Homemade quick attach

   / Homemade quick attach #71  
I would have used 1/4" if the machine shop that I got from would have had it in stock. Called DOM??? Normal pipe wont work as its measured OD, not ID, which is what you need to match your pin size.

That helps a lot, Steve. I will try to source 1/4" thick tubing. Your idea of cutting the tubing in half to make the cradles is a real lifesaver for me on this project, as I don't have a brake or anything like that to bend flat stock.
 
   / Homemade quick attach #72  
Regarding the torque tube: I agree with what has been said for the pupose of it. It is to keep the bucket cylinders tied together, moving in unison when no bucket is attached. But there are stresses applied to it when it is attached and needs to be able to withstand the stress and/or spring back into place.
Example: Without a QA (normal pin on bucket) you go into a dirt pile and unknowingly hook right front corner of bucket under a heavy rock or tree root. Try to curl the bucket. The right side will stall first while the left cylinder still moves some applying some twist to the bucket. The bucket is built to flex some and spring back into shape when this happens. Now picture a tube tying the cylinders together, the same twist pressure is being applied so the torque tube either has to be strong enough to stop the twist or be able to spring back to oringinal shape.
Not to pick on any company or builder but here is the latest example of this type failure posted here on TBN. http://www.tractorbynet.com/forums/parts-repairs/265330-can-straightened-frame-machine.html. I have also seen posts like this in other Brand Name forums, even some of the major brand name design engineers that are relatively new to the QA system do not realize, or think about this possiblity.
 
   / Homemade quick attach
  • Thread Starter
#73  
I agree with what you say to an extent, the example you gave on that other thread doesnt add up though and raises more questions to me than what it answers. I can see tweaking the rod and not having it hook up as easily, but from the other thread I dont see the whole story on what happened, either he bent his bucket and quick attach setup (seems unlikely and would take some major abuse), or he didnt have it hooked up properly or something else failed allowing the connection to fall out of place and therefore bending the QA piece. Like I said with the pictures it just doesnt seem like he's telling the whole story, maybe to save face I dunno. I just dont see how it got bent that far out of whack while still being attached to a solid bucket.


ps- keep in mind the tube used in my setup is like 43" inches long so if there is a minor twist I think it can handle that easily given the length of it without any irrepairable damage.
 
   / Homemade quick attach #74  
I agree with what you say to an extent, the example you gave on that other thread doesnt add up though and raises more questions to me than what it answers. I can see tweaking the rod and not having it hook up as easily, but from the other thread I dont see the whole story on what happened, either he bent his bucket and quick attach setup (seems unlikely and would take some major abuse), or he didnt have it hooked up properly or something else failed allowing the connection to fall out of place and therefore bending the QA piece. Like I said with the pictures it just doesnt seem like he's telling the whole story, maybe to save face I dunno. I just dont see how it got bent that far out of whack while still being attached to a solid bucket.


ps- keep in mind the tube used in my setup is like 43" inches long so if there is a minor twist I think it can handle that easily given the length of it without any irrepairable damage.

I could see how it happened. Say, for instance, you attach a bucket, but one of the QA sides doesn't latch securely. Then you go pick up a load in the bucket. The loose QA side releases, so only one cylinder is holding the load. The uneven loading twists the torque "ell" as the still attached side moves with the force of the cylinder. That's why I will go with a torque "tube" (closed section) of sufficient cross section, rather than an "ell" (open section), when I build mine. It's the polar moment of inertia of the torque member that's either you friend or enemy in this situation.

My real reason for wanting a QA bucket with a torque tube is that the first time I unpinned my pin-on bucket, I made the mistake of bumping the FEL joystick. This caused the cylinder with the least internal resistance to move, while the other one stayed put. Later, trying to pin the bucket back on, I couldn't align the holes on the FEL with the holes on the bucket. Took a lot of time and profane language to get those pins back in.
 
   / Homemade quick attach #75  
I guess I'm a little unclear now on just how strong and/or flexible the torque tube needs to be. If all it was going to do was keep the loader arms aligned when the bucket was off, then it would only need to be strong enough to equalize the pressure in the hydraulic system. But if it's going to have to flex while the bucket is working, that will probably involve more force. Also, I'm not really sure whether it should be something very stiff, or more springy, to flex and return to true. I know that one poster here used some 1" solid square stock, but I got the impression that was just what he had laying around, not that it is specifically recommended. What do y'all think I should use?
 
   / Homemade quick attach #76  
Let me put it this way, there's not much that's going to stand up to a twisting motion driven by 2500 psi of hydraulic pressure applied to a 2" cylinder over a span of 40+ inches. So since it doesn't have to be super-strong, build it out of something reasonable, say 1.5 or 2 inch round or square tube with a minimum 1/8 wall thickness and you should be fine. The bucket or whatever implement you have will take all the stress anyway, and it's really only there to ensure the individual ends stay in sync when the implement is removed. Material that has some spring to it would be ideal, but mild steel will be fine too.

I'd use 2 inch square tube with 1/4 wall, but I tend to overbuild things.

If I remember correctly, when I removed my pin on bucket I could manually push in one curl cylinder and watch the other extend, so there's not a lot of opposing force there anyway.

Sean
 
   / Homemade quick attach #77  
Let me put it this way, there's not much that's going to stand up to a twisting motion driven by 2500 psi of hydraulic pressure applied to a 2" cylinder over a span of 40+ inches. So since it doesn't have to be super-strong, build it out of something reasonable, say 1.5 or 2 inch round or square tube with a minimum 1/8 wall thickness and you should be fine. The bucket or whatever implement you have will take all the stress anyway, and it's really only there to ensure the individual ends stay in sync when the implement is removed.

Sure, sure. That's kind of what I was thinking. Thanks.
 
   / Homemade quick attach
  • Thread Starter
#78  
I could see how it happened. Say, for instance, you attach a bucket, but one of the QA sides doesn't latch securely. Then you go pick up a load in the bucket. The loose QA side releases, so only one cylinder is holding the load. The uneven loading twists the torque "ell" as the still attached side moves with the force of the cylinder. That's why I will go with a torque "tube" (closed section) of sufficient cross section, rather than an "ell" (open section), when I build mine. It's the polar moment of inertia of the torque member that's either you friend or enemy in this situation.


Right, I agree I see how it could have happened too but from what I read he didnt put that in his post, the whole story doesnt seem to be there for whatever reason, maybe it wasnt relevant at that point because the damage was done, I just think there is more to it than whats in the post. The angle iron piece for that application probably is sufficient given what it does but obviously not enough for a mishap which is the reason that thread exists to begin with. :D


I guess I'm a little unclear now on just how strong and/or flexible the torque tube needs to be. If all it was going to do was keep the loader arms aligned when the bucket was off, then it would only need to be strong enough to equalize the pressure in the hydraulic system. But if it's going to have to flex while the bucket is working, that will probably involve more force. Also, I'm not really sure whether it should be something very stiff, or more springy, to flex and return to true. I know that one poster here used some 1" solid square stock, but I got the impression that was just what he had laying around, not that it is specifically recommended. What do y'all think I should use?


I think you're over thinking it. What is your loader capacity? Mines rated at like 1000lbs give or take. I've curled my 200lb bucket off the ground with one side attached and the other not by accident and im using 1.5 inch square i do believe with I thought was a 3/16 wallk thickness. In that instance it was strong enough and I had no issues, the lower pins obviously wouldnt go in due to my error so it wasnt as if I was going to dig a hole with my bucket unlatched thats for sure. I think it should be strong enough to at least lift your bucket unevenly because that is likely to happen.



ps- keep in mind if you have a smaller loader like me you dont really want to overbuild it to the extreme and take away your lift capacity.. I'm happy the way mine turned out, it doesnt seem to affect it much with the bucket a few inches farther out and I tried to keep the hitch as light as I could but strong where I needed it to be. I think mine weighs maybe 35 lbs or so.
 
   / Homemade quick attach #79  
I agree with what you say to an extent, the example you gave on that other thread doesnt add up though and raises more questions to me than what it answers. I can see tweaking the rod and not having it hook up as easily, but from the other thread I dont see the whole story on what happened, either he bent his bucket and quick attach setup (seems unlikely and would take some major abuse), or he didnt have it hooked up properly or something else failed allowing the connection to fall out of place and therefore bending the QA piece. Like I said with the pictures it just doesnt seem like he's telling the whole story, maybe to save face I dunno. I just dont see how it got bent that far out of whack while still being attached to a solid bucket.


ps- keep in mind the tube used in my setup is like 43" inches long so if there is a minor twist I think it can handle that easily given the length of it without any irrepairable damage.

After reading the thread starter, I think he might have tried lifting the log without the bucket in place, just a couple chains looped through the cradles.

Sean
 
 
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