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tracked vehicle build up

1M views 1K replies 181 participants last post by  87manche 
#1 ·
well i started about a year ago getting information about building tracks for a truck and always like the mattracks design but the price was umph... out of my well... you know... so i decided on building a set of my own so after looking everwhere on the net and other formus this was what i came up with......
 

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#577 · (Edited)
Funny you should ask. I spent several hours digging the two sets out of the 4 feet of snow and iced-in blue-tarps in the yard. The big set is the only one that bolts on the Samurai now that I have 6bolt toyota axles - I'd like to make an adapter for the small set that would let me bolt them on the Zuk AND maybe try them on my Arctic Cat 4-wheeler too. They'd be a bear to steet but the floatation would be amazing :D

I'm motivated to get the Zuk going because a friend invited me to go watch the Iditarod racers go by near their cabin. We could ride along on their snowmachines but it would be cool to take the Zuk and have a warm cozy seat in case it's windy. Plus it's the kind of thing I got the tracks for :D.

I plan to build a light plywood topper for the bed - that way I can tote a few kids back there too. I figure I can seat 3 adults on each side of the bed.

First draft.

http://i39.tinypic.com/iehys6.jpg

Not tall enough to sit up maybe - it's about 32" above the bed rail..
 
#578 ·
Funny you should ask. I spent several hours digging the two sets out of the 4 feet of snow and iced-in blue-tarps in the yard. The big set is the only one that bolts on the Samurai now that I have 6bolt toyota axles - I'd like to make an adapter for the small set that would let me bolt them on the Zuk AND maybe try them on my Arctic Cat 4-wheeler too. They'd be a bear to steet but the floatation would be amazing :D

I'm motivated to get the Zuk going because a friend invited me to go watch the Iditarod racers go by near their cabin. We could ride along on their snowmachines but it would be cool to take the Zuk and have a warm cozy seat in case it's windy. Plus it's the kind of thing I got the tracks for :D.

I plan to build a light plywood topper for the bed - that way I can tote a few kids back there too. I figure I can seat 3 adults on each side of the bed.

First draft.



Not tall enough to sit up maybe - it's about 32" above the bed rail..
Stay tuned, I already did that.
 
#579 · (Edited)
cool!


some more track-appropriate stuff for my-nanc's build thread :D
As those who have read allllll the other pages know, my tracks from the pics above...suck.

I bought them "as is" from a guy who didn't use them much after he built them.When I used them - they bend. First one, when I tried to climb a stump (tracks suck at that, all of them, not just mine).Then 3 of them when I ran them in the woods over some roots and such in marginally snowy conditions. Straightened them out, and parked them a year or so.

Loaned them to a friend/slash-potential buyer, with admonition that he NOT USE THEM as-is -they'd bend again.

He bent them, as is.

So they sat some more - I modified my Samurai, the Toy axles no longer fit the old units, got the "new" Unatracs (the big ones in the other pics) that bolt on to the Toy axles...and they sat some more.I'm working on them for: either the 4wheeler, or I can borrow a Sidekick that they'll bolt on.

I have some 4" cast iron rollers to put under the inner edge of the drum, and support it so the spindly-spindle doesn't bend again.



here are the previous rollers we tried --- soft, old-style snowmachine bogies. No good.



You can see the drum is squished down onto the bogies, and they didn't keep it from being bent.

I also dug up some 12" wide aluminum rims I have, and I'm thinking of making them into the new driver's for the track, and rebuilding them more like my-nanc and Mattracks, and all the other tracks that WORK :D

 
#582 · (Edited)
:D

Ever work with an Engineer who thinks too much? :homer:

These were built by an Engineer - really bright guy - however, he sometimes is so convinced by "calculations" that he misses the obvious.

The spindles are for a "2000 pound trailer axle".

The Samurai is less then 3000 thousand pounds - two axles (4 spindles) would be rated for 4000 pounds. No problem.

:smokin:

You can see that the spindle is trying to keep the entire carriage in alignment. If you have a load on just the inside edge of the track, it's about 14" away from the center-line of the bearings on the spindle, when the spindle was designed for a narrow trailer tire. It would be a little less stressed if the spindle was reversed, pointed out from the wheel, so the center line of the bearings was closer to the center of the tracks - but still you need as beefy a spindle as you can fit in there because tracks are WWIIIIIIDDE.

It's even worse when you try to climb a hard vertical object like a stump. When the carriage of the track gets mashed up against the stump, and can't slide over it, the track tries to compress the carriage, and the vehicle pushes against the carriage with the force of the other tracks. The distance/leverage of the carriage on the spindle from the very front is extreme. I've seen the Mattracks video of them climbing a 24" concrete step and it looked pretty stressful on them. If you could put a ram on the carriage, and force them to tilt up then it wouldn't be as bad - but as a general rule, tracks are for soft flat terrain, big tires are much better at climbing rocks.
 
#584 ·
frozen can you pm me with some more details on how you mount this hardware and also how the bearings are holding up i am going to be trying a wheel like this but 6"x1.5 wide and dont know if the roller bearings in it will hold up. also i am not to sure how you are bolting it all toghther, using snowmobile stuff is too expensive, also do these tires build up with snow?
 
#585 · (Edited)
So far the roller bearings have been holding up just fine and the wheels have been doing great also. I'm still on the original ones and they look good. I went with an 8" wheel that is 2" wide though.

I'm about 1,700 miles away from the tracks (down in Houston Texas for a few months for work) but I did dig up some pics that I had on my harddrive so hopefully these will help.

To mount the wheels, I cut spacers out of round stock that was 1/2" ID and 1" OD. To get the bolts to work out, one of the spacers is more like 3/4" ID and I hammered one of those 1/2" nuts that are like an inch long into it. I have two opposing grade 8 bolts go into this to hold it together.

Here are some of the parts on the bench:

You can see that I used 1" spacers on the outside and the inside spacers were a little over 3" long. One of the 3" spacers has the nut hammered into it.





Here is a mockup of it on the bench. I left spacing to show where the 1/4" uprights go:



Here is a closeup of that nut in a spacer setup:



Originally I was going to grind it down to fit good and then tack it into place but it was so tight that its not going anywhere. Especially with two opposing bolts into it.

Here is a closeup of it on the frame. The plan is to weld the spacers onto the uprights. They are not welded yet in this pic:



I dont have any pics but its the same setup on the rear where the tension is but instead of a hole with welded spacers, there is a 1/2" slot and tension will be like a snowmobile setup.

If you need anymore pics, they are a few months away. :D
 
#586 · (Edited)
soooo 2 weeks ago was the Iditarod Sled Dog race. I have a friend with a cabin near where the racers go by, and planned to hang out and watch - figured I'd run the Unatracs, since they bolt on.

Since it's been pretty cold lately, I built a "camper top". I have a Red Dot heater in back and it kept me warm with the soft top, I figure it will heat up a plywood box. I made it extra big to accommodate cold kids, and have room for "stuff". Of course, I have no garage :D Long story: took me two weeks working outside as cold as -20. Short story:
as I got it done, and the tracks on, and worked to get it on the trailer:


I blew the high pressure power steering line. So it sucked. I didn't go :( . Got a new line built the next week.



Key ingredient on new one is they brazed a fitting to the ZF pump banjo fitting - so it can use standard hose/standard fitting. Ak Rubber does great hydro stuff.

Next I will add ram assist - and I plan to mod my Unatracks to be more like the later modles (1973 vs 1971, lol) that "tipped up" the bogies on the front and back, leaving just 6 in contact with the ground, and easier to turn. I plan to cut and weld the chassis of each of the 4 tracks. Might have to pull a segment out of the tracks if they shorten enough.

cut along the dotted lines:




and the "new version" for comparison:





,
Not track related, but I was to go on a trail-run this weekend - wheels this time, it's a packed, heavily used trail -but I got an air leak on the fuel lines. Lucky it happened close to the parking lot, that's the good news. I was able to restart it, and get it home. Had it fixed properly the same day.
Lesson - prep your gear!

 
#587 ·
Guys,

I have a few questions on the Unatrack design with the rollers on the center section of the drivers.

I've read through this thread and the others before it, and the design of the Unatracks seems pretty simple and bulletproof. Any comments on why they would not work? The spindle bearing setup won't work on my rig due to the large stickout of the rear axle (full floater) and it's also a lot more complexity.

I am trying to decide between a setup like the Unatrack and something similar to a newer style Tucker Snow-Cat (solid link to axle tube from the skid frame). On the rear the tucker style setup is easy but the front is a lot more complex.

Just looking for some feedback one the Unatracks. I understand the track material is coming apart due to age and the attack/departure angle is not great, but otherwise they seem pretty rocks simple...

Cheers
 
#588 ·
It will work great as long as you don't use snowmobile tracks. They are too soft and will bend around the wheels and will not work as good. On a track with less give, they would work better. Or you could add sliders like I am doing and be fine.

Have you thought about using a unit bearing setup to get around the hub? It actually might be easier to setup and use instead of the spindle-hub way.
 
#589 · (Edited)
lol I was going to say they would work great IF you use snowmobile tracks :D

I think the Wide Track in current use might work with Una Tracks. The length in 1970 was unheard of at about 154, so the multi-piece tracks were the only option. I found an ad for the tracks - they were sold as "grass racing" and "all around tracks" - the ad claimed they were lighter and stronger than the usual tracks available - but this was 1970, so?

Anyway - they were sold in 2 widths as replacement snowmachine tracks - if the widths have stayed about the same, the new wide tracks will work, because they make them long enough now.

Were you planning on building your own or buying a set of Unatracks to work from? They can be pretty cheap, like 1 or 2 grand, partly because you can't get the plastic tracks anymore.

edit: I finally got the zuk out the next weekend after my failure to lauch:



 
#590 ·
Just to clarify on wide tracks, there are actually two widths of "wide track" - 20X156 and 24X156 (SkiDoo Skandic SWT). I have both a 20 inch and 24 inch wide machine so I have spent a lot of time messing with these tracks.

I think the 24 inch wide tracks would work great but they are super expensive and rare. I have a couple that are spares for my Skandics. The 20 inch tracks are a lot more common and I figure I could probably find some if you look. 20X156 would give an excellent floatation ability.

The other option is a grouser and belting track, like most of the other snowcat machines. That would be great as you can make them as strong as you want, and as long as you want. The rubber belting can be bought cheaply on ebay and the grousers can be just about anything.

From what I have read online the rubber belting and grouser tracks are not as smooth and cannot run as fast. It seems like the fastest machines (BV206) have one piece tracks like a snowmobile.

My idea was to try and find 4 20" 156 tracks, and build a unatrack style setup with smaller idlers and sliders, like a snowmobile, and a raised leading and trailing edge. I think it would be simpler and cheaper than the hub style setup...

Any other issues with the Unatrack setup? For steering etc? Do they come off the center idler when you try and steer too tightly? I even thought about some sort of center strap that would keep the hub from becoming separated from the skid frame...
 
#591 · (Edited)
they have a center strap as you are thinking, and as you see above(on the orange suzuki), the later models have a raised front and rear bogie.
They are much easier to steer with the raised front/rear - I'm putting mine away for the season, so I'm sending them with my friend with an aluminum welder to modify them to be like the earlier style.

One issue with the Untrac is they have a special square shoulder'd bogie for the drive wheel to roll on, and they fit tightly against the inner sides of the drive wheel, and help guide it/keep it straight. Lots of friction there. For the rears, I'd consider running a support strut to the axle to help keep things lined up - still simple, really strong, if a little bit less bolt-on/unbolt at will.

Like this one:


or, like a Unatrac with that type of support to the axle :), to help keep things in line, control over-rotation. I am thinking something that bolts to the Toyota knuckle on my tracks, for the front, so the support will steer with the knuckle.

What is the width between the drive windows (side to side) on 20" track? It's closest to the 20" dimensions I'm sure. It's not 24 anyway.
 
#595 ·
Looks like they have some rollers under the tires so that you don't have to drive backwards to go forwards :D - there is a little "hold-down" unit bolted to the wheel, piggy-backing on 3 of the 6 lugs - the rest is just rollers to guide it straight and chains to keep from over-rotating. The fact that they don't have a triangle of track going up and over the wheel/rim/sprocket of the usual tracks means they have more clearance too. I've thought about adding little ski-tips like they did to help with climb on snow. It's a pretty great add-on track system for a stock rig - it would work for the rock rigs and crazy buggies too - it just need some stock-size tires to go with the tracks is all.
 
#597 · (Edited)
#602 ·
ha ha we got out first snow fall yesterday it will melt away but gets a guy going on this again, got some new ideas i am going to try in neex couple of months just draged in the steel to the shop today so back to work we go!! post when i got something.
 
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