Mini Dozer - Project near complete

[workinprogress]

Boggie wheels ordered from Surplus Center but with the holiday I haven't received them yet. Should have them by the end of week. Took the machine out for a little run yesterday but with all the recent rain everything is mud. Machine goes fine it just makes a mess of everything. Can't wait for the ground to freeze to put it through hard testing.

 

[EddieWalker]

Cat came out with a new dozer, the D7E that is electric powered. They spent allot of time on this, with all the latest, greatest features. They also eliminated the high track system because it wasn't as effective as a conventional track design. There is some argument that with the bigger machines, D8 and bigger, that the high track has it's advantages, but in smaller machines, it doesn't.

Eddie

 

[DanQuip]

Great thread and excellent work on the tracks and drive. I have not fabricated anything like this before however I repair track and wheel skid steers for a living. I would recommend finding a junk yard near you with some junk skid steers in it. That will be a great source for axles bearings (very heavy duty), sprockets and 100 size chain (grainger has the kingpin links). Those spockets also use a short shaft about 18" long, splined on the sprocket end and a key way on the axle hub end. The shaft is about 2" in diameter with bearings supporting it at both ends... now that is for a 40+ hp machine but it gives you some ideas of the forces you are dealing with.
Another great source of parts would be junk mini-x machines, you need lots of rollers on the bottom of the track frame to support the machine weight. This will also allow you to reduce the tension on your track.... you'll find most commercial track systems don't have much tension at all. Too much tension causes the tracks to stretch and wear out.
I'd also suggest a compact diesel engine with hydraulic pump attached, surplus from golf course applications. We get them often at less than a $1000 running. Yanmar 4 cyl diesel with about 35hp. That's a great start for any hydraulic platform. The machines are all rusted out due to the fertilizer on the golf courses but the engines and hydraulics are fine.

Great work! Sure looks like a fun build.

Thomas
Houston, TX

 

[2manyrocks]

Time for the moderators to add a new category for "Frankentractors"

 

[hammerdwn20]

any progress?

 

[workinprogress]

Well I am sorry to say not much progress. The boggie wheels came in and I put the dozer in the garage to work on the design. I picked up two sizes (5inch and 3 inch) wheels. I really felt the 5 inch 1000lbs capacity wheels were the way to go but couldn't get things to fit together well without redesigning the track tensioner and other parts of the sub frame. While I continued to think about the project a few things happened.

Cold snap (don't have heated shop)
Car died and pick up an low milage Buick cheap which needed an upper and lower intake gaskets.
Holiday's and lots of time with the family

During all this I kept thinking about how to place the boggie wheels to result in the least amount of reengineering. I shifted gears and looked into ways to build spring tensioner for the drive chains. With the design figured out I had to find materials. I found interstate plastics and they sell a materal called IPX http://www.interstateplastics.com/docs/IPXInternetFlyerIP.pdf which appears to be a type of UHMW that can handle UV. So I ordered material for the chain tensioner and enough material to make two 36 inch slides which I will try instead of the boggie wheels. Since the cost was somewhat low ($12 each side) for a 0.5x3x36 I figured it was worth a try. The track slides will run the length of the track and ride on the chain.

Should have things next week.

Couldn't resist playing in the snow with it. I have to take some picture but basically in the 14-18 inches of light snow dozer just keeps moving. The tracks are cover up with snow and the front of the dozer is pushing snow but it keeps going. Could have spent hours playing in the snow but had a problem when the engine died. Big surprise you need to have gas in the tank for the engine to run. After that point I figure I better put it away before I get into trouble.

 

[Hooked_on_HP]

This is a great build. Just curious, what do you plan on using it for. Or were you just curious as to whether you coud build one. I am always building somthing just for somthing to do.
Bill

 

[workinprogress]

At first the project started out as an idea to help get firewood for my house. I burn about 4 cord a year and have been cutting it on my property but unless conditions are perfect (dry ground or frozen with no snow) my garden tractor (2wd) just won't cut it. I saw the Struck Mini Dozer and thought this might work for a couple years until I get a larger tractor or something. I started collecting parts and developing a plan. I mentioned this to a couple people and a few weren't sure I could pull it off. At that point it became more of a challenge. I enjoy working on projects like this and have built other things for the garden tractor (3 pt Hitch, hydraulic Johnny Bucket, Modified ATV snow plow for tractor).

As I told my wife I could be doing worse things than working in the garage on projects.

 

[tthopskin@yahoo.ca]

I love it I was going to make one the same only I was going to run my hyd motors to a gear box the track was going to be the drive chains out of a champion grader and weld angle iron on the chain started my collection of parts had all the bearings I needed one more gear box well one day I went to get a bearing for the board bandit and all my bearings gone thanks to my fathers friend he took them for his saw mill but that was a long time ago but it is nice to see it to,,,to me I know now it would have worked thanks for the pic ps I love modifying and building too keep up the good work

 

[2manyrocks]

I suspect if we could all vote on a project that someone else has done to "test" in person, this one would be in the top ten. There would be guys lined up around the block waiting their turn.

 

[Iplayfarmer]

I suspect if we could all vote on a project that someone else has done to "test" in person, this one would be in the top ten. There would be guys lined up around the block waiting their turn.

It's on my list of "builds I'd like to drive"!

 

[o2batsea]

Pardon my ignorance, but why do you need chain drive to the tracks? Can't you just fit the motors direct? Seems like the drive chains add complexity and failure points.

 

[Willl]

The only reason I can see would be to keep the drive motors out of the muck.

 

[workinprogress]

Chain Drive is for two reasons: Gear reduction (currently 3.4 to 1) and ground clearance.

While both of these can be address in different ways this is where I ended up. I cannot mount them directly to the drive shaft of the track. The track sprockets are to small and it would result in 2 or 3 inches of ground clearance. I am still thinking about mounting a smaller third 100 pitch sprocket connected to the hydraulic motor which would directly drive the track. This would be similar to some other dozers. Still a potential and will continue to think about it as an option. Getting multiple contacts with this drive sprocket is a concern but could be overcome.

Have most of the steel cut for the 36 inch track slide which will support the track between the sprockets. While I have things apart I will closely examine if I can get a small sprocket (9 teeth or so ~4 inch dia) mounted high on the track. I finally found small sprockets but they are over $20 each. This would drop me down to a 2.3:1 ratio.

 

[workinprogress]

Well I got most of the remaining parts cut but not welded or drilled yet. The two picture show the slide I am working on to support the track between the sprockets. My plan is to pop rivit the UHMW stock to the flat steel with 8 (4 on each side) 1/4 inch pop rivits. I am thinking about rivits because they are easy to install and countersink the heads. The material is much wider than the chain so the heads should never come in contact with the chain. I only have two supports which is to help keep the track tensioner open to adjust/improve it. The open end of the square tubing will be enclosed I just left those parts off for the photo.

Also I plan on bolting the slide supports to the track frame so I can removed the slides for repair and if needed I can shim the slide supports as the UHMW wears.

 

[Willl]

Screw the rollers, I like this 'slide' idea better.
Any thoughts of a slight groove to keep everybody in line ?
,
,
,
(must be some type of super glue holding those together)(yes, I know, just joking)

 

[workinprogress]

The chain is pretty stiff so it doesn't move much. I figured I will let the system wear and see if will make it's own grove.

 

[jd2305cd]

Just like a snowmobile, great idea.. Great project, but we really need A VIDEO of this beast in action..

 

[Kernopelli]

I like the idea of the slide too. I think the material you are using is similar to something I am familiar with. When I was a meat cutter, we used thick cutting boards that were made of a VERY durable high density plastic. We occasionally changed them out and I still have a few of them. They are great for making chain guides on dirt bikes, I've made wheel spacers for 4 wheelers out of them, turned bushings, etc. If it is at all similar, I think it will do the job and hold up very well....good idea!

...And yes, action video is a must! BTW, you have my 16 yr. old son sitting on the edge of his seat with this project!

 

[workinprogress]

Hello All,

Here is the video. Hopefully it works.


Video.flv video by workinprogress_2010 - Photobucket