Sporty setup help - Unstuck Chassis

[dna4engr]

Guys. I'm long time competitive scale and Moa crawler but new to sporty class.

Picked up an unstuck chassis. Using a wraith front axle with dlux sporty mount. And a tko rear housing with a modified hulksta rear link mount. Scx10 trans and od/ud gears.

I have a serious amount of torque twist that I can't get rid of. I've moved the upper links up and down the chassis and on the hulksta rear mount. Even went so far as to do the Mirror swap on the trans. Changed shock positions. No luck whatsoever. No perceivable difference.

I've asked some local experienced guys and everything they've suggested hasn't helped.

Here's pics of the link and shock locations. And some of how much twist it gets just from driving on a high traction surface. It makes crawling from certain approach angles really tough.

Couple other guys running unstuck chassis and not the same problem.

















Any help is appreciated


Sent from my iPhone using Tapatalk

[snapon boy]

Dana. Look at the losi page I did a build for Jr with the unstuck. I would take the skid out and flip it around so your long output is in the rear. I've got a classey cut customs rear link mount you can have it might help. Also the destroy plate is my favorite for the front. Call me if you need more help

149 r/c worx /scalerfab Team Driver

[Nicklepimp]

Have you tried flipping the ring & pinion in the front axle?

x2 on aiming the long output to the rear.

[dna4engr]

Originally Posted by Nicklepimp

Have you tried flipping the ring & pinion in the front axle?

x2 on aiming the long output to the rear.

Thanks guys.


That was my first thought. Do you mean move the pumpkin to the other side? Can't just flip the ring gear on the wraith axle since the rear is scx10.


Sent from my iPhone using Tapatalk

[dna4engr]

Lol. Yea but I never studied or had to design a driveline.

I could always add a swaybar. However I was testing Adams unstuck after the comp yesterday and everything on his was pretty stationary.


Sent from my iPhone using Tapatalk

[snapon boy]

Nerby is the man at setting up your rig. He and Robbob helped me out with Jr's.

149 r/c worx /scalerfab Team Driver

[dna4engr]

Sadly his setup doesn't work on my truck. We do have two completely diff trans.


Sent from my iPhone using Tapatalk

[snapon boy]

My Evo has some torque twist but it's the driver and the 13t 400 pullers fault.

149 r/c worx /scalerfab Team Driver

[WHITE-TRASH]

I have both versions of the unstuck and no torque twist. I run the front uppers at the top at the axle and at the chassis and the rear uppers at the top on the axle and second from the bottom on the chassis end. I'm running a bunch of power and I don't have these issues...

[Robbob]

I would try like White Trash says about the link spots. Your fronts are loosing a lot of weight transfer being low like that on the chassis. Higher up will keep more weight up front on power.

Also if you can, space the front upper links out a bit more at the axle. Itll help keep weight planted on the corners instead of the center of the axle.

I would spin the tranny also like mentioned, that would put your motor forward more helping to keep weight below the CG line of the chassis.

What shock oils you running?

You running over/under drive gears?

[dna4engr]

Originally Posted by Robbob

I would try like White Trash says about the link spots. Your fronts are loosing a lot of weight transfer being low like that on the chassis. Higher up will keep more weight up front on power.

Also if you can, space the front upper links out a bit more at the axle. Itll help keep weight planted on the corners instead of the center of the axle.

I would spin the tranny also like mentioned, that would put your motor forward more helping to keep weight below the CG line of the chassis.

What shock oils you running?

You running over/under drive gears?

Thanks for the feedback whitetrash and robbob.

I'll see what I can do to space out the front links and then I'll move them around on the chassis holes.

The trans/motor plate is in a mirror config now. I'll change it back to standard axial and just put the long output to the rear. With the motor endbell facing forward.

I'm running 30wt f/b i believe (pulled these off another rig). Any suggestions?

Yes it's Od/UD. So it pulls into a squat on grippy surfaces.

Thanks again.


Sent from my iPhone using Tapatalk

[Robbob]

Originally Posted by dna4engr

Thanks for the feedback whitetrash and robbob.

I'll see what I can do to space out the front links and then I'll move them around on the chassis holes.

The trans/motor plate is in a mirror config now. I'll change it back to standard axial and just put the long output to the rear. With the motor endbell facing forward.

I'm running 30wt f/b i believe (pulled these off another rig). Any suggestions?

Yes it's Od/UD. So it pulls into a squat on grippy surfaces.

Thanks again.


Sent from my iPhone using Tapatalk

I would spin the tranny just as it is, mirrored would put it on the right forward corner better. Thats just me though.

[Stuck]

What length shocks are you running? its sitting pretty high.

[dna4engr]

Originally Posted by Stuck

What length shocks are you running? its sitting pretty high.

They're cap modded big bores. The shortest ones. Still around 4" with the cap mod.

About the same length as the kyosho velvets adam nerby runs on his unstuck.


Sent from my iPhone using Tapatalk

[Stuck]

Originally Posted by dna4engr

They're cap modded big bores. The shortest ones. Still around 4" with the cap mod.

About the same length as the kyosho velvets adam nerby runs on his unstuck.


Sent from my iPhone using Tapatalk

Hmmm Chassis was designed around a 3.5" shock. Your front links should be almost level.

[WHITE-TRASH]

3.75 and 4" big bores both work well with the unstuck. I have the 3.75" in normal cap mod mode and the 4" have the rod end sideways at the chassis so they aren't so long.

4" on the V1



3.75" on the V2

[dna4engr]

Thanks for all the help guys. I have some good results and some issues.

I turned the skid. Which meant I had to swap the frame sides too. And then swap the pumpkin on the front to get the driveshaft inline. Moved the links like whitetrash and robbob suggested. After all that it has very little torque twist going forward.





I haven't really tested it hard though. Mostly because now the transmission/motor doesn't fit.

With the skid in this orientation. It puts the trans mounting holes further to the front. And since my motor is a standard 540 size. It hits the frame rail. Approx 1/4" or more from the mounting holes.



I put the trans in and mounted one screw to the wrong hole to test the torque twist. Like I said it's good so I don't want to change the setup. The motor is now where robbob suggested it be. The long output is facing rearward.

With the motor clear of the chassis. I can get the one screw in but nothing else.



So now the question. Do I drill 3 more holes and add spacers where they don't have a mounting pad? Or do I leave the trans as it is and swap the motor plate and motor to be rear facing?



Sent from my iPhone using Tapatalk

[Robbob]

doh .... my fault, I didnt even notice the full 540 can. I just think stubby motors all the time.

If you un-mirror the tranny it would drop back in with out having to swap the chassis sides around. Then down the road if you got a puller or Brood stubby motor it would be a benefit and easier swap.

[WHITE-TRASH]

I'd just notch the chassis.

[Robbob]

Originally Posted by WHITE-TRASH

I'd just notch the chassis.

Thats a big notch, almost half the width of the transmission