Loader pin root grapple

[dfkrug]

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 have used all sorts of material for pins, and my preference would be to
use mild steel (not hardened) material. It is certainly OK to use harder
material like drill rod (untempered) or chrome-plated rods. Often the rods
used in shocks and hyd cyls are chrome-plated, but mild steel underneath
the plating. The biggest issue I have is harder material (like stock Kubota
pins) is hard to cut and drill. With chromed rods, I grind off the surface
plating if I am going to use my bandsaw to cut or drill them. Kubota pins
can not be drilled, and if cut, have to be cut by abrasive wheel or flame.
1.000" mild steel rod stock is very cheap, BTW, and works very well with
those bushings that are 1.020".

I keep some old shock rods around as large pin drifts, and even some
M/C shock rods (tubes) as very strong breaker bars that fit well over
my 3/4" socket handle.

 

[JustGary]

Guys -

Thanks for the info on pins. I may head out and rummage up some milder steel for the pins. It would sure be cheaper and easier to cut and drill. I'm not too worried about the rust, since they'll end up covered in grease anyway. I could blacken them (like the Kubota pins) to help that a little bit.

We made some progress this weekend. It was slow going cutting and facing all of the bushings, but we got all of them done. I drilled the side of one from each pair in order to cross bolt them in place. The bushings and load arm boxes are fully welded in place, but everything else on the rake is just tacked for now. We'll have a big buzz party soon to fully weld everything. Chipping the slag from 7018 rod kind of stinks...

Except for that, It's down to the rest of the grapple (and the pins)!

Regards,

- Just Gary

Img 1: Facing the load arm box sides for parallel fit.
Img 2: Setup to weld the bushings in the load arm box sides.
Img 3: Load arm boxes. The plates at the ends are not welded on; I just laid them on to check square. I'll have to add some diagonal braces later.
Img 4: Setup to weld the bushing on the center grapple jaw. I turned a faint ring on the bushing to help with alignment.
Img 5: Front view of the rake without the grapple.
Img 6: Rear view of the rake with the center grapple jaw and cylinder tacked in place. The math worked out right, and the cylinder fits in place!

 

[JustGary]

Guys -

Another progress report.

I got a hurricane day off of work Tuesday, and it didn't even rain, so I spent the day in the shop messing with pins, then finished tacking the grapple together. I have a couple of small diagonal braces to put on, but they'll be easy, and I know that it all fits together now.

I hung it on the tractor last night for a final fit check (but I didn't bother putting the cylinder back on also; I checked it a few days ago). Lining up the holes to tap the pins in place wasn't too bad after I figured out where I could apply leverage to move the thing around a little. Once I could see a set of holes lining up I just stuck a small rod in and lined them up enough to tap the pin in place. Each one you get in place makes the next one faster. Not exactly quick attach, but quick enough for me.

We have a few other projects going on around the house right now, but I hope to finish all of the welding and start painting this weekend. I can't wait to try this thing out!

Regards,

- Just Gary

 

[JustGary]

Well, I finally got the rake and grapple painted and took it out for a test drive yesterday. The rake is fantastic for ripping out Yaupon, which I seem to have in abundance. Much faster than the loader bucket for that, and it got a few pine roots out too (although the tractor just doesn't have enough breakout force to pull pine roots very well). Of course, the grapple makes moving the Yaupon very simple after it pops out of the ground.

This evening I took the tractor off the trailer and told my son to try out the grapple by picking up the pine log that we chip on for fire starter. He lifted the log a few times and then asked why the cylinder bracket was tilted. Huh. So it is.

I had looked at the grapple cylinder attachment when I painted it and decided it was probably too flimsy to handle the full closing pressure of the cylinder. When I used the grapple yesterday, I closed the jaw on things just enough to do the job. When he picked up the log, he held the button until the jaw quit moving. Apparently the attachment really was way too flimsy.

I'll have to cut it off to fix it properly, because I don't think that I can get it straight like it is, even with heat. By cutting it off I can use a sledge and anvil to whack it straight. Once I do that, I can weld double side plates and a top plate on to beef it up a lot, and one underneath will keep it strong around the pin. That cylinder produces a lot of force, all directed right at the fulcrum. But hey, at least my welds didn't tear!

Regards,

- Just Gary

 

[kennyd]

Nice Job Gary! You will get it right!

 

[magicheater]

I sure have learned a lot from reading through this thread and the other one on grapple construction. I designed a similar grapple using the lever and fulcrum design and that is where it is, a design. I have a grapple w/that design and wanted to improve the force at the tip of the grapple. I have given up on that and going to the direct force design. I am using solidworks and will miss it when my 90 day trial is up. As I look at all the designs out there they all seem to be pretty similar, wonder when we will see something a little more radical?