This is courtesy of Ade (I forgot to turn on logging...)
[Begin]
[19:59] <Craig_Tou> well, what would you like to know?
[19:59] <Ade> Hows things? I take it the conditions didn't come through for you this weekend
[19:59] <Ade> ?
[19:59] <Craig_Tou> Wind was lighter than expected
[19:59] <Craig_Tou> topped out at 174 for the day
[20:00] <Craig_Tou> the plane starts feeling like it is in the groove at around 160
[20:00] <Craig_Tou> I'm still playing with the CG.
[20:00] <Craig_Tou> A couple of changes are being made
[20:00] <Ade> its certainly a very different circuit to what we have been using with the f3f ships
[20:01] <Craig_Tou> tight circuits are more fun
[20:01] <Ade> bigger, and smoother?
[20:01] <Craig_Tou> yep
[20:01] <Craig_Tou> less pilot skill required
[20:01] <Craig_Tou> lower flight loads on the airframe
[20:01] <Ade> yeh, well thats the idea behind using the high RE sections isn't it :-)
[20:02] <Ade> RN even
[20:02] <Craig_Tou> the idea is low drag at high speed
[20:02] <osborn> Craig, what kind of Cl's do you think are required for banging turns and for wide open DS turns?
[20:02] <Craig_Tou> you also get a thicker section which equals a taller spar
[20:03] <Ade> I have heard titbits of information from alex
[20:03] <Craig_Tou> taller spar equals bigger joiner
[20:03] <Craig_Tou> bigger is better
[20:04] <Craig_Tou> the next foil will be 11.3%
[20:04] <Craig_Tou> a turn banger
[20:04] <Craig_Tou> fun
[20:04] <Ade> apart from the section choices what makes the mofo different from your DS f3fer?
[20:04] <Craig_Tou> in general ... size and weight
[20:05] <Ade> there are obvious stuff like the hooge tail boom
[20:05] <Craig_Tou> in specific ... lost foam fuse - no seams
[20:05] <Craig_Tou> traditional tail
[20:05] <Craig_Tou> tail mounted elevator servos
[20:05] <Craig_Tou> two spars
[20:06] <Craig_Tou> mass balanced tips
[20:06] <Craig_Tou> bottom hinged surfaces
[20:06] <Ade> ahh.... 2 spars.... helps the tortional stuff?
[20:06] <Craig_Tou> foam wings
[20:06] <Ade> slow down a little :-)
[20:06] <Craig_Tou> spar in fuse
[20:06] <Fraze> is the tail all moving?
[20:06] <Craig_Tou> tapering to zero ailerons
[20:07] <Craig_Tou> no
[20:07] <Ade> heh
[20:07] <Craig_Tou> split elevator
[20:07] <Craig_Tou> an easy form of redundancy
[20:07] <Ade> why did you go to conventional tail?
[20:08] <Craig_Tou> simple pull for up configuration
[20:08] <Craig_Tou> reduced lateral loads
[20:08] <Craig_Tou> easy incidence
[20:08] <Craig_Tou> easy to build strong
[20:09] <Ade> do you think that a DLG style lower fin might help the torsional loads on the tail boom?
[20:09] <Craig_Tou> yes
[20:09] <Ade> but landing something like that could be interesting I suppose?
[20:10] <Craig_Tou> the way I land it would not last long
[20:10] <Ade> Alex mentioned the mass balanced tips. how did you go about getting the weight right?
[20:10] <Ade> and where are they balanced?
[20:11] <Ade> relative to the rest of the model
[20:11] <Craig_Tou> the tips are triple tapered
[20:11] <Craig_Tou> with a straight 25% chord
[20:12] <Craig_Tou> the first two tapers have lead in the LE
[20:12] <Craig_Tou> about 20 oz
[20:12] <Craig_Tou> it was a real pain in the ass
[20:12] <Craig_Tou> the lead was added before the LE wrap
[20:12] <Ade> was the weight just a guesstimate? how did you get to 20oz?
[20:13] <Craig_Tou> I used aluminum airfoil shaped tubing
[20:13] <Craig_Tou> when filled with lead it equalled 20 oz
[20:14] <Ade> sorry I mean, why 20oz and not 18 or 22?
[20:14] <Craig_Tou> it was a guestimate
[20:14] <Ade> do you think it helped at all?
[20:14] <Craig_Tou> I wanted the wing to balance on the 25% chord
[20:15] <Craig_Tou> I thought I would have errored on the heavy side
[20:15] <Craig_Tou> easy enough to add weight to the servo pocket if needed
[20:15] <Ade> I suppose if you have the "local" CG forward then that makes that part of the wing stable..... reducing the tortional loads and likelyhood of flutter?
[20:15] <Craig_Tou> turned out it was dead on
[20:15] <Craig_Tou> yep
[20:16] <Craig_Tou> I think that the tips are the most prone to flutter
[20:16] <Ade> my acacia would aggree with that :-)
[20:16] <Craig_Tou> control them and you have a bit part of them problem solved
[20:17] <Ade> like any problem you split it down to its components
[20:17] <Craig_Tou> the other problem is bending
[20:17] <Craig_Tou> twist, bend, twist due to bend
[20:17] <Ade> ahhhh....
[20:17] <Craig_Tou> the three biggies
[20:18] <Ade> the twist due to bend is fixed with the second spar....
[20:18] <Ade> as is the bend
[20:18] <Craig_Tou> straight 25% chord minimizes twist due to bending
[20:19] <Craig_Tou> super stout spar minimizes bending
[20:19] <Ade> are the 2 spars of the same specifications?
[20:19] <Ade> if not isn't one going to try to bend less than the other and give a twist?
[20:19] <Craig_Tou> the second spar is also the sub-trailing edge close-out
[20:20] <Ade> cool so doubles as extra support for the surfaces
[20:20] <Craig_Tou> yep
[20:20] <Craig_Tou> and houses the torque pin
[20:21] <Ade> torque bin?
[20:21] <Ade> pin?
[20:22] <Craig_Tou> the pin that keeps the tip aligned also transmits any torque to the center panel
[20:22] <Ade> incedence pin ?
[20:22] <Craig_Tou> same thing
[20:22] <Ade> ahh ok
[20:23] <Craig_Tou> except this one is 1/4' steel
[20:23] <Craig_Tou> 1/4"
[20:23] <Ade> blimey
[20:23] <Ade> one in the LE too?
[20:23] <Craig_Tou> trying to minimize slop with the larger diameter
[20:23] <Craig_Tou> no
[20:24] <Craig_Tou> just one big one
[20:24] <Ade> What about the control surfaces? I was supprised to see flaps, I was expecting spoilers
[20:24] <Craig_Tou> gotta slow this pig down some how
[20:25] <Craig_Tou> my flaps do not reflex
[20:25] <Ade> ahh so you lock them against the subspa
[20:25] <Ade> r
[20:25] <Craig_Tou> I placed stops in the close-out area
[20:25] <Scrap> hi all
[20:26] <Craig_Tou> under load and without snap-flap the hinge is in tension
[20:26] <Ade> hi scrap
[20:26] <Craig_Tou> minimal load on the servo
[20:26] <Ade> what did you use for the hinging?
[20:27] <Craig_Tou> 1.4oz kevlar +-45 deg
[20:27] <Craig_Tou> the veil cloth is in the hinge too
[20:27] <Ade> i see
[20:27] <Craig_Tou> the aileron hinges were left stiff
[20:28] <Craig_Tou> expecially toward the tip
[20:28] <Ade> One thing I have noticed on the moulded stuff is that there is quite a large gap between the subspar and the hinge
[20:28] <Craig_Tou> adds a spring (return) to the system
[20:28] <Ade> my acacia has actually delamed that area
[20:29] <Ade> the subspar on the mofo must be right on the hinge line?
[20:29] <Craig_Tou> peel ply hinges can delam there
[20:29] <Craig_Tou> CA will fix it
[20:29] <Ade> yeh thats what I did
[20:29] <Ade> just shows yet another weak spot
[20:29] <Craig_Tou> yes, right at the hinge line
[20:30] <Ade> I bought an opus recently
[20:30] <Craig_Tou> nice plane
[20:30] <Ade> to save the beatings my acacia is getting, seen any fail?
[20:31] <Craig_Tou> I have had a wing fly off my Acacia
[20:31] <Ade> I mean the opus
[20:31] <Craig_Tou> pulled the bolts right out of the fuse
[20:32] <Craig_Tou> nope
[20:32] <Ade> ouch
[20:32] <Ade> which acacia was it?
[20:32] <Craig_Tou> It was the old Acacia i
[20:32] <Ade> ballast in the wing?
[20:32] <Craig_Tou> nope
[20:32] <Ade> hmmm same as mine ;-/
[20:33] <osborn> Craig, Ade, can I ask a question?
[20:33] <Ade> we generally don't run balast in DS
[20:33] <Craig_Tou> I don't want ot talk too much about production planes
[20:33] <Ade> heh ok
[20:33] <Ade> understandable
[20:33] <Craig_Tou> what's up James?
[20:34] <osborn> I'm still trying to understand what Cl means in designing planes...
[20:34] <osborn> So, what are typical Cl's for a Mofo style plane...
[20:34] <osborn> And for a hard turn banging style plane?
[20:34] <Craig_Tou> .3-.6
[20:34] <Craig_Tou> .2-1.0+
[20:35] <osborn> So what would happen if you pulled enough elevator with the Mofo going 200 mph?
[20:35] <osborn> Would it stall? Or just slow down?
[20:36] <Ade> my aerodynamics is a bit limited..... a heavy plane at low speed and high angle of attack is running high CL?
[20:36] <Craig_Tou> It would scrub speed
[20:36] <Craig_Tou> the top of the wing would serparate
[20:36] <bing> hi all, craig, i'm wondering... i think i read the auw of the mofo on the 202 run was ~15lbs. how much of that was removable ballast? or is ALL that weight integral to the structure?
[20:36] <Craig_Tou> the bubble would add to the thickness of the wing
[20:37] <Craig_Tou> all integral
[20:37] <bing> are there any good closeup pictures of the mofo avail. on the web?
[20:37] <Ade> heh... do you suffer from a 7k (just over 15lbs) weight limit in the US?
[20:38] <Craig_Tou> the heavy tips require more vertical tail volume to stabilize
[20:38] <Craig_Tou> a longer tail boom increases the volume without having huge tail surfaces
[20:39] <Craig_Tou> huge tail srufaces would be hard to build to handle the load
[20:39] <Craig_Tou> adding a spar in the boom is easier and more controllable
[20:39] <Craig_Tou> net result 8 lb fuse
[20:40] <Craig_Tou> Dave will have some shots in his next video
[20:40] <Craig_Tou> The plane is still a work in progress
[20:41] <Craig_Tou> Things will change
[20:41] <osborn> Gotta go, thanks for the discussion Craig. Cheers.
[20:41] <Craig_Tou> CYA
[End part #1]