Tracked vehicle construction?

Gravity Mike · Post by **Gravity Mike** » Tue Aug 15, 2006 8:50 pm

Oh yeah, DUH! My conceptual overload (being dyslexic and all).

Now I get it. Of course.

Gravity

Elliot · Post by **Elliot** » Tue Aug 15, 2006 9:19 pm

.
"Of course"... AFTER we figure it out. It's the sort of thing we all take for granted in everyday life and never give a thought until we start BUILDING STUFF! Ain't BUILDING STUFF great!

dragonfly Jafe · Post by **dragonfly Jafe** » Wed Aug 16, 2006 7:30 am

After fiddling with the tracks abit, it seems that (up to a point) a loose track works better than a tight track (as far as preventing de-tracking goes).

Any 'Dozer operators out there care to comment? How tight should the tracks be as a general rule?

Oh yeah, had it in 11th gear this morning - no problem! So the entire range of gears (15 I think) are useable...

Mister Jellyfish Mister · Post by **Mister Jellyfish Mister** » Wed Aug 16, 2006 8:28 am

Bravo!

dragonfly Jafe · Post by **dragonfly Jafe** » Wed Aug 16, 2006 4:46 pm

...well, turning is not so easy. Much greater torque (as predicted by all), the drive slips. It wants to turn, I can see how it will, but I have to do a better job keying all the shafts and stuff. It slips in one spot (where there is no keyway...)

Tiahaar, how is your's turning?

Elliot · Post by **Elliot** » Wed Aug 16, 2006 8:22 pm

Jafe:
On Henry Ford Goes Surfing, I have these BMW motorcycle transmissions.The output flange has a tapered hole that fits onto the tapered output shaft and the nut is torqued to 250 pound/feet. It still comes loose. Yep; splines or keys!

But it sure sounds like you are building one heck of a good machine. And yes, I would guess that the tracks would "want to have a little room to find their own way" across all those rollers and sprockets.

I'll be at the Tactical Races for sure.

Tiahaar · Post by **Tiahaar** » Wed Aug 16, 2006 10:42 pm

dragonfly Jafe wrote:...well, turning is not so easy. Much greater torque (as predicted by all), the drive slips. It wants to turn, I can see how it will, but I have to do a better job keying all the shafts and stuff. It slips in one spot (where there is no keyway...)

Tiahaar, how is your's turning?

Hey Jafe, I have a confession...I don't know how well the (newly re-renamed, in order to give you full first use Trak rights for BioTrak heheh) TerraKrawler does or can turn! When building it I got ahead of myself and couldn't finish the track band brakes because they were buried under the suspension and tracks. Now that the tracks are off I'm finishing that up in-between a dozen other things to get ready for next week. BUT there's good reason to be optimistic 'cause 1: in lowlow I can turn the pedals by one hand and creep the thing forward so should have the power to allow locking one track up and spinning just the other to turn in place, and 2: though I can't begin to lift one end anymore I could grap it and slide it sideways without straining much...very smooth wide tracks, slide easy, low ground pressure. This rig would be Very Very Bad traversing a sidehill

Oh, and what are the engagement rules/challenges in this tactical vehicle event? Any clues?

Rockdad · Post by **Rockdad** » Wed Aug 16, 2006 10:51 pm

dragonfly Jafe wrote:After fiddling with the tracks abit, it seems that (up to a point) a loose track works better than a tight track (as far as preventing de-tracking goes).

Any 'Dozer operators out there care to comment? How tight should the tracks be as a general rule?

Oh yeah, had it in 11th gear this morning - no problem! So the entire range of gears (15 I think) are useable...

does it have a tension idler wheel?

dragonfly Jafe · Post by **dragonfly Jafe** » Thu Aug 17, 2006 4:46 am

Rockdad wrote:
dragonfly Jafe wrote:After fiddling with the tracks abit, it seems that (up to a point) a loose track works better than a tight track (as far as preventing de-tracking goes).

Any 'Dozer operators out there care to comment? How tight should the tracks be as a general rule?

Oh yeah, had it in 11th gear this morning - no problem! So the entire range of gears (15 I think) are useable...
does it have a tension idler wheel?

The bottom rear wheel set is on an adjustable (screw) mounting, so I can alter the tension in the track (and de-track it when I need to). I can make it so tight, the chain barely turns, or anything in between.

Elliot · Post by **Elliot** » Fri Aug 18, 2006 5:50 pm

.
Gravity Mike:
The PM system seems to be down.
Art Bike Parade Thursday 31 August at 5 PM (17:00 hours). Meet at Center Camp, on the Man side.

You human-powered-tracked-vehicles guys may want to join in!

dragonfly Jafe · Post by **dragonfly Jafe** » Fri Aug 18, 2006 6:02 pm

Well. I think it is safe to say that BioTrak is not going to be a graceful turner. While I have not yet finished my mods to the turning drive, I decide to see if skid steering was on option. I chained an axle (to simulate the ultimate brake) and BioTrak would not turn. In fact, I bent part of the front drive assemblies! These are huge forces.

I think that for the race, we will have to allow "Moop Noodle Bitches", whose jobs are mainy. First, they will pick up any Moop resulting from direct hits, near misses, over stressed vehicles (or drivers), and the like. Second, they will be allowed to assist the vehicles in turning. They MAY NOT engage directly in combat with other vehicles, although playa talking is of course always allowed. If a driver gets out of the vehicle before the race is over, 30 seconds is added to their time.

Rules;

First contestant over the finish line (after adjustments for penalties and "hits" in combat) wins. thecourse shall consist of 2 pylons and a start/finish line. The contestants must go around pylon #1 then pylon #2 (if #2 is gone around first, it does not count).

Weaponry;

There are 2 main categories here;

Water

anyone hit by a sufficient quantity of water must immediately come to a stop, then down a fresh beer before proceeding further. Shooting may continue while this is occuring, just not movement (note: if a contestent is driving a powered vehicle, a note is made of the number of "beers" owed, and the contestent has a choice of either drinking a beer for each one owed, or adding 2 minutes to their time for each one owed, or any combination in between.)

Projectiles

projectiles must be made so as not to actually damage the vehicle or occupants. Projectiles may not be thrown (exception: PBR cans, see below), they must be launched using some mechanical means (air, bow, etc). The exception to this is PBR cans, which may be thrown IF they have just been fully drank. Anyone caught pouring out a PBR can is penalized 5 minutes.

When hit by a projectile, the same effects as for water are applied.

thoughts?

dragonfly Jafe · Post by **dragonfly Jafe** » Fri Aug 18, 2006 6:12 pm

Well. I think it is safe to say that BioTrak is not going to be a graceful turner. While I have not yet finished my mods to the turning drive, I decide to see if skid steering was on option. I chained an axle (to simulate the ultimate brake) and BioTrak would not turn. In fact, I bent part of the front drive assemblies! These are huge forces.

I think that for the race, we will have to allow "Moop Noodle Bitches", whose jobs are mainy. First, they will pick up any Moop resulting from direct hits, near misses, over stressed vehicles (or drivers), and the like. Second, they will be allowed to assist the vehicles in turning. They MAY NOT engage directly in combat with other vehicles, although playa talking is of course always allowed. If a driver gets out of the vehicle before the race is over, 30 seconds is added to their time.

Rules;

First contestant over the finish line (after adjustments for penalties and "hits" in combat) wins. thecourse shall consist of 2 pylons and a start/finish line. The contestants must go around pylon #1 then pylon #2 (if #2 is gone around first, it does not count).

Weaponry;

There are 2 main categories here;

Water

anyone hit by a sufficient quantity of water must immediately come to a stop, then down a fresh beer before proceeding further. Shooting may continue while this is occuring, just not movement (note: if a contestent is driving a powered vehicle, a note is made of the number of "beers" owed, and the contestent has a choice of either drinking a beer for each one owed, or adding 2 minutes to their time for each one owed, or any combination in between.)

Projectiles

projectiles must be made so as not to actually damage the vehicle or occupants. Projectiles may not be thrown (exception: PBR cans, see below), they must be launched using some mechanical means (air, bow, etc). The exception to this is PBR cans, which may be thrown IF they have just been fully drank. Anyone caught pouring out a PBR can is penalized 5 minutes.

When hit by a projectile, the same effects as for water are applied.

thoughts?

dragonfly Jafe · Post by **dragonfly Jafe** » Fri Aug 18, 2006 6:23 pm

Well. I think it is safe to say that BioTrak is not going to be a graceful turner. While I have not yet finished my mods to the turning drive, I decide to see if skid steering was on option. I chained an axle (to simulate the ultimate brake) and BioTrak would not turn. In fact, I bent part of the front drive assemblies! These are huge forces.

I think that for the race, we will have to allow "Moop Noodle Bitches", whose jobs are mainy. First, they will pick up any Moop resulting from direct hits, near misses, over stressed vehicles (or drivers), and the like. Second, they will be allowed to assist the vehicles in turning. They MAY NOT engage directly in combat with other vehicles, although playa talking is of course always allowed. If a driver gets out of the vehicle before the race is over, 30 seconds is added to their time.

Rules;

First contestant over the finish line (after adjustments for penalties and "hits" in combat) wins. thecourse shall consist of 2 pylons and a start/finish line. The contestants must go around pylon #1 then pylon #2 (if #2 is gone around first, it does not count).

Weaponry;

There are 2 main categories here;

Water

anyone hit by a sufficient quantity of water must immediately come to a stop, then down a fresh beer before proceeding further. Shooting may continue while this is occuring, just not movement (note: if a contestent is driving a powered vehicle, a note is made of the number of "beers" owed, and the contestent has a choice of either drinking a beer for each one owed, or adding 2 minutes to their time for each one owed, or any combination in between.)

Projectiles

projectiles must be made so as not to actually damage the vehicle or occupants. Projectiles may not be thrown (exception: PBR cans, see below), they must be launched using some mechanical means (air, bow, etc). The exception to this is PBR cans, which may be thrown IF they have just been fully drank. Anyone caught pouring out a PBR can is penalized 5 minutes.

When hit by a projectile, the same effects as for water are applied.

thoughts?

dragonfly Jafe · Post by **dragonfly Jafe** » Fri Aug 18, 2006 7:48 pm

Well. I think it is safe to say that BioTrak is not going to be a graceful turner. While I have not yet finished my mods to the turning drive, I decide to see if skid steering was on option. I chained an axle (to simulate the ultimate brake) and BioTrak would not turn. In fact, I bent part of the front drive assemblies! These are huge forces.

I think that for the race, we will have to allow "Moop Noodle Bitches", whose jobs are mainy. First, they will pick up any Moop resulting from direct hits, near misses, over stressed vehicles (or drivers), and the like. Second, they will be allowed to assist the vehicles in turning. They MAY NOT engage directly in combat with other vehicles, although playa talking is of course always allowed. If a driver gets out of the vehicle before the race is over, 30 seconds is added to their time.

Rules;

First contestant over the finish line (after adjustments for penalties and "hits" in combat) wins. thecourse shall consist of 2 pylons and a start/finish line. The contestants must go around pylon #1 then pylon #2 (if #2 is gone around first, it does not count).

Weaponry;

There are 2 main categories here;

Water

anyone hit by a sufficient quantity of water must immediately come to a stop, then down a fresh beer before proceeding further. Shooting may continue while this is occuring, just not movement (note: if a contestent is driving a powered vehicle, a note is made of the number of "beers" owed, and the contestent has a choice of either drinking a beer for each one owed, or adding 2 minutes to their time for each one owed, or any combination in between.)

Projectiles

projectiles must be made so as not to actually damage the vehicle or occupants. Projectiles may not be thrown (exception: PBR cans, see below), they must be launched using some mechanical means (air, bow, etc). The exception to this is PBR cans, which may be thrown IF they have just been fully drank. Anyone caught pouring out a PBR can is penalized 5 minutes.

When hit by a projectile, the same effects as for water are applied.

thoughts?

Elliot · Post by **Elliot** » Fri Aug 18, 2006 9:09 pm

.
Thoughts? My thought is "how long would it take me to put a track and a water-cannon on Henry Ford Goes Surfing"! I think I'm gonna like this Burning Man thing.

capjbadger · Post by **capjbadger** » Fri Aug 18, 2006 9:13 pm

Mwhahahahaha!! I think I already built the perfect cannon. I get a feeling the non-pedal powered cars are going to get ganged up on. lol

Tiahaar · Post by **Tiahaar** » Fri Aug 18, 2006 11:46 pm

dragonfly Jafe wrote: thoughts?

hoho! this is gonna be fun! there could also be random pieces of lumber/rebar/surplus dome struts scattered around the course to hinder whatever conveyance methods the vehicles are propelled by. drat and what canned nonalc beverage may this pbr challenged krawler pilot sub in for the suds...lipton tea??? gatorade??? (wait thats in bottles) must remember to bring hardhat!

dragonfly Jafe · Post by **dragonfly Jafe** » Sat Aug 19, 2006 4:24 am

...any canned beverage may be substituted for a PBR if the contestant does not drink alcohol. Why PBR as the only alcoholic beverage allowed? Because this race is being hosted by Apokilptika, and PBR is the beer of choice of the Apokilypse!

oh yeah, and depending on the environmental conditions (wind), additional rules might apply. All crews and the MNB's must ensure that nothing blows away.

robotland · Post by **robotland** » Sat Aug 19, 2006 5:52 am

Dammit Jafe, now I HAVE to try to perfect the PBR gun. I'll probably be working on it Wednesday night, before I @#!! leave. SO relieved to hear that it's not just a contest of speed, but that drinking and beating upon each other will play a part. Rrrrarghhhhh! *throwing antelope bone into the air, where it turns into an orbiting weapons platform- Cue Blue Danube*

Mister Jellyfish Mister · Post by **Mister Jellyfish Mister** » Sat Aug 19, 2006 8:03 am

Techno music by HAL 2000.

dragonfly Jafe · Post by **dragonfly Jafe** » Sat Aug 19, 2006 9:52 am

...the Tactical Mutant Vehicle Race is officially registered on the website...BioTrak and crew are looking forward to competing! Thanks to all who have followed, critiqued, or helped with BioTrak. It has been a hoot designing and building her, and even if turning is a slight problem, I'm considering her a success.

See you all when we get home in a week or so!

Tiahaar · Post by **Tiahaar** » Sun Aug 20, 2006 11:43 pm

Wonderful inspiration and tips from everyone, can hardly wait to get on-playa and meet you folks & compare vehicles! Its gonna take me like 6+ hours to assemble the TerraKrawler once its offloaded from the mothership...may be pulling an allnighter Monday after a mid-afternoon arrival. But Its Done. Yay! I had to "borrow" the handlebars from a friend's bike 'cause they were straight and the ones I bought were too curved (Jack...you always said you wanted more curve height in your playa bike handlebars, right? your bike is coming a bit different this year...) so now the brake levers are on and the shift links are made. Done except for spray painting. Don't know if the brakes work, don't know if the sonic canon works, don't even know if the thing can turn, but its SURE gonna look like something that belongs on the playa.

deviceone · Post by **deviceone** » Mon Aug 21, 2006 1:27 pm

Id be happy to help any of ya'll assemble these monstrosities. Ill be onsite with many tools monday.

And FYI, in case anyone needs it, Ill have a limited selection of specialty bike tools and will be offering free basic bike services at 3:33 and destiny..
Ill try to post a sign

Im not bringing a workstand or truing stand this year due to space and logistics issues.

//Adrian

dragonfly Jafe · Post by **dragonfly Jafe** » Wed Sep 06, 2006 7:38 am

BioTrak got to the playa, and did work (kind of). I will post a detailed post-mortem later (just got home after a blown radiator with a fist-sized hole we managed to patch enough to crawl into the nearest town).

Basically, the sideways forces were too great for my design, and my treads sheared off.

It DID move appx. 20' and turn 10 degrees or so before I stopped (lost 4 treads in that distance). I now know what went wrong and how to fix it, maybe I will in 2007.

The flame cannon was a hit tho' and it was a good static art piece, so I am declaring it a success.

Never got to find Tiaharr, however (I was injured from thursday on, missed all the burns too)

capjbadger · Post by **capjbadger** » Wed Sep 06, 2006 11:14 am

Dachs Gabe made it to the playa as well, but suffered from the arms that held the drive wheel being albe to flex too much (damn wood constuction). The chain kept comming off. Got a few blocks before the problem became too bad to continue.

Proof of concept though!

Half a ton of ship was moved by a 3.6hp engine and the thing can turn on a freakin' dime! Watch out for next year...

dragonfly Jafe · Post by **dragonfly Jafe** » Thu Sep 07, 2006 11:34 pm

BioTrak Post Mortem;

The basic concept was sound. It is definately possible to make a bicycle powered tracked vehicle. BioTrak weighed maybe ~800-1000 lbs empty, and I could easily pedal it with 2 passengers on board (maybe 1500# total). If anything, I would gear-up the ratio a bit, as the lowest 6 gears or so were basically wasted.

Using EMT is not a good idea. Yes, it is cheap. But it is toxic to weld, and it bends really easy (especially when you gear stuff down). I easily twisted the frame during my first turning test without realizing it.

Triangle EVERYTHING you can, squares don't work well (even with sheet metal riveted to them).

Rivets pop loose - use bolts or welds instead for anything that will take a load (like track treads).

Anything that is a single point of failure needs to be incredibly strong. Have someone else look at your design and point out what you have missed. No matter how many times you look at it yourself, you WILL miss stuff.

Pound on your welds with a hammer to check them.

Don't use rubber wheels as the primary track mechanism, they will shred quickly and yield under load. A sprocket should be at the rear as well as the front to help keep tracks on course, maybe even for the road wheels.

The side loads for turning a fully tracked vehicle are ENORMOUS. I would guess that at least the vehicle weight was applied to the ends of the tracks (1000-1500lbs minimum). Don't rely on a single point that rotates, make sure the ends are constrained in vertical slots/shafts so no twisting can occur.

Support all shafts and axles as close to the ends as possible, with all sprockets inside the supports.

Use teflon/uhmd tensioners instead of sprocket idlers as they do not add friction in the chain (friction=lost power)

Do not use aluminum rivets, no matter how large, to attach the treads to the tracks. They will shear. I imagine steel ones would not be much better.

Have spares for all critical parts (you will loose/forget something).

Have a lock for the vehicle to prevent Yahoo's from messing with / breaking it.

If people can throw their trash in it, they will.

golf balls make great ball bearings for turrets.

more later as I think of it....

Mister Jellyfish Mister · Post by **Mister Jellyfish Mister** » Fri Sep 08, 2006 7:27 am

Jafe: Thank you for your hospitality and quick tour of the tank. It is indeed elegant and I am rooting for a comeback in 07 with those design improvements. You came so very close to getting it fully mobile that I would simply love to see your dream manifest. It's your call, though, as I know the staging and repairs/change-outs are a daunting task.

You remain my good friend, if not a better one.

Sincerely,

Jellyfish

unjonharley · Post by **unjonharley** » Fri Sep 08, 2006 8:27 am

DRagonfly Jake, You had a great machine on the playa this year. My son and I come back for a second look. Sorry we missed you that time. Sure you will have a new and inmroved one for o7. Should I build a tank retriever just in case

How about taking a look at a "BOcats Front Loader" steering control. Or as far as that go's. There speed/gear control. It uses a expanding pully. There is a lose of torque but a study could help. Might get hold of a expanded, parts view of the thing.

deviceone · Post by **deviceone** » Fri Sep 08, 2006 6:47 pm

Im glad I saw it and got to drive it, albeit in a straight line. It was an amazing creation. Like I told you out there, perhaps recessed bolts into the tracks would fare batter than the rivets. Then changing a section of track could also be easier...

I too never saw Tiaharr's beast...

Next year..

good burn :)

//Adrian

dragonfly Jafe · Post by **dragonfly Jafe** » Fri Sep 08, 2006 7:37 pm

My thoughts for next year are revolving around a half track, with the drive tracks being smaller and in the rear, and either 1 or 2 motorcycle tires up front for steering. One pedaler (maybe with electric assist making it a moped), 1-2 passengers (possibly also pedaling). Oh yeah, and the flame cannon of course for night. Smaller, lighter, stronger, and faster. And open for the public to ride (sans the flame cannon of course). I am envisioning a sign-out process where people can borrow it, with a sign saying to return it to my camp when done. I regret more people did not climb aboard and use it for photo's (my intention in leaving it out front this year).

I think I will weld the track treads on. No chance of MOOP then. I should have enough for 2 spare tracks that way also. And I will put small bends on the outside of each tread to assist in turning.

I have an extra 20' of #100 attachment chain if anyone wants to follow my madness. I would consider gifting it to a suitable individual that can convince me they are serious about building a tracked vehicle....(about a $200 value)

Anyone with questions about bicycle creations, feel free to contact me. I am hooked now.

Oh yeah, my turning radius was appx. 125' radius, far more than predicted (I was hoping for 30' radius). Turning in place did not work so well (frame bent). Turning while moving was much easier. I did not try skid steering on the playa, it may have worked better.