Painted axle

Just chipping away at an easy task on an unexpected weekend day off, I put a coat of paint on the new axle.  The steel had some light surface rust already starting to grow, so it was time to add protection.

I simply brushed on Rustoleum black semi-gloss enamel paint.  The axle went from looking reasonable to looking awesome.  Paint makes such a difference visually, and I really hope that it protects the metal beneath (expect three coats, and inside the open square tube also).

Trailer to do's are now:

• paint axle assembly with some enamel paint
• repair left tail-light wiring
  
• buy more Argon gas
  
• finish weld the vertical elements
• epoxy-coat seal the ply decking
• install and wire running lights on the sides
• add reflective tape on the sides
• create a rear door that can be quick-pinned in place
• figure out front/side/back walls
  
• dream up a top lid
• figure out how Goat parts sit in the trailer
  
• take all of Goat for its first trip around the neighborhood

For the first-flight:

• backyard final assembly and thorough pre-flight check, including weight & balance
• re-weld the tow hitch release (I'm now doubtful it had good penetration) 
  
• buy tow rope, weak-links, and end rings
  
• buy/borrow radios (1x airborne, 1x car)
  
• find a place to fly
• travel
• fly

After the first-flight:

• add leather patch to wing tips where will rub the ground
• install leather patch guides for elevator control lines
• paint trim color
• install wing root kiss seal
• build a wing tip dolly
• build a wing wheel
• jury strut fairings
  
• main strut fairings (after flying to figure out the right angles)
• emergency parachute
  
• real variometer (LXNav with a TEK probe is my intention, if it is sensitive at low speed...)
• dogue chute

Mega-axle!

The torsion axles are not going anywhere ever again.  The frame is going to bend before this axle dies.

Welding steel is so much more enjoyable than aluminum.  It took about three hours to work my way around all the open edges, but it wasn't that bad.  The arc is more stable and it seems like this is the way welding should be.  I must be doing something wrong with the aluminum setup.

The axle assembly is bolted back to the frame now.

I thought about going for a short drive around the neighborhood, but I've done this before.  One of the aluminum truss members has broken tack welds from yesterday's crash.  Without the ~200b of plywood being bolted back on, the trailer will ride light and bounce around.  I'll save the drive for another day.

Next up is liquid wet stuff.  Enamel paint for the axle.  Epoxy-coat for the plywood decking.  It'll be a few days in the garage, so I might not get to this for a while.

There are some repairs to do from the broken axle event last night.  The left trailer light rode on the asphalt and destroyed the wires and scraped away some plastic.  Ironically, I have a spare left light assembly if this one not repairable.  Some of the metal frame also scraped away and needs inspection.  It never ends.

Trailer to do's are now:

• weld axle assembly
• drill holes in axle assembly
• mount axle assembly
• paint axle assembly with some enamel paint
• repair left tail-light wiring
  
• figure out how Goat parts sit in the trailer
  
• take all of Goat for its first trip around the neighborhood
• buy more Argon gas
  
• finish weld the vertical elements
• add reflective tape on the sides
• install and wire running lights on the sides
• epoxy-coat seal the ply decking
  
• create a rear door that can be quick-pinned in place
• figure out front/side/back walls
  
• dream up a top lid

For the first-flight:

• backyard final assembly and thorough pre-flight check, including weight & balance
• re-weld the tow hitch release (I'm now doubtful it had good penetration) 
  
• buy tow rope, weak-links, and end rings
  
• buy/borrow radios (1x airborne, 1x car)
  
• find a place to fly
• travel
• fly

After the first-flight:

• add leather patch to wing tips where will rub the ground
• install leather patch guides for elevator control lines
• paint trim color
• install wing root kiss seal
• build a wing tip dolly
• build a wing wheel
• jury strut fairings
  
• main strut fairings (after flying to figure out the right angles)
• emergency parachute
  
• real variometer (LXNav with a TEK probe is my intention, if it is sensitive at low speed...)
• dogue chute

Axle, axle, then no axle.

Steel is significantly easier to tack weld.  The welding arc is much more stable and produces a small and stable melt pool.  I tacked together the assembly in just a couple hours.

This is what the axle assembly looks like (the bolt plates are not yet tacked in place, and I missed a picture of those in this view).  It looks similar to the original leaf spring axle assembly, but isn't red.  I'll either see if work can powder-coat, or I'll paint it with enamel paint later.  I did weigh the old axle components at 80lb toatl (30lb axle; 25lb/ea leaf spring, angle, fenders).  The new torsion axle assembly weighs 52lb (22lb as shown below and 15lb/ea for the half-axle assemblies).

Show partially bolted in place in this view, the half-axles transfer load to the bar, which transfers loads to the steel angles, which transfers loads to the main aluminum beams.  The bolts are just there to hold the assembly in place.

 

But, it turns out that the few tack welds did not survive the neighborhood drive.  I was only rolling about 10mph, but the left axle literally broke off and rolled forward while the back corner of the trailer dragged along the ground.  It was quite a noise and one neighbor came over.  Two large c-clamps were enough to hold things together enough to limp home.

What's the saying from the movie Rounders?  "If you can't spot the sucker, then you are the sucker."  Said another way, "I am the crazy neighbor." It's probably more fun to be the crazy neighbor.

Torsion bar for a torsion axle

Steel for the axle assembly arrived today and it fits together as expected.  All I have to do is drill four holes, clean it, align everything nicely, and learn to weld steel.  This may be a weekend project.  I'm hoping to not need to borrow a friend's MIG welder, but that is a backup idea.

Here's what the physical arrangement will look like.  For now, imagine the prettiest welds you've ever seen.

Our of curiosity, I weighed the individual pieces (5.1kg + 2*1.5kg + 2*369g + 2*420g) and get a total of 10kg (22lb) before welding and hardware.  Now we know.

Halfway to a torsion axle

I removed the wheel from the old leaf spring assembly and clamped the new torsion axle in place to get a rough idea of the fitment.  As a starting point, at least the same wheel fits on the new axle.  With zero mounting structure yet, the new axle height is reduced by several inches relative to old.

It took some elbow-grease to remove all of the old axle assembly parts.  Leaf springs are unbelievably heavy, and the old steel axle is itself also crazy heavy.  I've removed probably 100lbs so far, and only maybe half of that weight will go back on.  The new ride height is definitely too low, but it was nifty to see just how low the deck could be.

The torsion axles were simply clamped to an existing cross-member for the time being.  With all of my body weight, the axle appears to move roughly 1/8" in height.  That does not seem very soft yet, though the leaf spring compressed probably 0.0" height.  At this moment, I wish I bought the 550lb set.  They use the same mounting bolt pattern, so perhaps I can exchange this set for the other if it still rides too stiff.

With some scrap steel square tube, I mocked up the structure that will be welded together as an assembly.  This isn't perfectly representative, as one tube will be 2x2 square (vs 1.5x1.5 square shown) and the other will be a 2x2 angle (vs 1.5x1.5 square shown), but was enough of a mockup to feel confident in ordering materials.

Materials are on the way...

Trailer to do's are now:

• bolt the ply decking to the floor
• buy torsion axles
• uninstall leaf spring assembly
• buy torsion axle materials (and associated welding stuff)
• weld axle assembly
• drill holes in axle assembly
• paint axle assembly with some enamel paint
• mount axle assembly for keeps
  
• figure out how Goat parts sit in the trailer
  
• take all of Goat for its first trip around the neighborhood
• finish weld the vertical elements
• add reflective tape on the sides
• install and wire running lights on the sides
• epoxy-coat seal the ply decking
  
• create a rear door that can be quick-pinned in place
• figure out front/side/back walls
  
• dream up a top lid

For the first-flight:

• backyard final assembly and thorough pre-flight check, including weight & balance
• re-weld the tow hitch release (I'm now doubtful it had good penetration) 
  
• buy tow rope, weak-links, and end rings
  
• buy/borrow radios (1x airborne, 1x car)
  
• find a place to fly
• travel
• fly

After the first-flight:

• add leather patch to wing tips where will rub the ground
• install leather patch guides for elevator control lines
• paint trim color
• install wing root kiss seal
• build a wing tip dolly
• build a wing wheel
• jury strut fairings
  
• main strut fairings (after flying to figure out the right angles)
• emergency parachute
  
• real variometer (LXNav with a TEK probe is my intention, if it is sensitive at low speed...)
• dogue chute

Torsion axles arrived

They are quite stiff.  Hopefully this works!  We're going to find out...

We're also going to find out if my welder can TIG steel also.  It does do stick-welding, but that's so messy...

Decked. But now too stiff in bending.

A beautiful fall weekend was an excellent time to install some decking.  The three plywood boards were all bolted down with stainless steel hardware.

I did manage a couple drives around the neighborhood with the deck bolted down.  The anti-rattle hitch makes a huge difference.  But, the trailer is now fairly stiff in bending, to the point going over bumps is harsh, and the trailer once literally jumped when going over a pothole.  This is not good for the relatively fragile structure of the Goat wings.

After some deliberation and talking with some friends, a Flexiride 935lb torsion half-axle set is now on order to replace the leaf springs from the good ol' Harbor Freight donor trailer.  I struggled with putting yet another $500 into the trailer.  But, thinking about the decade of time into this project Goat, it makes more sense to protect that investment.

The trailer weights are:

• 180lb aluminum (160lb estimated, 180lb attempted measurement)
• 175lb plywood (estimated at 70lb each 4x8ft, including a seal-coat)
• 150lb Goat (the nose section rides in the back, but additional trailer structure for strapping down)
• 15lb miscellaneous (hitch, chains, hardware, lights, wiring)
• 520lb total

Flexiride has a 550lb option and an 925lb option... that was a tough decision, selected because trailers never get lighter, and I need some margin for bad bumps.  We'll find out if this was the right call.

Speaking of the wings, I tried the second real loading of the wings into the trailer bed with a deck installed.  The first wing half fit nicely, which is great to see.  However, it rested directly on the plywood, and it will be a harsh ride without any padding.  Laying the second wing directly on top of the first is a bad idea, so I clamped temporary cross-support members into place.  With some foam pool noodles and a couple more cross-members, I think this might work out okay.  I now really wish I'd made the ailerons and flaps fold all the way against the wing upper surface.

The wings fit comfortably with the 20ft overall inside length.  This pic was with setting the wing on 2x4's and starting to look at how to run straps.  But ignore that.

That's all for this weekend's edition.  Hopefully I can keep up some momentum next weekend!