Another Mini-Dozer

workinprogress · May 3, 2012

From my minidozer build I have found this more of a trial and error thing. When the track is tight I had problems with snow building up in the teeth as well as dirt. The track just kept getting tighter until it wouldn't move. When the track is loose I tended to throw the track during a tight turn. That being said I run mine tighter than that. Basically I tighten it until the slack is gone but the tension spring is just starting to be compressed.

RangerRick · May 3, 2012

Hi Bob,

Having owned and operated a Deere 400g since 1989, if that were my machine, I would tighten up the track by moving the idler forward only about 1/2 inch more. I think that would look about right and prevent you from hopping the track. The spring would allow movement for small rocks and dirt in the sprockets.

Glad to see you back in the saddle, somewhat at least. Get Well Soon.

Rick

wrangler6831 · May 3, 2012

I cant wrap my head around why some would suggest that the bogey needs to spring forward or either way for that matter. Ive never seen one on any dozer of any size do that. Maybe on a TANK that has some suspension built in but not on a dozer. I think it will be fine like it is. Fantastic job!

rawinok2 · May 4, 2012

Iplayfarmer said:
My uneducated, unexperienced, speculative advice is to run it like it is.....

cschulz said:
I think it should run like it is....Just my $.02
Chris

Brahmus said:
....i run just a slight amount of droop between the sprocket/top roller/idler....

workinprogress said:
....Basically I tighten it until the slack is gone but the tension spring is just starting to be compressed....

RangerRick said:
Hi Bob, I would tighten up the track by moving the idler forward only about 1/2 inch more....

Thanks guys ! I will take all of your thoughts on the matter into consideration.

wrangler6831 said:
I cant wrap my head around why some would suggest that the bogey needs to spring forward or either way for that matter. Ive never seen one on any dozer of any size do that. Maybe on a TANK that has some suspension built in but not on a dozer. I think it will be fine like it is. Fantastic job!

Now that's the advise I've been waiting to hear !! :thumbsup:

Renze · May 5, 2012

wrangler6831 said:
I cant wrap my head around why some would suggest that the bogey needs to spring forward or either way for that matter. Ive never seen one on any dozer of any size do that. Maybe on a TANK that has some suspension built in but not on a dozer. I think it will be fine like it is. Fantastic job!

Track sets under an excavator (that just carry the excavator) maybe not, but the traction crawlers i've been around (Vogele asphalt pavers, a very old Case trackloader) were tensioned by a big cylinder full of grease. Every morning you gave the system a stroke of grease, it would take the slack off the track before putting any on the lube areas itself..
This gives an overload protection (too much pressure by a foreign object means that your idlers will be greased

) and a very frequent adjustment to keep the chain tight.
Oh, and the Fiat 70C tracked tractor with an aftermarket loader in our "factory museum" had some very big coil springs to be able to give in when you high center the track over a rock right inbetween two idlers, or get a stick of wood between your sprockets...

rawinok2 · May 13, 2012

I tried running it while it was up on blocks and found that the track would rotate just fine in reverse, but in forward, the cleats would get hung up on the floorboard reinforcement gusset. That made sense I guess because in reverse the track is being "pulled" on the top and "pushed" on the bottom. In forward it was just the opposite so by being "pushed" on the top, whatever slack was present caused the cleats to rise up just enough to get hung up. I removed the track and ground off about 1/4" of material from the support gusset. That was enough to get it to clear. However, there is no telling what may happen when it is removed from the blocks. I'm starting to wonder if adding springs to the idler bogey is the best way to go. I am going to wait until my daughter can come over to test drive it for me so I can observe how well it is working. She is busy this weekend being awarded a "Masters Degree in Speech Pathology".

cschulz · May 13, 2012

Masters degree!! That is great Bob. You and your wife must be proud.
Keep us up to date as you can.

Chris

marklund · Sep 20, 2012

Very inspiring work! I have read most of the post and have seen the question "how well does it push dirt" but have not seen the answer. Given the 16hp engine and the belt transmission, how well does it function as a digger? Thanks for posting all the progress photos!

ben2go · Sep 20, 2012

Has anyone heard from rawinok2?

rawinok2 · Sep 20, 2012

marklund said:
Very inspiring work! I have read most of the post and have seen the question "how well does it push dirt" but have not seen the answer. Given the 16hp engine and the belt transmission, how well does it function as a digger? Thanks for posting all the progress photos!

Sadly, I was down all summer with my bleeding feet and ankle problems (if you havn't read about it yet, keep reading). I haven't been able to see how well it pushes dirt because I am still working out a few problems. My daughters have been too busy to come by and help me with more test drives. I finally was able to get my wife to help me. She observed while I drove. It seemed that the left track would, in the course of a revolution, ride up on the sprocket as if it was trying to come off but then would, all of a sudden, snap back on again. I figure it might be something as simple as not having the tension springs equally tightened. If any one has any other ideas please post them. :anyone: Thanks in advance !

plumbstraight · Sep 29, 2012

You might consider using some guides to keep the track centered. Having sprockets on both ends there cannot be any slippage on the front idler.
You have put a lot of work into the tracks and they look wonderful. I wonder if it wouldn't have been better to just have gone down and bought some conveyer chain as it comes in all guages and widths and sprockets are available for any of them. would have just been the process of making the pads to fit the chain.
I have ran all sizes of dozers from a 40C which I own along with a 350C to an D11 Cat. All have some sort of spring except the high sprocket systems. I guess the weight of the track off the high sprocket to the front idler is enough to hold tension as well as give enough slack as needed.
Good luck with your project, is fun to tinker.

marklund · Oct 1, 2012

Thanks for your reply. You might try to make a magnet mount for your video camera to really see what is going on. I suspect that the track is not hitting the notch in a place or two.
I'm sorry about your health issues, hopefully your doctors can offer a solution.

Camdigger · Dec 14, 2012

Loudo said:
Sir, I have just read through the thread,Now that's a project,:thumbsup: your skills as a welder and fabricator are awesome, I also would like to see a video. Now I've retired maybe this would be a good project for me as well as She who must be obeyed will not let me buy a small dozer. Can anyone tell me where I can get build plans? I also hope your new doctor can sort your legs out. After reading what has happened to you my aches and pains are trivial. All the best and god bless. Kerry.

PM me if you want a copy of the Struck plans. They're old enough they're off patent protecetion, but may yet be copyrighted.

Camdigger · Dec 14, 2012

rawinok2 said:
Sadly, I was down all summer with my bleeding feet and ankle problems (if you havn't read about it yet, keep reading). I haven't been able to see how well it pushes dirt because I am still working out a few problems. My daughters have been too busy to come by and help me with more test drives. I finally was able to get my wife to help me. She observed while I drove. It seemed that the left track would, in the course of a revolution, ride up on the sprocket as if it was trying to come off but then would, all of a sudden, snap back on again. I figure it might be something as simple as not having the tension springs equally tightened. If any one has any other ideas please post them. :anyone: Thanks in advance !

Is it possible there is an alignment problem? The tendency of the track to climb the edge of the sprocket might be solved by tapering (slightly) the sides of the sprocket teeth. Commercially made sprockets are not generally squaare cut, but have a "lead in" radius to help guide the chain onto the sprocket.

The "climbing" issue could also be a function of the track chain tension. A little more tension may help.

I know this is wayyy late, but in some of my research, I found that Struck did not use standard profile VEE belts on the belt driving the counter rotating shafts. They used a hex cross section belt specifically designed to drive standard pulleys from either side. They are common on older combines back in the grain sieve section. I bought mine from a local transmission supply house. They are big $ compared to a standard section belt . IIRC the84" or so HH section belt I bought was +/- $60 CDN.

Hope you are doing OK with the skin thing. Being robbed of your health and mobility sucks for most of us who aren't true couch potatoes.

Marcle · Dec 21, 2012

rawinok2 said:
I have finished installing the additional bogey wheels which I had mentioned in my 2nd from last post. This should take the sag out of the track and relieve some of the stress on the individual links. I had posted my project on a welders web sight and one of the members spotted a problem, which, luckily, I was able to easily correct. He noticed that I had installed the engine-to-jackshaft idler pulley in the wrong location. Since the engine rotates CCW, the idler pulley should be on the return or slack side which in this case, is the bottom side not the top. If all goes well, I should be able to post a video of it in action soon.

Idlers.... I had the same set-up on a Rotavator/Tiller. The machine used to destroy belts in no time at all, even though the 'idler' was mounted on the 'slack' side. What I did in the end, was to mount the motor on some sliding rails to do away with the idler which forced the belt in to an non-natural position (breaking its back comes to mind). Since fitting the sliders, I'm very pleased to say its no longer eating the belts. The sliding motion is controlled by some rods to an old handbrake lever, so the ratchet on the handbrake mechanism holds the motor in position to give drive. I would post a photo, but but friend has 'borrowed' my machine..... so not available.

Marcle · Dec 24, 2012

Re Linear Actuators.

I fabricated a 3pt linkage type arrangement on the back of my garden mower to attach my rotovator/tiller on. Unfortunately it would lower fine, but struggled to lift. What I did to solve the issue was to fit a pair of large pull springs (I think they were originally used on 'up-and-over' garage doors to counteract the weight). These counteracted the weight of the attachments, so that all the linear actuator was 'position' the attachment at the desired height. This may not look as good as having just the actuator, but it does solve the issue.