Mini Motor Grader build

[sawdustdad]

Originally Posted by DRohacek

Frank, I have been thinking about your crawler idea. If you have the front rear turned around do you need to turn the charge pump 180 degrees because the drive shaft will be turning the opposite direction? Another thing I was thinking about is you can swap the ring gear to the left side and that will change direction instead of messing with the swash plate. You could change the linkage to move the control the same direction for forward then. The Cub rears can have the ring gear on either side. It makes no difference. In tractor pulling some guys run their tractors off the pto side of the engine instead of off the flywheel. When they to that they change the ring gear to the opposite side.

Yes, I was thinking I'd need to change the charge pump around.

I need to look at the rear ends and assess the difficulty in swapping the ring gear. Never messed with the rear ends before, so I'm not very familiar with that stuff. But it makes sense and sounds like the way to go.

I'm going to have to start another thread if I get serious about the crawler. I had been thinking about an articulated tractor, but that's been done a lot, so looking for something a bit more unusual, though there have been a couple tracked conversions. If I do the crawler, it needs to look and operate like a scale model of a real bulldozer. A mini D10. The D0.1.

This would be a project for next winter with some planning and testing/prototyping between now and then.

[DRohacek]

Frank I just watched what I believe is your latest video on YouTube. The ride along video of the motor grader. Very nice ride. I’m using a belt tensioner also. I haven’t tried to start it without disengaging it I just assume it won’t. I built a bracket on the left side of the frame and have a spring on the tensioner. Once it starts I pull the belt tight and lock it in a keyhole slot. You can see the bracket in the picture. I'm not happy with the handle sticking out so I am thinking of putting a pin through a yoke so that the handle will lay down against the side when the belt is pulled for tension.

[sawdustdad]

Originally Posted by DRohacek

Frank I just watched what I believe is your latest video on YouTube. The ride along video of the motor grader. Very nice ride. I’m using a belt tensioner also. I haven’t tried to start it without disengaging it I just assume it won’t. I built a bracket on the left side of the frame and have a spring on the tensioner. Once it starts I pull the belt tight and lock it in a keyhole slot. You can see the bracket in the picture. I'm not happy with the handle sticking out so I am thinking of putting a pin through a yoke so that the handle will lay down against the side when the belt is pulled for tension.

I posted another video of a new tool-less belt tensioner.

[sawdustdad]

Originally Posted by DRohacek

Frank, I have been thinking about your crawler idea. If you have the front rear turned around do you need to turn the charge pump 180 degrees because the drive shaft will be turning the opposite direction? Another thing I was thinking about is you can swap the ring gear to the left side and that will change direction instead of messing with the swash plate. You could change the linkage to move the control the same direction for forward then. The Cub rears can have the ring gear on either side. It makes no difference. In tractor pulling some guys run their tractors off the pto side of the engine instead of off the flywheel. When they to that they change the ring gear to the opposite side.

I swapped the charge pump around on my "test" rear end and voila! The rear end works backwards with the input spinning clockwise. No need to swap the ring gear or change the swash plate.

I need to start another thread now.

[guido]

Originally Posted by sawdustdad

I swapped the charge pump around on my "test" rear end and voila! The rear end works backwards with the input spinning clockwise. No need to swap the ring gear or change the swash plate.

I need to start another thread now.

Interesting. I look forward to following this.

[Ambush]

If you change rotation you'll have to change the pump valve plate too. You currently have a right hand plate.

[sawdustdad]

Originally Posted by Ambush

If you change rotation you'll have to change the pump valve plate too. You currently have a right hand plate.

You're over my head a bit on this. I rotated the charge pump housing 180 degrees, and drove the input clockwise, and the entire rear end seemed to behave exactly opposite of the way it did before. What does changing the pump valve plate do?

And what would I change it to? A left hand plate? Where would that be found?

[Ambush]

Yes, you'll need a left hand (counterclockwise) valve plate. At any kind of pressure the pump will vibrate and hammer with the wrong rotation.

This is going to be just like the "front or rear of the engine" debate. All pump's and motor's rotations are looking at the input end and technically this Sundstrand is being driven from the back.

When you're looking at the valve plate of a pump, you'll see the slots, V shaped notches or rare times a couple of holes. Now think of the port holes as a fish swimming and the notch is the tail. If the fish is swimming clockwise it's a right hand or clockwise rotation pump. Opposite for left hand.

[sawdustdad]

Originally Posted by Ambush

Yes, you'll need a left hand (counterclockwise) valve plate. At any kind of pressure the pump will vibrate and hammer with the wrong rotation.

This is going to be just like the "front or rear of the engine" debate. All pump's and motor's rotations are looking at the input end and technically this Sundstrand is being driven from the back.

When you're looking at the valve plate of a pump, you'll see the slots, V shaped notches or rare times a couple of holes. Now think of the port holes as a fish swimming and the notch is the tail. If the fish is swimming clockwise it's a right hand or clockwise rotation pump. Opposite for left hand.

Yeah, they are swimming CCW, so left hand (right hand looking from the axle side?). OK, that means I need to retain the same rotation as in the Cub, CCW from the hydro side, CW from the axle side. Might turn the engine around, then. Thanks for the insight.

[Ambush]

Definitely a right hand or clockwise valve plate in your hydro. Holding the plate in your hand, so you can see the wear surface, the “fish is swimming” clockwise. In this case the pump is driven from the back, so looking at it from the axle end it is turning clockwise. The pump doesn’t care which end you drive it from as long as the plate matches the rotation.

If you want to turn the hydro the opposite rotation, you’ll need a left hand plate.

But this does show that you’re slowly talking yourself into another unique project!