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Collector of many tractors
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Older Magna-trak uses garden tractor trannys and then chain drives down to another axle that drives the tracks...
 

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Josh
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Discussion Starter · #42 ·
I thought about that same principle, but I really liked the idea of large drive wheels in the rear and small ones in front. If you look in some of the photos when I was first trying to see what it would look like with tracks under it, the front drive wheels were really small. I'm glad I came up with a better solution cause it would have looked bad with those small ones.

I'll let ya know when I hear about those poker runs. I heard there is one outside of bartonville in a little area across Rt 24 from the power plant. I have some family that lives there so I should be able to find something out.

Anyone have an idea where I can get the rubber belt/strips that I need to put around the drive wheels? Would conveyor belt material work?
 

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Very nice build you have going, I've been lurking and learning as I enjoy what your are doing.

I would have one concern about the rubber to rubber drive you are considering for the tracks. If that gets some mud or snow in there you may well loose traction and have the drive wheel spinning inside the track. This would cause premature wear on both I think.

What made you decide to do away with the lug drive? I can see where it would be advantageous to have more lugs on the drive wheel to spread the load on the belt but it would surely be positive. Was the problem the outer circumference of the wheel not coming out even for the belt lug spacing? If this is the case perhaps a bit of metal or rubber between the lugs to enlarge the diameter would work.

Again, a super build. Looking forward to more pictures and commentary.

Mike
 

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Josh
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Discussion Starter · #44 ·
That's exactly the problem and I don't want to spend another $100 to fix it with new rear drive wheels... that will throw off the front end measurements too. I'm not going to be using this for mud and snow a lot. Its mostly to show off and drive around on nice days for fun... parades come to mind

Again, thanks guys for the comments and encouragement... much appreciated!
 

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I'd rather be threshing!
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Just came across this thread while trying to catch up a little Cub...

Outstanding project! I can't wait to watch YOUR youtube video!

Keep up the great work, and thanks for the pictures!
 

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Premium Member
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It sure has turned out great. Can't wait to see it in action.:thThumbsU
 

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My True Colors-Red+Silver
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728 Posts
nice build! i always wanted to put tracks on one of my tractors. The stacks are a nice touch. Your helper Tigger looks like my Butterscotch only much younger, and not attacking another animal or house pet.
 

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Josh
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425 Posts
Discussion Starter · #48 ·
Ahhh, the problem with the rear drive lugs is bothering me. I think the idea of using a rubber strip would work, but I sure would prefer to use the drive lugs if I can just figure out how to make that work. Is there anyone here with an idea of how to calculate this out mathmatically. I know it is possible, but my degree is in psy, not engineering! :)
 

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Josh
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Discussion Starter · #49 ·
Is it even possible to make the drive lugs on the drive wheels engauge with the teeth on the track without changing the diameter of the drive wheels? In my mind, only the diameter of the drive wheels can influence the number of drive lugs that are put onto the drive wheels. That said, no matter how wide the drive lugs or how far apart they are spaced, they will still never engage the track teeth properly unless I have the correct diameter first.

Am I right or am I missing something besides my mind?
Thanks!
 

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Lindeman crawler fan
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That sure is a good looking crawler. It has a nice stance to it.
I really like your idea of the springs on the front.
 

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Is it even possible to make the drive lugs on the drive wheels engauge with the teeth on the track without changing the diameter of the drive wheels? In my mind, only the diameter of the drive wheels can influence the number of drive lugs that are put onto the drive wheels. That said, no matter how wide the drive lugs or how far apart they are spaced, they will still never engage the track teeth properly unless I have the correct diameter first.

Am I right or am I missing something besides my mind?
Thanks!

Been thinking about this a bit and it seems reasonable that the lugs must match the "tooth" spacing of the belt. It would seem if you measure the distance between the centers of, say for instance, twenty of the teeth then divide by the number of teeth measured you would get a good average distance. With this number it would be easy to find the required diameter of the drive wheel.

Simple as this sounds it makes me wonder if it will work. If it were my project I'd probably make a plywood mockup of the drive wheel and try rolling it down the track to see how it fit. Shape of the lugs may have a lot to do with how well it engages and releases from the track under load. Probably it would be best to have the lugs shaped to give the maximum surface area contact between the lug and the teeth on the belt to minimize contact wear.

I suppose there is a simple way to do this with some math but that's beyond my degree in TLAR engineering.

Mike
 

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Lindeman crawler fan
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Lay the track out in on a flat surface
Measure the length of say 10 teeth. This would be the circumference of the wheel diameter that you will need.

To find the diameter: divide the circumference by Pi ( 3.14 ).
This will give the diameter of the wheel and the number of teeth.

If this is too small a diameter, then measure more teeth. If too big, measure less teeth.

Hope this helps.
 

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Josh
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Discussion Starter · #54 ·
Okay, here are some figures:
Diameter = 18.25"
Circumfrence= 57.305"
Distance between teeth (center to center) = 2.5125
Length of 10 consecutive teeth = 25.125

So, if I take the circumference and divide it by 2.5125, I get 22.81. Obviously I cannot put 22.81 teeth on the wheel. I either have to make the circumference smaller and put 22 teeth on, or larger and put 23 teeth on.

If I move the teeth out just little further along a circle that has a circumference of 57.7875 (diameter of 18.4), I can get 23 even teeth on my drive wheel. I think this approach will work, but its going to take some careful cutting and welding on my drive wheels. Looooong hours ahead!

Did I get it right?

Now, on the flip side, since this won't really be used in mud, water, or snow, what do you guys think about me using rubber to grip the steel sections of the tracks. If you look at the tracks carefully, you'll see that they are really two 3" wide sections of rubber held together with steel bars that span an open 1.25" gap. That gap is currently where my guild wheels fit into the tracks, thus holding them from slipping side to side. If I wrap my drive wheel in some sort of rubber belt, it will grip the steel bars via friction, turning the tracks.

Does tractor supply company stop conveyor belt material? I think they do and this is what I might use to try this theory of mine.
 

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Josh
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Discussion Starter · #55 ·
Note to those who are following this thread to learn from it... If I am right, my whole drive engagement system is messed up because an 18.25" wheel should have been 18.4" instead. Who knew two tenths of an inch could cost so much to fix. The lesson is to spend more time with a calculator than a welder!

Thanks so much for your input guys, much appreciated!
 

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Is that 1.25" open area in the center going to be the full width of support for the track? I would worry about the track wanting to walk side to side without some kind of wider support.

With having to increase the diameter of the drive wheel by .15" you are going to add .075 to each side of the circle. Not much and very hard to weld into place. There's got to be an easier way out of this dilemma. Your idea of a rubber drive surface may be the best thing considering the use intended. Heck, it may hang on so well you couldn't get it to slip if dipped in bacon grease.

Wonder if you were to take something like a cogged belt, maybe a timing belt off an engine, turn the cogs outward and fasten this around the drive wheel rather than using the metal cogs or a piece of belting? You could also put inner and outer "widening" rings on the drive wheel that would make, or nearly make, contact with the outer areas of the track to add stability and prevent the track from wanting to twist off the drive wheel.

Another possibility would be to replace the wheels you have worked so hard on and use a solid caster type wheel with a metal center. Something along the line of a heavy duty shopping cart wheel but much more robust of course.

Eliminating the need for properly spaced cogs would be the simple solution for sure. It may even be possible to find a pneumatic tire and wheel assembly that could replace the present system.

Whatever you decide the present steel cog system can always be returned to if it's needed.

Just a few thoughts to add to the confusion.

Mike
 

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nice project. keep up the good work. From what I see you need to look at the cog layout in degrees instead of inches or you will never get them in time. You are probably going to need a spacer to get the diameter to work for you. I noticed in your pictures that your cogs were at 90 degrees from each other
and in the real world that is way to simple.
 

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Well, what does Tom Hanks say in Apollo 13 "Why can't I work this out?":banghead3 In the end he did and so will you. Great thread and :goodl:
Look forward to seeing the video.
Dave
 

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Lindeman crawler fan
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Now, on the flip side, since this won't really be used in mud, water, or snow, what do you guys think about me using rubber to grip the steel sections of the tracks.
Does tractor supply company stop conveyor belt material? I think they do and this is what I might use to try this theory of mine.


I don't see why the metal bars riding on a rubber wheel would not work.
Here is a photo of a crawler conversion on a Power King tractor and it is just a metal track on rubber tires.
They have made track conversions like this for rubber tired tractors and skid steers for as long as they have had rubber tires on tractors.




If you can't find conveyor belt at TSC, you can buy it from McMaster-Car. Here is the link.

http://www.mcmaster.com/#conveyor-belts/=5kglx8
 

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USMC
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cub2900, hang in there you'll figure it out. You just may need to take a day or two and think it through. Sometimes just stepping back and looking things over will give you a solution. slkpk
 
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