Experimental Producer Lift Struts

[stretchedpacer]

Since there are guys on this site building and flying producers/stretched pacers, I thought I would post the question here since it might make a good resource for others later.

As background, I am building a stretched pacer and it is experimental. Fuselage, landing gear and fuel system are pretty well squared away as are a bunch of other small details (read - I still have a long way to go).
I am getting ready to build the wings and since I am ordering new spars I want to go ahead and order the strut material to make the most of my oversize shipping charges.

I am looking at a couple of options but am open to suggestions.

Wag-Aero sells a kit for the 2 + 2 which should work but it is 2.68 (on the long axis in cross section) streamlined tubing for all four struts. The wag tubing is .049 wall, presumably 4130 instead of the original 1010 mild steel.

This is strange to me as a supercub front strut is 3.938 inches on the long axis in cross section and the rear strut is 2.438 inches on the long axis in cross section. Basically, it seems the wag-aero kit might be undersized. While I am not as concerned about pulling the wings off in flight, I live in Montana and snow loads are a real consideration if this thing gets tied down overnight somewhere in the open. The Wag kit is attractive because it is an actual kit with forks, barrels, etc. - and the 2 + 2 is about as close as any kit I have seen to what I am trying to build.

The other option is to purchase the D&E aluminum lift strut kit. Seems there could be a problem with corrosion on this kit as the kit uses steel and aluminum. I have not heard of problems though so I may be overthinking the problem.

In sum, I would like to just weld up a set of sealed steel struts but certainly do not want them to be undersized as they are a critical component. The D & E kit would probably be the easiest to build but I dont know anything about its strength or the history people have had with the struts. When one considers shipping costs all of these kits end up being pretty comparable at the end of the day when it comes to overall cost.

If anyone has any other ideas I would love to hear them. As well, if anyone has measurements for the front and rear lift struts that would be great as well. As it stands I get to re-invent the wheel and hope I dont get to take a second (expensive) crack at it later.

Thanks for all the help.

Brad

[Wheelie Wayne]

Blanton's plans use the regular short wing struts but lengthens each wing 18". This is what I am planning on for my stretched Pacer project. I don't know what the cost difference is between the D&E struts, I do know that the performance of the Riblet airfoil on the D&E wings is pretty impressive though. If I did not already have the wings to work on I would have bought the D&E wings.

[stretchedpacer]

Wheelie Wayne,

You bring up a good point that I should have clarified. I am building new wings which are similar to PA18 wings - however the wings will have 8 foot flaps and 8 foot ailerons. On this particular project each wing panel will be 17 feet plus a little bit for whatever tips I go with.
I thought about the blanton plans but decided to just build new wings. The down side to building new wings (aside from the extra work and parts) is that you have to adjust the strut attach fitting from where it is to somewhere in the neighborhood of 20- 21 degrees (dont have the info directly in front of me right now).
You are correct thought that the Blanton plans let you re-use the old struts which is a plus. Still probably need to think about putting sealed units with larger forks but you may already have these items. I think my plans from Blanton give some info on that subject.

Good luck with your project.

Brad

[Steve Pierce]

Cub Crafters is using aluminum struts on their Sport Cub. I imagine it is a major weight savings. I wonder if you could get Cessna struts from a salvage yard or maybe the aluminum fittings and make them fit the D&E struts? I have a couple of bent Cessna struts. Univair sells an open strut kit where you finish out the top. We have used these on a Clipped wing Cub we wanted the wings totally flat on. Just kinda thinking out loud here.

[stretchedpacer]

Thanks Steve,

I didnt know that univair sold a kit like that. I hadnt even picked up the univair catalog for this aspect of the project. My stamped univair ribs sure are nice though so maybe the kit would be as nice.

I know that some bearhawk builders are salvaging cessna lift struts but Im not sure how the length works out. I think the struts on the bearhawk are pretty short (at least they look that way).

Nice to know that CC is using aluminum. Do you know if the CC lift struts have steel forks? I assume they do but it would be interesting to know just the same. If I recall correctly, the D & E forks are steel, the threaded end (where the fork screws in) is aluminum, and the strut itself is aluminum. The D & E strut kits also have some kind of semi-adjustable attach point where the strut attaches to the wing.

Brad

[Stephen]

Steve is correct on the CC wing parts, they should have a solid weight saving as their stamped ribs have larger holes than other I've seen and the spar also has large lightening holes in none stressed areas.

Depending on the size engine I would think that saving weight could be important for performance in these stretched Pacers.

The wing splice on a standing Pacer wing would be the easiest and cheapest approach, I would consider putting in my own lightnening holes.

[Airwrench]

Brad,
We used the D&E struts on one of the Experimental Producers, N915RD, and they worked out reasonably well. They had a lot of adjustment and appear to be stronger than the steel struts. They were more affordable and Scott at D&E was good to work with. With the bolt in blocks they are not as astheticly pleasing though. The steel struts are more difficult to build and all of the angles have to be matched to the wing that you are using. Your wing and strut attach fitting will also directly affect the overall length. Either way you should also add jury struts for the longer span of these struts. - SB

[Steve Pierce]

The Cub Crafters struts appear to have aluminum fittings. I will post pictures if they ever get my internet working at the hanger. :evil:

[stretchedpacer]

Steve and Steve,

Thanks for the info on the aluminum struts. I contacted D & E today about them and am thinking that I will probably go with the Aluminum struts (and jury struts as well). Its good to know that they seemed possibly stronger than the steel versions. Snow loads are a real concern and I would hope to keep from collapsing a set of struts. The nice thing about D&E is that they sell struts and spars which works out well when one considers the cost of shipping. I look forward to seeing the CC pics if your computer gets up and working.

Brad

[chrisg]

Are Blanton's plans still available? I'd like to see the wing plans...does anyone have a digital copy they can share? If not, where can I find a set?

Do the Blanton plans increase each wing 18" or total wingspan 18" (i.e. 9" per wing)?

Thanks,
Chris

[stretchedpacer]

Chris,

Blanton's plans are still available. I dont have the contact info directly in front of me. The wing extension is 18" per wing panel. Essentially Blanton's plans have you splice new sections of spar material and then add a diagonal brace and a few other stiffeners. The aileron can also be moved outboard to the tip and the left over space is made up with additional flap. For mine I just bought 17' spar blanks and am building the wings with those and of course, new struts since the strut attach points are now further out. I like this plan a little better and it should give eight feet of flaps and eight feet of aileron.

Brad