Another Mini-Dozer

[RangerRick]

Hi Rawinok2,

I agree with Renze on this proposed modification. As shown, your dozer will be going about twice as fast as you have it now. You may be breaking keys or belts and if they don't break, you may be thrown off the back of the machine if the engine is powerful enough.

As I stated previously, changing the pulley on the motor to half its diameter will slow the speed down by half. Did you try that yet? You can put idlers in the center of the belt (top and bottom) if you have too much belt slop.

Changing to the smaller pulley would give you twice the torque at startup also.

Seems to me that all you need to do this would be a new pulley and possibly a new belt if you don't want to introduce the idlers to take up the slack.

Rick

 

[Gypsyman]

I may have missed it but what is the length or "wheelbase" of your tracks?

 

[rawinok2]

I would put the pulleys opposed to what you sketch in the pictures, when the big pulley drives the smaller one, the speed will increase...

OOPSY DAISY !! You are absolutely right ! :ashamed: As the kids say "MY BAD !!". (See new sketch.)

I'm not qualified to speak on the dozer project, but when I start a reply and want to change it (like to a multi-quote) I simply hit the "Back arrow" on my browser which SHOULD take you o the prior screen, and start all over. If the text I was writing was good, I copy it BEFORE going back.
Be well,
David

THANKS FOR THE HELP !!!

Hi Rawinok2,
I agree with Renze on this proposed modification. As shown, your dozer will be going about twice as fast as you have it now. You may be breaking keys or belts and if they don't break, you may be thrown off the back of the machine if the engine is powerful enough.As I stated previously, changing the pulley on the motor to half its diameter will slow the speed down by half. Did you try that yet? You can put idlers in the center of the belt (top and bottom) if you have too much belt slop.
Changing to the smaller pulley would give you twice the torque at startup also.Seems to me that all you need to do this would be a new pulley and possibly a new belt if you don't want to introduce the idlers to take up the slack. Rick

OK, but I am taking the advice of someone who stated earlier, that I should plan on Installing a hydraulic pump when I can afford one. Would the added shaft and pullies not be a good idea as long as I assemble it correctly as shown in sketch ?

 

[rawinok2]

I may have missed it but what is the length or "wheelbase" of your tracks?

36" from center of shafts or 48" from furthest point on sprockets.

 

[Gypsyman]

Thanks. Just trying to get a reference for overall machine size.

 

[Dscrew]

Didn't you say earlier that you were building this from the struct corp plans?

If so did you deviate from them or is this just the way that their machine runs as well?

 

[RangerRick]

OK, but I am taking the advice of someone who stated earlier, that I should plan on Installing a hydraulic pump when I can afford one. Would the added shaft and pullies not be a good idea as long as I assemble it correctly as shown in sketch ?

Hi Rawinok2,

I suggested you go hydraulic when you can afford it, but I don't think your extra pulleys at this time would save anything in the future. When you go hydraulic, you would have the hydraulic pump mounted on the engine shaft and then hydraulic hoses running from the pump to two separate hydraulic motors that will have chain drives to sprockets attached to the final drives on your rear drive wheels. So I think you would be cutting some of your pulleys out to switch to hydraulics.

Speaking of drive wheels, I noticed you put drive sprockets on the front rear of your dozer. On dozers, usually the rears have the drive sprockets and the fronts have what look like idlers that run on top of the inside track. I believe it is done that way to reduce wear on the pins. Just curious why you did it that way even though it does look like you have four wheel drive. LOL

Bob, I hope you don't take my input the wrong way. I think your project is a beautiful piece of work and I've welded on many occasions over the past 30 years but I can't come close to the nice welding I've seen you have on your machine.

Keep up the good work!

Rick

 

[hawkeye08]

I just read through this, nice build!

 

[Short Game]

I just read through this, nice build!

Durned good show, alright!

 

[rawinok2]

Didn't you say earlier that you were building this from the struct corp plans? If so did you deviate from them or is this just the way that their machine runs as well ?

I think I mentioned on the first page or two that I used the Struck plans just for, what I refer to as, "the transmission". That would be the size and location of the pullies, belts, sprockets, chains, shafts, bearings etc. The frame, body and track were my design.

Hi Rawinok2,
I suggested you go hydraulic when you can afford it, but I don't think your extra pulleys at this time would save anything in the future. When you go hydraulic, you would have the hydraulic pump mounted on the engine shaft and then hydraulic hoses running from the pump to two separate hydraulic motors that will have chain drives to sprockets attached to the final drives on your rear drive wheels. So I think you would be cutting some of your pulleys out to switch to hydraulics.
I understand what you are saying but that is something I'd never do with this particular unit. If I ever can afford to build a hydraulically driven unit, I'd start from scratch. I figure if Struck's pulley driven units have worked for them the last 40+ years, then I shall get this one going tweak by tweak or else! The hydraulic pump that I was referring to would be a small one for operating the attachments (front and rear blades etc.). Then I could get rid of those lousy electric actuators!

Speaking of drive wheels, I noticed you put drive sprockets on the front rear of your dozer. On dozers, usually the rears have the drive sprockets and the fronts have what look like idlers that run on top of the inside track. I believe it is done that way to reduce wear on the pins. Just curious why you did it that way even though it does look like you have four wheel drive. LOL

I am not sure what you are talking about here. Do you, by any chance, have a photo of an example of this? I have attached a photo of the keyed rear drive sprocket as well as the free-wheeling front sprocket fitted with sleeve bearings. Hope this clears things up for you.

Bob, I hope you don't take my input the wrong way. I think your project is a beautiful piece of work and I've welded on many occasions over the past 30 years but I can't come close to the nice welding I've seen you have on your machine. Keep up the good work!
Rick I appreciate any and all critisism. One is never too old to learn.

I just read through this, nice build!
Thank You !

 

[ben2go]

I would add zerks to those free wheeling sprockets.Make'em last as long as possible.

 

[Stonehaller]

OK, but I am taking the advice of someone who stated earlier, that I should plan on Installing a hydraulic pump when I can afford one. Would the added shaft and pullies not be a good idea as long as I assemble it correctly as shown in sketch ?

Adding the jack shaft with the pulley arrangement as you have shown will definitely slow down the dozer. Be sure to add a provision for belt tension either by hinging the jack shaft mount or allowing the mount to move up and down. Or is the rear idler used for tension?

Others have suggested reducing the size of the pulley on engine by half. Although you could make it slightly smaller, I would not go as far as one half the size of what you currently have as that so reduces the surface area that you would probably have belt slippage and greatly reduced belt life.

 

[Redneck in training]

Very nice work.
If you want to use the jack shaft to drive the hydraulic pump make sure that it has sufficient rpm. You might be better of driving the pump directly from the engine or by separate belt.

 

[RangerRick]

Hi Bob, Attached is a picture of a dozer side view. Note that the rear drive is a sprocket and the front is an idler. (without the teeth)

Rick

 

[rawinok2]

I would add zerks to those free wheeling sprockets.Make'em last as long as possible.

Done! See photo.

Adding the jack shaft with the pulley arrangement as you have shown will definitely slow down the dozer. Be sure to add a provision for belt tension either by hinging the jack shaft mount or allowing the mount to move up and down. Or is the rear idler used for tension?
Yes, the rear idler is spring loaded but I would need an idler on the front belt.
Others have suggested reducing the size of the pulley on engine by half. Although you could make it slightly smaller, I would not go as far as one half the size of what you currently have as that so reduces the surface area that you would probably have belt slippage and greatly reduced belt life.

I agree with that ! :thumbsup:

Hi Bob, Attached is a picture of a dozer side view. Note that the rear drive is a sprocket and the front is an idler. (without the teeth) Rick

Well, I'll be... I've never seen that before !. Like I said, one is never too old to learn !

 

[chaffe]

Hi Bob, Attached is a picture of a dozer side view. Note that the rear drive is a sprocket and the front is an idler. (without the teeth)

Rick

Always thought that was the norm, the reason being that the main driving direction (forward) will pull the track directly on the ground, so that there is no tension over the top and round the idler (this would be the case in reverse, not ideal as it puts a lot of strain on the idler and frictional loses would be higher, not to mention any slack in the tracks would cause a delay in drive.)

 

[Renze]

Others have suggested reducing the size of the pulley on engine by half. Although you could make it slightly smaller, I would not go as far as one half the size of what you currently have as that so reduces the surface area that you would probably have belt slippage and greatly reduced belt life.

Thats what i was thinking too... bending a belt too tight will cause fatigue cracks in the rubber, and reduce the friction area between belt and pulley.

Our Husqvarna rider lawn mower has a special heat resistant belt for the wheel drive, because its used as a clutch as well: Despite that, i still have to replace it every 3 years.
So if your dozer belts fail prematurely, check for them heat resistant belts.

 

[Grayson Klassen]

There is an edit button ...

My Bad. Sorry I am a lowly silver member, when I am an elite I will do better. LOL

 

[beppington]

My Bad. Sorry I am a lowly silver member, when I am an elite I will do better. LOL

Well, I wouldn't have said anything but I spent like 2 hours looking up teo pulleys.

 

[rawinok2]

Rawinok,
When you get some down time away from your excellent fabrication, will you post some more details of how you slowed down your drill press. Every since
I saw that it's been eating at me to do the same thing to mine.

I'm adding my"aye" to that proposal!:thumbsup:

+1 on that one from me.

...Oh ya the drill press thing too.
Chris

... Count me in for the drill press also.

Well, I've got some down time now so I thought I'd give you the run down on the modification that slowed my inexpensive Sears drill press from 620 RPM to about 205 RPM. The first thing I did was purchace a 1.5" diameter pulley (1/2" bore) from DrillSpot.com | Online Hardware Store for $3.82. Next I purchased a 4.5" dia. pulley (1/2" bore) from www.pheonix-mfg.com for $15.30 (about twice of what I should of paid for it!). Then, from www.McMaster-Carr.com I purchased a 1/2" dia. x 9" long keyed shaft for $16.90, two 1/2" dia. pillow block bearings for $21.90 and two 1/2" shaft collars for $1.50. This made the total $59.42 (plus the cost of one additional belt).
The Surplus Center did not have any of those parts at the time but it would probably be worth checking with them first for maybe a better price. I then scrounged around in the scrap pile and found a piece of 4" square tubing (3/16" wall x 5" long). On the side of the tube I welded two pieces of 1 x 1/4" flat bar drilled and properly spaced for both mounting the tube to the drill press as well as mounting the motor to the tube(refer to photos). I drilled the tube so that the two pillow block bearings could be mounted to the inside.
I welded a 1/2" thick tab which was drilled and threaded for a 1/2" bolt on the outside of the tube for the motor belt tensioner. I cut the sheet metal shroud away so that there wouldn't be any interference with the added pulleys. Note: Making this modification throws the center of gravity back enough to make the drill press want to tip backwards. It will either need to be bolted to the bench (if it is a bench model) or mounted to a heavy plate which extends out towards the back at least 6". I then assemble it and purchased an additional belt and presto! Before I knew it I was knee deep in shavings !