Tractor side SS quick attach build

   / Tractor side SS quick attach build #1  


Platinum Member
Feb 28, 2008
Ottawa Ont Canada
3940HST Montana
I have been working on this for a while and recently started the actual fabrication work. I have a Montana with their style of QA (sliding pins) and it works ok but I find that it makes a sloppy connection. It's also not compatable with any others.

My dad also recently purchased a 'bota L3400 with the crappy 3ph ;)and a pinned-on bucket - they don't have a QA for his loader. I looked at the aftermarket SS adapters but I don't like how far the push the bucket out; this would not be too big of a deal on the Montana (because it already has a QA) but the already marginal L3400 loader would loose to much lift, etc. I decided that I would design and build my own.

My design is based around the following:
1. Has to be simple - use standard materials available with no special tools required ('normal' people don't have mills, surface grinders, etc :D)
2. The basic form of the SS assembly and lock mechanism has to be compatible or easily adapted to any loader configuration (width) for compact tractors (probably 25 to 50 hp).
3. Light weight
4. Only one release handle is needed to operate both lock pins:cool:
5. If possible, allow the possibility of adding a power lock/unlock feature:cool::cool:

The following tools are required to build: disk grinder, chop saw, welder, drill press (max 7/8 hole is required). I also have a small Myford lathe that I used to modify some parts but those parts are easily substituted for 'off the shelf' items.

This is a cross section view of the design (from AutoCad).
0 concept.JPG

The side plates (the actuall angular parts that engage the SS) are rectangular tubes, 2x4". I had the shop cut the angles for me to make sure they were true. The lock pins are connected to each other by a tube so that both can be released by one handle.

Pictures and more details next.

   / Tractor side SS quick attach build
  • Thread Starter
Here is the rectangular tube with cut out. The cut out allows extra room for the release / lock mechanism to work. The round pin keeps the lock pin captive against the tube wall.

1 rec tube.jpg

Here I fitted the tube and lock pin to my neighbors bucket to test fit.
2 rec tube fit bucket.jpg

The lock pins are made from 1.5" sqare tube. The tube allows for ligher weight and also contains the lock spring. The tip will be cut off and left open for drainage.
3 lock pin.JPG

Lock pin parts. I turned some delrin to make a bearing surface between the spring and lock mechanism. A nylon bolt (5/8") could be substituted.
4 lock pin parts.jpg
   / Tractor side SS quick attach build
  • Thread Starter
Here is an exploded view of the lock pin parts

Assembled. Note the slot in the side of the pin that allows spring compression.

Now back to the rec tube. This is the main bearing and lever mechanism to drive and lock the pin. The lever mechanism will lock with an "over center".

here the lock pin and lever mechanism have been installed. The main bearing collar has only been tacked in place for now. I will also add a grease zerk above the set screw. The set screw locks the bronze bearing sleave in place; this allow the lever to adjusted to clear the cut out.


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   / Tractor side SS quick attach build
  • Thread Starter
lock pin in the 'in between' position - unlocked and half retracted
View attachment 126226

Lock pin in the fully retracted position
View attachment 126227

Now Have to weld the top cap plate to the rec tube.
View attachment 126228

This plate must finish flush on the front side. The angle of this plate is 45 deg.
View attachment 126229

View of the bottom plate with pin installed.
13 weld top plate.jpg

Now back to the bench to finish the other set. More info (hopefully) tomorrow.



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   / Tractor side SS quick attach build
  • Thread Starter
Seem to be running into some techincal difficulty with the pics :mad:

If a mod can make them stay as thumbnails please do!
   / Tractor side SS quick attach build
  • Thread Starter
One more pic; here the 'finished' part is locked onto my neighbors bucket. Fits extremely well. I will finish dressing the burrs, etc later.
15 locked to bucket.jpg
   / Tractor side SS quick attach build #7  
well let me be the first to say Great Job!! and I noticed on your other thread you said you would consider sending plans on your SS attach to those interesed.... Count me in as #1....:D
   / Tractor side SS quick attach build
  • Thread Starter
:)Thank you, and I will provide drawings and material list...

Now for the cross tube:
16 dry fit of cross tube.jpg

The main difference in this design is the ability to lock and unlock with only one handle. A thin wall torque tube is used to connect the latch levers. When I welded the short levers to the keyed shaft I was careful to align the key the same way. Before welding the torque tube to the hubs I bottomed both levers in the locked position to make sure they are oriented the same way. I turned the V-series 5/8" hubs down to fit inside the 1" steel tube; to avoid lathe work a large pipe size could be used. I preferred to turn the hub down to a light press fit to ensure they were square when welded.
17 latch tube.jpg
18 latch tube assembled.jpg

Both sides are done; I have to make a short handle to fit the torque tube and then move on to fitting the QA to my tractor. My dog is a little camera shy;)
19 latch tube done.jpg

Family will keep me busy until after Easter though:( :)
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   / Tractor side SS quick attach build
  • Thread Starter
Here are some more drawing details and a parts list.

This is not complete yet so changes may be made.

View attachment Quick attach - Universal drawing.pdf

Materials list:
View attachment Quick Attach Parts List.pdf

I have not weighed it yet but in the last picture posted (with the dawg:)) I can still easily pick it up with one hand. I would estimate it weighs about 60 lbs so far, final weight (with the loader pin - on plates) I hope will be around 100lbs. I will weigh everything when complete.

   / Tractor side SS quick attach build #10  
Looks interesting, but what is an SS