Mini Hägglund

[Steinbruchsoldat]

Hi,
this would be a lot of work, and won`t work with the idler wheels...

For the sprocket i`ll cut a steel plate to weld the tubes to, like on the brake disk. Then i`ll gusset the hell out of it, so stresses won`t be a problem...

That`s the solution for the articulated driveshaft:

[trek]

Originally Posted by Steinbruchsoldat

It steers the same way the real thing does. The front and rear car are tilted against each other. You can compare it with a wheel loader. The final drive gearbox is just a normal axle, locked in the Hägglund. I think i`m going to weld the diffs too...

Started with the first track and sprocket design today. First mock up of the sprocket:



Jig for the holes in the track:





Tightening the bolts:



First part finished:



Rear wheel:



Sprocket, with updated design:



Joint between both parts of the track:

your trak won't work. you'r gonna loose your bolt reel fast out of the ruber. lol here is a short story of my childhood that explained it. i bolted the tire of my bmx to do some in winther. put some 3/4" lenght bolt & some washer on both side of the tire. it performed flawlessly with a second tire to protect the tube.
my friend was amazed and he wanted to do it on it's montain bike. he grab 2" bolt lenght. make the bolted tire and he rolled on it. it funny cus it work for first 2-3 gears has speed grow he start receving bolts behind the head! lol it dident took long befor he stops.
the bolt was to long. leverage pop the washered bolt out of the tire.

you need to solidify the bolt with the trak. bigger washer or plate that grabs 2 bolts in tha trak wide.

good luck!

[Steinbruchsoldat]

Hi,
those bolts are just about 1 3/4" long, and stick out about 1 1/4"...

A lot of dirt track racers bolt those bolts through their tires and race it without losing bolts. Those tire belts are really heavy duty, there`s no way to rip those bolts through them. I think they break instead of ripping out...

[jtr]

Subscribed.

[87manche]

I thought this might be useful.

Extreme Hagglunds - Track Building - YouTube

plus the extended cab colorado converted to hagglund is sweet.

Extreme Hagglunds - Take a Tour - YouTube

[Steinbruchsoldat]

Because of the fact that the Hägglund will be smaller than a car, i`m able to build it in my other shop. So i started to organizing both shops and getting all my metalworking stuff in my shop. Before:





When i called it a day:







The old shop:



I also cut up all the tires and finished one track:

[RoosterBooster]

interesting idea ... but IMHO i think you will run into a couple problems;

your bolted together "track" will not last long (without at least a little overlapping / vulcanizing) ... i would try to find a "one piece" belt loop (bigger tires ?!?)
you will most likely peel the track off the running gear in the first turn (your design has marginal side load support)
to much friction when your "driver wheel" engages the bolts; it will grind them down in no time.
questionable traction of the (worn tire) track.
...


when i grew up in switzerland i was often riding shotgun in "Pistenfahrzeuge" like this;

as somebody else already suggested i would take a close look at that style of tracks ;
rubber loops with cross-ribs and driver "zahn-raeder" (sprockets ?) that engage into the ribs.

[RoosterBooster]

Originally Posted by 87manche

I thought this might be useful.

Extreme Hagglunds - Track Building - YouTube

plus the extended cab colorado converted to hagglund is sweet.

Extreme Hagglunds - Take a Tour - YouTube

cool videos ! .... gives me stupid ideas ... its not like i really need another project

[Steinbruchsoldat]

Hi,
the connection between both tires will be updated, this is not the final design. But, here`s a connection on a Bombardier BR160 snowcat, this is a big rig and as you can see, it`s not a big connector:



Look at this video. The track has almost no side support, and is only driven by friction. It obviously works. So, the forces can`t be that big. The one in the video does really sharp turns, mine won`t be able to do this because of the articulated steering. So there are a lot less sideway forces. I think my system is far superior in both things to the one in the video, so why shouldn`t it work?

Personal Tracked Vehicle - YouTube

I`m going to use this offroad too, so no Pistenbully tracks. But i`m going to add some u-brackets on the outside of the tracks for winter driving...

[Elwenil]

You will note in the vid that there are guides at the front and rear to keep the tracks on the tires. Also, it has very little power and probably weighs about as much as a riding lawn mower. You are taking about making a two part articulated vehicle that will not be a skid steer, but will turn based on hydraulic rams bending the vehicle to turn it. The act of bending in the middle may very well be enough force to push a track off the road wheels. If you are going to stay pretty lightweight, I'd probably look at using snow mobile parts since it's a proven setup and probably wouldn't cost that much to source and import if not available locally. Building something from scratch is always cool but there is not much point in redesigning the wheel, so to speak. Just my .02

[Steinbruchsoldat]

Hi,
i know that there are guides on the front and rear, i bought the build plans from this guy. But it think the point where the track want`s to move sideways and needs to be guided is where the weight lasts on, it`s on the ground. This setup even works with the guides up in the air, where not much sideways force is applied. You don`t want to tell me that the bolts don`t hold the track better in place than those two guides?

There are also a lot of examples for tracked vehicles using tire tracks with almost no sideway guides, even with car engines in a bigger size, and all seem to work. It`s not like redesigning the wheel, it`s more looking what works and build it like that...

I don`t know if i posted it before, but used snowmobile tracks are around $800/piece in germany, so i won`t spend $3200 on tracks if i can try to make them myself...

Here`s a example of a Mattrack, using exactly the system for the sprocket and sideway guides that i wan`t to use:

[HandBuilt]

The bolted connection in the track is pretty common on older machines, a lot of machines running grousers will just overlap the belt a bit and bolt it together, but since your belting material is so heavy and thick a hinge type of connection will work better. Keep in mind that the BR hinge has a a lot of surface area and the backing plates are large and reach back into the track pretty far. What you have now will break very quickly.

That said I think your driver setup is going to last less than a 100 meters before it all flies apart. All machines have a rubber or poly on metal drive setup. Either they use poly sprockets and metal grousers or metal sprockets on rubber track nubs. Metal on metal is not going to work for very long.

For a very low buck system I think you should double up the track material and run metal grousers (cross bars) between the belts, something like every modern belt type track setup uses. That would give you a lot more track width for floatation and you could drive off the grousers. Then make some drive sprockets out of plastic (HDPE). You could easily cut them out of plastic with a router, double up the material for thickness, until you have a sprocket about 50mm thick.

I've been thinking about building something similar and I think this would be the ultimate setup for a low-cost track setup that will work well and provide some floatation. The track width you have is likely too narrow for good floatation.

edit: On the Pistenbully tracks, look into Nodwells, they use steel grousers for off-road, no problem.

[Steinbruchsoldat]

Originally Posted by HandBuilt

The bolted connection in the track is pretty common on older machines, a lot of machines running grousers will just overlap the belt a bit and bolt it together, but since your belting material is so heavy and thick a hinge type of connection will work better. Keep in mind that the BR hinge has a a lot of surface area and the backing plates are large and reach back into the track pretty far. What you have now will break very quickly.

As said before, this is not the final version and needs an update. I`ll double it up with some long strips of conveyor belting...

Originally Posted by HandBuilt

That said I think your driver setup is going to last less than a 100 meters before it all flies apart. All machines have a rubber or poly on metal drive setup. Either they use poly sprockets and metal grousers or metal sprockets on rubber track nubs. Metal on metal is not going to work for very long.

I`m going to add some plastic over the steel tubes, so it`s not steel on steel. But i`m curious to hear what you think will fly apart?

Originally Posted by HandBuilt

For a very low buck system I think you should double up the track material and run metal grousers (cross bars) between the belts, something like every modern belt type track setup uses. That would give you a lot more track width for floatation and you could drive off the grousers. Then make some drive sprockets out of plastic (HDPE). You could easily cut them out of plastic with a router, double up the material for thickness, until you have a sprocket about 50mm thick.

I've been thinking about building something similar and I think this would be the ultimate setup for a low-cost track setup that will work well and provide some floatation. The track width you have is likely too narrow for good floatation.

I can`t make the tracks wider, because then it wouldn`t fit in my L300 and i couldn`t transport it...

I don`t need floatation for deep powder snow and something like this. Where i`ll run it is always a groomed trail, where the hunters use ATV`s with Mattracks and a Pistenbully, so the snow is always packed, you could always drive a car on it...

[HandBuilt]

I think the bolts will bend or wear very quickly. The angle steel welded to the rim will also probably fail or vibrate like heck. If you are limited with track width maybe you can split the material you have lengthwise and put grousers across it. I really think that a plastic drive sprocket driving the grousers directly would be the easiest and most reliable system.

However, if you are not running powder, why tracks? Large tires with a lot of floatation (like a Rolligon) are no doubt cheaper and mechanically simpler. Then again a used snowmobile with a large sleigh would be cheaper. I doubt you can build anything cheaper than a used snowmobile needing some repairs.

[Steinbruchsoldat]

Sorry man, but did you read the whole thread? The sprocket with the angle iron was bullshit, and i already posted the updated design, that`s almost the same as the Mattracks use:

Originally Posted by Steinbruchsoldat

Here the updated sprocket design. I think something like this could actually work...



Please note that this is just a try, not the finished design...

Again, for winter driving i`m going to put grousers on the outside of the tracks to increase traction.

Why built it with tracks? Just because i want a tracked vehicle and i think the Hägglund concept is fucking awesome. I always wanted to build something like this...
And i think it has it`s advantages compared to a wheeled vehicle...

And to say it again: Snowmobile parts are expensive as hell. I think i can built this vehicle for about $500-$1000, a used snowmobile would cost me at least $2000...

[HandBuilt]

Sorry, I thought you were going to use the rotor with the tubes welded to it as the rear idler.

Good luck with the project. I think it will be a learning experience for you.

[Steinbruchsoldat]

No problem man, i'm going to use the big wheel in one of the first posts as rear idler wheel...

I think most of this project will be trial and error, because no one (that i know) has done it before. But, as we say in Germany: Theorie is when you know everything and nothing works. Practice (?) is when everything works and you don't know why...

[87manche]

Originally Posted by Steinbruchsoldat

Theorie is when you know everything and nothing works. Practice (?) is when everything works and you don't know why...

I'm totally stealing this the next time I have to deal with a software engineer.

[Steinbruchsoldat]

Worked on the shop today. First i made a welding cart out of a old wood cart. The saw will be bolted on top:



There will be tools hanging on the wall:



And something to get the welding fumes away:

[Nathan]

Do yourself a favor and mount a fire extinguisher onto your cart. Not sure why every welding cart doesn't have one.

Do a search for the DTV shredder. I'd sure like to buy one, but they're not in full production yet. Maybe you can get some ideas from their website.

[Steinbruchsoldat]

There`s always a fire extinguisher mounted in my shop. Would be stupid if a firefighter burns his own house because he didn`t have a fire extinguisher ready while welding...

[Steinbruchsoldat]

Put some more work in the shop today:

[87manche]

this guy:
http://www.youtube.com/user/Gizmo4t?feature=watch

builds 1/2 scale tanks that run and drive. He's got a bunch of tech related videos on there that might be useful.

[mudtoy67]

Cool build!

I'm not sure if you've seen it yet, but there's a good thread in Gen4x4 with a lot of info and ideas on track design:

/forum/general-4x4-discussion/854333-tracked-vehicle-build-up.html

[Steinbruchsoldat]

I`ve read that thread many times, there`s a lot of interesting tech going on there...

Finished the shop today:











The red markers show the dimensions of the Hägglund:



When i`m back from skiing i`ll pick up the donor car and start the project...