Brushless Snow vehicle suspension question?
 

i have started my winter vehicle build and wondered if any one had comments on how im planning to do the rear suspension.
here are the pics:
The angles and shock set up are based off the way an arm is mounted.
parts cut, t-maxx lower arms and two rustler chassis:
it will have a hinge pin for the rear to the chassis:
parts are still rough as im still trying out things.
http://i258.photobucket.com/albums/h...x/partscut.jpg
quick mock up of cut parts:
http://i258.photobucket.com/albums/h...ckupshocks.jpg
body off:
http://i258.photobucket.com/albums/h...ckupnobody.jpg
body on:
http://i258.photobucket.com/albums/h...ckuplenght.jpg
found a set of zero offset rims, i will have to move the paddles over to these rims. This cut off about one inch off the rear stance width:
blue box is how much on one side:
http://i258.photobucket.com/albums/h.../new_width.jpg
i have cut off about 3-4 inches on the rear stance compared to a stock rustler. and gone about 2 inches wider on the front.

Weird. I get the feeling the suspension will be totally mushy unless you run rather stiff springs on one or the other of the 'towers'...

does it need to be a solid axel to have the linked suspension in the middle?
im not sure thats why im asking the questions
would it ride better as a a solid axel?

That much suspension is overkill. But it looks cool as hell, if you want to run it, then run it.

You may want to consider duals on the rear, or 14mm adapters and maxx size paddles. I've run those same paddles on a rustler in the snow, and it didn't go very far.

Either of those suggestions requires a very stout drivetrain, but I believe to be an effective snow machine you will need more traction.

this is what i ran last winter, she did really great.
http://i258.photobucket.com/albums/h...nowslash61.jpg

ok so it is over kill. thank you. i kind of figured that but i had seen a car someone made into a snow vehicle with a 4 link system and solid/locked rear.
i wish i knew where that pic is it was out of some old RC magazine. it was really long. so i thought i could use the way an arm is connected and not have the side to side say a crawler has. my thinking is the was snow is all aver the place an not just smooth so i wanted the rear to be able to soak up bumps but then have each arm be able to move on their own to make contact with any random hole

Just use a turnbuckle instead of a shock on the rear tower to arm connection to "lock it out" and then you will solely be using your hinge suspension which I believe will be better for a snow machine.

It looks fun!! I got stuck all the time, but I was in deep snow.

Crawlers wont have that nasty side to side sway if the suspension geometry is setup correctly, unless you mean the way the suspension actually works when its *is* done correctly?

When you hit the throttle the middle of the truck will bottom out under acceleration, the same way a normall MT does when it has rear springs that are too soft, or atleast thats what I envisage..

If you just had a solid rear axle, then the suspension would only go up and down in the middle, keeping the rear arms level and thus giving you the same suspension feel as dumper truck :lol:

I think what your trying to acheive is something akin to the way a Tamiya madbull's rear suspension works; it has a sollid rear axle, with a shock on either side copnnected to the upper chassis, but then on the bottom it has a swivel joint as such that allows the axle to rotate about its center, lifting only one wheel as that side drives over a bump.

Might be worth looking at, otherwise I'd say just go for the extended chassis with normal independant suspension- bigger wheels like Harold suggested is a good idea though, maybe mulchers or paddles perhaps?...

thats what i have to use to lock it out.
what about using a 4 link system like a crawler instead of a "hinge"?
i was looking a snow machines and they were pretty ridged.

edit: sorry i had not seen the last 2 posts before i posted this.

you simply don't need the articulation or adjustability a 4 link provides on a snow machine. Your hinge would be fine. A 4 link would be cool, but unless you know what you're doing they are complex. I have a basic understanding of them, and know just enough not to mess with them.

lol yeah me too. hmmmmm
thank you guys.
suicideneil: what you said about the middle pivot point sound right.

this is what i get with no RC money (wife took my RC allowance away) and the drive to make something from nothing. you should see the poor slash that gave its life for this project.

but this is what i needed to insure i have a functioning snow vehicle and not some folding "dumper" :whistle:LMAO

Why is it that women always want to spoil our fun? You dont see men saying to their wives 'hunny, Im affraid you arent allowed to spend any more money on makeup or shoes anymore, we need it for the house/car/baby/etc'..

I am single :smile:

i have been married for 14 years. got married when i was 20. my oldest kid is 8. :mdr:

guess im going for a stretched chassis with independent rear arms. good thing i have one more chassis. last one. two nights ago i had 3. LOL

Subscribed. Looks like a cool project. Should do rather nicely in the snow.

a little update:

i decided to just go ahead and make it.
i used a t-maxx bulkhead half, lower arm and shock tower.
here are the parts cut out:
http://i258.photobucket.com/albums/h...shackparts.jpg
together:
http://i258.photobucket.com/albums/h...maxx/shock.jpg
close up on chassis:
http://i258.photobucket.com/albums/h...axx/shock1.jpg
and mock up on car:
http://i258.photobucket.com/albums/h...axx/layout.jpg

Interesting, eager to see how that susp setup will work.

I like it! :mdr: I hope it performs as well as it looks. Do you plan on jumping? If so you will want the stiffest springs possible on those center shocks and probably 80+ weight shock oil.

update pics
 

update:
after about 10 hrs of dremeling my work desk was a mess, but i had everything cut out:
http://i258.photobucket.com/albums/h...x/notclean.jpg
time to clean up and take part count:
the parts are getting fewer and fewer:
http://i258.photobucket.com/albums/h...xx/cleaned.jpg
i made a jig to keep parts straight, i CA glued them first in place to make sure they work, then drilled and screwed them in place.
http://i258.photobucket.com/albums/h...ldmaxx/jig.jpg
here is her stance, with out anything like motors/batteries or servos on it. once everything is put on im hoping the stance will flatten out. then when in the air the rear will move down (like a snowmobile). i will use a bandit body in the end, but for now, an old school hornet body from the mid 80's. the shocks still need to be cleaned/resealed and find the right springs/oil - these are just for mock up now.
http://i258.photobucket.com/albums/h...erviewsnow.jpg
http://i258.photobucket.com/albums/h.../frontsnow.jpg
http://i258.photobucket.com/albums/h...ontlowsnow.jpg
http://i258.photobucket.com/albums/h...x/snowside.jpg

Nice work. :yes: You can always throw a few pre-load spacers on the shocks if it flattens out too much.

Kind of a dumb question, but is a rear suspension even needed? I can maybe see the need if racing on hard packed snow or ice, and/or plan on doing jumping. Dunno, just thinking out loud here.

I would make the center suspension really stiff and make each wheel rather light but limit the travel. So under normal driving the individual suspension soaks up all the bumps but on a larger jump that uses more travel, the stiffer springs will keep you from bottoming out.

Very cool original idea. Keep it up.

Is ANYTHING you speed maniacs do around here necessary? :lol: I agree that simpler is often better, but sometimes it's all about going above and beyond what is practical just for the fun of it, and seeing what will happen.

Similar to the concept of dual-rate springs, but separating the hard rate and soft rate into the two separate sections of the suspension. I think it's a cool idea too. Can't wait to see how it works!

probably not but im going for a snow only vehicle that will move down in the snow on bumps and holes. kind of like a snowmobile (or from what i have seen and researched).
here she is almost done, just need to rebuild shocks and install my VXL. the Vxl is in another vehicle till it snows. i am going to have to wait a while. I have had the lipo for a while but have never ran it, this will be my first taste of lipo.
I looked at snowmobile suspension and found what i had laying around that matched it somewhat. Turned out to be a t-maxx bulk head half, arm and shock tower. all angles are correct as they are used on the t-maxx, so i didn't have to worry about making the shock at some weird angle.
still need a bandit body (have to wait till they come in stock from tower (new version))
http://i258.photobucket.com/albums/h...stfinished.jpg

I like the snow plow you got on the front!

its from a roller blade knee pad, cut down. i was going for a boat hull front, sorta. :whistle:

I have a feeling you might need to get the Maxx paddles for it if you get a lot of soft snow. Maybe you should anyways... they have a much wider/deeper tread. :mdr:

Great project! Those Sand Paws are good for ~1 inch of snow, maybe 2 inches if it's not too soft but much more than that and they aren't much good. Later in the year when it gets cold and the snow crusts over they are AWESOME!

i have thought about it, but i have run these tires on a slash all last winter and they did everything i wanted them to do. expect flex down to get the holes and ditches. but yes i will keep this in mind, also this is a scrap pieces build. only bought parts are the waterproof rustler radio box and a set of jato arms. the body will be new as well, but still deciding on the easy way of waterproofing with a bandit body or go fun and get to use the heat gun and get a Hornet body. My wife will not give me an RC allowance :whistle: so i if i want to make something it has to be from the scrap pile.
with the maxx size tires i would need some driveline upgrades and with out any money to spend, it's never gonna happen.
i am limited by my parts, but my imagination says go big and fast and pick up the pieces later.

well.. poo... just got off the phone with Tamiya and the hornet body has the front/rear and grills already cut out, even with the uncut lexan one. i guess its gonna be the bandit body.:grrrrrr::slap::no:

any one have thoughts on if the pro-line or the panther paddles for the maxx trucks would be better for snow, on this snow rustler? or how the paddles hold up? i have run sand paws and are very happy with them. My thought would be the panther as it looks like it would move more snow. Also do you know of any drive shafts for the bandit or rustler/slash if its my only option. That will hold up to Maxx size paddles running a VXL. running on snow only.
panther:
http://i258.photobucket.com/albums/h...r/pahc1005.jpg
pro-line:
http://i258.photobucket.com/albums/h...r/proc1084.jpg

I vote for the Panthers. On driveshafts, the FLM CVDs have a very good reputation. They'll take pretty much whatever you throw at them. Plus, Mike sells them. :smile: