Bill,
I’ve only looked at it regarding some numbers – not pricing. I was assuming
it to be much more costly than that so I never bothered investigating it
further. It certainly is appealing in particular for something like a hybrid
tank where you can weld heavier ends on for non protruding coupling. For a
tank, the thinner wall not only reduces dry weight per unit section, it also
increases wet mass loading per given section. The same would apply to a solid,
and you can probably reduce your liner margin somewhat – especially for
regressive pressure profiles as the material will handle much more heat than
AL-alloys for even more additional wet mass loading.
Troy
From: arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx] On ;
Behalf Of William Claybaugh
Sent: Wednesday, 12 January 2022 5:11 AM
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: fiberglass conduit
John:
Have you or anyone you know ever looked at Titanium tubing? I’m finding that
0.050” wall 6” outside diameter tube can be had for around $700 per 60” length
vs. about $240 for an aluminum tube at 0.125” wall.
That would come in at about two-thirds the weight of the aluminum tube, saving
three pounds or about 10% of the current dry mass of my 6” motor. It would
require going to button head fasteners rather than countersunk so drag would go
up some but that weight savings appears to be worth an about 10% altitude gain
and thus might be worth the extra $500 per flight.
Bill
On Tue, Jan 11, 2022 at 9:17 AM John DeMar <jsdemar@xxxxxxxxx
<mailto:jsdemar@xxxxxxxxx> > wrote:
The phenolic looks interesting as a motor casing. They spec axial tensile
strength but not radial. 60% the weight of aluminum but only 17% the tensile
strength. There goes the weight advantage unless one adds a carbon fiber
overwrap. And hydrostatic tests it. Still, there's the issue of attaching
closures to the tubing... appropriate adhesive, plus pinning, plus insulation.
-John DeMar
Las Cruces, NM
On Tue, Jan 11, 2022 at 8:16 AM James Fackert <jimfackert@xxxxxxxxx
<mailto:jimfackert@xxxxxxxxx> > wrote:
maybe of interest for airframes and solid motor builders-
championfiberglass.com <http://championfiberglass.com>
has glass epoxy and phenolic epoxy conduit in 3/3" to 8" sizes, three wall
thicknesses, 10 foot lengths
lots of coupling anf fitting options
even split clamp over repair/reinforcement tubes.
should be reasonable prices since its a commercial product.
