Broke my grapple ( Am I the only one?)

[Groo]

I think people need to understand that these grapples are made for smaller machines that don't have loaders that can lift a ton. Every extra pound added is a one less pound it can left. It does look like a little more engineering could have been done to spread the load across more metal without adding too much more weight

I don't care how weight conscious you are being, if it needed 3/8" steel for the bracket, it shouldn't be welded to a 1/8" box without some sort of plate to spread the force out. Its pretty obvious they made it beefy were it was easy to see and scrimped where you won't see it until it is too late. That is almost fraud. It is certainly intentionally deceiving the customers.

and they sure as heck should be able to take a little pushing on the front of the grapple, because people are going to do a little pushing with it.

 

[JimP]

I wouldn't say the grapples are built too light overall. Mine is on a Kubota 5240 with the 824 loader. I don't know where (or how) mine started to fail but it seems that opening and closing lengthened the initial crack in the top box around the weld zone. There's no doubt this area could be beefed up but there doesn't seem to be failure in the lower tines or other stressed areas.

 

[IslandTractor]

I'm glad you guys have reported this issue. I'd never heard of it and agree that the 1/8 tube construction is pretty lame.

I thought the OP reported that he pushed with the closed grapple against a tree. I can imagine that would put some stress that the grapple was not designed for. The upper jaw on this style grapple is really just a clamp to secure the load and should probably never be doing anything more than that. The bottom tines are designed to push, shove, dig, lift etc but the top is really just a clamp.

That said, I am still surprised by the 1/8" square tube. Compared to how my Millonzi grapple is designed, the WildKat seems to have an inherently weaker attachment point for the hydraulic cylinder on the top tube. If I am seeing the two examples correctly it appears the Wildkat mount is just welded to the top of the square tube. If you look closely at the third and last Millonzi photo below it appears that they have an attachment bracket that distributes the load over both front and top of that same top tube. It also appears there is an additional piece of steel welded on top of the top tube that would also strengthen it further. The forces from bashing the top grapple into a tree would therefore be distributed more broadly and would push directly into the tube rather than put all the stress on a mount tower welded to just the top of the top tube.

I've had my Millonzi 48" grapple for about six years now. I've bent some tine tips but never come close to this type of serious damage. I've posted some photos below of the grapple design. I imagine it has thicker square tube but I think maybe the design of the attachment could be even more important. I'll look this weekend and get some more detailed photos so we can compare the basic design and I'll see if I can confirm that the tubes are thicker than 1/8th too if I can without drilling holes etc.

 

[buck12]

I'm glad you guys have reported this issue. I'd never heard of it and agree that the 1/8 tube construction is pretty lame.

I thought the OP reported that he pushed with the closed grapple against a tree. I can imagine that would put some stress that the grapple was not designed for. The upper jaw on this style grapple is really just a clamp to secure the load and should probably never be doing anything more than that. The bottom tines are designed to push, shove, dig, lift etc but the top is really just a clamp.

That said, I am still surprised by the 1/8" square tube. Compared to how my Millonzi grapple is designed, the WildKat seems to have an inherently weaker attachment point for the hydraulic cylinder on the top tube. If I am seeing the two examples correctly it appears the Wildkat mount is just welded to the top of the square tube. If you look closely at the third and last Millonzi photo below it appears that they have an attachment bracket that distributes the load over both front and top of that same top tube. It also appears there is an additional piece of steel welded on top of the top tube that would also strengthen it further. The forces from bashing the top grapple into a tree would therefore be distributed more broadly and would push directly into the tube rather than put all the stress on a mount tower welded to just the top of the top tube.

I've had my Millonzi 48" grapple for about six years now. I've bent some tine tips but never come close to this type of serious damage. I've posted some photos below of the grapple design. I imagine it has thicker square tube but I think maybe the design of the attachment could be even more important. I'll look this weekend and get some more detailed photos so we can compare the basic design and I'll see if I can confirm that the tubes are thicker than 1/8th too if I can without drilling holes etc.

I think your grapple and the Wildkat have a similar design (see photo). Your grapple may be made of heavier tubing.

 

[IslandTractor]

I think your grapple and the Wildkat have a similar design (see photo). Your grapple may be made of heavier tubing.

View attachment 265770

Yes, I see that now. Still looks like the whole bracket is ?1/4 inch too. I know my top bracket is 3/8. I will still take more detailed photos and measurements of my Millonzi this weekend.

In the meantime, I would certainly suggest that anyone who has had this failure notify Wildkat. And, that anyone about to purchase a 48 economy grapple see if they can specify an upgrade to heavier gauge tubing all around. It would easily still be the cheapest grapple around if they put another 100 bucks into heavier tubing.

 

[GregbkH]

I'm glad you guys have reported this issue. I'd never heard of it and agree that the 1/8 tube construction is pretty lame.

I thought the OP reported that he pushed with the closed grapple against a tree. I can imagine that would put some stress that the grapple was not designed for. The upper jaw on this style grapple is really just a clamp to secure the load and should probably never be doing anything more than that. The bottom tines are designed to push, shove, dig, lift etc but the top is really just a clamp.

The grapple jaw was open when pushing on the tree. I had the grapple tilted down a bit too much causing the top jaw to contact the tree before the bottom tines. My fault, I just didn't see it. However, after looking more closely at the operation of the grapple, it is just a matter of time before the cylinder bracket will fail. There are two reasons for this. One, repeated clamping of the jaw is going to fatigue the top of the box tube where the welds are especially with 1/8" wall tube. Two, the cylinder bracket should have been extended further across the box tube toward the back of the grapple. I believe that you mentioned this previously.

 

[JimP]

Lets not single out Wildkat. Mine has no name (bought at auction) but it had a very similar failure. The top tube is just less than 1/8 thick, the cylinder bracket is 3/8 thick with front and side gussets similar to GregbkH and Island Tractor's. The box seems to mostly be a spacer for the tines, its only that one section where the cylinder mounts that needs to be beefed up to prevent this failure. Mine cycles pretty rapidly so I think a flow restrictor would also help lessen fatigue.

 

[IslandTractor]

I just drilled a hole in the 3x3 top square tube of my Millonzi Light Duty 48" grapple to measure the wall thickness. The wall is quarter inch thick mild steel.

The fact that some of the grapples with this avulsion of top tube mounting post are made of 1/8" tube may therefore be a simple matter related to inadequate base plate dimension to stand the load. While it would be best if WildKat and others simply used thicker walled tubing, the alternative would be to add a plate to distribute the load better as some of you have done to repair the broken grapples.

If I were to order a Wildkat 48 economy model now I think I'd discuss an upgrade in material with them and wait for the next batch. I'm guessing that the material cost upgrade from 1/8 to 1/4 3x3 tubing couldn't be more than $25 to them. I'd happily pay that or even an upgrade to 3/8 wall.

My 1/4" wall grapple has been heavily used as indicated in various bent and twisted bits over the years. However, the top tube is undamaged even after twisting the whole upper grapple arm which must have put forces on the attachment points similar to what tore the OP's top tube.

 

[Legacy1]

It seems like these are all the "economy" versions. I wonder if the standard and HD models are breaking as well.

 

[IslandTractor]

It seems like these are all the "economy" versions. I wonder if the standard and HD models are breaking as well.

My Millonzi was also an economy model. I think the lesson here is that while the basic economy grapple size and design are well proven, that as buyers, we'd better start paying more attention to materials. 3/8 tines are well proven. I think we can conclude the same about the upper grapple mounts. Basic cylinders seem to be fine. This issue with the top tubes has just come to light and it is probably reasonable to conclude that the top tube needs to be 1/4" steel at a minimum unless there is some additional support for the upper jaw mount.

It is reasonable for economy grapples to be adequately built rather than overbuilt as the weight saving go directly towards increased load capacity. 1/8" unsupported top tubes do seen to have taken this a bit too far. If I were in the market for another grapple I would be quite happy to pay the difference in material cost for 1/4" top and bottom tubes. I hope one of the current Wildkat owners gets back in touch with the company to give them this feedback. They have an opportunity to get quite a lot of business from TBN members and I hope Wildkat management is smart enough to secure their reputation by upgrading construction in problem areas. It is clear they would still be the best bang for the buck in town if they raised prices by a hundred bucks or so and put most of that into more steel or better design.