Make your own torsion chassis...

[Demodude]

I got this idea after buying the DP Torsion chassis and since it had the stock chassis lying around I decided to give it a go
I'm not sure how fast I'll be able to work on this but, here goes the progress so far:
I'm using .036 dental wire which may be a little soft. I may go to .040.
I figure with this design you can adjust your ride height just by bending the wire.
It would probably be wise to not use the stock holes in the chassis and eliminate the second helix. The new holes would go where the extra helix is.

[Sh0rtBus]

Interesting concept you have there. And of course thicker wire would make for a stiffer suspension. Curious to see how it performs.

[Demodude]

I figure it's going to be something cheap that performs as good or better that the store bought one or a colossal fail...lol

[Sh0rtBus]

Originally Posted by Demodude

I figure it's going to be something cheap that performs as good or better that the store bought one or a colossal fail...lol

Hey....cheap investment, right? Not like it really cost you much to produce.....depending on how much you value your time.

[Demodude]

So, I'm happy to report that the home made torsion chassis works! I ran the truck for about 15 min on my inside course. It's the same if not a touch better that the DP chassis. The DP was really stiff to to point of having to sand the torsion arms. I'll say that I have a touch more articulation and some nice sag when the truck is placed on the ground giving it a tiny bit of droop.
You can see a tiny bend in the middle of the two brass balls (lol), that is where the height adjustment came in. It was too drooped before the upward bend.
I think .040 would be too stiff.

[elsewhere]

I did the same thing before I ended up using bicycle brake cable..
Looks good tho!

[Sh0rtBus]

Nice find! Has this subject been sticked before? If not, it should be. Should be in the mod list for micros.

May have to try this with the McRC I have at home. Currently on an unidentified custom chassis and I was going to throw in a set of HR shocks, but I may try this first. Where do you get the wire from?

[Demodude]

The wire I get from my lab (I own a orthodontic lab). I comes in 14" lengths. I think its $4-5 for 10 lengths of wire. It's designed to have a bit of spring to it. You may need to experiment with wire from a store as you have to be a Lab to order this stuff. You need 2 wires, one for each side.

Keep in mind I bend wire for a living, I have the proper tools. It may be a bit hard to form the wire if you don't have a heavy duty "birdbeak plier".

This was the first design that came to me but, I think it could be done in many different ways. For instance you could drill a hole laterally through the brass ball and run the wire through the ball.

I might add that you can limit the articulation by tightening the screws at the front and back.

On some of the articulation pics to follow the rear wheel is off the ground-

[elsewhere]

Looks good regardless. Sometimes scale follows performance in this hobby..

[Demodude]

Originally Posted by elsewhere

I did the same thing before I ended up using bicycle brake cable..
Looks good tho!

I saw your thread with the tuber chassis and that was pure awesome, great job.
I'm do my own bike mechanics (mountain biking). Brake cable is a very soft braided cable, are you sure your not talking about a bike spoke?

[elsewhere]

thanks!
nope its the brake cable itself..
its twisted steel strands are just springy enough flex and just strong enough to support the weight.
i did the same thing at both ends as u did in the middle by tweeking it at the collars i could
adjust the sag/ preload.

i like your idea about drilling though the ball studs, it was my original idea to have two ball studs on the chassis
and run grub screws into the allen holes to lock it in place with piano wire but it was too stiff..
i couldnt find anything like u have at your disposal.

ill be watching how yours evolves for sure!

[Demodude]

I'm going to have to give the DP torsion chassis another shot. After playing with my mod I learned a few things. I thought there was generally two settings for the arms with the screws: tightened all the way down, and loosened up a touch. Well I was wrong. I didn't know you can loosen the screws a lot for much more articulation. The reason for this is: as one wheel lifts up the arm will resist in an upward motion but also in a twisting motion. By having bigger gap between the servo mount and the screw head it allows more uninhibited articulation. I hope that made sense.
When I get a chance I'll swap the chassis back to the DP just to see if I sold it short! It would help if they had some instructions, lol.
This is not to say my mod isn't kick-ass, curiosity is telling me to try, try again. I'll post findings soon

[elsewhere]

Bring a few cups of water to a boil on the stove.
Drop in the chassis halves for 5 minutes or so.
They will be nice and soft after that.

[89redranger]

I've been using the DP chassis for around 2 months now. I think you sold it short, but I really like your work at the same time.

The thing with torsion chassis is that they love wheel (non-suspended) weight. Keeping the chassis as light as possible, and the axles as heavy as possible seems to be the magic combo. With my rig, I have BWD solid weights double stacked on each front wheel, the small-hole weights double stacked on the rears, a single large hole ring on the inside at all four corners, 30 BBs in the front wheels, 15 BBs in the rears, and the battery on the rear axle tray. The only thing in the chassis other than the trans/motor is the RX/ESC, which is now decased and sitting behind the front bumper over the axle.

In total, I believe I've added around 3-4 ounces in non-suspended weight, while eliminating 1-2 ounces of suspended weight.

I too am playing with my own torsion design, but I haven't given up on the DP chassis.

BTW- I've been using music wire for my attempts. The LHS carries it in MANY sizes and it is spring steel.

[Demodude]

Ok fellow trail trail trekkers,,,, the verdict is in and I believe it's a tie.....


I never started this project to diminish the ability of the DP chassis. I just wanted a bit more suspension movement. I'll admit ignorance on my part in not understanding exactly how the torsion chassis worked. But that's the fun isn't it, learning or trying something new, and going on.

Keep in mind that I previously sanded the torsion bars on the DP chassis to obtain a bit of flex. Also there is no weights in the tires.

I swapped the chassis back to the DP and ran the torsion screws all the way out (almost) to allow the axles to move more freely. I like the way the chassis handles and in some ways better than my home made torsion bars.

Things I noticed:
Less bouncy of a ride with the DP chassis
HM chassis can run more "sag" or "Droop" and ride height can be adjusted
Home made chassis can "list" to one side if not very accurate with your bends.

Besides those things they handle about the same with a nod towards the DP chassis. I like how both are a lower stance

I will be getting the Miclaw tires soon with weights and am interested in what adjustments I'll need to make. I'm going to try this setup for a while but I have some crazy other Ideas rolling around my head...he he he

pic one- how I used to run the screws
pic two- how I tested it today
Pic 3,4,5,6 Flex shots