The Quadractor TM

[davej]

I was left a few items from my grandparent's estate, and this seemed about as good as anywhere to document some of them. This odd little duck is the brain child of Bill Spence and called a Quadractor, manufactured by the Traction, Inc company in North Troy, VT. Best I can tell from some interwebs was they produced it in the late 70's and early 80's, intended for small logging operations. I think my grandfather got this one in around 1982 or 84, nobody new for sure. I also don't know if he bought it new or used, but with only 3 or 400 produced I'm guessing the used market wasn't very robust back then. 

Basic specs: 

• ~500lbs
  
• 31" of ground clearance
  
• 8hp Briggs & Stratton engine
  
• Vertical, 4 wheel drive
  
• 4 wheel steering
  
• 72:1 drive ratio in low gear
  
• capable of skidding out a 4000lb log with the belly winch 
  

It is all belt driven and cable steering, and I remember Gramps saying the steering wheel might as well just be a decoration and that you steer with the foot pedals. (like a skid-steer). 

I've got a million memories riding all over the farm with him on this as I grew up, and I'm hoping we'll have a good time getting it back into running condition. There's a few write-ups about them still on the web, and for the tractor nerds, here's a bit of an overview. 

A Triumvirate of Engineering Features
The Quadractor is comprehensively engineered for complete traction, and this single-minded approach is responsible for the machine's
"muscle." Three related but separate and distinct engineering features contribute to the unusual vehicle's incredible versatility:
[1] First and foremost in importance is the patented design of the four identical vertical drives to the wheels. The Quadractor operates
continuously in four-wheel drive, with its left and right sides controlled by separate clutches. Each wheel's power is transmitted from a
pulley to the vertical shaft, then down the shaft and through a set of bevel gears to a small pinion gear, which operates the large finaldrive
cog.
As the pinion gears on all four shafts turn, they tend to walk up the outside of the large final-drive gears. As they climb, the cogs transfer
the weight of the vehicle to the tires while simultaneously causing the wheels to revolve. Because the pinion gear housings are offset
from their respective wheel hubs (and at the same time are allowed to "travel" within a 15° arc of the drive gears' circumference), the
effect of this mechanism is to lift the chassis of the vehicle just at the moment the machine begins to move forward. It's a little like the
sensation when the front end of a tractor lifts off the ground, but all four of the Quadractor's "feet" are firmly planted and the weight of
the machine—and its burden—is converted into that all-important traction.
[2] Another unique construction feature is the Quadractor's chassis, which is designed to flex over uneven terrain. This "twisting" keeps
all four tires securely on the ground and "biting."
[3] Finally, both the position and the design of the hitch contribute to the vehicle's performance under load. The "Spence Hitch"
distributes the weight of any implements, logs, etc. to all four wheels instead of to the rear tires alone, as does a conventional threepoint
tractor hitch.










It is currently at my father in laws back in NY, so updates will probably be few and far between. I was able to free up the engine with a little Marvel Mystery Oil in the cylinder, but not getting any spark yet so I'll look at the magneto next time. 


  Quadractor.Article.pdf (Size: 802.21 KB / Downloads: 0)

[Senor_Taylor]

Wow, that thing is WEIRD! I love it. It also looks very dangerous. Take it off some jumps at slow speeds.

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[D_Eclipse9916]

Really cool project!!! Riding around with family memories and then getting it to restore is just pure magic.

[ScottyB]

that is bonkers and i love it. that belt tunnel looks like a nightmare but i'm sure its more simple than it appears. i went down the youtube black hole watching these things do trails and snow and they look waaaay more capable than i thought an 8hp tractor on stilts could be.

super cool you have personal memories with it and you definitely need to keep this thing going if they're that rare!

[NTIman]

That is awesome. I had no idea what I was going to see when I clicked on this thread, but I like what I see.

I kind of want one now.