FEL bucket grapple installation

nickel plate · Apr 22, 2011

From the design to the freight depot to the bucket mounting:
2002 New Holland TC40S w/ 72" standard bucket.
Michigan Iron and Equipment MIE LBG-72, a 24" grapple with a 10" cylinder stroke.

I did a lot of reasearch on this type of FEL grapple and landed on MIE to do the build. Their approach to me was quite effective as they were the only company to ask for a full size loader bucket side profile which I did in cardboard, Exacto Knife cut into five or six pieces and marked edge to edge (puzzle style) so they could re-assemble what I sent to them in an 8x10 envelope. The side bucket profile was then handed over to their engineer and I was then sent an engineered pdf to approve-I did make a few small dimension changes and then it went into production. All of this was because they had not yet built one for my model of tractor bucket.
The grapple came with a well written owner's manual/installation instruction booklet and a set (2) of plate steel load bar drilling templates-I did not use them but elected to fit/mock up the load bar with my shop clamps and then drilled the bucket holes to my findings. Do notice the zirk grease fittings!

Today I had the last set of hoses pressed from the grapple to the torque bar so I am done with the hydraulic fabrication phase but several more posts to follow including custom built (hacksaw, grinder and file) bulkhead fitting brackets cut out of standard sized steel pieces, routing, etc.

VE6IAZ · Apr 22, 2011

That's a nice looking grapple and I realy like the way you have the bucket teeth mounted. That will be a mean machine! It's always nice to work with a company that will listen to what you want and that is willing to work with you. Leon (a tractor attatchment supplier here in Canada) was the same way with me when I ordered a dozer blade for my Kubota M6800. They had not done one for that model but they asked me to do some measurements and a series of pictures and vola I had a dozer blade. Not cheap mind you but they were the only ones who would do it. You have a nice looking unit.
VE6IAZ

nybirdman · Apr 23, 2011

Looks good,I have a Green's Machine thumb,Markham tooth-bar,good set up.
I found I had to replace the forward clevis pin with a bolt...was always losing them in the brush piles.A lot less money and weight than a full grapple.
Just the spring clip not the whole pin!

jake98 · Apr 23, 2011

Nice looking grapple. It seems like a lot of force to be going to the bolts tho.. I bet you end up welding it on eventually.

nickel plate · Apr 24, 2011

jake98 said:
Nice looking grapple. It seems like a lot of force to be going to the bolts tho.. I bet you end up welding it on eventually.

Hello jake98,
Before I received the grapple, I asked MIE if the bucket mounting bolts were supplied or do I need to buy them myself and the answer was that they were supplied so I took it no further as to the size required. They are 1/2" grade 8 and I too think they should be at least 5/8" even better 3/4" and I have plenty of room to drill them out, the side ears of the box beam are 1/2" thick. I intend to start out tender and work up to some stump carrying. This is not by a long shot their first grapple build, just their first for my NH bucket style. Thanks for your observation.

MichiganIron · Apr 24, 2011

Good observation on the bolt size...

It's by design. Every piece of equipment needs a designed in "Fail-Safe", i.e -shear bolts on a PTO drive-line. On our bucket grapples, it's the side-wall bolts. The design of a bolt is governed by 3 criteria, shear / tension / and bearing. With the thickness of the bucket side-wall, we decided to size the bolts a 1/2" Gr 8. In straight shear, the combined sidewall bolt capcity exceeds the cylinder pin shear capicity. Since the bolts have an eccentric load, the pattern is designed to shear the front bolt before the cylinder or the cylinder pin are damaged. Easier to change out a bolt than deal with an expensive repair to the grapple or the loader bucket.

We have never had a bolt fail ...that we know of.

Just our design approach, it has served us well.

jake98 · Apr 24, 2011

That sounds like a good approach.. as a nail-banger, I never think to calculate the shear to less than a more expensive part. :thumbsup:

nickel plate · Apr 24, 2011

MichiganIron said:
Good observation on the bolt size...

It's by design. Every piece of equipment needs a designed in "Fail-Safe", i.e -shear bolts on a PTO drive-line. On our bucket grapples, it's the side-wall bolts. The design of a bolt is governed by 3 criteria, shear / tension / and bearing. With the thickness of the bucket side-wall, we decided to size the bolts a 1/2" Gr 8. In straight shear, the combined sidewall bolt capcity exceeds the cylinder pin shear capicity. Since the bolts have an eccentric load, the pattern is designed to shear the front bolt before the cylinder or the cylinder pin are damaged. Easier to change out a bolt than deal with an expensive repair to the grapple or the loader bucket.

We have never had a bolt fail ...that we know of.

Just our design approach, it has served us well.

Glad you came in to the 1/2" bolt question-saved me a phone call. I would not had done any drilling without running it by you first.
I'm down to final tightening on the hydraulics-so far so good-It's been a long process but I am very pleased with the outcome.