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Old Sep 22, 2013, 02:17 PM
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Reasonable attempt at the tricky area ? (see photo in post#2)
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Old Sep 27, 2013, 06:39 AM
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Stegla:
Are you aware of Dave Rees' Tunnan for EDF FF?

Nice build!

-Dave
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Old Sep 28, 2013, 04:03 AM
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Thanks for the post, I was not aware of that Tunnan. There is a nice Tunnan for Rapier on Mike Stuarts site http://www.ffscale.co.uk/plans3.htm

There has been progress on mine with the fuselage having been tissued and doped. Getting a bit worried about weight however, the target AUW of 150g would give a wing loading of 25g/dM^2.......... don't really want to get above 30g/dM^2 so 170g should be ok!

Steve
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Old Sep 29, 2013, 05:50 AM
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There is a snag, namely, the cg is too far aft and the last thing this flying lumberyard needs is noseweight

Shall move the fan unit to under the cockpit............ shame because I spent a lot of time getting nice smooth ducting.

Steve
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Old Sep 29, 2013, 04:38 PM
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It looks like the Rapier powered Tunnan doesn't have a duct. Everything behind the engine is wide open. It may not be as pretty, but its probably more efficient.
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Old Sep 30, 2013, 03:07 AM
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The Tunnan duct is pretty efficient for EDF. Efficiency is not quite the issue for F/F compared to R/C, however, a nice efficient setup is kinder to the gear and chances of success are greater.

From past experience I don't anticipate needing more than 2/3 throttle to power the new Tunnan.

Steve
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Old Oct 12, 2013, 05:05 AM
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It has been flying weather recently...........so not much building.

Nevertheless, there has been a little progress with the 'flying lumberyard'

Steve.
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Old Oct 15, 2013, 02:05 PM
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Vac-formed the canopy using a home-made vac-former

Here's a link to the vac-former thread............
http://www.rcgroups.com/forums/showthread.php?t=1672236

The plug is balsa covered with 1oz glass.

Steve
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Old Oct 23, 2013, 05:48 AM
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More progress. Toying with the idea of tissue over mylar for the surfaces...........haven't done tissue over mylar for years, maybe someone can jog my memory how it's done


Test flying will be at an AUW of about 130g. AUW with paint and detailing should hopefully be near to the target 150g

Steve
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Old Oct 27, 2013, 05:25 AM
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The surfaces have been covered with 5 micron silver Mylar stuck with Balsaloc. Next job is to cover again with Esaki tissue.

Steve
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Old Oct 29, 2013, 11:46 AM
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Dunno if useful info: one need not do a flawless finish on a vacu form plug.
Simply do a second Canopy pull over the first one.. Neatly removes any plug surface imperfections that telegraph through.

V nice build by the way.
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Old Oct 29, 2013, 04:42 PM
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Thanks for the tip Bare......... shall definitely try it next time as I try to avoid using epoxy where possible.

Steve
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Old Nov 02, 2013, 01:32 PM
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I've done the surgery neccessary to move the fan-unit 4" forward. The fan-unit simply sits in the saddle and is held in with sticky-tape.

Easy access to all the gear is essential.

The timer fitted is an early prototype of the KP timer............ might as well use it! The ESC is a 10A Pentium.

The wiring has been kept as short and lightweight as possible.

Steve
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Old Nov 02, 2013, 05:41 PM
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A downthrust vane in the exhaust.
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Old Nov 06, 2013, 01:34 PM
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A few details added..........

A prominent dorsal aerial, wing to fuselage fillets and wing-fences.

Steve
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