Single-seat ultralight puddlejumper: the "Carbonmax"

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Steve C

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Neat project!
There have been a few models built with "wave spars", but they didn't seem to catch on.

Some are doing the shear web as a wave of carbon laminate that goes from front to back to front of the spar caps.

I've seen an ultralight with bagged blue foam core tail surfaces and flaperons. It was fantastic and I wish I knew what they were called . If you do them like we used to build model wings, they wont be that heavy.
 

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Mavigogun

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Some are doing the shear web as a wave of carbon laminate that goes from front to back to front of the spar caps.
Could you point us in the direction of the construction method for the pictured elements?

I've seen an ultralight with bagged blue foam core tail surfaces and flaperons. It was fantastic and I wish I knew what they were called.
So, a solid foam core with only glass or carbon skin?
 
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Steve C

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I don't recall seeing exactly how those were made. Mostly guys shared how they look finished. I know Jaro Muller did one for production but I can't find anything about it now. He does a lot of strange things in construction and control. All very interesting.

Yes, solid core dow blue foam with glass skins. I've done quite a bit of that in the past with models and these 2 ultralights I saw around 1997 had parts that looked very familiar to me.
 
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TFF

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RC planes are generally very strong for the weight. Just about any material is overkill. The question for the wave spar webs is how do you tie it all together to attach it to a fuselage for a full size plane? Fittings at each point? An end rib interface?
 

stanislavz

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Neat project!
There have been a few models built with "wave spars", but they didn't seem to catch on.

Some are doing the shear web as a wave of carbon laminate that goes from front to back to front of the spar caps.

I've seen an ultralight with bagged blue foam core tail surfaces and flaperons. It was fantastic and I wish I knew what they were called . If you do them like we used to build model wings, they wont be that heavy.
But according to orientation of fiber - skin is a shear web ? Waves have 0/90 fiber irientation. Best for buckling. Nil for shear..

I could not see fiber orientation on skin..

But this technology lend itself to one piece solid wing in biplane configuration ? And spar in the skin itself..
 

proppastie

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tie it all together to attach it to a fuselage for a full size plane? Fittings at each point? An end rib interface?
probably could do a one piece wing, sit on top of it or hang from it...would need additional span wise structure to attach to, maybe from the inside of the wing skin. the fiber orientation would have to account for all the loads. (duh) Use polystyrene and dissolve with gasoline when done?...if you were in production you would make a mold to make the polystyrene form.....sort of like a lost wax casting method. I look forward to your posting on the fabrication of this wing and I will not be sending a bill.
 

proppastie

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Incidentally talked to "Large aircraft company designer"....He said they made thin stainless steel forms for inside of the autoclaved CF parts They collapsed them to remove from the finished part.....Would love to see it.
 

proppastie

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Simplest structure I saw in CF was female top skin mold with spar and buildups for skin reinforcements (like ribs).....Female bottom skin mold. both bagged and autoclaved,..with CF molds.....Glue the bottom skin on after cure. Probably pretty standard, a known quantity, easy (?) to stress.
 

Geraldc

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The wave wing could be done like yacht spars with aluminium
extruded mandrels inside.When cured at temperature the alloy expands more than the carbon fibre and when cooled shrinks enough to remove.
A bit much for a home builder though.
 

Geraldc

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. The words in the picture might explain if they were readable.
The sheets are first molded on the flat ground.
Before they are fully cured the 1.5mm thick sheets are pressed between 2 forms made in a 4 axis cnc out of polystyrene and fully cured.
For proof of concept they are joined with double sided tape.
 

proppastie

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The sheets are first molded on the flat ground.
Before they are fully cured the 1.5mm thick sheets are pressed between 2 forms made in a 4 axis cnc out of polystyrene and fully cured.
For proof of concept they are joined with double sided tape.
why is it shaped in the end like a Greek letter, are they makng signs or saving space?
 

Geraldc

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Text from bottom of photo.
The final prototype had a length of 27 feet and was strong enough to carry its own weight an withstand small wind gusts. When fully assembled this strip would be fastened to its neighbours and become part of the segmented shell.
 

proppastie

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foolonthehill

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The Dodge Viper factory race cars had rear wings made with what is being called "wave spars" here. I've wanted to do something with that Idea on an aircraft ever since Isaw those back in the late '90's.
 
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