my crawler I really just used the old setup from the original chassis

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[MRCrackhead]

Originally Posted by Detour

Okay but doesn't that make it go backwards

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Yes it will.

You can just reverse the motor wires and reverse the direction.

If the wires are soldered directly to the esc, you'd have to de-solder them and swap the pos and neg, either on the esc, or the motor poles to do it.

Hopefully you have some sort of bullet style connectors between the motor and esc, then it's simple. Just unplug, and swap them.

If you can get some pictures of the chassis from the top down and looking from the side with the tires, and without, it would help.

Guys on this board are very quick to point out the obvious and save you a lot of trial and error.

It will help get you a good "starting point" setup almost right away.

Dialing it in will be up to you, tweaking things and experimenting.

The picture you did post is sideways with the crawler resting on the skid plate.

It's very hard to tell what your suspension looks like that way (beyond being sideways...lol).

It needs to be sitting on the tires, or on the axles.

That way we'll be looking at it "at ride height".

[Detour]

I really don't have one I thought I did put I just got It my rig built tonight I had some esc issues earlier and just got a picture on the stand I can get one up tomorrow and on the transmission turn I can do that with no problem at all chassis skid comes out then just spins and goes right back up

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[Detour]

This is just with wheels

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[Detour]

here is those pictures

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[Silvertip]

your bottom control arms will work better if you move them out some! less axle steer, and better articulation.

[Detour]

Originally Posted by Silvertip

your bottom control arms will work better if you move them out some! less axle steer, and better articulation.

Okay I will try that never thought about that but it makes sense. Thank you


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[MRCrackhead]

Also, move your rear upper links to the top of the link plate instead of underneath.

It's not a hard fast rule, but trying to get your upper links as close to level with the ground is a very good starting point. Then tune from there.

Looks like your rear uppers could be moved back in the chassis a bit to get your pinion up higher.

Tuck the rear pinion up so it's even with the bottom of the rear links for better clearance when sliding over obstacles. The driveshaft spinning on rocks can push you off your line, or destroy the shaft.



Total quick rebuild suggestion:

With the tires on, take the shocks, front upper links, and rear upper links loose from the chassis.

Block the front of the skid plate up @ 70mm.

Shim the rear of the skid @ 75mm.

Point the rear pinion up some, and the front pinion close to level.

Now attach the upper links level with the ground.

This will give your skid a "rake" that helps forward progress.

Now re-attach the shocks at about the angle you have them.

Take out the shims and see if the shocks need a bit more adjusting to hold the measurements @ the skid.

Not hard fast rules, again; but a very quick and easy starting point similar to a whole bunch of rigs on this forum.

Drive it and see what you think.