Grapple Failure

[bhh]

Well it's happened. About 1 year old with only 25 hours of use. I've been easy on it so I'm not really sure how it happened although I suspect the opening pressure of the cylinder had something to do with it. These forums is where I found out about this particular grapple but the "value" vanishes pretty quickly after something like this. The warranty is only 6 months but I contacted them anyway to see if they would offer a replacement at cost or other gesture to indicate they stand behind their product. The woman on the phone ask me to send photos and said someone would give me a call back but that was several days ago and no one has responded yet. I knew not to get my hopes up however when the woman said something along the lines of that is their cheapest grapple and you get what you pay for. Anyone have any ideas about exactly what happend or if this is repairable.

EDIT: I'm not sure if it is appropriate to mention the company here or not. Are there forum rules regarding that? I don't want to be seen as ripping on the company but think people should be able to make informed decisions about products and the companies that sell them.

EDIT 2: Since I am getting PMs anyway, I might as well go ahead and note that this grapple is from Wildkat Attachments.

 

[oosik]

I think you had better go into more details regarding the problem. I do not see any component failure in the pictures you submitted.

 

[allen in texas]

I think you had better go into more details regarding the problem. I do not see any component failure in the pictures you submitted.

The tower (for lack of a better word) where the cylinder mounts is shoved backwards from what I see. Looks like the mounting point is not strong enough.

 

[bhh]

This weld has failed where the bracket that hold the cylinder is attached to the top cross bar. The result is the grapple will not close all the way (about 12" open in closed position). The bulge in the crossbar indicates to me that there has been considerable pressure on it. I think if the cylinder was not installed and adjusted properly, opening grapple jaws all the way could have forced the cylinder bracket down through the crossbar. Its a little hard to describe.

 

[CalG]

Well, It sure looks like an easy fix!

Problem is the post won't take the pressure when you are clamping down on a load.
Pushing the tower back, or actually rotating the tower relative to the beam it's on. That's how the weld failed "inward", shearing the HAZ next to the weld fillet.

The fix?

Chain the grapple jaws together and use the hydraulics to try to OPEN the jaws. This will pull the tower back into it's useful position. Go slow, Look all around to make sure you are not tweaking something else!

Then when in position, vee out and weld the crack.

Then, BOX in that tower! I would plate down and across the transverse beam (the one the tower is on) on both the back and front of the tower. Triangular plates out to the full width of the present gussets and about 3 inches more. the plates should go to the lower edge of the beam, and up to the cylinder end mount. End up with a sandwiched tower and plates that are now in compression and tension and not a weld in bending..

$50 in 3/8 plate and a couple pounds of filler rod should do it!

Best to set the grapple off the loader arms so you can get access to the weld areas.

 

[allen in texas]

Well, It sure looks like an easy fix!

Problem is the post won't take the pressure when you are clamping down on a load.

Yes, it appears to be an easy fix but wouldn't you think that something like that should be strong enough to take the entire force of the cylinder closing the grapple? In my mind, whoever built this unit should consider that regardless if it is the least expensive model.
"you get what you pay for"? I could say that about something I buy if I try to cut corners but to have the manufacturer say that. Come on.
As far as the repair, after it's fixed the cylinder could be replaced with a smaller diameter cylinder. That would reduce the muscle the cylinder has when closing the grapple.

PS edit...
as far as naming the manufacture goes, I know that I wouldn't want to buy one of these and experience the same failure. A private message to me and anyone else who asked naming the manufacturer and the model number would be an OK deal. Might save me some grief down the road.

 

[bhh]

Well, It sure looks like an easy fix!

Problem is the post won't take the pressure when you are clamping down on a load.
Pushing the tower back, or actually rotating the tower relative to the beam it's on. That's how the weld failed "inward", shearing the HAZ next to the weld fillet.

The fix?

Chain the grapple jaws together and use the hydraulics to try to OPEN the jaws. This will pull the tower back into it's useful position. Go slow, Look all around to make sure you are not tweaking something else!

Then when in position, vee out and weld the crack.

Then, BOX in that tower! I would plate down and across the transverse beam (the one the tower is on) on both the back and front of the tower. Triangular plates out to the full width of the present gussets and about 3 inches more. the plates should go to the lower edge of the beam, and up to the cylinder end mount. End up with a sandwiched tower and plates that are now in compression and tension and not a weld in bending..

$50 in 3/8 plate and a couple pounds of filler rod should do it!

Best to set the grapple off the loader arms so you can get access to the weld areas.

Thanks Calg, that sounds like it could work. I couldn't figure out how to "unbend" it but chaining the jaws together will probably do it. I don't weld but I've got a neighbor that is pretty handy with a welder whom I'm sure I could trade a little seat time with to do this. How long do you think something like this would take? Thanks so much for the advise.

 

[allen in texas]

Also, and I guess I'm on a roll here, why should you have to "be easy" on a tool that you buy to work. I'm not talking about abusing the thing but you shouldn't have to baby it.

 

[bhh]

Also, and I guess I'm on a roll here, why should you have to "be easy" on a tool that you buy to work. I'm not talking about abusing the thing but you shouldn't have to baby it.

I agree, when I say take it easy, I mean bashing the thing into trees or what not. I also agree with your thoughts about the manufacturer. I was terribly turned off by the response. Its not like I am running it on skid steer or a 60HP tractor or something.

 

[k0ua]

Well, It sure looks like an easy fix!

Problem is the post won't take the pressure when you are clamping down on a load.
Pushing the tower back, or actually rotating the tower relative to the beam it's on. That's how the weld failed "inward", shearing the HAZ next to the weld fillet.

The fix?

Chain the grapple jaws together and use the hydraulics to try to OPEN the jaws. This will pull the tower back into it's useful position. Go slow, Look all around to make sure you are not tweaking something else!

Then when in position, vee out and weld the crack.

Then, BOX in that tower! I would plate down and across the transverse beam (the one the tower is on) on both the back and front of the tower. Triangular plates out to the full width of the present gussets and about 3 inches more. the plates should go to the lower edge of the beam, and up to the cylinder end mount. End up with a sandwiched tower and plates that are now in compression and tension and not a weld in bending..

$50 in 3/8 plate and a couple pounds of filler rod should do it!

Best to set the grapple off the loader arms so you can get access to the weld areas.

This sounds like it would work to me. And is how I would attack it also. yes the top square tubing is too light, we have heard of this before, but it can be "worked around" and repaired for not a whole lot of money, just some time. I think this is well within the grasp of a hobby welder like me, but if you cannot weld, or don't feel confident, at least get the tower pulled back out of the top tube using the hydraulics like CalG suggested and then take it in to a local welder and they can fix you up. The original welds don't look all that good to begin with, but the tubing is just too light duty, and that is the root cause.

 

[CalG]

bhh
If I were limited in fabrication equipment, I would make up cardboard templates for the front piece (s) IT looks to me like there will be some complications associated with getting fitted up to the tower. So work that out with cardboard and not steel.

'Not sure where you get your metal, but I would then take the templates to a weld fab supply (we have a good one in my area, Hope he never gets old!)
Have the pieces burned out. Then the welding would be a matter of final fit up and some smoke.

I would expect the cutting to template out to be less than $100 and the weld time less than 2 hours from set up to clean up**. You get to do the painting when things cool off! ;-)

** (Note: my expectations on costs and time have NO direct link to anything that you might experience!! ;-))

 

[bhh]

PS edit...
as far as naming the manufacture goes, I know that I wouldn't want to buy one of these and experience the same failure. A private message to me and anyone else who asked naming the manufacturer and the model number would be an OK deal. Might save me some grief down the road.

You know what, I gave them an opportunity to stand behind their product. The least they could have done is call me back and offer a discount on a replacement or some advise on how best to repair it and prevent if from happening again in the future. It's from Wildkat Attachments. This particular grapple has had a fair amount of discussion on the forums here which is where I found out about them. I was originally pretty happy with the price but the fit and finish is not so good. This grapple has been stored in a barn and never seen a drop of rain. I love having a grapple but will probably invest in a better one (EA?) when I can justify purchasing a second one if the fix doesn't work out

 

[bhh]

bhh
If I were limited in fabrication equipment, I would make up cardboard templates for the front piece (s) IT looks to me like there will be some complications associated with getting fitted up to the tower. So work that out with cardboard and not steel.

'Not sure where you get your metal, but I would then take the templates to a weld fab supply (we have a good one in my area, Hope he never gets old!)
Have the pieces burned out. Then the welding would be a matter of final fit up and some smoke.

I would expect the cutting to template out to be less than $100 and the weld time less than 2 hours from set up to clean up**. You get to do the painting when things cool off! ;-)

** (Note: my expectations on costs and time have NO direct link to anything that you might experience!! ;-))

I'm going to ask my neighbor to take a look repairing it. I'll pay for the steel and any fabrication and allow him to suggest what he thinks is a fair amount of my seat time on his property to help out with some chores. Everyone w/o a tractor has a mental list of things they'd like to do if they had one but don't want to trouble the neighbor with. I'm sure he'll jump at it actually.

 

[CalG]

Just looked at their Ebay offerings.

That is a LOT of steel for $1000! Seems like it just needs to be viewed as a good start, with the "Improvements" suggested by experience such as yours.
The way I see it, your repair will be no more complicated or time consuming than if it had been done the same way by the mfg. And will likely cost the same too ;-)
Just that now you get to supervise the work and act as the QA manager too. Double WIN!

Now don't you feel fortunate!
Plus, You get to offer sage advice from knowledge gained by experience.

Myself, If I were in need of a grapple for picking up brush etc, I wouldn't be turned off that brand based on your experience. Heck, I've tore up stuff a lot faster than that!
I would look to that specific area as something that could be improved.

Do I see that there is an add length of angle iron across the back of that beam on the latest models? Continuous Improvement is a sign of a good outfit.

Run 'em till they fail, then add material so that it doesn't happen again.

But maybe it just part of the SSQH..............

Bottom line for me, Based on the photos, The beam might be strong enough, but if the weld and HAZ is just a little off, that's were it will fail. And it did.

"If you would have bought the unit made on Tuesday, when the welder was feeling his best, this may have never happened" ;-)

 

[jlgurr]

On a side note, looks like your right front tire is mounted backwards. Just sayin'....

 

[bhh]

Lol, it does indeed appear to be on backwards! Good eyes jlgurr. I just had the local tire shop do some permanent repairs to a couple of plugs I installed last summer and it looks like they flipped it. I didn't even notice when I installed it. Taking another closer look at the pictures, it looks like there is something else going on with how that tower attaches to the beam as well, obviously the same forces at work here. I'm referring to area labeled as #2.

 

[CalG]

I saw that, That's is why the suggestion to plate all the way down to the lower edge of that cross member.

And the idea that fitting those front pieces might get a bit complicated. A bit of a kink in new support plates might be the best idea. Every man will have a different way of going at it.

You just want to spread the grapple clamping load over as big an area as you can, while trying to optimise "leverage" . If you make one part "h*ll for strong" but it just transfers the same load to the weak spot next to it, The repair just breaks next to the weld ...again..... ;-)

 

[joshuabardwell]

This may be naive, but I think hydraulic implements should be designed so that the cylinders can go full to the stops without damaging the implement.

 

[IslandTractor]

This may be naive, but I think hydraulic implements should be designed so that the cylinders can go full to the stops without damaging the implement.

Absolutely.

I'm not wonder so much about the design as the material. What wall thickness is the top tube? It really should be 1/4 inch. Some of these companies try to save a few bucks and use 1/8 or something less than 1/4". Bad idea. This is exactly the type of damage that will occur although not usually due to simple grapple opening and closing. Damage occurs when pushing with the open upper jaw or even just using the upper jaw closed to push. No grapple is built to tolerate that sort of leverage and misuse. The upper jaw is simply designed to clamp down on whatever is in the grapple maw. Push with lower jaw.

 

[k0ua]

Absolutely.

I'm not wonder so much about the design as the material. What wall thickness is the top tube? It really should be 1/4 inch. Some of these companies try to save a few bucks and use 1/8 or something less than 1/4". Bad idea. This is exactly the type of damage that will occur although not usually due to simple grapple opening and closing. Damage occurs when pushing with the open upper jaw or even just using the upper jaw closed to push. No grapple is built to tolerate that sort of leverage and misuse. The upper jaw is simply designed to clamp down on whatever is in the grapple maw. Push with lower jaw.

Pretty sure that is 1/8 tubing.. that is the crux of the failure. But it can be fixed.