jebster's mud truck

[jebster]

after seeing all the people having fun in the wet and muddy places I normally try to avoid (I hate frying electronics!) I decided I wanted to join in. I want something that can handle water and mud but still be as low maintenance as possible. i don't need a monster that can bash everywhere (not my style) so the parts list isn't going to be top end everything, just durable enough for reasonable trail runs through the back yard. I don't get a lot of time to run my rigs so I want to avoid a lot of post-run cleaning and maintenance. so the requirements are:

• stainless hardware everywhere possible
• no steel chassis (plastic and aluminum) with easy access for cleaning and no pockets that will build up mud
• easy to maintain axles with plentiful parts support
• transmission that is simply and as few moving parts as possible
• waterproof electronics that can handle splashes but have them mounted high in case I'm in deep water

I'm using a ridgecrest chassis as the base. nice support and plastic so no corrosion or rust. plus I have a lot of mounting points.

axles will be stock ar60s with all stainless hardware. i'll pack them with grease. these work well and I have a lot of spare parts.

Going to use 2.2 mud basher tires, probably on plastic beadlocks. that is unless C*H*U*D gets his aluminum beadlocks out for sale!!! (check them out in his mega truck build thread)

The transmission is going to be different. I'm going to incorporate a kyosho fo-xx ve chain drive transmission. my thinking is this: bulletproof, simple (2 sprockets, 4 bearings and a chain) and I can mount the motor higher in the chassis. this transmission is also easy to clean, just a blast of wd-40 on the chain and bearings with a little shot of oil afterwards. plus, I always like something unique in my builds and I don't have a rig with a chain drive yet!

electronics are still being worked. servo will be an xpert 7000 waterproof high torque servo. powerplant may be a hobbywing or kinexsis waterproof brushless combo.

the one item I'm having trouble deciding on is the body. I want a truck body in the ballpark of a 12.5" wheelbase. I could extend the wheelbase if needed. I like the look of the proline topkick but not sold on it yet.

I'm still collecting parts but will post of pics of things as it comes together.

 

[JatoTheRipper]

Ceramic bearings would be better than regular bearings for corrosion resistance. I'm not sure if you want to spend that much on bearings though.

The chain is a bad idea for mud and water IMO. That's going to rust unless you are meticulous about cleaning and oiling it.

 

[goobs]

yeah chain/sprocket is a bad idea. the sediments in mud - dirt, sand, debris - act as sandpaper and will wear out the chain and sprockets very fast and can cause them to bind/lock up along with what JTR said.
i run an axial trans as a transfercase stuffed with marine grease and smear clear caulk on the outside seam.

 

[monster 550]

For the ar60's I'd at least put hd gears. Have you looked into SC bodies? My 4x4 slash is just over 12.5" in WB. Check out the CC combos. WP and only around $100. Good luck on your build and have fun.

 

[jebster]

For the ar60's I'd at least put hd gears. Have you looked into SC bodies? My 4x4 slash is just over 12.5" in WB. Check out the CC combos. WP and only around $100. Good luck on your build and have fun.

yeah chain/sprocket is a bad idea. the sediments in mud - dirt, sand, debris - act as sandpaper and will wear out the chain and sprockets very fast and can cause them to bind/lock up along with what JTR said.
i run an axial trans as a transfercase stuffed with marine grease and smear clear caulk on the outside seam.

Ceramic bearings would be better than regular bearings for corrosion resistance. I'm not sure if you want to spend that much on bearings though.

The chain is a bad idea for mud and water IMO. That's going to rust unless you are meticulous about cleaning and oiling it.

I appreciate the feedback. I have gotten mixed feelings from people on the chain idea with valid points on both sides. my personal experience dates back to a kyosho rocky 4x4 buggy that was chain drive. beat the crap out of that in dirty, dusty places and never had an issue with the chain. but this is a different setup so I may run into issue. cleaning and oiling are the goal and I'm setting it up to be easy for that. (once I get pictures up you'll see what I mean.) if it doesn't work I can always go back to a standard axial tranny.

I agree that ceramic bearings would be better. I haven't looked up how much they run in awhile so i'll do some research. maybe I do those for the exposed bearings around the chain drive transmission and leave the axles alone.

upgrades to the axles will happen over time, with HD ring/pinion being on the list. hell, I'm starting with dogbones vs universals just to play!

I will look into SC bodies. if the wheelbase is around 12.5" that could work. I did see a build thread (something about an stretched scx10 mudder) that used a proline topkick body. I thought that looked nice too.

 

[jebster]

Got some work done on the truck the last couple nights. Made a deck for the tranny to mount on and some custom skid plates that tie the bottom of the tranny to the chassis. I decided I'm going to go for a cantilever steering setup do I mounted the steering servo on the deck.

Pics should give you an idea where I'm taking this.

I'm thinking about going with trailing arms for the lower links. Saw some cheap aluminum ones on ebay I might get. (http://www.ebay.com/itm/4pcs-Rear-C...7c61160&pid=100005&rk=6&rkt=6&sd=262772950004) They would work because they are open on the bottom so water and mud wouldn't accumulate in the shock mounting channel. They will extend my wheelbase from 12.5" to 13.5" but I can deal with that.

More to come. Feedback welcome.

 

[jebster]

Finished the internal frame and mounted up the tranny and motor to size things up. I'm liking the setup. It will be top heavy but the tradeoff is the electronics will be at least 4" up and away from the muck. Looking at the wheelbase and track width I think extending it another inch by using yeti trailing arms would work fine but I will need to run wheels with less offset to narrow this rig up.

Need to figure out a battery mounting tray for up front, which needs to hang out over the front axle.

You can also see what I'm thinking for the cantilever steering setup. Should work out fine, although I will need to fab up anow "L" arm with bearings for the front axle.

 

[monster 550]

That's looking pretty neat. If you're worried about it being top heavy though, why go with a narrower offset?

 

[jebster]

That's looking pretty neat. If you're worried about it being top heavy though, why go with a narrower offset?

You are right the wider the better it would compensate for the high COG but I also don't want it crazy wide. It will be a tradeoff.

Just ordered up the trailing arms so once they arrive I'll have a better feel.

 

[monster 550]

I have .850 hubs on mine with ar60's and it doesn't seem too wide. Mine sits pretty high though and has a blazer hard body so it has a real high cog.

 

[jebster]

Got one of the newest parts for this project in today. I've read good things about this servo. Hope it works for my needs.

Next I need to find some kind of bellcrank or cantilever arm to use. If I can't find something I'll just cut one out of aluminum.

 

[jebster]

I was looking through the parts bin and found a dlux front axle truss. Perfect addition to give me a mounting point for the bellcrank I'll use for the steering. Pivot point is going to be a twin hammers cantilever shaft. I have a chunk of aluminum and some bearings to finish the job.

More work to go.

 

[jebster]

Got the steering laid out. I made the cantilever arm long to start with to see how much throw I will need. I can cut it down later. Added a temporary link to check out function and it works great. The final link will need a little downward bend to clear the upper link. It also has very little bump steer since it is closely aligned to the upper link mounting points and length.

 

[calcagno45]

No bumpsteer with that setup? Very interesting.

 

[jebster]

I wouldn't say no bumpsteer but it is surprisingly little.

 

[jebster]

Figured out how to get the battery up front. Had some parts from a wheely king that I put to use. Still need to make some similar aluminum uprights for the rear mounting point.

 

[jebster]

Finished up the top mount. Makes the overall chassis very rigid and will provide a place to tie up any wires.
Also got the steering finished up. Moves nicely.

 

[C*H*U*D]

I love builds like this! Are you concerned at all about mud and other debris getting into the chain?

I want to hide my servo as well, but I don't think a traditional CMS setup will work. I'm thinking your bellcrank idea is the ticket I'm looking for.

 

[jebster]

I love builds like this! Are you concerned at all about mud and other debris getting into the chain?

I want to hide my servo as well, but I don't think a traditional CMS setup will work. I'm thinking your bellcrank idea is the ticket I'm looking for.

I am a little concerned about the chain. Given chain drives are run on some pretty durable rigs I hope it works for me. I'm probably not going to be running this in bogs so a little splash here and there should be ok.

I've wanted to add a canteliver steering setup to a rig for awhile. Seems pretty solid. Hope you have luck using it for your rig.

 

[jebster]

Love the steering!!

Thanks. it seems strong but only time will tell. the rig hasn't moved under its own power yet!