Loader pin root grapple

[kennyd]

Nice looking job JG

[3RRL]

Oh man Gary, the hydraulics turned out SWEET !!
I see you the Mrs to help you out too. It's great to see someone else besides us do our tractor projects together. I sent Loretta this link so I'm sure she'll be very happy to see that you mentioned her project in your thread.
When are we going to see your custom grapple mounted?

[mjncad]

Good work Gary, keep at it with more stuff.

[JustGary]

Wow! By some coincidence, the last post to this thread was exactly a year ago (where did the year go?). I bought a mill last year and have used it for many things unrelated to my tractor. Anyway, I have finally gotten back to this project and have an update.

Last month I found someone to plasma cut the parts for me, so I now have everything I need except for the pins. The rake is tacked together, and I'm working on boring the holes for pin bushings in all the parts that need them. I'll tack the grapple together after I get the bushings in place so I can hold it all together with pins while I weld it.

A few changes:

- I decided to go with 1/4" A572 grade 70 plate instead of 3/8" A36. This will save about 33% of the weight while providing about 30% more strength.

- I decided to go with 3/16" wall A500 square tube instead of 1/4" wall for the same reason.

- I changed the angle of the rake slightly to allow less tuck and more rollback.

- I extended the rake braces to nearly the tips of the rake teeth to help keep everything solid, especially with the thinner stock.

- I sloped the braces downward about 10 degrees to help shed dirt as the rake moves through the soil.

I think that since my tractor has limited lift and breakout strength, I should be OK with these changes. After spending a few weeks pushing out Yaupon with my standard bucket, I am confident that this will work fine. Only time will tell, though.

I'll post more pictures of the progress if you are interested.

Regards,

- Just Gary

[JustGary]

So I was out in the shop boring holes for the pin bushings when the phone rang. When I went over to the corner to answer it, I almost tripped on part of the junk pile. And what did I trip on? Of course! Those two old shock absorbers from the F-150! I kept them rolling around on the floor for about ten years because they have 1" steel rods that I "might use one day..."

Today I cut them open just below the top weld. That turned out to be a great place to cut, since the top will then pop off and let the inner tube and rod slide out. After pouring out the fluid (which does seem to mildly irritate skin, by the way) into a container, I found out that the valve at the bottom of the inner tube just pops off. The result from each one is a 1" pin roughly 15" long, with a ring welded about 5" from one end.

I now have two long pins to use for alignment purposes while I weld up the rest of the grapple. I'm strongly considering using them for the actual pins when I get to that stage. I suspect that they will be strong enough, but maybe you guys know better. Any reason I shouldn't use them as pins for the grapple? Note that I only need them for the grapple and cylinder. I will use the stock Kubota pins from the original bucket to pin the rake to the loader arms.

Regards,

- Just Gary

[mjncad]

I'd say they would work just fine. You might check and make sure the rods are a true one-inch and not 25mm since most automotive stuff is metric now.

[JustGary]

mjncad:

Actually, it's not either. The rods from the shocks measure 0.980", while the pins from Kubota measure 0.985" (25mm). The Kubota bushings are 1.015" or so, which gives about 0.020" of clearance. I bored out my bushings to fit those pins (so I can still use them on the loader arm ends).

The DOM tubing I have measures about 1.000" inside (how they do that reliably in a volume production, I don't know), so with the shock pins I would have 0.020" clearance. So, the clearance will be the same as the stock pins and bushings.

I'll have a problem with the grapple cylinder, though. The cylinder ends have 1.020" bushings, so my 0.980" pins fit like socks on a goose. I have some 1" drill rod, but didn't want to deal with hardening it. I'm seriously considering using it for pins and leaving it unhardened. Anybody got any idea how hard the pins should be? I'm thinking that as long as they don't shear, they are hard enough. After all, the bushings aren't hardened.

Regards,

- Just Gary

[SuperDuty335]

I like how the teeth are notched into the rails. Keep it coming.

[mjncad]

Originally Posted by JustGary

mjncad:

The DOM tubing I have measures about 1.000" inside (how they do that reliably in a volume production, I don't know), so with the shock pins I would have 0.020" clearance. So, the clearance will be the same as the stock pins and bushings.

Regards,

- Just Gary

I wish I knew how they did it too; but that's why it's more expensive than standard tubing. It sure is a pleasure to use.

Based on your measurements, I'd say the shock rods will work quite nicely.

[jmc]

Originally Posted by JustGary

mjncad:

Actually, it's not either. The rods from the shocks measure 0.980", while the pins from Kubota measure 0.985" (25mm). The Kubota bushings are 1.015" or so, which gives about 0.020" of clearance. I bored out my bushings to fit those pins (so I can still use them on the loader arm ends).

The DOM tubing I have measures about 1.000" inside (how they do that reliably in a volume production, I don't know), so with the shock pins I would have 0.020" clearance. So, the clearance will be the same as the stock pins and bushings.

I'll have a problem with the grapple cylinder, though. The cylinder ends have 1.020" bushings, so my 0.980" pins fit like socks on a goose. I have some 1" drill rod, but didn't want to deal with hardening it. I'm seriously considering using it for pins and leaving it unhardened. Anybody got any idea how hard the pins should be? I'm thinking that as long as they don't shear, they are hard enough. After all, the bushings aren't hardened.

Regards,

- Just Gary

Gary,

A couple of things- I think Kubota's clearance calculates out to .030 instead of .020 so .040 isn't that much worse. Clearance in general probably affects wear due to the amount of surface contact and, maybe, the way grease distributes itself when lubing. Rust might be an issue on your (unplated) drill rod. As far as shearing 1 inch pins, you have to shear them in two places and even if it was soft A36 steel, that would take over 50,000 lbs. (assuming shear stress is approximately equal to yield stress-36,000 psi. I didn't look it up) So if you are hardening it to resist wear, and the bushings are soft, I'd rather replace the pins than the bushings.

Thanks for the insight on junk shocks. I'll never look at them the same, knowing there's a pearl inside! I bet that shaft is hardened, so that may bite you if you have to drill it.

John