Advice Wanted: Best way to make a LodeRunner go through a foot of mud?

[Steam Monkey]

I'm looking for some advice on the best way to mod a LodeRunner to be able to handle mud. Not a little mud, but a LOT of mud - 1 foot deep.

Things that come to mind are...

Must do everything possible to keep things from getting into the mud (adds drag)
Wheel diameter should be at least 2x max mud depth
No chains or other gear below axle (to keep out of mud)
Enclose the wheels in discs to keep mud from gumming up on the spokes


Any other suggestions? Ultra low gearing? Tiny narrow tires to slice through the mud to the hard surface below for traction for example?

This is by the way for use in a Kinetic Sculpture race if you've heard of the beasts. See http://davinci-days.org/kinetic_challenge.php Vehicles in the race here have to go through about 100' of mud that can vary from thin to thick. There's a hard packed surface underneath the mud, so there is traction down there (if you can get down there).

[Patrike]

I learned this years ago - go around!:jester:

[Steam Monkey]

Heheh - the rules of the race require you to go through the mud in 10 minutes or less. Also up a big sand hill, over a number of miles of road, and down a mile or two of a river.

Check out http://www.flickr.com/search/?w=all&q=kinetic+race+corvallis&m=text for a bunch of pictures from the race over the years.

The smaller one person tricycle designs always seem to do best.

[badcheese]

I've never done a kinetic sculpture race, but I've done a lot of mountain bike trails with mud. It's always better to stay on top of the mud. I wouldn't count on getting to the hard surface below, and if you try to slice through the soft mud on top, you'll definitely have trouble steering! You want a huge contact patch, i.e. very wide tires to spread the load, with aggressive tread for traction. The first thing that comes to mind is the lightweight hollow plastic wheels used on some children's pedal-cars. Those wouldn't be strong enough, but I think I've seen similar larger wheels on some garden equipment. Oversized pneumatic tires are the more obvious choice, but they're heavier and their softness gives them more rolling resistance. You could use a dune buggy tire and rim laced to your hub flanges.

Mud is likely to get thrown around a lot and end up on everything, including parts that are well above the axle. You can shield the moving parts as much as possible from stray mud by adding guards. Chains and sprockets can handle getting muddy, and you probably can't protect them entirely. I would concentrate more on keeping the drivetrain simple and robust. It's more important to have a single speed that works reliably than a derailleur setup that will fail when submerged in mud. In addition to having only one speed and no slack in the chain line, you might want a pair of fixed chain guides (front and back) that will prevent you from throwing the chain, especially if your chain line is long. They would be like derailleurs, but fixed and beefy. You could combine those with some brushes or flaps that would scrape excess mud off the chain.

Hope that helps spark some more ideas! Good luck. I can't wait to see what you come up with.

[Steam Monkey]

Good advice BC.

RE: Tires. The vehicle does have to complete the entire race carrying all parts with it. That means you can have a set of "mud tires" that you put on for the mud, then swap them out for the "road tires" later. Some people do that.

RE: Chains. Yea, slipping chains is a HUGE problem for people in the mud. Most vehicles have a range of gearing for the road, but only go into the lowest gear for the mud. Perhaps some kind of a changeout system where you've got a derailer for the road, but then slip it over to a 1-gear low gear setup for the mud. Racers are free to do modifications and change their vehicle like this during the race, as long as you carry it all with you.

RE: cutting into the mud to the bottom. This is a pretty successful tactic for some vehicles, but they have to have weight to do it, and/or very narrow tires. Some vehicles even have wheels made out of large discs of plywood with heavy duty rubber hose around the rim as tread.

One really whacky idea I had was to make the vehicle hinge in the middle - just forward of the crank. To advance in the mud, you'd lock the front wheel brake, then pedal forward, arching up like an inch worm. Them release the front brake, lock the back, and let the front go forward. Maybe have some kind of a hand winch to help it straighten out.

Of course you'd need a big lock mechanism to make the frame rigid for non-mud road work.

For floating down the river, I'd put a pair of inflatable pontoons on either side of the vehicle, and a paddle wheel on the rear shaft. Some people actually attach paddles to the wheels, turning them into large paddle wheels - but of course they'd really catch a lot of mud.

[PeterT]

SM,
If you allow the principles of driving a 4WD through mud to be a type of guide, then you will want as wide a footprint as possible to float across the surface of the mud, so big fat soft-sided tyres with very little air pressure in them will allow you to do that.
Here is thought for you to consider,... team a pair of wheels together on each side at the rear (shaft type wheels allow this to be done if you build the first one onto the end of the shaft, and build the second one with just the flanges being held apart by a spacer, and then sliding second wheel onto shaft and welding into place!) and then wrap a car tyre tube liner over both wheels, and make yourself a tractor tread for the rear, and mount a thin pair of cut down skis on brackets that keep just the actual tread part of your front wheel in contact with the mud, ie on the road, your tyre is in contact with the road, but you have skis sitting level with the rim, angled slightly upwards to lift the wheel out of the mud whilst still being able to steer it.

With regards to the gearing to cross the mud, you want it geared so that you are going fast enough to cross the surface, but not slow enough to get stuck by the surface tension, and you want your momentum to stay constant whilst in the mud.

If you run a single freewheel to your drive wheel, then you can build your proper driveline well clear of fouling in the mud, using the same sort of technique used to gear a tall bike, however if you remove all the bearings from a hub, re-tighten cones and nuts till they cant be tightened any more, and then apply liberal welds to axle bolt, and run now solid axle on external bearings, you will have a live axle which transmits power equally to both sides of the bike, and can drive two sets of wheels on two axles , equally! Just add freewheel to your live axle (both sides) and run a secondary chain to the shafts (see my intro blog to find my pics of how i have done this on my Streetfighter) or check here to see the pics
http://viewmorepics.myspace.com/index.cfm?fuseaction=user.viewPicture&friendID=201463458&albumId=1858092

This live axle then also lends itself towards becoming a dual paddle wheeler on the river, if you have built your floats up under the rear part of the bike, all you have to change is the tyre tube protector to another that has small cups attached to it, and if the small skis on the front are used as the bottom of your front floats then you have actually covered three parts of your challenge in one hit ...mud & water & sand!

Check out the waterbikes online for further ideas, as some of those guys have taken the design work out of the design for you already. there is an address here somewhere in one of the more recent posts about a uni built/designed waterbike that is quite good.

Looking forward to seeing your progression towards final ride
PeterT

[John Lewis]

I recall an invention for 4 wheel drives that was a large drum like a coffee can on its side. Maybe not that long though. It bolted to the hub via the normal bolts. The diameter was a little less than the tyres. When the tyre sank in a bit the drum took up the load.

Would some thing like that be feasible.

John Lewis

[consultantTW]

Maybe trying something a little differant would work for you. Here I go again back to my farm days. My uncle had two old Oliver tractors and parts of another one that he used to keep the other two running. At any rate the Oliver tractors were of the narrow front end type. So on the back tires that stood 5' or so tall he mounted in the winter time a smaller wheel about 2' in frount of the bigger tires. Then installed over both the smaller wheel and the bigger wheel a track, making what is known as a "half-track".

The smaller wheel is mounted on the frame and doesn't touch the ground. Only the bigger wheel touches the ground, but as your rig sinks into the mud or snow or sand the half-track gives added traction and pulling power so that you can swim out.

Now if some floats were added under your rig. I don't see why you would need to add a paddle wheel, because the half-tracks would work on the water also.

Good luck.

[Patrike]

any big hills, if not, you could do a hovercraft!

[Steam Monkey]

I'm generally skeptical about tracks and (some) large tires after watching the race for a few years. Tracks inevitably gum up with mud, and anything that's in contact with the mud turns into a big suction cup from what I've seen. People seem to succeed by either being small and light with no drag in the mud, or massive 2000 lb vehicles.

Think about what it's like to walk through mud in a pair of shoes and how they accumulate a huge amount of mud. Or better yet in a pair of flip flops, which will rip off your feet in the mud. That's what seems to happen to anything that's not using massive and huge wheels with a 1500 pound vehicle attached, or is small, thin, and with no mud grabbing surfaces (like spokes) to gum up the works.

That said though, there are some people that succeed with big tires. Take a look at this picture for example...http://www.flickr.com/photos/27047646@N00/3327815499/ Those are old drag racing tires.

Here are a few more pictures of the mud being made, and various vehicles trying to get through. Out of about 25 only about 5 made it all the way.

http://www.flickr.com/photos/ygx/3736978366/

http://www.flickr.com/photos/28728868@N06/3738104124/

Here's one that made it. Huge tires, lots of weight. Note mud depth on wheels...
http://www.flickr.com/photos/28728868@N06/3738104562/sizes/m/in/photostream/

One that didn't make it, but usually does...
http://www.flickr.com/photos/ygx/3736982344/sizes/m/

[consultantTW]

Looks like fun. How about a type of ATV that floats over mud and water?