Another Joker....with a Twist...

[Colgout]

Ok I jumped to the bandwagon too and am building a Joker based sportsman. But mine will have a twist, I am not using AX10 axle but AR60 (full length). I always thought AR60 is too wide for spm but after seeing what Dlux can do with it, I wanted to try something different. I think AR60 has a lot of benefit compared to ax10 axle.

* It come with excellent wraith uni joint axle;
* It is strong without using beef tube (but i might have one later on);
* Offset pumpkin allow many interesting electronics placements;
* The diff cover offer easy maintenance of diff gear;
* Diff gear is reversible so does not matter which way the weight is placed, you can reverse the diff gear to counter act torque twist;

I am hoping I can have it running by the middle of the year.... I am a slow builder now....

Some Spec...

Chassis
Hulksta Joker chassis;
Stock XR10 gear;

Front Axle
Dlux knuckle with tungsten putty and brass slugs to tune weight;
Dlux upper link and servo mount;
Dlux machine wraith axle;
Over gear with Gripfab spool;
Topcad Chub;

Rear Axle
Dlux upper link mount;
Egressor One-piece Ti axle with 7075 locker;
Under gear;

Shock
TBD - either Truckstar shock or SCX10 shock;

Drive Shaft
Maxx with reinforcement;

Links
Home brewed 7075 Lower and steering links and 6061 tube for upper;

Wheel and Tyre
narrowed voodoo Silver with Hulksta CF wheel, narrowed panther with SLW wheel, Rover with buggy wheel;

Electrics
Truckstar Servo (30.6 kg at 7.4 V, will try running at 8V )
HH Br-Mini
HH LW 30T with checkpoint endbell
BEC and Futaba Rx

[Colgout]

have the front knuckle done, because it is the vital part to make full width AR60 axle to work, so I do this first. The dlux knuckle fit and finish is good, but I need to file slightly on my chub to make it smooth. With the kingpin ball bearing, you would expect it to be super smooth and it is. The larger bearings used in the knuckle (1mm larger than stock) contributed to the tightness of the assembly, even with the sloppy wraith uni joint, is it semi decent now. :dance:

I am excited to get this done as there are many weight options, I have 4 holes on the knuckle which can be filled with either brass lugs or tungsten putty. Or I can add ring onto it using the 2 hole on the outside of the knuckle (but this will add wheel offset and hence width to the rig). At the back of the knuckle, I can easily add some brass plate AND an adjustable steering stop to prevent steering over-centered, it happened to me a few times during the NATS especially in course 2 of SPM.... So hopefully this is the solution.

Some pictures.....







Thats it for the time being.... Now need to figure out how to assemble Dlux's truss....

[Colgout]

Front diff almost done. I am happy that the full width AR60 can be made to same width as the AXR10 diff. At it is with 350 hub and CF wheel with 18mm standoff, the outside of the rim is about 10.2", it even narrower than my current AXR10 spm front diff running wraith knuckle, KW and 800 hub.

I think I will run larger hub 475 or even 600 to bring the width same as my AXR10, I don't really like the axle thread is exposed for rock abuse.

[MRCrackhead]

Originally Posted by Colgout

Diff gear is reversible so does not matter which way the weight is placed, you can reverse the diff gear to counter act torque twist.

Could you explain this to me. I've pondered it for a couple days, since I read this, and I can't figure it out.

On my rig, the front driveshaft turns clockwise to propel the car forward.

Therefore, the ring gear is on the driver's side of the pinion.

The pinion is "pushing up" on the ring gear to spin it forward.

If I flip the axle, the ring gear would still be on the driver's side and "pushing up" to create forward motion.

How does flipping the axle change torque twist?

If the tubes were removable, you'd just swap them around, but the diff remains in the same orientation.

What am I missing?

It's giving me a headache.....lol.

[Colgout]

I though I read it somewhere, but i will try to explain it based on my understanding.

Say your existing drive shaft rotation causing you to lift the RH wheel (look from the back), your ring gear should at on the RHS of the pinion. Your motor or other components are at the LH side which does not help the torque twist. Then if you reverse the motor rotation (rotating the end cap 180 deg) and so now the drive shaft rotate at the opposite direction, but you need to the flip the ring gear (to the LHS of the pinion) so it still give you forward wheel rotation. Now in theory, you drive shaft will try to lift the LH wheel but hopefully with your motor and components located at LH it will minimise or reduced the TT.

Basically for AR60 axle you can change the drive shaft rotation and still give you froward movement, this can't be done for the original AX10 axle.

Am I making sense? or talking cock? I thought I saw something similar to either totarax or Dlux spm built for inspiration.,

[MRCrackhead]

Originally Posted by Colgout

I though I read it somewhere, but i will try to explain it based on my understanding.

Say your existing drive shaft rotation causing you to lift the RH wheel (look from the back), your ring gear should at on the RHS of the pinion. Your motor or other components are at the LH side which does not help the torque twist. Then if you reverse the motor rotation (rotating the end cap 180 deg) and so now the drive shaft rotate at the opposite direction, but you need to the flip the ring gear (to the LHS of the pinion) so it still give you forward wheel rotation. Now in theory, you drive shaft will try to lift the LH wheel but hopefully with your motor and components located at LH it will minimise or reduced the TT.

Basically for AR60 axle you can change the drive shaft rotation and still give you froward movement, this can't be done for the original AX10 axle.

Am I making sense? or talking cock? I thought I saw something similar to either totarax or Dlux spm built for inspiration.,

I think I get it.

Torque twist is not reduced, or eliminated, just swapped to the heavier side of the rig to help control the tire picking.

I thought it somehow became reduced by swapping rotation, but that didn't make sense.

Reverse rotation would just reverse torque twist.....makes sense now.

Unless there's more to it regarding the transmission being reversed (motor pointed forward in the chassis, or towards the rear), coupled with changing rotation.

Still a bit unclear, but I believe I have my axle oriented correctly for my current setup.

Thanks

[stankulas]

Originally Posted by MRCrackhead

Could you explain this to me. I've pondered it for a couple days, since I read this, and I can't figure it out.

On my rig, the front driveshaft turns clockwise to propel the car forward.

Therefore, the ring gear is on the driver's side of the pinion.

The pinion is "pushing up" on the ring gear to spin it forward.

If I flip the axle, the ring gear would still be on the driver's side and "pushing up" to create forward motion.

How does flipping the axle change torque twist?

If the tubes were removable, you'd just swap them around, but the diff remains in the same orientation.

What am I missing?

It's giving me a headache.....lol.

I'll try to give you a simple one i have run it in both directions and with the motor on the right side it tilts the chassis clockwise and blipping the throttle will lift the front end or take pressure off it creating more steering or tighter radius. motor on left side rolls chassis counter clockwise pushing it down creating down force or pressure on tires giving a little more traction. but can be bad in loose rocks by boring it self in a hole and it looses some steering. great on low bit rocks. running both ways i could not say which is better as i like both

[MRCrackhead]

Originally Posted by stankulas

I'll try to give you a simple one i have run it in both directions and with the motor on the right side it tilts the chassis clockwise and blipping the throttle will lift the front end or take pressure off it creating more steering or tighter radius. motor on left side rolls chassis counter clockwise pushing it down creating down force or pressure on tires giving a little more traction. but can be bad in loose rocks by boring it self in a hole and it looses some steering. great on low bit rocks. running both ways i could not say which is better as i like both

Haha!

Well that's no help at all, then.....lol

Thanks for the first hand account.

Very interesting.

[Colgout]

Some little update.....

The chassis is almost done....





I will replace the delrin cross brace with alloy one and also bend the bottom skid. Now move on to the rear axle....

[waggaclint]

Hows the rig coming along Dave, did you get around to finishing yet?