Heat

There has been some lack of progress following the failure of my shop heater.  I followed all the instructions in the owner's manual, and went through the troubleshooting guide, all to no avail.  I attempted to contact the manufacturer with the symptoms, with, to date, no response.

So yesterday I bit the bullet and bought a new heater.

It is slightly different than the old one and is working quite satisfactory.  In fact, about two hours into my projects today I had to shut it off. It was getting just a bit too toasty in the shop!

The old one is sitting forlornly behind the new one.  The old is quite a satisfactory little heater.  But if I can't fix it (and the owner's manual is quite emphatic about that) it is useless.  I bought an extended warranty for the new one.

Here is the project for today:

This is the fabrication jig for the the aileron hinges.  It needs one more small part, a support close to the 1/4" rod sticking up near the right end.  That part will be added after I have the component parts made so I know exactly where it needs to go.  The metal plate will protect the wood from the tack welding heat and provide a grounding plate.  I plan to do the tack welding with the TIG.

This jig will make sense once I have a completed hinge to show you.  Patience!

I worked on some practice pieces today as well.  The major lesson I learned is that I need to spend some time learning to control the TIG with the foot pedal.  Using a set amperage does not work when welding on small parts.

Pressing Matters

Some small progress got made in the last couple of days. 

First, a friend of mine welded up the SWAG Off Road press brake kit.  This is a high quality, very hefty product.  I am very impressed. 

Getting it home I couldn't wait to bend some metal and check out the results.  Which turned out somewhat disappointing.  On heavy gauge metal, like 1/8" and thicker, this thing is killer.  But the bend radius on lighter gauge metals (like .050") is far too generous.  Also, I couldn't bend a flange less than 3/4".  To do the fittings on the airplane I need to get down to 3/8".

After some soul searching, fussing, and inventing, I acquired various sizes of angle iron from 1" down to 3/8".  By stacking these in the female die of the press I was able to bend flanges down to 1/4" and achieve a reasonable bend radius with .050" 4130.

Here is the SWAG unit mounted in a Harbor Freight press:

And this shows, if you look closely, my modifications for lighter gauge metals.

I played with welding up my modification, but it works well loose.  I am not sure how well it work welded up.

I also considered grinding the taper on the male die to a sharper point.  But I am getting a good bend radius without taking that drastic step.

And here is the product of the day:

The wooden piece is the cutting template.  This part is the brace for the aileron hinge.  This is a great day for me.  I have not produced an airplane part since the end of August, the time (and money) being taken up figuring out how to bend up these parts without having to purchase a $2,500 press that would take up too much of my limited shop space.  The SWAG press works well, was a reasonable price, and takes up very little shop space.

Rough Roads

The EAA literature will tell you that many projects get stopped in their tracks by difficulties encountered by the builders.  This is especially true of plans-built projects as there are many more opportunities for problems and typically less support from the plans provider. 

I entered this project well aware of the problem and determined to slog through the difficult times. 

Well, I have been slogging through one of those times.  I have not completed an airplane part since August.  But work, and the expenditure of money, has continued.  The transition from the woodworking exercise of rib fabrication to the metal fabrication of the construction of the numerous fittings necessary to complete the wings has proved to be difficult, frustrating, and time consuming. 

The first difficulty was re-acquiring what welding skills I once had.  Only to learn that the skills I once possessed did not translate well to airplane construction.  My previous skills centered around fabricating tractor parts.  Welding heavy duty parts is actually a lot easier than welding the much lighter metals involved in airplane construction.  I am now reasonably confident in these skills.  But it took purchasing a lot of equipment (including both oxy/acetylene and TIG welding equipment) and a lot of practice.

Then I was stymied by difficulties encountered in bending metal fittings.  Perversely, while much of the welding is on thin gauge metal, an appreciable amount of the bending must be done on some heavier gauge metals.  I have solved the problem of bending small fittings from .060" to .090" 4130 steel.  But parts with dimensions greater than a couple of inches stopped me cold. 

My first attempts using the 18" bench top leaf brake that I own were total failures, despite the fact that the specs for the brake indicated it was up to the job.  Not even close.  I spent about a week fussing about the next step.  I contemplated purchasing the Harbor Freight floor model leaf bender.  Its specs were about the same as the little bench top model.  I was loath to spend the money for that brake only to find it was not up to the job, either.

But then I ran across a company called SWAG Off Road.  They manufacture a kit that converts the Harbor Freight hydraulic arbor press into a press brake.  This is a very impressive piece of equipment, so I sprang for the HF press and the SWAG kit.  While the hydraulic press is typical HF, but adequate for the job, the SWAG kit is very high quality.

Problem solved!  Not exactly.  The SWAG kit assembly requires welding.  I was not intimidated, what with my newly acquired welding skills.  But alas.  My welding equipment is sized for aviation welding.  Not the heavy gauge welding required to assemble this kit. I have been unable to get a puddle (welders will understand) going on any of the components.  The lightest components are fabricated from 1/4" 4130. 

At this moment I am awaiting the assistance of a friend with much heavier duty welding equipment than mine to complete the kit.  Until then, I am at a standstill.

I thank all of you who have been checking in from time to time only to see no progress.  Progress will continue in the very near future.

Just because some photos are better than none, here are some shots of my little shop as it looks today.

Slight Change

The airplane I am building is an almost exact copy of the Piper Vagabond with some changes to make it suitable for homebuilding.

When Piper designed the Vagabond they essentially took the Piper Cub, widened and shortened the fuselage, moved the back seat up beside the front seat, and shortened the wings slightly. 

I chose the Wag-a-Bond for a variety of reasons, not the least of which was the Cub heritage.  A big driver for choosing the Wag-a-Bond over the Wag Aero Sport Trainer, which is an almost exact copy of the Piper Cub, was that I harbored a hope that my wonderful wife, who is very supportive of my aviation activities, would, herself, develop a love of flying in small aircraft. That has not happened and is not likely to happen. 

So I have re-evaluated the comprises I made in choosing the Wag-a-Bond.  The Vagabond, and the Wag-a-Bond are great airplanes. The main reason for choosing the Wag was the side-by-side seating. Getting in and out of the Cub back seat is a bit of a chore. My wife actually had the opportunity of flying in a friend's Cub and found entry and exit to be difficult.

However, by shortening the fuselage in designing the Vagabond, Piper changed the ground handling characteristics of the airplane from quite docile to what is usually described as "quick".  By shortening the wings the airplane was made faster, but changed the flight characteristics that make the Cub such a good low and slow airplane. The side-by-side seating, while friendlier, actually reduces the visibility for both the pilot and the passenger. 

The upshot is that I have decided to switch from building Wag Aero's Wag-a-Bond to their Sport Trainer (Cub-a-like).  Fortunately all the work I have done on the Wag-a-Bond translates directly to the Sport Trainer. I will not have to start all over.  Wag Aero, like the old Piper company, uses as many common components in it's aircraft as possible.

Another consideration is that the Sport Trainer fits more easily into the Light Sport Aircraft (LSA) designation.  The effort necessary to maintain an LSA certificate is less than for the Private Pilot certificate, especially as it relates to the medical requirement.

The plans for the Sport Trainer are on their way.  After I build a couple more ribs and compression struts (longer wing) I will be off and running again.

 

Welding

So where has Reg been?  Reg has been off learning new skills.  Gas welding has come along, but it became apparent that I needed to add TIG (Tungston Inert Gas) welding to my bag of tricks.

After much research and agonizing I broke open the bank account and purchased a TIG welder.

The old timers, and those with deep pockets, will tell you that you MUST purchase a Miller, Lincoln or Hobart welder.  That the Chinese welders (which all the other brands are) are pure junk and not worth the price.

The folks who are actually using the Chinese units have a different perspective.  It is true that some, even many, of the Chinese welders are junk and should be avoided.  However, there are a handful of brands that are very decent units.   Some of the them are designed and engineered domestically and manufactured in China.

Eastwood is one such company.  Eastman has been around for a long time, and the reviews show very few units with problems and excellent customer service when one does develop  a problem.  Their welders come with a three-year warranty.

Obviously, the rub is price. A Miller unit with comparable capabilities and features to the Eastwood that I purchased raids the bank account for just shy of $2,000.  And that is with a one year warranty on the "the box" only.  My Eastwood was $900 (OK, $899.99) including shipping and that aforementioned three year warranty on all components.  The Miller may be a better machine, but it is not over twice as good. I prefer to buy "Made in the USA", but I am not going to cut off my nose to spite my face.

Surprisingly, I have read almost nothing but good reviews about the Harbor Freight TIG welder.  It doesn't have quite all the features of the Eastman, but it is even a few hundred dollars less.  So one can get into TIG relatively inexpensively.

So far the Eastwood has performed flawlessly. The only problems being due to my inexperience. I am constantly having to stop and regrind my tungsten due to touching either the work or the filler rod.

In addition to the welder, you will need a cart, a bottle of argon gas, and a good welding helmet. I bought the cart and a welding helmet from Harbor Freight.  The cart is completely satisfactory.  The helmet not so much.  Buried in the instruction manual it states that the helmet is not suited to TIG welding.  You would think they could put that on the box. All is not lost. It is suited to gas welding and the instant dark feature is pretty handy.  I purchased the argon bottle, filled with gas, from my local welding supply.

And thus started an extended period of practice. Which is why this blog has not been updated lately.  But I am back on track actually fabricating airplane parts.

Today I started the final welding on the compression struts.  The welds are not pretty, but they are structurally sound and getting prettier.

Here are the first four compression struts all welded up and ready to be primed and painted.  It takes about an hour to final weld each strut. Please do not blow this photo up and look closely at the welds. They are not exactly the "stack of dimes" appearance for which everyone strives.  But, as said before, they are structurally sound.

Once the remaining struts (8) are final welded and painted, it will be on to the next step.  Which is fabricating the aileron hinges.  Those will be a lot more complex than the compression struts.

First Compression Struts

Spent the afternoon fabricating and tack-welding the first four compression struts.

These are pretty simple parts, but they are the first metal parts I have fabricated in a long time.  I have been kind of reluctant to work on these.  They are not difficult, but my confidence in my abilities has been a bit low.  But these look great.

There are a total of 12 compression struts.  The remaining eight are of a somewhat different configuration.  Some of them are built from 5/8" tube instead of the 3/4".  The ends, which are Piper Cub parts and not easy to fabricate are sized for the 3/4".  I am thinking of fabricating short 3/4" transition pieces.  So far my attempts in that direction have not been particularly re-assuring.

Standard procedures requires a bird-beak transition in the larger tubing.  So far I haven't been very successful in figuring out how to cut the bird-beak. 

It will come.

COMPRESSION STRUT JIG

This project has been on the shelf for far too long.  This evening I finished up the jig for fabrication of the compression struts.  The compression struts are braces between the wing spars counteracting the pull of the drag wires.

The upright on the left has a rail on the bottom that runs in the groove, maintaining alignment between the uprights while allowing that one upright to be adjusted for length.  It is held in place with a C-clamp.

The components of the first strut are in place ready to be tack welded.  Actually, not.  They need to be cleaned up first. The metal on the jig will, hopefully, prevent me from setting the plywood on fire.  The middle brackets ensure that the tubing will not drop out while the tacking is under way.