Another Mini-Dozer

[kylebosch808]

Great job on the doozer so far! Great fab skills.
Is this thing going to have reverse? i dont see in the photos how its going to have a reverse gear?

 

[rawinok2]

Great job on the doozer so far! Great fab skills.
Is this thing going to have reverse? i dont see in the photos how its going to have a reverse gear?

Yes, zoom in on the drawing below and look at the 4 pullies on the right that are driven by one belt (this is the motor driven belt). You'll see that one of them has got to be running backwards because it is driven by the back of the belt. It is a flat faced pulley. That pulley drives the lower shaft (counter clockwise on the drawing) that in turn drives the two large innermost pulleys in the back in reverse.The four large outside pullies are driven by the upper shaft that is turning forward (clockwise on the drawing).
The two front shafts are always rotating in their respective directions as long as the tension lever is engaged. The rear large pullies don't turn until the slack in the belts is taken up by the idler pullies located on the hand clutches. Pushing the clutch levers forward tightens the forward driven belts and pulling them backwards tightens up the reverse running belts. Since the six large pullies in the rear (that drive the final chain drive) are on two independant shafts (three per track) the dozer can be steered by pushing one clutch lever forward while pulling back on the opposite lever.

 

[cschulz]

Here is a video explaining the belt system. About the 4:30 mark.
Also I was able to find a company that makes chain with attachment tabs to bolt the track too.


Chris
Jims Dozer #3 - Struck MD50 mini Dozer (7045) - YouTube
Attachment Chain from Renold Jeffrey

 

[sparc]

Looking at the photos of the belts I hope you don't have to change them often.

 

[GLyford]

Looking at the photos of the belts I hope you don't have to change them often.

As I understand it from a comment from an owner of one of these older machines on another forum, rapid belt wear was a big problem with this design and was why they changed to using a transaxle in later models.

There's a slightly different design that does something very similar, but uses only one belt per side that was more easily accessed for belt changes (fewer other belts, pulleys and linkages in the way). Also, it does not try to deliver power using the back of the belt where it has less grip and is more likely to wear out faster. It was used on early Bobcat skid-steers.

SkidsteerHistory.com goes into it, looks like there was a forward and reverse chain, and changing tension from the pulley on one side to the other changed which chain direction was driven?

 

[GLyford]

Hmmm... I bet if you designed the linkage to "over center" right, you could also get the control levers to activate a brake when centered, and release to either side before you got tension on the drive pulleys. Go-cart brakes (band or disk) are cheap easy to work with.

I would hope this would help make the machine safer and less "twitchy" because it wouldn't tend to drift to one side or the other in neutral, and it would mean some of your wear would be occuring in the brakes, not all in the drive belts.

 

[rawinok2]

Here is a video explaining the belt system. About the 4:30 mark.
Also I was able to find a company that makes chain with attachment tabs to bolt the track too.
Chris
Jims Dozer #3 - Struck MD50 mini Dozer (7045) - YouTube
Attachment Chain from Renold Jeffrey

Chris:Thanks for finding the chain. When I was researching my project, I looked and looked but couldn't find it. I may still need to use it if mine fails sooner than expected. This weekend I worked on installing the track. It went smoother than I expected. No pinched fingers, no extreme cursing !

 

[cschulz]

Chris:Thanks for finding the chain. When I was researching my project, I looked and looked but couldn't find it. I may still need to use it if mine fails sooner than expected. This weekend I worked on installing the track. It went smoother than I expected. No pinched fingers, no extreme cursing !

Looking great! Cant wait to see all complete and on its test runs. Be sure to post a video if you can.
Yes I wish the chain could of been found sooner. Looking at what you built for a chain must of taken a huge amount of time and pushed your fun meter to the max.

Chris

 

[GlennaR]

PowerHouse Engine Experience:

I purchased a log splitter with a PowerHouse (I thought it was PowerHorse) engine on it. So far AoK. After assembling the splitter n adding fuel n oil to the engine, to my surprise it started FIRST pull. Now two + months old it still starts first pull n just hums along.

One oddity: Even when the engine is warm or hot, you need to still use the choke in order to start it. It will NOT start with out using the choke no matter what.

Will it last ten years like a Honda?, only time will tell. However my splitter was just $3oo more with a motor than the same splitter designed to use my Kubots's hydraulic system to power the splitter. Seems to me it would have cost $2oo of that to buy the hoses n fitting to attach the splitter to the Kubota. So, for me twaz a no brainer to just buy the self powered (PowerHoarse) splitter....

So, from my vantage point, so far I vote a yes on the PowerHoarse gas motor......

 

[jsimp2861]

Would love to see the plans for this, I am hoping to build a small tractor using a vw engine and parts for general house work and getting in firewood. Any tips would be greatly appericiated.

Thanks
Jim