PT425 Grapple Build Project

[pequeajim]

J.J Who makes that grapple rake?

 

[stray]

Moss I sure am looking forward to you getting your grapple done. I really wouldn't suggest anyone building a grapple the way I did. Hind sight I think that there would be much less welding, less material and labor to build one the way Power-Trac does. Mine seems to work just fine it just took about twice as much everything than it should have.

 

[J_J]

I don't know right off hand. I saved that picture just to get some ideas. I have a bunch of grapple pictures. Some light duty, and some heavy duty

 

[pequeajim]

I want to put together a lighter duty grapple rake that I can use to do some sifting as well. When I say lighter duty, I mean something with an all up weight a little more than the 4 in 1 bucket, yet heavy duty enough to not bend or break very easily.

 

[J_J]

How about this grapple.

 

[J_J]

If you have a torch and welder, this one would not be too hard to fabricate. Thickness of the steel could range from 1/4 in up to 3/4 in. Spacing would depend on what you are sifting.

 

[pequeajim]

I don't have any welding equipment or experience. I have thought about getting the design and material together and paying a visit to a friend of mine who does weld. Then we could build it and I could learn a little about how to weld myself.

The grapple pics that you posted is something like what I am considering. May be a cross between the first one and second. The tines looking like the second, but extended to allow sifting of the soil away from the rock that you pick up.

 

[J_J]

How about this one. It is called a land planer. Just need to add a grapple.

 

[MossRoad]

Remember this project??? YIKES it's been a long time.

I have it built and working. Several attempts at geometry have proven futile. I should have stayed in math class more often.

I opted to put the hydraulic cylinder on top instead of on the side of the rear as PT does. First attempt proves that you need the rear cylinder attach point HIGHER than the side jaw attach points. Failure to do so makes the hydraulic cylinder want to pull the jaws shut instead of pull it open. With a 3" cylinder with 35,000 pounds of force, it didn't take long to fold the metal up on the front of the grapple jaws where the cylinder attaches.

So I moved it up higher than the side jaw attach points... too high. This resulted in a grapple that opens a whopping 4".

Two more tries and I got it to a reasonable opening width. However, it doesn't have much bite, yet. I'm convinced I need to study someone else's design and steal, ah, err, borrow the concept.

I will be playing with it this weekend and post some pictures when possible. After I get it juuusssst right, I'll paint it.

 

[J_J]

Remember this project??? YIKES it's been a long time.

I have it built and working. Several attempts at geometry have proven futile. I should have stayed in math class more often.

I opted to put the hydraulic cylinder on top instead of on the side of the rear as PT does. First attempt proves that you need the rear cylinder attach point HIGHER than the side jaw attach points. Failure to do so makes the hydraulic cylinder want to pull the jaws shut instead of pull it open. With a 3" cylinder with 35,000 pounds of force, it didn't take long to fold the metal up on the front of the grapple jaws where the cylinder attaches.

So I moved it up higher than the side jaw attach points... too high. This resulted in a grapple that opens a whopping 4".

Two more tries and I got it to a reasonable opening width. However, it doesn't have much bite, yet. I'm convinced I need to study someone else's design and steal, ah, err, borrow the concept.

I will be playing with it this weekend and post some pictures when possible. After I get it juuusssst right, I'll paint it.

David, Check these pictures out and see if they help'