Tractor grapple

[ridefst]

I bought a Massey Ferguson MF1240 recently, and was using it to load logs onto a trailer with just a chain on the bucket.
It picked them up easily, but they were hard to control.

I figured that it would work a lot better if I had a hydraulic grapple on the bucket to pick up logs. It'll also be really nice when cutting them up for firewood, as I should be able to just hold a log a few feet off the ground and cut it into 18" pieces pretty easily.

I started with a photo of the bucket and a tape measure, so I could scale it properly in SketchUp.


I played around with different shapes, and cylinder lengths - ended up with this:
I'm only building one grapple, but drew an extra one to picture it both open and closed.


I'm fortunate to have a friend working with a large laser, so I sent the files over to him to get cut out of 1/2" steel.

I'm not very good at stopping work to take pictures...
But here's where I got to after one evening of assembly




Here the cylinder mounts are finalized. Just took the plugs out of the cylinder and stroked it by hand to figure out exactly where they needed mounted. I couldn't move the cylinder at first, so used an air blow gun to get it started, but after that it wasn't too hard to push/pull by hand.




Waiting on hoses now, it'll be run by a solonoid diverter valve off the curl function.
Hoping to get it running by the weekend.

The welds are decidedly not awesome, I'm much better with MIG than stick, but my MIG is far too weak for 1/2" steel, so I had to use the stick for once. I'm sure they'll be strong enough, but they are nothing special to look at, that's for sure!

 

[Citydude]

Nice work! Looks to be up for the task.

 

[MinnesotaEric]

Excellent. Looks like you hooked up a to a computer controlled plasma cutter.

Well done.

 

[ridefst]

Excellent. Looks like you hooked up a to a computer controlled plasma cutter.

Well done.

Nope, this is a step above plasma. I believe it's a 2,500 watt Amana laser.
The 1' and 3/4" pin holes required about 30 seconds of grinding with a dremel to clean up one small bump at the exit, and then the pins slipped right in with almost zero slop.
The cut quality is just amazing.

 

[tvman]

That looks good! I built one similar but the full width of the bucket. I might suggest though that you weld on some stops at the grapple hinges to keep the lid from opening past center.

Mine worked great for doing just what you are doing. I also got some teeth to bolt onto the bucket lip, some thing are hard to pick up without it.

 

[ridefst]

That looks good! I built one similar but the full width of the bucket. I might suggest though that you weld on some stops at the grapple hinges to keep the lid from opening past center.

Mine worked great for doing just what you are doing. I also got some teeth to bolt onto the bucket lip, some thing are hard to pick up without it.

I think I'll be ok on opening past center - the cylinder bottoms out before it can go over center. Good to keep in mind though, we'll see how it actually works out with fluid.
I was wondering about teeth on the cutting edge, nothing planned at the moment, but I could definitely see adding those later, depends how much trouble I have grabbing logs off the ground.

 

[Mysfyt]

Very nice design! What cad program did you draw it on?

 

[nybirdman]

Nice.I have the factory make "thumb".A tooth-bar will make it a lot easier to pick logs.

 

[petegoud]

Nice job, you may want to build up the flat plate holding all the top brackets. I've experienced some bending there using a similar flat plate. A lot of pressure on the top of the bucket, especially when carrying a large heavy log, and bouncing up and down in the woods.

 

[ridefst]

Very nice design! What cad program did you draw it on?

www.sketchup.com
Very easy to use, and they have a free version to boot!

 

[ridefst]

Nice job, you may want to build up the flat plate holding all the top brackets. I've experienced some bending there using a similar flat plate. A lot of pressure on the top of the bucket, especially when carrying a large heavy log, and bouncing up and down in the woods.

Hmm, I dunno - that 1/2" plate sure looks strong to me at the moment.
I'll keep an eye on it though, if anything looks like it's starting to move, I hope I can get it braced up before it gets bent too badly.

 

[ridefst]

All done, and it works great!
I love how fast it operates, wish I could get the bucket curl running that fast!


Valve body is a little messy looking, but works well. Nothing gets stretched or pinched, though I might add a long spring to pull the grapple hoses off to the side when the bucket is curled back, just to make sure they don't find their way between the bucket and the stops.



First test


Pretty much maxed out the tractor with this one


Just a quick video of it operating

[video]http://vid5.photobucket.com/albums/y193/ridefst/grapple/Video%20Nov%2014%202%2006%2022%20PM.mp4[/video]

Works great holding smaller logs on end too!
Didn't have anybody else to film it, so I had to hop off for a few seconds - I know, not the greatest idea, but I was so impressed with the speed we were cutting up these logs, I had to get a video
The saw is kinda noisy, turn down your speakers first.

I could probably get more of these cut out pretty reasonably if anybody was interested in purchasing a "weld your own" kit of plain steel pieces.
I know a lot of people can assemble and weld, but not so many people have the equipment to design and cut something like this.
I've got files for an excavator thumb as well, that I built a few years back.

 

[GLyford]

Do you have an estimate of the added weight?

Might make the biggest difference in someone deciding to do this or not.

 

[ridefst]

Do you have an estimate of the added weight?

Might make the biggest difference in someone deciding to do this or not.

It really isn't bad at all.

The steel weighs right on 80lbs total.
The cylinder is probably another 10lbs or so.
The valve body and hoses are a few lbs more, but they're back behind the bucket, so that weigh has less effect on lifting ability.
So an easy figure is 100lbs total, most of which is all the way at the back of the bucket (particularly with the grapple open)

 

[Lifeman]

Looks Great!! I did the same thing to my L3800 bucket and it works great.

 

[MD09]

Would you be willing to share the design file? I have a shop near by that could cut the steel.

Thanks
Rob

 

[ridefst]

Would you be willing to share the design file? I have a shop near by that could cut the steel.

Thanks
Rob

Sure, no problem.
Shoot me a PM with an email address.

 

[Renze]

Judging by the size of that cylinder, you might want to consider adding a plate over the edge of that bucket top lip, down to where the tilt cylinders attach to your bucket, to prevent twisting the top edge of your bucket. That cylinder is quite beefy to put on a sheetmetal bucket without spreading the load in the direction of push.