Help! I can't figure out assembly of gear fittings

I am at a real loss here. I am trying to figure out how to assemble and weld the landing gear fittings on my 2+2. I am using stock PA-18 gear, and the fittings from Wag supplied with the material kit. The rear fitting is the current dilemma. I can't figure out the sequence to weld the parts in place. I need any and all directions here. Up to this point, the project has been pretty straight forward but this, I can't figure out at all So, if you would please :roll: take a look at my site www.xanga.com/martyfeehan and look at the top posting and the pictures and guide me through this you guys would be the best!

Thanks,
Marty57

Call one of the frame builders. Lee and airframes INC, Nick Smith. They will make sense of it all for you. Never done it myself.

When I have installed these on certified A/C they were all welded together as an assembly. I only remember two parts though. The ears get ground to fit the tube and then the tang on the bottom is heat formed around the tube. There is a tech guy at Wag that I have talked to before that could probably help. I will check my Rolodex but I think his name is Tom. I will also look at a fuselage and see if they are the same as yours.

Hi Marty,
In addition to the emails I sent you, try calling Tom Oneil at Wag (as Steve mentioned above). He is the answer man for Wag stuff.

Thanks for all the help, I think I have a better handle on this. I am going to call Tom at Wag and see why they use a three piece fitting rather than a two piece. If I am still uncomfortable with the three piece I will get new fittings from Airframes. Needless to say, no room for error here.

Marty57

Steve is right. these are welded together as an assembly then welded to the fuselage. I have only seen two pieces on certified planes. I don't think the pink one belongs in there. if you weld all three together, the strut forks probably won't fit over them.

John

I had the two piece rear fitting from Airframes. First, I believe the best approach is to do the front gear fittings first with the cabane on. Before you final weld anything, use a gear jig or old landing gear to get the spacing right front to rear. This also gives you a good idea of any final fitting/grinding you need to do for both sets of fittings.

When doing the rear fitting, I first welded on the upper fitting at the proper angle. After final welding the upper fitting, I then bolted on the lower fitting (verified alignment with front fitting and gear pivot axis, etc). When satisfied, I welded the lower fitting to the upper fitting + fuselage. The reason I did the upper fitting separate is because you get more weld contact points. If you put them together and then weld to the fuselage you are covering up additional contact points which are not visible anymore. At least that is how mine was. Also, by doing the upper fitting first it is easier to weld the inner gap where the fitting meets the longeron because the material is only 1/8" thick at that point. If they are preassembled then you need to weld 1/4" thick plate to a .049(or .035) longeron which is a PIA with a torch.

Good points all around. I would hate to have the forks not fit, did not think of that one. I haven't had a chance to call Wag yet, but at this time I am leaning at getting a set from Airframes or at least comparing mine to an Airframes set . When I hold the three pieces from Wag together up against the lower cross tube, the gap seems huge, another concern. On Bugs66's suggestion, I am going to build my cabane first, install the front fittings second (using cabane as a jig) and then install the rear fitting/lift strut attach. This should give me some time to figure out why Wag uses three pieces or to get a set from Airframes. Thanks for the help. Any other suggestions or anything else I am missing?

Marty57

Maybe we can get Tim or Clyde B to chime in. Clyde is on his second Wag Cub.

Never done anything with gear fittings yet. But after looking at the northland drawings it definantly looks like 2 pieces.

Gear fittings are one of the things I would not hesitate to buy for a project though.

Just bought a bunch of stuff for the j5...now my credit card is starting to melt!

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The plans call for an angle of 22degrees, 20 minutes. Ok, is it possible to get that accurate when welding 4130? With the expansion of the steel, the 20 minutes seems a bit much. Any body else out there used three piece fittings? Do I need a smart level to get the 20 minutes or do I simply use a template? How much play in the strut if off +/- the 22 minutes? It is looking better and better to go with Airframes fittings here. I don't suppose it has anything to do with gross weight? The plans call for max gross weight of 2200, three piece have anything to do with that? Together they measure 1/4" thick, same as the two piece kind. Any Wag builders hanging around? Thanks,

Marty57

T.J. said:

Tip:
If you don't want to remove the fitting after welding it in place, make sure the angle for the strut is correct!
I just did that. Bought a fitting from a known supplier, welded it in place, hung the wings. Damn! the forks would not go on the fitting! Wrong angle. I think they sold me a fitting for a Pacer, the angle was to high for a Cub wing.
Next one, I'll hang the wing and make sure the angle is correct.

Click to expand...

Wow TJ, that really sucks big time. I bet you were not a happy camper. I pray that doesn't happen to me. I did my fittings exactly 22.5 degrees +- as shown on the drawings. I made a template to jig it in place. I tacked welded that fitting all over to make sure it wouldn't budge before finish welding. My fittings on the wing are where they are supposed to be. I will hope it comes out ok. D&E Aircraft sell fully articulating aluminum struts. Ernie used to tell me over and over how great his design was because you don't have to worry about minor misalignment. Maybe he had something there. I believe D&E is flying those struts currently on their Taylor/Cub prototype.

Marty,
I welded up the three piece fitting like Bugs said. I used a smart level to set the angle, but I think I will do the final strut alignment when I get the wings done and rigged (or jigged) in place on the fuselage. My thought was to weld the upper strut attachment together and tack weld the Fork and barrel right on the plane?
Laz

Hi Laz,
It sounds like you have a good plan. How is your project going? I think I have a handle on this now. I welded together the two pieces that make up the lift strut attach fitting (comes in two pieces from Wag). I set the lift strut fittings up last night with a jig to hold it at 22.5 degrees. I wonder how easy it is (or difficult) to hold the fitting to .5 degrees? With the expansion of 4130 during welding can this degree of accuracy be held? I have also started preparing the gear fittings with the necessary bushings. I plan on welding the bushings in place on the “u” brackets and then bolting them to the landing gear. I will jig the landing gear in place and use the cabane I built to set the distance between the front fittings. So, if I can manage to jig the landing gear, cabane, and gear fittings in place, I should be able to weld everything together keeping it all true and straight. Sound like a good plan? This jig should be interesting.

Marty

Hi Marty,
I have the fuselage covered and painted (Airtec), sitting on the gear with the tailfeathers on and the cowling done and painted. The interior is all fabricated and the controls are in place, (whew!) A lot of work! I hope to build the wings this summer and maybe(?) fly next year.
Looks like you figured out the welding just fine!
Take care, Laz

The most reliable way I have found to establish the lift strut attach angle on the rear gear fitting is to use a jig that is made with a front spar and a lift strut to represent the actual wing. I have an old section of front spar that has the wing attach pieces bolted on the inboard end and the strut attach fitting bolted where it belongs. Then use a regular front lift strut to bolt to the spar and check the angle of the fitting on the bottom end before you weld it up solid. Be sure you keep the wing spar fairly well lined up with the front spar carrythrough tube of the airframe (so it's perpendicular with the centerline of the airframe). If your jig has the correct dimensions, you will be sure the lift strut will fit when you're done. Works on both sides. Good Luck.

I wanted to thank you guys for your help back in April as I struggled with the gear attachment fittings on my 2+2. As you can see, another success thanks to the great help here at Supercub.org! Next step is deciding how I want to do my shock struts. I am leaning toward a single die spring set up. I need to figure out the proper length to make the strut to give me proper camber both unloaded and loaded (aircraft, not me ). I have the correct length via my custom "wood shock struts" pictured. Any words of wisdom here?

Thanks,
Marty