Building a TXT Rock Climber and running into problems

[Rckcrwlr]

I have been into nitro trucks for years. Finally decided to tackle a rock climber. I purchased a TXT-1. I have lengthened the wheelbase to 17". Sitting it is 4.5" to the bottom of the chassis and 9" to the top of the chassis. I have moved the batteries to the front and added Wild Monster 19 turn motors with 9T pinions. I have Savage shocks mounted on the inside of the chassis on the cantalevers (only for a mounting point) and the bottom of the shocks are mounted to the links with rc4wd mounts. I have moved the links to the top of the axles on the inside. I just put on the Proline Narrowed wheels and tires. I ordered the new rc4wd wideners to get a wider stance due to the fact that my shocks were hitting the tires and I cannot get a tight turn with them.

Here is my question.

Is is very wobbly when I accelerate. Forward makes the chassis fall to the right and reverse makes it fall to the left. Is this a shock or spring issue or do I have to move my links out for a firmer stance.


I will be posting pictures as soon as my daughter gets off the computer.

Any suggestions would be greatly appreciated.


Also, in testing the truck for the first time I snapped a drive shaft where it fits into the cup. Is this a weak point and if so are there options? I will be calling Tamiya for a warranty replacement. Thank god it is winter...

Thanks

[Kev808]

Welcome... As far as your chassis going left or right its due to torque twist(common in shafties) remedies for would be running stiffer springs and heavier weight shock oil.
Try searching also to what some of the people here does to eliminate torque twist

[Rckcrwlr]

Thanks for the reply. I have 60W oil in the shocks. Do you think I need to go thicker or just go to, say black springs?


Here are some pics...

[Rckcrwlr]

And more... Any suggestions would be appreciated.

[EeePee]

Definately a stiffer spring. I did the right rear, and left front. I also went with 80 weight in those two, then 40 weight in the softer two.

[Rckcrwlr]

What do you think of the layout that I am using? Anything there that could be better?


Thanks for all your suggestions.

[Kev808]

Probably remount the shocks to your axles instead of the links.
mount them where your lower links are at, like at the farthest hole away.
Just so you can get your shocks to be more at an angle.
Get rid of your front and rear bumpers and either fab yourself a servo mount plate or you can buy some plates from some of the guys on here.
Bender makes some awesome servo plates.

[EeePee]

Originally Posted by RockCrusher90

Anything there that could be better?

I think your next step will involve removing chassis material.

I have a stickied thread in this Forum showing a basic version of a cut up chassis that makes these trucks work pretty good. Check that out for some suggestions maybe.

I think you should rework some stuff to get those lower links on the outside of the bumper mounts. For more link triangulation, better geometry.

[Rckcrwlr]

I don't think I am ready to cut the chassis. I read your thread a while ago...I don't want to change the integrity of the chassis yet. Will I then need to move the shocks to the outside of the chassis if I move the lower links out?


I appreciate all the input...

[EeePee]

Originally Posted by RockCrusher90

Will I then need to move the shocks to the outside of the chassis if I move the lower links out?

I think so. It looks like they might have some clearance issues. I see the metal bumper thing doesn't have the longer standoff like the plastic stock pieces do. Here's what I did:

http://www.rccrawler.com/forum/attac...tid=6641&stc=1

[Rckcrwlr]

Originally Posted by EeePee

I think so. It looks like they might have some clearance issues. I see the metal bumper thing doesn't have the longer standoff like the plastic stock pieces do. Here's what I did:

http://www.rccrawler.com/forum/attac...tid=6641&stc=1

I see...I should be able to fab something to create that stand off. My problem before was that the tires would have it them. I ordered rc4wd wheel wideners for the 23mm, so that should not be an issue.

I am really enjoying this...I wonder what my wife will say when the truckload of rocks gets dumped in my back yard.

[ExtremeOffRoad]

I would lower the ride heigth. you want your upper and lower links to be pretty much level when the truck is siting still. I would also try to get the shock as verticle as possible. The closer to verticle that the shocks are the more they are gonna fight the torqe twist. if you want pics of mine send me an pm with your email and ill send you some pics. i am running the cut style chassis with savage shocks.

[Rckcrwlr]

Originally Posted by ExtremeOffRoad

I would lower the ride heigth. you want your upper and lower links to be pretty much level when the truck is siting still. I would also try to get the shock as verticle as possible. The closer to verticle that the shocks are the more they are gonna fight the torqe twist. if you want pics of mine send me an pm with your email and ill send you some pics. i am running the cut style chassis with savage shocks.

Well thanks to Bender...here she is. The Shock mounts did the trick.

I have a couple questions now.

Check out the pics. Any suggestions based on what you see?

Should I run a separate receiver battery or just run it off the 7.2's?

I installed two motors but as I read more, I guess I should have gone with one and a GD600?

Any suggestions on where to place my batteries?

Thanks for all your help.

[Rckcrwlr]

Well guys...I started the post in January and now I am finally done with this crawler. It has gone through several versions but now I believe she is done. Special thanks to Bender and RC4WD for their patience and expertise on not only parts but technical questions. Anyone that does not realize the value of the forum is not coherent. I have learned more in the past several months about RC Crawling than I did in 5 years of nitro RCing. Here are some pics of the completed TXT.

Next is a TLT 12.5 WB SW2...Should be quicker on this one.

Thanks to all the RCC guys.

[RetroCow]

Looks good
but IMO I would try to get that battery as low and forward as you can, and cut the bottom of the chassis- the extra clearance is worth it.

[LIKES2CRAWL]

stock chasis are going for $10 and up on E-bay get one and cut it if you don't like it then you can keep yours the way it is.

[RetroCow]

And if you like it you will have an extra chassis to start another project!

[RetroCow]

Originally Posted by RockCrusher90

I am really enjoying this...I wonder what my wife will say when the truckload of rocks gets dumped in my back yard.

No worse than when I had a load of rock delivered...to my apartment

[Rckcrwlr]

Thanks.

I am definitely cutting the bottom this winter. The battery thing is the tough one. I tried to mount it on the upper links with velcro but it would move. Any suggestions on how to hold it?

[RetroCow]

Iv'e found that most people build their own packs and mount them to the front axle or inside the front wheels