Thor Hydraulic Fab and Installation

  It took a long time, but we "got 'er done"

Event Report 202001

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The Experience

Our initial experience with Thor's new living quarters spanned 3 months.  We identified several issues that we wanted to address including adding hydraulic stabilizers to prevent "house roll" when parked and occupied.  And, since the new setup did not have any tool boxes, we needed to add extra space.

Upon our return to San Diego, we launched into what would end up being a multi-month effort that was repeatedly put on pause due to external causes.  While it took much longer than we expected, in the end we "got 'er done".

We selected "ProTech" as our tool box vendor since we needed full-custom dimension  boxes.  These boxes are very sturdy and robust, but quite pricey at $650 each.  Since we needed 6 boxes, the final price was substantial.  To order the boxes, we needed to find a local vendor which turned out to be the Peterbuilt dealership in San Diego.  The order took 8+ weeks to fulfill, but  we used the down time to addressed other issues.  Hydraulic cylinders were ordered online and shipped to the house.  Ancillary components were acquired or located within my local inventory (AKA my garage) and we awaited the delivery of the boxes.

The photos below are what we saw.

Harbor Freight had a sale and I purchased an additional welding table for the task.  Above, one of the outrigger spars is being fabricated.

Due to the China trade tiff, delivery of my hydraulic pump was months late.  In the interim, the material was rusting.  Fully useable, but with a bit of surface preparation.

Feet for the outriggers were made of 3/8" plate.

  The fork-with-eyes end attaches to the truck pivot point.  A 1/2" bolt/nut combo secures a hydraulic pivot point.  Loosen the bolt, and the collar can slide to hone final geometry.

Kathleen helps with the surface preparation tasks on the 2x0.25" truss strip.

The objective of this process is to transform a 2x2 inch square spar into a truss.  Our plan was to position and tack a strip of 2x0.25" from the end of the fork-eyes across the short tube in the photo above and then on to the foot-end of the spar.  Our plan was to brace, clamp, tack, heat with torch, bend and tack the far end.  Our friend Kai lent me his oxy torch for the job and it worked like a charm.  Both spars were "trussed", cleaned and painted.

Right side installation was done as a test-fit.  We had custom hydraulic hoses made and the truck came to me.  Three times.  Turns out that this was the very first new hose installation that the guy had ever done.  Every other job was re-creating an old hose from existing equipment -- all design choices were already made.  All the guy needed to do was reproduce the part.  This installation required some thought and planning.  The hydraulic control was mounted on the outside of the rear tool box.  Both power and hoses needed to be run to the box and the hydraulic pump was installed in the box.

Preparing to truss the other spar.

The final adjustment decision was confirmed and the remaining collars were hard welded to the vertical rails.

Once the collar was welded, no further changes in geometry were possible.  The sliding collars allowed us to test adjustments to the baseline geometry and insure success.

Passenger side deployment.  Orange blocks were removed to test the full range of motion.

Driver side deployment.

Next, we moved on to mounting the custom tool boxes.  These boxes were beautiful, if you can say that word in the same sentence as tool box.  Mirror smooth and nary a scratch, our first action was to violate the box.  We initially left the protective plastic on the box .  To get the boxes to mount flush to the bottom of the trailer body, a slot will have to be cut in the top of the box.  For the slot, I used a Makita worm-drive saw with a Diablo metal blade.

The cold-cut saw was used to prepare shims and braces.

The slot in the top-rear of the box was cut and left/right weld-on braces were fabricated.

We thought we were being thwarted by the radius of the trailer's z-beam.  It took several cuts to get the real dimensions correct.

The real issue, it turns out, was not the radius of the beam but rather some interferences lower on the frame.  To make both problems go away, a 1/4" standoff was welded to the back of the box.  Holes were drilled to allow correct positioning and grounding of the welder.  During installation, the box will be pop-riveted to the weld-on braces and flange of the beam.

Not surprisingly, the first box was the hardest.  The first box was attached to an in-situ rear brace, the trailer frame and a weld-on brace.  Above, Kathleen is cleaning the chips and curls from the saws and drills.

The next box was cut and stand-offs were welded on.  Note that this box also required a clearance hole for one of the bolts that hold the house to the frame.

The final external configuration.  The hydraulic tool box is attached to the 4x4 blackwater tube holder and the hydraulic controls are attached to the tool box.  Electrical enters the box at the bottom left.

Inside the box is the hydraulic pump and support circuits consisting of  the control switch and a 150A high-current fuse.

View of both rear tool boxes with stabilizers deployed.

Two weld-on braces were needed for the next box: one fore and one aft.

The rear-ward box was a snug fit.

Where possible, existing braces were co-opted for mounting the boxes.

Rear view with stabilizers deployed.

A final view of the intrusion of the z-beam into the tool box interior.  These slots will be sealed with black RTV.
  The pop rivets at the rear of the box are visible (one hole yet to be riveted) and the discolorations are from welding the stand-off to the rear of the box.

This was a ton of work and involved facing some unseen challenges (extended delivery times due to trade issues).  These projects can be very time consuming because of the details required for a good job.  Kathleen hung in there like a trooper and supported me to the end.

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