torsion box inner material

[mickthetree]

hey all

Need to make some torsion boxes in the near future and I'm sure I've seen a cardboard inner honeycomb sort of filler in the past, but can I find it now?!??!!

it comes quite small but expands out to fill the gap.

Maybe it was an american site I saw it on perviously.

Failing that I'll have to makeup a framework from some mdf

 

[celston]

If you find a source, I'd be very interested in it!

 

[xy mosian]

I wonder if egg trays would work, or even polystyrene sheets?
xy

 

[marcros]

i think i would be tempted to use thin mdf.

If i recall my OU days, the strength is in the bond to the top and bottom skin and having as wide a gap between the two skins as possible isnt it. the cardboard, i presume will rely on having plenty of glue sloshing about. Egg trays, i dont think would work because it is a W shape, whereas honeycomb is IIIII in cross section. polystyreme should work though

 

[xy mosian]

Egg trays, I was partly jesting and of course the 'flat' surface tends not to be too smooth. Good glued contact might be difficult.
Polystyrene, on the other hand, would be very light but a suitable glue might prove tricky to find. I have used epoxy resin to glue aluminium to polystyrene very successfully. That should work, but would be expensive.
The amount of glue used in honeycomb doors is substantial. Removing it cleanly is the biggest job when reducing such doors beyond the softwood edge, to fit another edge.
xy

 

[xy mosian]

http://www.dufaylite.com/honeycomb-technology
This, I think, answers the original question.

xy

 

[Steve Maskery]

If you end up making your own, I suggest this as a suitable MO:

Cut all the strips to width.
Bolt all the long ones together.
Cut a slot in the whole lot. You need to have a RK and guard on your TS which will allow this.
Do the same for all the short ones.
Then all the slots will line up to make your grid.

HTH
Steve

 

[Mike.S]

I built some units using the cardboard honeycomb - see here and here.

I have some 32mm and 38mm honeycomb left - very straightforward to use. Let me know if you're interested - Dufaylite did have a min order of £150 but could supply different thicknesses.