Low Buck grapple build

[Ryan03]

The grapple is 36 inches wide from the outside edge of one jaw to the other, bucket is 60 inches wide. Joe, the chains actualy work pretty well on hardpack snow and for getting over tree roots on the trail up my ravine, steering is not the greatest, but the straight line bite is prettygood, have a set of R-1 ags with rims on the way that should work much better in the woods than my current R-4s and chains, I figure that I will swap between R-4s and ags depending on what projects I have planned for upcoming month or so. 3RRL, I thought about building a all in one gusset/mount for the rear, but decided that due to the complexity of all the angles, I would be better off making the bracket shown, welding it on, and then making seperate triangular gussets to weld onto the front of rear bracket and tie into the entire front section of angle iron

 

[3RRL]

I think 3RRL meant to say "but not too wide". I agree and I don't know why other bucket grapples are not this wide. For some reason the more common width is about a quarter or a third of the bucket width. I think half the bucket width makes more sense and I don't see any downside. With the wider grapple you can trap more stuff, especially brush, that would otherwise work its way loose and fall out while driving with a load.

Thanks Island, that is what I meant to say.

 

[Ryan03]

Grapple is actualy 32 inches wide, not 36 like I posted last night, sorry for the mistake.

 

[IslandTractor]

Grapple is actualy 32 inches wide, not 36 like I posted last night, sorry for the mistake.

But that is still about 50% of bucket width which makes a lot of sense.

 

[jmc]

I think half the bucket width makes more sense and I don't see any downside.

One downside may be that extra width causes more twist on the grapple when its contacting the load harder on one side than the other side. For example, no log is a perfect cylinder, so you will always have asymetric loading when you clamp, since it will contact the larger diameter first.

John

 

[IslandTractor]

One downside may be that extra width causes more twist on the grapple when its contacting the load harder on one side than the other side. For example, no log is a perfect cylinder, so you will always have asymetric loading when you clamp, since it will contact the larger diameter first.

John

Understood. There would be some twisting force but consider that clamshell type grapples have a full length upper jaw and these seem to function well. I don't notice significant twisting with my grapple (roughly 50% upper jaw) when I can see that only one tooth has contact with the solid object (eg log). The jaw seems pretty rigid in those situations and does not twist.

 

[KentT]

Understood. There would be some twisting force but consider that clamshell type grapples have a full length upper jaw and these seem to function well. I don't notice significant twisting with my grapple (roughly 50% upper jaw) when I can see that only one tooth has contact with the solid object (eg log). The jaw seems pretty rigid in those situations and does not twist.

I don't see significant twisting on mine, which is full width. But, it is mounted on each end of the bucket.

 

[jmc]

I didn't mean wider grapples would necessarily flex. Its just that a properly designed one needs to be beefed up beyond what would be adequate with a narrower one. That's a downside from a weight and expense standpoint.

John

 

[3RRL]

No, you have a good point jmc.
A wider grapple will need more support between the jaws to keep it from flexing. You may have seen the movable jaws I built for my backhoe and they needed extra support between the jaws in this thread MOVING MECHANICAL THUMB.
I was going to mention that to Ryan, but after seeing his photos, it looked pretty beefy and supported.

 

[Ryan03]

Hello all, well I had to order my peice of 1 inch plate today, I could not find any in my local steel suppliers scrap bin, they said they are backed up on orders and probably would not have it cut until late Friday morning, oh well, the peice that I ordered is 12inches by 12 inches by one inch, total cost will be $36.00, which is 3.6 times my estimate from my earlier post. While working on a Case 580 series 2 backhoe today, I noticed the controls for the third function, they are 2 rubber buttons, each about the size of the top of a pop can and about 1/2 inch high, they operate an electric solenoid on the remotely mounted valvebody that pushes the spool back and forth, I was thinking [thats how I usualy get into trouble] that if I were to get a similar setup, and mount the foot controls to the right floor board in the front section, right behind my brake pedals, that sure would be a great way to operate the grapple, with my right foot, this would leave my eyes on the bucket, my right hand on the loader joystick, my left hand on the steering wheel and my feet near the pedals, where they should be. While I am waiting on the steel, I will investigate the cost of doing the controls in this manner.