Tracked skidders, again

[sprucebunny]

Coon and I both have tracked skidders we're working on. I'll let him tell you about his and we can be 'backseat engineers' or is that 'seat-of-the-pants-engineers' ?

My project is a fifty year old J5 Bombardier and I need some bushings. Plain steel bushings. Look like pipe. I almost fell out of my seat when the first quote was $55 each for a 1/2" ID x 3/4" OD 1" long bushing. There's plastic ones (not cheap either!) and bronze ones but steel ones are hard to find. Drill bushings are a possibility but might be too hard ? Does anyone know ?

I've finally found some at Connex but there's a $50 minimum (that's fine ) and they ship COD. That's OK too. Thiers is spring steel and supposed to be the part that wears out.

These go to a shock absorber that's between the front bogey axle and the rear tandem bogey assembly.There is an inner and an outer bushing.Unless someone has better advice, I was going to use drill bushings for the big part and the Connex things for the small part.



http://www.connexusa.com/HTML/application.html

[Coon]

Well  as Joan has mentioned I am building a tracked skidder that I have a few questions for you experts here.  I will try to explain everything to the best of my ability.  I do not have a dig cam as most of you know so you will have to picture the project in your mind.  Any and all help is very much appreciated.

The project is to put a 1976 Subaru DL car on tracks with very little to no money available for the project.  I do although have alot of resources available that include old farm equiment for steel and parts as well as a variety of tools to work with.

  What I plan on doing is using the steering clutches and drive components from a John Deere 200A Self propelled swather that will be driven off of the Subaru's transmission via a common shaft.  My first dilema is whether the steel I have will be sufficient for the rails and undercarriage.  The steel is 3"x3" boxbeam that has 3/16" walls.  It is from an old cultivator and is in very reasonable condition with no visible cracking or cracks that have been welded up.  I was wondering if it would be strong enough for rails if I welded one on top of another and put in a few cross braces to hold the binding from happening?


There will be more to come but I have to lay my aching back down.  Too much snow shoveling I guess.

Brad.

[Burlkraft]

Sounds like a fun project.....    

Good Luck...    

[Stephen1]

Sounds like a great winter project. But maybe building a snowblower would be a better project. 

[woodbowl]

Well  as Joan has mentioned I am building a tracked skidder that I have a few questions for you experts here. 

OK Brad, fire away when your ready. Be sure to include lots and lots of pics! 

[Coon]

Woodbowl, pics aren't a possibility right now, no dig cam.  I will be taking some the old way though with the 35 mm. 

What is your opinion of using the 3x3 x 3/16" boxbeam for rails and undercarriage?  Will the Subaru be to heavy for it?

What do you guys and gals think of of using tractor tires for tracks?  Probably would have to use two tires for each side and cut some of the sidewalls out as well as make some keepers out of angle iron.?

Will get to more questions as they arise during the project.

Brad.

Brad.

[KGNC]

Sprucebunny:
Drill bushing are mostly precision ground on the ID and OD and they are expensive.  I could not tell a lot from the photo. Do you thing the bushings have to be steel? You can get Bronze bushings at McMaster-Carr for about $3.45 each. How hard are they to get to? You might try the bronze and see how they last, would be a not to expensive experiment.
http://www.mcmaster.com/ and look up part # 2867T21

[Ed]

The bushings you found at Connex are probably your best bet.
Powered metal (the generic oilite type bushings) are not designed to handle an impact load. With the constant cycling of the shock absorber they will break apart. There are tougher "bronze bushings" (cast bronze instead of powered) available, but the price will probably scare you away & I don't think they will hold up as well as the Connex bushings.

Ed

[thurlow]

Coon, there was a detailed article in Farm Show magazine a few years ago about a fellow doing exactly what you're doing; I've got a CD around here somewhere with that on it;  I'll try to find it................don't hold your breath.

[RSteiner]

There are many different alloys of bronze available for bushings of that sort.  One material I have used before that is very tough is Ampco 18. 

There must be a small machine shop in your neck of the woods that could turn up what you need.  Material is not cheap these days but you should be able to find some one to sell you what you need and not have to purchase more than you need.

Randy

[woodbowl]

What do you guys and gals think of of using tractor tires for tracks?  Probably would have to use two tires for each side and cut some of the sidewalls out as well as make some keepers out of angle iron.?

Coon, I've been looking for info about that for a long time, even posted a topic about it.  http://www.forestryforum.com/board/index.php?topic=15394.msg218736#msg218736  There is some good stuff here, I just wish there were some pics.

Thurlow, you found dat CD yet? 

[thurlow]

Nooooooooooooooooooooo;  it's on my to-do list, but not right at the top.   You might poke around in here........http://www.farmshow.com/index/searchdb.asp

[sprucebunny]

Thanks for the bushing advice, fellas. 
I'm going to use the Connex. The old ones were steel and some are worn. My next concern is the outside bushing which is worn on a couple of them. And does anyone have an opinion on whether to use grade 5 or grade 8 bolts


Coon :  the steel 3x3 you have weighs 7 pounds per foot. You might want to envision what the whole machine will weigh in relation to the engine's power and there will be more friction in the track. You could look for used conveyor belt for tracks >3-5 ply. Then you could make grousers out of angle iron and the inside keepers out of flat steel with a diagonal half 2" slices of the 3x3 like the letter 'P'.
Just thinking with my fingers

[Reddog]

Grade 8 will wear longer.

[Mr Mom]

     You might call a CATERPILLER dealer and get their hight strength bolts there are stronger than grade 8.



     Thamks Alot Mr Mom

[Coon]

Can you elaborate on those keepers sb.  I am not quite sure whether I know what you mean. 

I have a friend that used tractor tires for tracks long ago when I was still in high school.  He used them on a unit he completely built from the ground up.  It was very small and used about a 10 or 12 hp garden tractor engine and transmission to drive a couple of steering clutches from a swather.  It was slightly underpowered because of his choice of engines and was what he had around.  Actually he used his running garden tractor  for parts just so he had an excuse for his wife to let him get a new tractor with all the bells and whistles.  He had an even better plan in store though which he knew would work.  The tractor they had was pretty worn out and the wife wouldn't run it.  He knew that if they had a new one she would be on it working the garden and mowing the lawn before it even needed done.   I guess with thinking like that you could understand why their marriage lasted for so many years.  They have been married now for just over 60 years.

Back to the tracks.  I will be joining the tractor tires together with homemade hinge-type system.  I may not have to cut too much of the sidewalls out if I can manage to get the right size tires which I will get for free from the local tire shop for taking taking them off his hands.  I will be running 16 inch 4x4 tires on implement rims.  I will also be bolting on pieces of angle iron to the track to be used as guides to keep them inline with the world.

What should one be using for suspension for such a rig as this one I am building?  Coil springs?

Brad.

[woodbowl]

  You might poke around in here........http://www.farmshow.com/index/searchdb.asp

I did and here is what I found. http://www.farmshow.com/index/detail.asp?article_id=60032475&source=FARMSHOW

It seems we can't view it online, rather we have to buy the back issue.

[sprucebunny]

Coon, here is a pic of the grouser set ( inside and outside of the rubber )
You can see the P shaped part that helps guide the tires and the sprocket .



And here is a track hanging from the sprocket and an old sprocket propping it up. The little axle you see is a bogey and attached by a coil spring to the back tandem axle.

[Coon]

Thanks Joan.  Those are almost exactly what I was thinking they were and just had to make sure.  The keepers I am going to make are out of angle iron with some fishplating to keep it from bending closed.  I don't have my tires yet so I don't know what size I will be using.  I was also thinking that I could possibly make those keepers from scratch using a single piece of iron, and bend it similar to those you have.

What is the measurements of your "P's"?  What is the measurement from the long flatside to the point of the "P"?  What angle are they bent at?  I would like to know more about your whole machine if possible and Yes, I have read most of the info you have posted on the forum. (I think)

Going to sit down tonight and figure out some of my gearing I need to do.

Brad.

[sprucebunny]

What do you have for a sprocket, Brad ? The number of teeth will have alot to do with gearing. There are machines that just use tires but all eight wheels are driven. Argos and tracks

The size of the P relates to the width of the track and the width of the tire. Any width tire will work.The larger diameter, the better, to increase ground clearance. I'll measure the angle and post it a little later.
 A suspension picture.



The left side ( the side with the bent axle stub )



This is an axle from the Thiokol. It would have a full leaf spring mounted on each end and a tire at each end of the spring.