Quick Attach Forces Questions

[mmranch]

I have Quick Attach on my tractor. On any of the implements... the Quick Attach plate basically consists of the overhang on top and some holes on the bottom and the mateplate at the back. The FEL plates tuck under the overhang and the Quick Attach pins go down in the holes which pushes the FEL plates against the mateplate.

The overhang steel seems substantial (steel all across the top keeping the FEL plate edge from popping out). But the pin tips going down in the holes only go down a little bit... (I haven't measured but it looks like 1/2 to 3/4 of an inch).

(Seems to me that a for a better connection, the pins should go deeper into the holes? (Why don't they go deeper?))


Here's my theoretical question:

What if I took a blank quick attach plate (made of 1/2" steel) and welded a 15' long - 4"x4" square steel pipe (parallel) to the flat face of the quick attach.

When considering the quick attach plate connected to the tractor FEL... when the quick attach plate is vertical, the pipe stands up like a flagpole. But when the quick attach plate is horizontal, the pipe is horizontal to the ground. When the pipe is vertical, the forces on the quick attach connection seem workable. But when the pipe is horizontal, it seems the forces would threaten the connection making the pin tips or something fail. If there was weight out on the end of the pipe, it would seem the failure threat would be much greater.

Any idea how much weight would be required to make the connection fail? For example, if I put 300lb basket on the end of the pole, when the pole is vertical - no problem. But when the pole is horizontal, would 300lbs added to the end make the connection fail?

Thanks for any ideas!

 

[hawkeye08]

If I understand correctly, the forces that would apply when back dragging your bucket if bucket bottom is perpendicular to the ground and catches on something? I hope the bucket comes loose before my FEL gets bent up. Perhaps it is a designed weak point? I have never had anything come loose that was properly attached.

 

[ovrszd]

I've saw this issue many times. Different manufacturers build to different specs. Some of my attachments have a deep pin set, some a shallow pin set.

Only time this is an issue would be a similar situation as described by hawkeye08. Under normal situations all of the load is carried at the top.

I wouldn't worry about it. The concept in having the tips angle cut is so they constantly tighten.

 

[RNeumann]

You don't specify where in the 15' the 4"x4" is welded- center or one end etc. But even in the center that's about a 6' lever outside of one of the FEL arms. I know folks grapple logs without issue but they tend to grab them in the middle as opposed to creating an extreme side load.
Ive never seen SSQA specs although I assume they exist. But from a practical standpoint I'd hope my failure occurred at the SSQA instead of causing a failure to a FEL arm, ram, frame or pivot point.

 

[mmranch]

Thanks for the ideas!

I'm not talking about digging with this apparatus... just lifting the weight of itself. So for example, this device would be stored with the pipe (& quick attach plate) horizontal to the ground. Tractor would roll up and have to attach with the plate horizontal, then when attached... rotate the quick attach plate upright so the pipe rotates into the vertical position. It would be used with the pipe in a (mostly) vertical position and then rotated back down to the ground for storage.

I'm wondering what weight on the end of that pipe (during horizontal rotation) would be acceptable before the quick attach link fails?

Thanks again.

 

[mmranch]

Sorry, I should have been more clear.

About 16" of one end of the pipe would be welded to the flat side of the quick attach plate. The pipe would not be perpindicular to the flat plate... it would be parallel. So when the quick attach plate is vertical... the pipe would be pointing to the sky. When the plate is horizontal the pipe would be pointing straight out in front of the tractor.

Thanks!

 

[mmranch]

I guess the more I think about it... the weight when the pole is horizontal (out in front of the tractor) would still be causing the quick attach plate to be pressing strongly against the FEL plates... thus continuing the connection.

Hmmm.

 

[k0ua]

I guess the more I think about it... the weight when the pole is horizontal (out in front of the tractor) would still be causing the quick attach plate to be pressing strongly against the FEL plates... thus continuing the connection.

Hmmm.

True, BUT, a 15 foot 4x4 steel tube sound like a big load to start with. That is a heck of a lever sticking out there. What does the 4x4 tube weigh just by itself? What is its wall thickness? And what if you roll that back over past vertical and over the tractor and your own head? What the heck are you up to anyway? Also have you thought about how fast that 15 foot pole is going to move and how well you will be able to control it. Better have a very fine control on that curl/dump valve. Anyway , just some thoughts. If your tractor is big enough it can work, and from the avatar, it looks like yours is pretty good sized. I wonder if you could lift a 300 lb basket out on the end of a 15 foot pole. Maybe... but that is a ship load.

 

[k0ua]

Richard, you have experience with big ole loads sticking way the heck out there in front of your loader.. What do you think?

 

[ovrszd]

Richard, you have experience with big ole loads sticking way the heck out there in front of your loader.. What do you think?

I don't worry about those loads if the QA plate is mostly vertical. This wedges the load into the top angle brackets.

When horizontal we are dependent on the spring loaded wedge pins to keep the upper bracket tight. Not good. If the lower pins were of a latched type so no movement was allowed I wouldn't worry so much.

I've got some great pics of applying tremendous forces on the top angle brackets. I'm on my phone now and can't access them. I'll post tomorrow. Sorry.

 

[mmranch]

These are the concepts I was trying to get at.

I don't like the pins only going in a little bit. What would be better (in my mind) is if there were some 1" holes aligned in both the FEL plates & quick attach plate so that when coupled, you could slide in some big bolts to help keep the attaching attached.

Thanks again!

 

[countrybumpkin]

Wanting to build something similar to this?

 

[ovrszd]

These are the concepts I was trying to get at.

I don't like the pins only going in a little bit. What would be better (in my mind) is if there were some 1" holes aligned in both the FEL plates & quick attach plate so that when coupled, you could slide in some big bolts to help keep the attaching attached.

Thanks again!

What you are desiring is the Euro style quick attach. John Deere has used this type for years as well as others. Solid attachment with no worries about it separating regardless of stress angle. Here's a Google link to a bunch of pics.

european quick attach - Google Search

 

[ovrszd]

Looking at Bryan's pic and/or mine below you can see that we don't put stress on the lower pins. By keeping the FEL QA plate in a vertical situation the load is always carried by the top angle brackets. Bryan's is an excellent example of a properly built boom pole designed to apply the stress properly on the Quick Attach.

To see how inefficient the SSQA is with the mounting plate in a horizontal position raise your Bucket until you can easily see it from the tractor seat. Then dump the bucket as far as it will go. Then jiggle the curl function and watch the bucket. You'll see it "slopping" in the brackets. It's not designed to carry load in that position. I've read horror stories here on TBN of operators putting stress on their attachments in that position and having them come unhooked. I'm very conscious of this when using my Grapple.

 

[Xfaxman]

I have Quick Attach on my tractor. On any of the implements... the Quick Attach plate basically consists of the overhang on top and some holes on the bottom and the mateplate at the back. The FEL plates tuck under the overhang and the Quick Attach pins go down in the holes which pushes the FEL plates against the mateplate.

The overhang steel seems substantial (steel all across the top keeping the FEL plate edge from popping out). But the pin tips going down in the holes only go down a little bit... (I haven't measured but it looks like 1/2 to 3/4 of an inch).

(Seems to me that a for a better connection, the pins should go deeper into the holes? (Why don't they go deeper?)) Because they are spring loaded to go as deep as possible, compensating for manufacturing tolerances and wear in the slots.


Here's my theoretical question:

What if I took a blank quick attach plate (made of 1/2" steel) and welded a 15' long - 4"x4" square steel pipe (parallel) to the flat face of the quick attach.

When considering the quick attach plate connected to the tractor FEL... when the quick attach plate is vertical, the pipe stands up like a flagpole. But when the quick attach plate is horizontal, the pipe is horizontal to the ground. When the pipe is vertical, the forces on the quick attach connection seem workable. But when the pipe is horizontal, it seems the forces would threaten the connection making the pin tips or something fail. If there was weight out on the end of the pipe, it would seem the failure threat would be much greater.

Any idea how much weight would be required to make the connection fail? For example, if I put 300lb basket on the end of the pole, when the pole is vertical - no problem. But when the pole is horizontal, would 300lbs added to the end make the connection fail?

Thanks for any ideas!

Here is a visual of your theoretical question with a 24' cedar:

The SSQA plate is still tight. :thumbsup:

This is a light weight pallet fork frame that came off of the SSQA, when I tried to lift too much weight:

If there is too much gap at the bottom, the plate can slide up when back dragging and come off of the top of the SSQA, usually on one side, twisting the cross tube.

 

[Rustyiron]

Back dragging or picking up the weight of the machine with the bucket/forks front edge put's the most "work" on those lower pins. I have bent the top edge like in xfaxman's pic on some, I'll repair by cutting out the (unnecessary) middle, straighten out the sides and weld in a new support about 12" in from the side's just enough to clear the machine side contact points. This cut's the span between support way down.

 

[mmranch]

Thanks very much to all for the great pics and explanations!!

Those pics basically show the pole welded perpindicular to the quick attach plate... like this:

-------|


I will be welding the pole to the quick attach plate in parallel with the plate... like this:

__ (*sorry, I tried to make this quick attach plate line over on the right side of the pole)
---------- (this is what it would look like with with pole on the ground before attaching tractor to the quick attach plate.

When the quick attach plate is rotated and the pole is raised up, it would look like this:

|
|
|
|
|| (this would be the primary operating position and all weight would be pressing downward on the quick attach plate/FEL plate connection).

The idea I'm contemplating is basically a man-basket on top of the pole (don't worry about how the man get's into/out of the basket, that will be done safely with ladder, etc).

What I'm concerned about is the raising of the pole from ground position to upright position. The basket on the end of the pole weighs about 250-300 lbs without the man inside (not too much). But the length & weight of the pole influences the forces put on the connection during the raising. I was thinking about making the pole 12-15' long.

I know that when I try to lift/rotate the bucket with too heavy a load, the hydraulics will just bypass when it can't do it. I want to make sure that the tractor is capable of rotating/lifting the load into the upright position. I'm pretty sure the lifting is possible, but want to make sure the rotating is possible too before I build this thing.

I would use a 1/2" steel quick attach plate to reduce the possibility of bending the plate.

Thanks again!

 

[Xfaxman]

I recommend gussets or extra bracing so that the top lip can't bend when you are rotating the pole up to vertical.

Here are the gussets used on my stump bucket:

And the bracing on the bucket:

 

[bigdeano]

If the curl cylinders won't lift it from horizontal, you could rest the cage on a sawhorse to give it an upwards push until the cylinders have better leverage. I have a 20' boom pole I used to use to pull well pumps. It would raise from horizontal, but it was working to do it at the start.

 

[Rustyiron]

Did I miss exactly what you want to make & do in this "structural" discussion?
I knew a guy that built pole buildings that welded a 4x4 (20') to a ssqa plate and he used it to set trusses. Being able to drive into a building (on dirt, no foundation) you don't need the "reach" of a crain. Once the truss & pole were close to vertical the 200# truss was virtually no load to the skid steer or pole and he was basically right under it.
I took his idea and embellished it a little.