Grapple Grapple research and tentative conclusion what may be best for me; what do YOU think?

[dstig1]

Bottom line is that some gap is desirable and I'd imagine a minimum of 1/4 inch or so. Again, the key issue is how far the retaining pins protrude from under the mount when locked.

The folks at Gator were concerned that my gap was 5/16-3/8". They sent me 1/4" shims as they said no more than ~1/8" is acceptable. I agree. It fits much better after I did that, but then the upper hook design was still an issue that I fixed later on. It did slightly bend the original lower attachment hook when it popped out the first time or two, so yes, I would say having it loose on the mounts does add additional stress as it is applying stress out of position vs the design intent.

Based on what I was told and saw, I would put 1/4" at the upper limit.

Yes that would put strain on the pins. Typically though we tend to lift and curl more than pull directly backwards. Again, with appropriate length pins it wouldn't matter.

I often find with solo logs I have to lift them straight up with the grapple in full dump, otherwise I end up scooting them along the ground forever without anything to stop them, and with my hilly terrain, I don't have a lot of ability to change positions or I get pretty tippy going cross-hill.

 

[beppington]

Last week I bought the bottom 1/2 (the bucket part) of a 66" HD grapple from Connie at Wildkat Attachments (see 1 of Wildkat's pics below), & it has about a 5/16" to 3/8" gap between my QA securing pin's sloped surface & the securing surface on this new bucket.

It is very sloppy. With it on & "secured" I can easily lift the front end of the bucket up quite a bit & jiggle it all around to show just how not-secure it is. I prob can't actually dislodge it from my loader by yanking it around by hand myself, but I'm pretty sure that at some point I'll do something with it either too strenuous, or put too much strain on one of the front corner teeth, & it'll pop off ... So, rather than waiting for that to happen, I'm going to modify it by filling in the gap to where it tightens up securely like my OEM Kubota bucket (no play/ slop at all).

Also, there is very little of the bucket that contacts the 2 large flat surfaces of my loader arms. There is contact at the upper "lip", of course, & contact at the bottom slope ... although not all the time due to the slop ... but only one small section of vertical bar that contacts the front flat surface of my loader arms. This may not really matter, but it would sure "feel" better if there was some large chunks of steel plating on the bucket to contact the flat surfaces.

Those 2 issues aside, this thing is a beast! Every tooth is 1/2" thick steel with 1/2" steel triangular horizontal braces on each tooth. The vertical pieces across the back are 5/16" steel. Connie says it weighs 500 lbs., & it seems like that might be accurate; this thing is huge & heavy. $700 + shipping. I don't think my tractor could bend it even if I tried (of course that may or may not be a good thing )

 

[IslandTractor]

The "universal" skid steer mount that we all refer to was originally a Bobcat quick tach standard and then copied by others. There is no official bureau of standards for these things as best I can tell. The modern Bobcat mount is therefore the defacto standard. The general width of a modern quick tach measures 44" max from the outside to outside. There is variation and the Kioti outside to outside dimension as I recall is on the narrow end of the acceptable spectrum. A Kioti loader can mount a Bobcat implement but a Bobcat cannot mount a Kioti bucket. That means there are typically several inches of "slop" laterally when using the KL401 loader and a "universal" skid steer attachment plate. My grapple shifts from side to side about three inches when a sufficient lateral force is applied. It is annoying but doesn't seem to cause any problem. ​

Vertical distance of the mount is another issue. The vertical distance from top angle to bottom angle is supposed to be 16 inches on a universal skid steer mount. I don't know if Wildcat or Kioti is the one who missed the mark here as I've never measured either. ​

The final element of a quick attach is the locking pins. There are two pins that push out of the bottom of the mount when locked and the pins measure 32" on center. I don't know if there is any specification for how long the pins should be. ​

Main point here is that "universal" is not really well defined in the industry. There is variation in dimensions. There may be a problem with Wildcat fabrication accuracy or it could just be a bit of Wildcat and a bit of Kioti variability. ​

 

[dstig1]

Actually there is a standard:

 

[dstig1]

Bep - Yes - I think that is a common design flaw, the more grapple I see. They should put a solid plate in the section where the SSQA hits. The SSQA is already blocking any view through that section, so the visibility argument doesn't fly. Leave the rest of the back open, but make that section solid. My 2 cents...

 

[IslandTractor]

Actually there is a standard:

I stand corrected. Thanks for posting that. Looking at it I can see what part of the problem may be. For starters there seems to be an allowable 5/16th variation in the height of the mount. I might be misreading that but there is a variation noted.

In additiona, the Bobcat diagram shows the vertical distance of the mount as 16 inches. The SAE standard is 16 5/8 to 16 9/16ths. A manufacturer might choose the SAE standard and the loader mount manufacturer could use the original Bobcat dimensions. That gets you up to a 5/8 inch gap right there even if fabrication tolerances are exact.

 

[dstig1]

No sure where the Bobcat diagram comes from or if it is official, but the SAE spec is actually pretty tight for weldments - That's only +/- 1/32" on the height (5/8" = 10/16", so the tolerance range is 9/16" to 10/16" - you may have messed up your fractions). Over 16+" on a "farm attachment" that is pretty tight, IMHO.

 

[IslandTractor]

No sure where the Bobcat diagram comes from or if it is official, but the SAE spec is actually pretty tight for weldments - That's only +/- 1/32" on the height (5/8" = 10/16", so the tolerance range is 9/16" to 10/16" - you may have messed up your fractions). Over 16+" on a "farm attachment" that is pretty tight, IMHO.

We agree on the fractions. However the SAE document had a notation on figure 4 about an 8mm (5/16") range on two of the dimensions. At least that is how I read it. I'm not a mechanical engineer and didn't even sleep in a Holiday Inn last night so I may have misinterpreted the notation.

The Bobcat diagram came from one of the implement manufacturers. Most of them specify clearly the width and the pin holes but little mention is made of the height of the mount.

 

[dustinfox]

Actually there is a standard:

So if I am reading this correctly it should be 15 7/8 from top to bottom?

 

[Rockgod]

The folks at Gator were concerned that my gap was 5/16-3/8". They sent me 1/4" shims as they said no more than ~1/8" is acceptable. I agree. It fits much better after I did that, but then the upper hook design was still an issue that I fixed later on. It did slightly bend the original lower attachment hook when it popped out the first time or two, so yes, I would say having it loose on the mounts does add additional stress as it is applying stress out of position vs the design intent.

Glad you got them to admit the 1/8" mark as well as making things right. It makes you wonder if all these companies actually test fit. As a business owner I can't imagine sending out a product that "might fit"