Cantilever Suspension

[Natedog]

I concur with Crawlinwithacat, great advice! Cantilevers are more sensitive to small changes too.

[Brake Weight]

Originally Posted by Natedog

I concur with Crawlinwithacat, great advice! Cantilevers are more sensitive to small changes too.

Yep. The ratio of the cantilever is how much sensitive it is. Be it 2:1, 2.5:1, or whatever.

[OGTrout]

Thanks everyone.

More options for tuning and adjustment was about what I thought. Hopefully I can get a chance to switch them over and do some testing over xmas, then I'll report back

[Brake Weight]

Look for touring and drift car shocks/springs to tune with.

[crawlinwithacat]

Originally Posted by Brake Weight

Look for touring and drift car shocks/springs to tune with.

Agreed.

[Bray D]

I figured I'd bump this thread rather than making a new one. I'm in the planning stages of a 1.9 build and I think a canitlever rear suspension would work awesome for my application, which is a fairly lightweight scaler build. Likely around 5lbs once complete.



60-70mm shocks would likely be best. That has me looking at the Losi Mini T shocks and the Revo stuff.



I don't know much about either shock but I do know that spring kits exist for the Mini T so there would be a decent chance of getting the spring rate dialed in. Rocker geometry and preload are also variables I have to work with, I just want to make sure I don't miss the mark off the bat.



What's the go-to canti shock? Will the Losi's be too soft?

[soze]

Originally Posted by Bray D

I figured I'd bump this thread rather than making a new one. I'm in the planning stages of a 1.9 build and I think a canitlever rear suspension would work awesome for my application, which is a fairly lightweight scaler build. Likely around 5lbs once complete.



60-70mm shocks would likely be best. That has me looking at the Losi Mini T shocks and the Revo stuff.



I don't know much about either shock but I do know that spring kits exist for the Mini T so there would be a decent chance of getting the spring rate dialed in. Rocker geometry and preload are also variables I have to work with, I just want to make sure I don't miss the mark off the bat.



What's the go-to canti shock? Will the Losi's be too soft?

Kind of off-topic, but @Bray D... I've always been curious how you get models of the chassis, tires, etc. into CAD to work with? I can't imagine that people are drawing everything up from scratch to mimic existing parts. I'm sure there's something people use to analyze an existing object to create a mesh body to import?

[Bray D]

Originally Posted by soze

Kind of off-topic, but @Bray D... I've always been curious how you get models of the chassis, tires, etc. into CAD to work with? I can't imagine that people are drawing everything up from scratch to mimic existing parts. I'm sure there's something people use to analyze an existing object to create a mesh body to import?

There are a few file sharing sites online where people upload models. Some are classic reverse engineering work and I'm sure some are scanned mesh files. Accurate scanning equipment is extremely costly though, so most of this stuff is probably made sitting at a desk with said part and a pair of calipers, measuring and modeling as you go. It's fun. I've made my own wheels and stuff for my SCX24.

I pulled the servos, tires/wheels, axles, and trans from grabcad.com. Can't remember where I got my body model from, but I've had it for years and used it for building my 1:1. I stripped it down and scaled it for this 1.9 build.

Frame rails (measured and modeled from existing parts), crossmembers, brackets, and links are all me.

[TexasSP]

ProLine makes some shorter shocks too. I have them on one of my builds (not cantilever) and they are very nice. They can be built 70 or 75 mm.

https://www.amainhobbies.com/proline...axqsyqyzqxactz

[Stollenritter]

Hi Bray-D,
nice work on the 3d-modelling. I have used Vaterra canti-shocks from a Twinhammer. The HR / Dinky-RC seems a bit small for a SCX-10 based truck (in my opinion). I plan on using the Dinky-RC cantis on a Losi MRC based build.
Keep the canti-ratio in mind: a ratio 2:1 will require a 2x higher spring rate and damping ability as well as 1/2 of the desired travel. So using standard shocks in a canti setup will require more tuning.
Keep the good work going!

[Bray D]

Thanks for the replies guys. I thought I’d try to use what I have so I started modeling around the 100mm shocks.

A frame extension off the back frees up the real estate, and I was able to stuff a 1:1 rocker in there so spring rate should be pretty similar to a traditional vertical shock setup.

I tied it all together with a massive crossmember to stiffen it up. Luckily all of this fits under my body too.

I’m currently 3D printing for a real world mock up. Full stuff > ride height > full droop

[Bray D]

I thought through how I wanted to do the physical pivot and landed on a fixed pin that the rocker rotates on. I had some 1/4” round stock handy that I had already machined into long 3mm spacers. Perfect for a pivot pin.

That forced me to make my rocker pivot pretty big, but it feels robust. The 100mm shocks I had ‘on hand’ are actually coming in the AR45 axle kit and they’re not here yet. Here it is mocked up with an old Stampede shock body. It’s pretty close.

Looks like I may have some issues at full droop due to the large rocker pivot. That interference will be worse once I have springs installed. Back to the drawing board (or internally limit the shocks, haha).

[Bray D]

Modified rocker seems to work fairly well, but I’m still struggling to get full travel out of the shock. Things are a bit ‘hitchy’ at full droop and the angles get crazy at full compression. I think a massive rocker would solve these issues, but I don’t want to give up the space yet.

Either way, I have a functional prototype using existing parts right now so that’s a win.

[Bray D]

Last post then I’ll stop hijacking this thread. I printed some temporary electronics trays and got it running under its own power.

My only gripe with the 1:1 rocker is that the lever arms get pretty short at the limits of travel. So much so that the friction in the pivot prevents it from settling down into ride height unless acted on by an outside force.

I threw some pen springs in the shocks and that did the trick. I prefer to run internal springs anyways, so it’s a win all around. Ride height is dialed and the suspension is controlled. No immediate desire to move away from the stock 100mm shocks.

I’m stoked to get my body and finish this build.

[AnimalHippie]

Hey guys, working on the CODYBOY trx-6. I'm most definitely going to use a cantilever setup. I'm trying to use the shocks I have which are 90mm limited to 80mm. I have a demo set of 1:1 rockers my buddy printed for me. I'm noticing that I might need to go with a 2:1 rocker. I'm thinking the twin hammers rockers are going to be my best bet.

From reading everything here I have a couple questions for you guys. What's your thoughts on running the full size shock? How are things holding up after use? Would you do it differently? Just trying not to do a bunch of trial and error due to low budget and little tinker time available.

Thank you guys for any help and advice!!! Have a great day!!!

[Voodoobrew]

If you use shorter shocks with stiffer springs and oil, I would imagine you can shorten the top of the triangle and solve some problems.

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