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4130 3/4'' X .035 Looking for enough to front half a Smith MiniPlane 100 ft.

footloose

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I have decided to replace the front half of my fuselage and want to do it with 3/4''. Today's prices have gone through the the hanger roof . Looking for possibly a kit that has been bought or extra mtl. and put on the shelf and needs a new home . Don't mind payin but $4.00 a foot is a bit much for a starter in a Mini . Post here or 918 916 0140 .
 

Lotahp1

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What’s wrong with the front of the Mini plane?
 

footloose

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The Mini has had some repairs . Hard landing after engine failure . Both lower (rear) wing attachment fittings as well as the crossmember between . Splices were made for and aft of the fittings . Must have been a heavy impact , both lower wings are new with exception of hardware ie. compression struts , drag anti drag , Log book has everything logged and they look very nice and all repairs appear to have been done correctly . The log book is a replacement for a lost log book and I don't know what I will face when re certification time comes . I am very meticulous and see no problems with the repairs but the larger issue is cockpit size . I cross the scales at 240 and stand 5' 10'' . I did get to see pictures of Mark , race 38 s cockpit and like the mod that was incorperated into his Smith . He and I are pretty much the same size , he being a bit taller . With all considered , I lean towards a new front half , extended 6'' between instrument panel and shoulder bar , seat bottom moved rearward 3'' , as in the Pitts design . All other dimensions remain the same except length and tubing size . Weight difference from tubing size would be small but strength in length would feel like a good a insurance policy . Your thoughts and thanx for your response .
 

race38

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Not having the plans any more, I can’t recall but believe the original seat was completely removed and the crossbar at the shoulders was laid back 4”. Rudder pedals were pushed as far forward as possible. Aluminum seat pan was attached to the longeron and up the back to the new crossbar with its vertical support as well as the angle bracing from the original cross location.
Lots of room, a little tight with a backpack chute on. The canopy that was on the airplane was a PITA. Last few flights were open cockpit. Not a bad ride in that configuration.
 

footloose

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Thanx again Mark . Part of my , (I'll call it a problem , but it's not) is that I have a set of plans and sometimes I can get carried away and go over board in my thinking and krap house engeniering . I'm thinking that the last time you posted , you had mentioned that your upper longerons were replaced with 3/4'' tubing and I guess that caught my attention . I haven't had a chance to put the wings and tail back on but that is where I want to start . That will let me know if I have a truly straight airframe to work with . All existing repair work looks very good but my thinking on replacing the front half is two or three fold . 1st is fabbing this with 3/4'' would add strength to the stretch with minimal weight increase , 2nd , grafting the existing back half would be fairly simple but with caution to alignment and fitting the diagonals , and 3rd eliminating the previous repair work . I haven't studied or researched what this modification would do to re certification but I'm sure there's an out for the mod . Building the box for the front half would be a simple way to clean things up and get the fit that I would be comfortable with . I know , it's a Smith , that's where I'm at . All input is welcome
 

asport22

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YMMV, but here's my experience with the Jodel. The wreck ripped the right main gear off, and took a big chunk out of the box spar at what is basically the most highly stressed point. Repair might have been possible, but it seemed better to me to build a new wing. I talked to the FAA FSDO before I started, expecting him to tell me that I would need a DAR inspection and a lot of paper work because it was a major repair. His answer was that all I needed was a log book entry and a condition inspection - a repair is a repair. (Apparently the FAA takes a bit different view on certified aircraft and frown on building a new airplane around a data plate. I guess they don't think anybody would bother to do that with a homebuilt.) I do have to put it in Phase 1 test for five hours after the repair, but with the IRAN on the engine, I probably wouldn't want to get too far from the airport for a few hours anyway.

One thing to watch for is that the FAA will probably offer to give you a new set of operating limitations if you talk to them about this. Depending on what your existing operating limitations are, that might or might not be desirable. The current ones have language that REQUIRE following all manufacturer life limits, etc - TBO becomes mandatory. There was a bit about this in the latest Sport Aviation - apparently this came about because of stuff related to helicopters and turbine warbirds. EAA is trying to get them to acknowledge that this was never intended to apply to ordinary piston homebuilts and issue new guidance, but it's something to be aware of currently.

Warren
 

race38

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Make sure you consider CG before you stretch it. Mine had forward issues, I would bet with the Cont yours will be aft.
Dropping the seat and moving the top of the seat really adds a lot of room.
 

footloose

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Thanx guys . Yup , C/G is probably the most serious concern . I don't want to build anything with control issues from the get go . Short coupled homebuilts already have , at best , their own instabilities . I've given a good deal of thought to the subject , especially with an 0200 on the front . I am planning on using an Ultimate cowl that I will have to reduce in size , for the 0200 , and probably will have to have a prop extension , plus at this point , I don't really know what prop or prop weight so the engine mount length is a definate ? My reasoning on the 0200 is also weight . 30 lbs lighter than an 0235 and close in HP if the 0200 is cammed up a bit . I also think that selecting the right prop can add as much to the preformance as well as the engine options . No electrical , of course . I'll not be a threat to Tucker or Stewart , just wanting to build an economical , light weight Smith and keep it in the Light Sport envelope . I did , at one time own a Smith and still haven't gotten over it . Here we go again . Thanx for all input , trying to not miss anything in the planning stages . Dennis
 

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