Super Cub build part scratch part kit

Hey fellas,

new to the forum. I’m getting everything together to start a cub project. I am planning to scratch build the fuselage and take things in stride. I’m a little intimidated by scratch building the wings and am looking at Dakota cub or cub crafters for that. I have been building some projects with carbon fiber over the past year and plan on building as many parts as possible out of that. The engine is planned to be a fuel injected 360 but I’m on the hunt for the right engine at the right price. I would love to have an unlimited budget but that’s not the case. Also planning on extended gear with 31s. Any tips or advice on things to do or stay away from is greatly appreciated.

adam, first thing i see in your post when you talk about building your frame with different wings. dakota cubs wings and javrons hook to the frame like pipers, cubcrafters dosent. they have there rear attach mount or fitting about 3/4 inch higher i believe. or maybe your aware of this. the ramifications as far as working with that, you would have to figure it out. i dont know. anyway good luck and lotsa help here. want to add, bill rusk on here just did a thread on wing assembly, very nice.

I would look into Javron wings. Also, if you are going on 31’s then extended gear will really put you up high, I would rethink extended gear, at least 6” extended gear and 31’s. I know some have this set up and like it but wow, that is waaaay up there.

tempdoug said:

adam, first thing i see in your post when you talk about building your frame with different wings. dakota cubs wings and javrons hook to the frame like pipers, cubcrafters dosent. they have there rear attach mount or fitting about 3/4 inch higher i believe. or maybe your aware of this. the ramifications as far as working with that, you would have to figure it out. i dont know. anyway good luck and lotsa help here. want to add, bill rusk on here just did a video on wing assembly, very nice.

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You are correct good sir! I spoke with CC last week to see if they would share drawings on the frame so I could accommodate their wing if that’s the way we go. Anyone have any insight on pros and cons of each wing?

Adam Gordon said:

You are correct good sir! I spoke with CC last week to see if they would share drawings on the frame so I could accommodate their wing if that’s the way we go. Anyone have any insight on pros and cons of each wing?

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are they willing to work with you?

If you are going experimental I would not do a Dakota wing. They have excellent parts, stout as hell and will fit most any cub wing. Great for a certified cub. But they are heavy. I think you can get as good a wing from Javron and it will be lighter. Also better flap options. CC has light stuff but I think they pretty much have a stock wing. If I was to build it would be a square wing with big flaps, so depends on what you want in that case. Several points to be made with tire and gear size depends on the mission. I tend to have older passengers so for me a bit lower is better. I am trying to come up with a better gear step/steps for the back seat myself.
DENNY

tempdoug said:

are they willing to work with you?

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Ha! Go with a wing that lets you use Pstol flaps now or down the road. Carbon cub wings won’t give you that option.

tempdoug said:

are they willing to work with you?

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They are supposed to get back with me early in the week.

I have not talked with javron. I will have to give them a call on Monday and see if they are willing to help me along. I appreciate the insight.

Adam, Since you do not have an unlimited budget you will be money ahead going with Javron over Cub Crafters.

I just started scratch building my cub also. Good luck to you and I’ll be following along

I built a new fuselage last year for my machine and used fittings and parts from Javron and Airframes Alaska and found both to be of very nice quality.

I’m looking at options for a tubing notcher or have VR3 cut everything to length. Any have any experience with VR3?

Baliegh and others make some nice notcher’s.


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Had a great talk with Jay at Javron. He was incredibly helpful and looks like that’s the way the project will go at least from the kit parts.

Adam Gordon said:

I’m looking at options for a tubing notcher or have VR3 cut everything to length. Any have any experience with VR3?

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Just use a pair of strait aviation tin snips. Works fast and well.

See the tools and jigs thread for tube profile copiers I made/ copied


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There are several computer programs from the bicycle building world that allow you to input the tube size and angles and then print out a paper profile that you cut out and then wrap around the tube to transfer the cut line. They are surprisingly accurate and can be used multiple times. Short jawed tin snips as Mike suggested work very well in addition to grinding with mounted stones in an angle grinder or grinding wheel to help to finish the edges. Learning those skills will be helpful even if you go with VR3.

I’ve used a couple tube coping web sites. Most work pretty good, just need to mark a centerline to be sure you use the same center on both ends of the tube.

Someone mentioned using aviation snips to make the cope. They work OK for gas welding, but leave a pretty good gap if you are going to TIG weld the frame.


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Adam Gordon said:

I’m looking at options for a tubing notcher or have VR3 cut everything to length. Any have any experience with VR3?

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Decades back when I first started on airframe work I used a bench grinder that I shaped a radius to each wheel. I was able to efficiently form gap free joints.
Today I use hole saws on a milling machine.

I don’t know about y’all but I’m usually looking for any semi legit reason to get a new fancy tool for the shop. I’m looking at the baliegh machines the hardest. I think it would make a better finished product and less headache along the way.

If you're just building one fuselage you would be better of spending money on expensive parts over expensive tooling. Most of my tooling to make tubing fits is homemade. You can do a lot with minimal tooling. Many of the acute angles in cubs and similar types have to be hand fit anyway unless you spring for Vr3. I've built cubs, bearhawk , many homebuilt designs, 14 fuselages over the last 41 years. Lots of rusty longeron repair too. The popular hole saw notchers all the tool people sell is pretty much worthless on small diameters except for perpendicular cuts. Everybody loves tools including me, spend wisely.

For many years EAA Sport Aviation magazine has had an ad in it for the Ol' Joint Jigger.

I use a harbor freight notcher attached to a drill press. Also would recommend with and method you try to get some cheap scrap tube. Probably not 4130 make some practice notches. Try the complex angles first then you know how to do them on the real tubes

jimboflying said:

There are several computer programs from the bicycle building world that allow you to input the tube size and angles and then print out a paper profile that you cut out and then wrap around the tube to transfer the cut line. They are surprisingly accurate and can be used multiple times. Short jawed tin snips as Mike suggested work very well in addition to grinding with mounted stones in an angle grinder or grinding wheel to help to finish the edges. Learning those skills will be helpful even if you go with VR3.

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This is how I used the computer programs with the paper profile and cut out and finished with a grinding wheel rounded

I built tube holders for every size tube I would be notching that fit into the tool holder on my metal lathe. Put a hole saw in the lathe chuck and away you go. Those worked OK on most tubes unless the length was really long. I couldn’t do offset notches with this set up.

I also notched tubes in my mill but those were limited to 90 degree intersections.

I bought a tube notcher from Baileigh that says it will do tube sizes from .5 up to 2.5” but the jaws won’t close down enough to grip a .5” tube tightly enough. That worked better than my other two methods......in most cases, especially for offset notches.

You need to buy good quality hole saws for all three methods above. Cheap stuff doesn’t last, teeth break off and then tubes get bent.

When I was about 80% done with notching tubes I started using snips to get the rough shape and a rotary file in a pneumatic die grinder to get the final fit. This worked the best and was by far the fastest. A grinding wheel shaped to profile the proper tube size is faster but I didn’t have room for several more bench grinders. I have two and they are set up for other operations. Wear leather gloves because every once in a while the rotary file catches and climbs out of the notch and over your fingers. Those things eat meat much faster than they eat metal. I also started wearing a leather welding apron because the metal flakes coming off the file burn small holes in my shirt. Also, rotary files larger than 3/4” are expensive and hard to control in a small die grinder.

As mentioned in previous posts, mark the centerline the full length of the tube. Most tubes are notched on both ends so the centerline keeps everything aligned. Tubes perpendicular to the longitudinal axis on the top and bottom of the fuselage should get a mark dead center. I used a spring loaded nail set that left just a pin prick and then touched it with a silver marker. I used a laser mounted on the jig table centerline to keep all the tubes lined up, making sure the laser line fell right on the pin prick marking.

Never had any of those weird hole saw tube jigs. Did try the lathe/ tool post method a few times. Scared the crap out of me when I rolled the top edge in. Strait tin snips is best method with a finish up grind on edge of belt sander if needed. Fast and accurate Try it, you won’t regret it. I can do it on my mill also but it’s not worth the setup time. Remember piper just used a copy punch nibbler


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One part about cutting the fishmouth on a lathe, there is no way to watch the cut. When the cutter grabs, nothing good comes of it.

Here is a couple of clusters fitted the way Mike describes in post #27. All done with snips, files and small drum sanders. I done so much of this that I can draw the first cut with silver pencil and be close on the fit in a short time and move along at a good pace. Setting up hole saw tooling isn't for me on anything other than perpendicular cuts. I occasionally cut fish mouths in my lathe with a V block and fine pitch roughing mills but those are perpendicular cuts as well. For .058 wall and thicker I have a couple grinding wheels shaped just for tubing. Everybody has their own way and work shop habits, these are some of mine.

I guess I consider myself lucky that I have invested in a milling machine, well two actually. First one was an older Bridgeport step belt which did me well for decades but has some wear to it. I then about 20 years back had enough money in my pocket to buy a fresh from overhaul variable speed Bridgeport. This is a sweet machine.
For me tube joints have become second nature from when I started with snips and files to now, just clamping a tube in the vice and cutting.
These tubes are as cut, no filing, no second process work.


For me the part that is getting harder over the years is I have aging eyes and little dexterity in my right hand, My duty cycle to produce the perfect welds all day long are something of the past. I am thinking I have to find a skilled kid to hire to make sure the tough to weld spots are done perfectly.