Tractor side QA mechanism

[SPYDERLK]

I like the idea of the really strong torque tube on my adapter. It is beefy enough that I can wrap a chain around it and lift heavy objects without having the added weight of a bucket. I've even thought of welding hooks near each end for convenience so they are there no matter what I have attached. The other reason is that I have a toothbar and often have uneven loads on the bucket when popping rocks or roots. The torque bar helps to ensure the bucket does not twist, or at least that's my perception. I also think that some lightweight implements like bale spears might not have a lot of built-in torsional strength. By having it on the loader side, you never have to worry.

[[My torque tube is not just face welded onto the inside of the QA adapter. It goes all the way through and is welded on all surfaces.]]] In the photo below, you can see my 3PH QA adapter also has a brute of a torque tube. It's a NH adapter and is built extremely heavy. It was only $250. I'm sure steel prices have driven up the price of all these items in the last few years.

[[This is a highly functional and worthwhile practice, missing on some.]] Somebody in the design was not paying attention in ME class tho. Otherwise they would have used round tubing to resist the torsion. Square tubing is a very inefficient use of metal in that function and effectively ensures that you carry around more front weight than you would need if the proper shape were employed. Since every bit of overhung front weight destabilizes the tractor it really surprises me to see a manufacturer apply reinforcement weight out there in so cavalier a fashion.
larry

 

[Spudland_Dave]

I have not talked to my dealer, but looked at the various non-NH alternatives, and they are $500+, and assumed the NH system was more. One can get just the QA lock system for 400. I was somewhat shocked. I will talk to the NH dealer, and report back.

I couldnt tell you exactly what the JD Unit cost because mine was part of the Tractor/FEL package, but I want to say MSRP is in the 300-350 range.... I know the factory Kubota one is a little more "un-refined" and is a little cheaper as well...

 

[dynasim]

The list price for the 17LA NH QA attachment is 500$ through whole goods, and $730 through the parts department. That is right at the cusp of me just buying it new.

Thanks to all for the advice.

Chris

 

[Spudland_Dave]

The list price for the 17LA NH QA attachment is 500$ through whole goods, and $730 through the parts department. That is right at the cusp of me just buying it new.

Thanks to all for the advice.

Chris

Since you were looking to play with the welder and such, you could always shop around the various OEM's and see who's cheapest.... Pretty much everybody has a Skid Steer QA either Standard or available as an option.

 

[mwb]

[[This is a highly functional and worthwhile practice, missing on some.]] Somebody in the design was not paying attention in ME class tho. Otherwise they would have used round tubing to resist the torsion. Square tubing is a very inefficient use of metal in that function...

This is very true however the tube is not necessarily only in torsion. For this to be true the torsion tube would have to be centered on the loader pins - I think the JD pictured is closer to doing that. If you look at some aftermarket designs for example the "torque tube" is actually a significant distance away from the pivot point - at the top of the QA. As you move away from the pins the torque is diminished and becomes a bending moment.

I think the NH pictured uses a square tube that is fairly close to the pins but I don't think either a round or square profile would have a significant advantage. For my design I have finally decided to use a rectangular tube but I won't call it a "torque tube"; the rectangular profile will give me sufficient rigidity with minimal profile.

Cool thread!

 

[Spudland_Dave]

Honestly, I think people are trying to reinvent the wheel here....

I dont think a "torque tube" of ANY sort is required...when a bucket/attachment is connected, IT should be the device that makes the Bucket/Assembly stiff so to speak. I've used a buddies 300cx with the standard JD Paddle QA and I'll tell you without a doubt the Skid Steer QA on mine is MUCH Stronger. If you think about the way the bucket hooks up it makes for a strong completed unit when "assembled"...the little "torque rod" on the JD setups (both) are for keeping the paddles aligned for easy hookup and thats pretty much it.

Another way to look at it.....
If you had NO QA at all...old fashioned type "permanent" bucket what keeps everything stiff...yep, the bucket itself.

 

[skipmarcy]

My Mahindra came with a conventional pinned KMW loader and I later purchased the KMW QA (universal skid steer) unit thru my Mahindra dealer at the time - it was right at $600. Instead of 2 individual units attached to the loader arms with something connecting them (or not), KMW made it all one flat piece with some cut-out areas to reduce weight. On the back side of the plate is a fairly large channel iron-type piece welded to the plate and the pins/handles/springs etc. are sandwiched inbetween. This QA unit is extremely stout and only sets the bucket out maybe 2" further than the conventional pinning. Didn't notice any difference in loader performance from the extra weight or extension and I do alot of loader work and know my machine pretty well. I don't think leaving the pads in 2 seperate units without a solid connection between them would be very good on your loader arms - just my opinion. Good luck on your project !!