Building a Junior Ace

Tench745

Master member
I haven’t updated much recently, but I have tail surfaces tacked together. Apparently I don’t have pictures of the completed assemblies.

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I then painted over the tail outlines and starting laying out fuselage sides today.
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Tench745

Master member
I haven't been very active on the forums lately. Besides the cold, snow, and raging winds, I've been occupied with other things. Namely, I've been working on my Jr Ace fuselage. I now have all the tubes cut and tack-welded together into a fuselage shape. I'll have to wait for the shop to warm up more before I can start finish-welding the fuselage. Luckily, I have many fittings to make in the meantime and I'll make up some more clusters of scrap tubing to get in some more welding practice.
I have a lot more pictures than this, but I picked the most illustrative for now.

Here's all the tubing cut for one fuselage side, and that same side in the jig.

IMG_1606.JPG IMG_1603.JPG

Once both sides are tack-welded they get stood up in the jig and I can start fitting and welding in the cross-tubes and diagonals.
IMG_1607.JPG IMG_1612.JPG IMG_1636.JPG IMG_1638.JPG IMG_1639.JPG

Also, I bought myself a TIG-welder for when I have to weld aluminum for the fuel tank and stainless steel for the exhaust. Yes, you can oxy-acetylene weld these materials, but I want to learn TIG too.
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FYI, Aluminum is very hard to weld. UGLY.
IMG_1646[1].JPG

I've been thinking about airplane building, the amount of money I'm spending on this project, the time investment, etc and I've come to the following conclusion. Building an airplane isn't about building an airplane; it's about building myself. I'm learning skills and attitudes that will hopefully benefit me for years to come. Having an airplane when I'm done is just a side effect.
 

Phin G

Elite member
I haven't been very active on the forums lately. Besides the cold, snow, and raging winds, I've been occupied with other things. Namely, I've been working on my Jr Ace fuselage. I now have all the tubes cut and tack-welded together into a fuselage shape. I'll have to wait for the shop to warm up more before I can start finish-welding the fuselage. Luckily, I have many fittings to make in the meantime and I'll make up some more clusters of scrap tubing to get in some more welding practice.
I have a lot more pictures than this, but I picked the most illustrative for now.

Here's all the tubing cut for one fuselage side, and that same side in the jig.

View attachment 193852 View attachment 193851

Once both sides are tack-welded they get stood up in the jig and I can start fitting and welding in the cross-tubes and diagonals.
View attachment 193853 View attachment 193854 View attachment 193855 View attachment 193856 View attachment 193857

Also, I bought myself a TIG-welder for when I have to weld aluminum for the fuel tank and stainless steel for the exhaust. Yes, you can oxy-acetylene weld these materials, but I want to learn TIG too.
View attachment 193858
FYI, Aluminum is very hard to weld. UGLY.
View attachment 193861

I've been thinking about airplane building, the amount of money I'm spending on this project, the time investment, etc and I've come to the following conclusion. Building an airplane isn't about building an airplane; it's about building myself. I'm learning skills and attitudes that will hopefully benefit me for years to come. Having an airplane when I'm done is just a side effect.
Yes aluminium is very hard to weld and to get a clean edge. You could use a welding pic to nock of the untidy parts or use an angle grinder. For welding 2 bars with a stick welder i just put a block of wood ontop of the welding rod and the 2 parts that i want to weld. There is a vid of a person doing ot and it works very well. It has been 2 years since i have used a tig welder as i had one at school but not aty dads workshop. Looks like a really nice build and love the framework.
 

Piotrsko

Master member
In regards to the price: have you looked at spamcans lately? The prices for super cubs is obscene, back in the day you could get a whole fleet for that. Flying is not for the cheap and lazy.

Gas or mig (or some related varient) for tubes because the term heat control is important to avoiding the blobs. But by now, you should know that.

Aluminum welded fuel tank.....man that's a ton of welded work which will test your skills like nothing else unless you sealer cheat.
 
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Piotrsko

Master member
After watching many exasperating attempts of fellow EAA fuel tank building: aluminum fuel tanks are really hard to weld up so they don't leak
 

Tench745

Master member
After watching many exasperating attempts of fellow EAA fuel tank building: aluminum fuel tanks are really hard to weld up so they don't leak
Yeah, I believe that; it is not easy. I'm considering having a shop weld it up for me, but I'll cross that bridge when I come it. This project is about learning, and welding aluminum is something I want to learn. If I don't master it, I still learned. I can always make another set for a new tank if this one doesn't work out.
 

Taildragger

Legendary member
Heh. More like 70% done 70% to go. I’m planning to knuckle down and post some updates as the weather gets cooler.
80% done and 90% to go is always how it goes with homebuilts! Can't believe I never saw this thread before, inspiring! I need to get started on mine sooner than later.
 

Piotrsko

Master member
Most home builders stop way before 99%, sly jokes apparently don't work here in the forum.

70% would be almost ready to cover, didn't know you were that far along. How did the fuel tanks work out?
 

Tench745

Master member
Most home builders stop way before 99%, sly jokes apparently don't work here in the forum.

70% would be almost ready to cover, didn't know you were that far along. How did the fuel tanks work out?
Ok, maybe not 70% then. Time wise I think I'm past half way, but it's hard to tell. Still need to make cabanes, wing struts, turtle deck, and weld on tabs for the fuselage stringers. Lots of little things in between.
Still need to weld up the fuel tank, but I'm happy with how the end caps and skins came out.
 

Taildragger

Legendary member
How hard was it to weld the fuselage? Did you oxy or tig? And what size tube is used for the main structure? Sorry for so many questions but I need to know!
 

Tench745

Master member
How hard was it to weld the fuselage? Did you oxy or tig? And what size tube is used for the main structure? Sorry for so many questions but I need to know!
Happy to answer any questions!
Welding the fuselage wasn't terribly difficult. It's definitely an exercise in fitting yourself into weird spaces while still trying to have enough support for your hands and see what you're doing.

Most of the fueslage is oxy-acetylene welded, but I bought a TIG machine part-way through and that has been wonderful for welding strut and landing gear fitting onto tubing clusters. I feel like learning Oxy-fuel first was a great help with learning TIG. I like the Oxy-fuel for things like tubing clusters because it's hard to see and/or get the TIG torch in there. TIG is great for places where you need a lot of heat.

The fuselage is 4130 seamless tubing. The longerons and all tubes from the cockpit forward are 3/4" x 035 wall. Moving aft from the cockpit, the diagonals in the fuselage reduce to 5/8" then 1/2" tubing to save weight, all .035" wall thickness.
Some structural things are larger or heavier. For instance, there's a cross-tube in the cockpit that the control stick mounts to that is 3/4" x .049" and I believe the cabanes are 1" x .049" tubing.
 

FoamyDM

Building Fool-Flying Noob
Moderator
Happy to answer any questions!
Welding the fuselage wasn't terribly difficult. It's definitely an exercise in fitting yourself into weird spaces while still trying to have enough support for your hands and see what you're doing.

Most of the fueslage is oxy-acetylene welded, but I bought a TIG machine part-way through and that has been wonderful for welding strut and landing gear fitting onto tubing clusters. I feel like learning Oxy-fuel first was a great help with learning TIG. I like the Oxy-fuel for things like tubing clusters because it's hard to see and/or get the TIG torch in there. TIG is great for places where you need a lot of heat.

The fuselage is 4130 seamless tubing. The longerons and all tubes from the cockpit forward are 3/4" x 035 wall. Moving aft from the cockpit, the diagonals in the fuselage reduce to 5/8" then 1/2" tubing to save weight, all .035" wall thickness.
Some structural things are larger or heavier. For instance, there's a cross-tube in the cockpit that the control stick mounts to that is 3/4" x .049" and I believe the cabanes are 1" x .049" tubing.
This update and detail is great @Tench745. Thank you.
 

Piotrsko

Master member
Not using streamline for the cabanes? cub struts were free a while back when they failed the punch test at the base.

If you thought building ribs was boring just wait until you cover and have to stitch ribs. Think I had something like 800 knots in each wing panel, and I was only 150 kts VNE.