New member building a PA18-95

Congrats! An instrument rating is an excellent tool off you keep your proficiency up.

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As always I enjoy reading your posts. Your work looks outstanding! So neat that your involving your family in your build, I'm sure they will all look back on it with fond memories.

More wing parts

Took an intro course on how to use a mill and lathe last fall at a local tech school. I was able to make my lift strut spacers and aileron/flap bearings after going through the class. A real machinist will take one look at these and know a rookie did them, but it was a fun learning experience for me. I'm not throwing them away. I didn't bother with a mill or lathe for the spar stiffeners and spacer bushings. Made pulley cages today, they were easier than I thought they would be. Angle grinder, dremel, hand seamers. Lots of time in this little pile of parts. Its been fun.

Post more pics soon.

Thanks,

Jim

Great job Jim.. an inspiration to us all!

Nice work and you'll love the set-up you have...now all you must do is get all the farkles for the lathe and mill. I bought a cheap one but it does the little things I want. Just finished turning an AR-15 barrel down for my wife who was whining about her's being too heavy...now it's 1lb 2oz lighter.

Keep up the good work!!

Flap bell cranks and part holder

You end up making a lot of "things" to make things. There is a smart guy in South Dakota who makes exhaust who had a picture of something similar to this involving a bowling ball. I spent some time making something that would work for me to hold small parts at odd angles while I burned the hell out of them with a torch. I like it so far, it doesn't rob the heat from the part and you can quickly flop it over to weld the other side and not dump a bunch more heat at it. I made up a set of gator clip attachments for it to solder wire and the like. The rock looking things are heavy used rusty steel mill balls. They aren't perfectly round which would be ideal, but they are better than what I had.

I used .100 4130 for the bell cranks. They were 6.6 oz. each. They are more complicated than what they need to be, might be heavier, and took some time, but I don't think they will break and they were pretty close to what I had in mind. If my count is right, I have 14 more little steel parts to make.

Thanks,

Jim

Looks great Jim! Keep it up and you'll get there. You'll be lighter than you think the way your keeping track of the weights of each individual part
BTW we just did a preliminary weighing of the cub that I'm helping a guy build and with a metal prop and 0-200 it's going to be 760-770 empty.

Good looking work Jim. If you haven't already, try rotabroach's. They make nice round holes. I love 'em. The kit's on amazon are reasonable.

Thanks Clint and Kevin. I'll research the rotabroach thing tonight when I'm behind a real computer. To the shop..

Thanks,

Jim

Had to change the code

A while back, I sold the C-90 basket case I had to a friend who had history with it and will put it to good use. It has been bothering me for a long while that I hadn't changed my building code. I know it is a silly thing to worry about, but without something accurate and meaningful in writing as a guide, for me it's like going on a long trip without directions. The only points that changed were points 4 and 6. They changed a long time ago, they obviously are big things. The biggest struggle for me has been what to do for fuel capacity, still keep it light, and where to stow it. It has taken me until recently to fully decide. Thank goodness this has been a slow process, it has allowed me to really look at what other people have done, weigh the pros/cons and come up with something that makes sense to me. My vision for the airplane has never changed, a bare bones lightweight Supercub. Sorry for the blah blah blah Oprah stuff, but here's the new code. This time, I'm laminating the shop copy.

Jim's Building Code

1. I'm going to scratch build a mostly stock PA-18-95 with flaps.
2. It will be built to operate primarily from wheels and skis with future floats in mind.
3. I will involve my family as much as I can on the build.
4. It will weigh 875lbs. or less when I am done.
5. It's wings will have aluminum spars and ribs.
6. It will be powered by an 0-320.
7. I will not compromise safety to make my target weight.
8. I will scrutinize everything that goes into the aircraft and everything I leave out.
9. I will build it as inexpensively and as quickly as I can and stay within a budget of $20,000-$30,000.
10. I will fabricate as much of it as I can.
11. I will log my hours, track spending, take photographs, and document the build from start to finish.
12. I will rely on others who have built before and/or are qualified to provide inspiration, information and help with my build.
13. I'm going to start on June 1st 2013.
14. I'm going to finish no sooner than June 1st 2017 and no later than June 1st 2020.
15. I will need to spend an average of 8-14hrs./week on the build in order to finish within my time frame.
16. Above all I will enjoy the building process and be happy with what is created in the end.

Thanks,

Jim

Diagonal bracing on ribs

I'm planning to leave the #2 rib in tact and run wires through two smaller tanks with front and rear crossover tubes and vent in bays 1 and 2 on both wings totaling 18 gal. per side. Cubcrafters does something similar with their extended fuel machines. Originally I was thinking 1 smaller tank in each wing and a fuel pod underneath, (again something similar to Cubcrafters), but I didn't want to rely on a pump, a hand pump in my case, (no electric) to refill tanks in the wings as I run them dry. My logic is that both wings will resemble the right wing in a -95. There will be no beefing up to the rear spar behind the fuel tank bay because I'm not cutting the top out of the second rib. I also won't need a heavy tank cover. Because my individual tanks will be smaller, the tanks straps will also be smaller. I will set it up so I can install a light guage tank cover (what could possibly leak?) over the first two bays with the second rib in tact. I may just fabric over them originally, but have it set up for a cover. We'll see how I feel when that day comes.

I'm adding diagonals to my ribs similar to Dakota Cub ribs. What I had works well for others and would likely be just fine, but adding diagonals was suggested and makes sense to me. It will add 1.21lbs. total, but if my math is right, it will be far less weight than boxing in the top of the rear spar in the flap area to ease my mind.

Anyway, pictures are of before and after diagonals and kids spending some time with Dad in the shop.

Thanks,

Jim

Forgot to mention, new flap/aileron rib 10.3oz, gained .7oz, new nose rib 1.4oz, gained .1oz.

Thanks,

Jim

Always good to have a plan and stick to it as best you can!! Stay on top of your inst. work and take time out for the family...otherwise full steam ahead!!

Nope

Reality set in with the 4 smaller tank thing. Too heavy, too complicated, likely to leak like a sieve. Back to two 12 gallonish tanks with provisions for a fuel pod if I decide I need it. It will be hard enough to make two tanks that don't leak.

You can do it Jim!!

I built two 20 gal tanks all TIGed up and I got no leaks in 36 hours of 5 psi of air pressure test and I still covered all the seams and welds with ProSeal...just...well because!

I know I can make them and have them not leak on the ground. The real trick will be making them last for a long while on land and in the air.
Remember the old Samsonite commercial with the gorilla playing with the luggage? Thats what I imagine them needing to stand up to. From a least likely to leak standpoint and ease of install, it looks to me like a shear plate is the clear winner followed by single through tube and then double drag wires. I also feel like weight will follow the same order. What I was thinking with two tanks tied together with hoses between a rib likely wouldn't be much lighter than a single through tube. The gorilla will easily make the two tank hose creation leak first. I don't relish the thought of moving fuel around with a fuel pump, especially an electric one (I drive GM). But I do like the idea of light most times heavy when I want to be. 24 gallons should give me about the same range as a J3 with a 12 gallon tank up front. I might decide that is enough for me. If not, build a pod. If the pump fails, take about an hour to swear and find a suitable place to land, use my creative climbing skills and replentish the tanks with my coffe cup(lots more swearing). To the shop!

Thanks,

Jim

Answer...no rides for gorillas!!

I have a 48 C-170 that just developed a leak last summer at one of the straps. Best I can tell it is the original tank and it never leaked until then and it's probably 0.040 and not the 0.050 I used so I'm pretty confident with my tanks.

I've always used Holley electric pumps and they seem to work flawlessly...heavy but they work for me.

Couple quick questions

Aileron horn stops- looks like some guys use them, some don't. I'm making them, may or not use them, don't know enough yet. There are two dimensions for them. It looks like you cut them off slightly at the end for final adjustment. Make two of the longer ones? (this seems to make good sense...)

How much space needs to be built into the gap between the flap and aileron? Aileron and tip? Extending the flap inboard from the first hinge, exactly 3" or something else?

From Jim math and the drawings, I'm not coming up with definitive conclusions.

Thanks,

Jim

Jim A. said:

How much space needs to be built into the gap between the flap and aileron? Enough so that the aileron doesn't hit the trailing edge of the wing when it is full up.

Click to expand...

Jim A. said:

Aileron and tip? 1/4" or so.

Click to expand...

Jim A. said:

Extending the flap inboard from the first hinge, exactly 3" or something else? Not so much that the flap hits the window when it is hanging down. Extending the flap outboard is more effective since that portion operates in clean air.

Click to expand...

Hmm? SJ did something that made me add more words to post.

From the prints, and not sure again if I am interpreting them right, it showed 9/16" of a gap between the aileron and the tip. If I add up the lengths of the stock aileron and flap and divide the remainder by 3, I'm coming up with a number between 3/8"-1/2", or in other words a 3/4"-1" gap between the flap and aileron and a 3/8" gap on the inboard side of a non-inboard extended flap. Doesn't seem right.

My flaps are extending both ways, just curious if someone has a number inbound for the flap that will work without hitting. It looks like you do some fairing either way.

Thanks,

Jim

Just measured my Cub:
Center of inboard flap hinge to inboard end of flap 11".
Gap between flap and aileron 1/4".
Gap between aileron tip and wing tip 1/8".

Don't forget to allow for the thickness of the fabric when you build your surfaces.

Jim A. said:

Aileron horn stops- looks like some guys use them, some don't. I'm making them, may or not use them, don't know enough yet. There are two dimensions for them. It looks like you cut them off slightly at the end for final adjustment. Make two of the longer ones? (this seems to make good sense...)

How much space needs to be built into the gap between the flap and aileron? Aileron and tip? Extending the flap inboard from the first hinge, exactly 3" or something else?

From Jim math and the drawings, I'm not coming up with definitive conclusions.

Thanks,

Jim

Click to expand...

Aileron stops, set the stops at the ailerons to the right degrees up and down and then go in the fuselage to the control sticks and set those stops. I still think my one 24 gallon tank in the left wing is the cats meow, except for traveling, wish there was more. But i do have a 1 quart header tank. Wanted to add, i put a little drain hole at the lowest part of the aileron hinge in the center bottom, dosent need to be very big.

Just realized what I wrote in my first post last night was written incorectly. What I should have written was 3" inboard from the edge of a standard flap or 10" in (7+3) from the center of the first flap hinge. If your first hinge is where it normally goes in a Supercub wing, this tells me 10" from the center of the hinge should clear easily. I'd rather be safe than sorry. Also good to have actual numbers for the remaining gaps after cover that work on your plane. Thanks again Pete! Doug, I noticed that hole you mention on store bought units. Likely a good reason for it. Thank you for mentioning it. Yes, the more I think about it, the more I am convinced that I'm going the right route for me with 24 gallons and provisions for a pod. It will never burn gas if I keep stewing over it!

Thanks,

Jim

Center of inboard flap hinge to side of fuselage 12". This gives 1" gap from end of flap.

Last parts before putting wing together.

I finished putting diagonals in all my ribs and nose ribs. I converted the two full ribs I made into aileron ribs. 138 small chunks of aluminum and 276 rivets later, I'm done with my ribs again. I didn't want to revisit my ribs again, but felt it necessary. Now that it is done, I'm glad I did it.

Remember those 14 parts I thought I had left? Turns out I had a few more. I think these are the last 38 parts I needed to make before putting the wings together. I still have to make my tanks, tank straps, and wing tips but those will wait.

All of the parts I've made in the last year just barely fit in a 5 gallon bucket. Looking forward to blasting them and getting a finish on them.

The airplane factory has to convert to a canoe factory for a few weeks. We're making two more so we all can go to BWCA this summer. I plan to build up both wings at the same time and will have to get the canoe thing done first from a mess/space standpoint.

Thanks,

Jim

Nearing completion on the Allen Armada

Boys and I started these on April 23rd. The little guys are excited about their first Boundary Waters trip next weekend. They are also anxious to sling paint on their hulls. Amine blush and curing epoxy resin, a lesson in patience.

Once these are out of the shop and the mountain of a mess is cleaned up, we're going to learn something new. It won't be cheaper and it won't be faster, but it will be a learning experience. I'm going to zinc plate and yellow/clear chromate my steel parts myself. Plan A was to just paint them, but a lot of this stuff is just hardware, and I'm concerned about getting good spray coverage on some of the parts. All will get plated, some will get painted as well. Kids will likely have to observe from afar, but they'll learn how this magic works anyway.

Once I get the process dialed in, I'll post some pictures.

Thanks,

Jim

Two canoes in two weeks, they look great your boys will remember this adventure for a lifetime. If you are so inclined you should write up a short story of your build and Boundary water trip for submission to Wooden Boat Magazine. This is the sort of thing that they like. http://www.woodenboat.com/

Thanks Pete! Oldest boy may be interested in submitting a story. He would get a kick out of it if it made print. I'll need to get back to business so I can post some airplane related pictures!

Thanks again,

Jim

Beautiful canoes! Looks like the boys share your interest in building, that's great to see! Great thread, I've enjoyed following your projects.

How will you be hauling them?


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