Backhoe Build A Backhoe For PT425... It Could Happen

[BobRip]

Well, I measured some things tonight. In order to get 140 degrees of swing I will need about 19-20 inches of cylinder travel with an 8" arm sticking off the side of the boom pivot box. I have those free cylinders that have 21" of travel, but they are smaller diameter than I would like. However, I could put two of them on, one on each side, and have one push while the other pulls. That may give me enough power for the swing. It will also save me the cost of a very large cylinder, and it should eliminate the problem of faster swing in one direction that I mentioned above.

So, what's everyone think about that? Does anyone see a problem with two cylinders in the same circuit, one pushing and the other pulling? From what I've read in a few other places, it should work, but I'd like some opinions.

On my PT quick attach hydraulic modification, if I leave the valve open then the quick attach cylinder and the attachment cylinder will both operate, although one usually completes its cycle before the other one starts to move. Maybe this will help you.

 

[RegL]

Is that how the steering works on the PT?

 

[J_J]

Well, I measured some things tonight. In order to get 140 degrees of swing I will need about 19-20 inches of cylinder travel with an 8" arm sticking off the side of the boom pivot box. I have those free cylinders that have 21" of travel, but they are smaller diameter than I would like. However, I could put two of them on, one on each side, and have one push while the other pulls. That may give me enough power for the swing. It will also save me the cost of a very large cylinder, and it should eliminate the problem of faster swing in one direction that I mentioned above.

So, what's everyone think about that? Does anyone see a problem with two cylinders in the same circuit, one pushing and the other pulling? From what I've read in a few other places, it should work, but I'd like some opinions.

David, That arrangement should work OK. The push or pull force will depend on the hook up points. Hooked up to a short tab, will give less power, and hooked up a long tab/bracket will give the most power. If the cylinders swings the backhoe to fast, you can put restrictors in the lines.

 

[MossRoad]

The cylinders I have now have funky metric ball swivel ends. I cut them off of one cylinder tonight. Where can I get weld on clevis ends?

 

[J_J]

The cylinders I have now have funky metric ball swivel ends. I cut them off of one cylinder tonight. Where can I get weld on clevis ends?

David, Try Bailey's . Request a catalog if you don't have one or go on their website. I cut off my cylinder ends and welded on some tube ends cut from
1 in ID pipe, 1/4 in wall .

 

[MossRoad]

I downloaded Bailey's catalog last night before I went to bed. Looks like they have them in the parts section. I need clevis ends on the boom end on mine, but I think 1" tube will work on the end that attaches to the frame. I'll just have to cut and drill some more brackets.

 

[J_J]

Well, so much for waiting two weeks... the kids worked on their projects unsupervised with no problems, so I got to work on mine again.

Finished drilling the holes for the dipper stick cylinder and mounted it and the rear brackets. Tacked everything in place and tested for articulation... man, it swings smooth!

This is the 10" cylinder. I could probably go 12" or 14" without any modification, but I want to make sure that I cannot accidentally hit the backhoe pivot point or boom as J_J mentioned that someone he knew did this and damaged the boom cylinder. While my boom cylider will be on top, I still don't want to be hitting anything. I think I will use the 10" and see how it operates. If I am dissatisfied with it, I can always add a longer cylinder, or I have another choice... It is currently set for maximum lift height, which will also give it maximum depth while sacrificing the ability to dig close to the tractor. I could put another set of holes closer back to wards the tractor on the dipper brackets. I could then sacrifice lift and depth for digging closer to the tractor. It would just be a matter of removing the pin and relocating the rod end to another set of holes. I think I'll leave it as is for now and only make the modificaton if I need it.

Oh, yeah, I forgot... here's some picture goodness!


Running totals:
Time = 26.5 hrs.
Approximate Cost = $380

David, In picture # 02, is that the setup that you will be using, Something seems wrong to me. The geometry doesn't seem right. Here is a picture of mine. This is the dipper arm end. The cyl on the right will push or pull the bucket.

 

[MossRoad]

Yes, that is the way it looks for now. The brackets are overly large. When I get a few minutes, I will superimpose mine onto yours and then show you what could be cut off mine without hurting anything.

The first time I looked at it lying on the ground I about cried! I thought I had just welded everything on backwards!!!

But it passes the articulation test, so that's the way it will stay.

 

[J_J]

David, Will that 10 in cylinder allow the dipper section to fold up with bucket curled as in trailering and stowing?

 

[MossRoad]

Probably not. I think I will need a 12 or 14 for that.

Nice picture, by the way! Is that your summer look?