Root Rake/Grapple For Kubota B2910

[rswyan]

More parts accumulating after being cut:

 

[rswyan]

These four 1/4" x 6" plates will form the towers/masts into which the upper jaw will mount. They were tacked together in pairs for machining/drilling:

In hindsight it would have been better had I tacked all four of them together - which would have left no chance of any variation in hole placement, even if a bit unwieldy ...

As it turned out, one of the series of holes was slightly off between the two sets ... no biggie: grind a little out and fill it with weld ...

 

[rswyan]

Drilling the holes. Lennox Bi-metal holesaws were used to cut the larger holes:

 

[rswyan]

Drilled and ready to have the rectangular hole cut out:

 

[rswyan]

Completed:

The additional (large, round) holes in the inner two plates (near the bottom) is for routing the hydraulic hoses to the cylinders from the center of grapple into the towers/masts.

 

[Deerherd]

I'm always impressed when someone on here takes on a project of this scope. I have to learn to weld....

I have the same W.R Long grapple, only wider. The one suggestion I have would have is to add an additional angle to the lower jaw. It appears from your drawing that it is straight.

It would increase your brush carrying capacity, put the "spades" on the lower jaw in a better rooting position and give you a better hold on whatever you are carrying. I handle lots of logs and for ease of picking them up it's a great design. Just drive up to the log, give it a little push to make sure it's resting on all the spades and close the grapple. It pulls the log into the lower angle every time.

Here's a photo of what the lower angle looks like. Good luck and nice thread.

Edit: While typing this thread you posted lots of updates so it looks like you are past my suggestion.

 

[rswyan]

Was having an issue with the bandsaw tracking correctly when I cut the chisels for the lower rake ... so I used the Delta Sharpening Center to square them up and put an edge on them.

One on the right is straight out of the saw, the one left has been squared and sharpened ... you could shave with it :

 

[Walkin Horse]

I am blindly gathering parts to make a grapple. I'm still stalled on what the geometry is for the cylinders to close. I will be watching your build so keep posting. Are you making it qa or pin on? I have gotten 2 4" square tubes and a bunch of 3/8 x4" flatbar. Looks like I need some sch 80 pipe.

 

[rswyan]

I'm always impressed when someone on here takes on a project of this scope.

Thanks ...

It will be the first one of this level of complexity that I have done.

I have to learn to weld....

It isn't really all that hard ... particularly with MIG ... a friend who is a welder showed/coached me.

Really learning to weld well is a bit more involved I'm sure

I have the same W.R Long grapple, only wider.

Yes ... I used your pictures along with NHBotanut's) when I was laying it out and modeling it

The one suggestion I have would have is to add an additional angle to the lower jaw. It appears from your drawing that it is straight. It would increase your brush carrying capacity, put the "spades" on the lower jaw in a better rooting position and give you a better hold on whatever you are carrying.

Interesting that you should mention that ... as that was in the original design from a couple years ago ... the one I lost in the hard drive crash.

I took it out this time around as I was starting to get a little concerned about overall weight and was looking to economize.

I handle lots of logs and for ease of picking them up it's a great design. Just drive up to the log, give it a little push to make sure it's resting on all the spades and close the grapple. It pulls the log into the lower angle every time.

Cool ...

I'm really looking forward to using it once it's done ... to the point that I might go ahead use it once I get it finished but wait to paint it until next year ... since it appears I'm running out of good weather for both.

Here's a photo of what the lower angle looks like. Good luck and nice thread.

Thanks !

Edit: While typing this thread you posted lots of updates so it looks like you are past my suggestion.

Yeah ... I welded the lower rake teeth on night before last i think ... but I can always modify it later if need be

 

[rswyan]

I am blindly gathering parts to make a grapple. I'm still stalled on what the geometry is for the cylinders to close.

Yeah ... that was a bit of a mind flock for me ...

I'll try to post a better explanation of how to do it (locating attachment and pivot points) ... might be a few days though. Having access to a CAD program is helpful in figuring it out ... but it isn't a show stopper if you don't.

In terms of ease of fabrication though, you want to these locations to be easy to find/locate ... example: '... drill the hole for the pin 2" in, and 1" down from the top right corner of the plate ..."

I will be watching your build so keep posting.

Will do.

Are you making it qa or pin on?

SSQA ... but I still have to build the tractor side SSQA

I have gotten 2 4" square tubes and a bunch of 3/8 x4" flatbar.

I used 1/2" x 3" flat bar (upper jaw arms, rake teeth) ... but there's no reason 3/8" x 4" couldn't work, providing it's properly reinforced.

The strength is really in the depth (4" in your case)

Looks like I need some sch 80 pipe.

Always handy to have around ...

Pipe (of the same wall thickness) will handle stress/forces better (from any direction) than square or rectangular tube (whose ability to handle forces is more directional than pipe)