Martin Roberts

Depends really on whether a fixed prop or folding prop is used and of course the fine the pitch the more drag...how about a nice big three blade

looks like my next build, maybe scaled to 4.0 mtrs....hmm would that be a Foka 4x4?

Hi Danny, I am back after a few years away, looking real good, never mind the windows, just take a deep breath...no, not whilst you are mixing the resin!!!!!

Hi BEB, very interesting so far....pick up price - very enticing

Hi Danny and Ton, hoping you guys have had a great Christmas - and great to see you back on line, if you look at the pivot point pics on page 19, and the comments I posted then... "As far as my tuppence goes, I probably would have designed the 'hinge' as 'a single rod running through the aileron with a z bend to (the appropriate center point that you calculated) a bearing fixed into a cleat each end, a cleat similar to a control horn soldered midway to the rod would be located to a bearing soldered onto a rod located similar to the detail in the photo (above) for the flap ... ok so the detail would not be perfect but far simpler to model and the same outcome as your design and the rod passing through the aileron would stop any warping of the aileron.." This would allow for the aileron to be fitted up after skins, additionally there is in the same group of pics, a view of the wing/fus intersect (top angled view) which shows the flap pushrod attachment...., maybe I should draw a detail of my interpretation and send same to you Danny for your thoughts Marty

Hi Danny, Ton and everyone reading his thread Merry Christmas and a Happy New Year to you all from Marty Down Under

Hi Danny, if you import those sections into Turbo and use the offset command at 4 mm, select the line then click inside the line, you will have the cut out (4 mm = 2mm for the outer skin of the fus + 2 mm for the inner (false) skin so that the window cut outs can lie on top) no need to CNC these parts, and if the profiles are cut from 2 mm balsa or ply, the space would have to be 18 mm, 18 + 2 = 20, this is because the 'surfaces' Ton is cutting have no 'thickness' as such just like a piece of tracing paper - Marty

Danny, at 20 mm this would be 300 mm, you forgot the starter with zero thickness plus 15 x 20mm. I have made that mistake many years ago cutting material for balustrades LOL, oh well at least I can weld steel back together - harder in hardwood - Marty

Hi Dan and Ton, yes you guys are on the right track, nice idea to go with the foam if you were making a fiberglass mould, unless you are skinning the foam with ply/balsa? Either way, I obviously explained well enough for you two to be on the right track... Hopefully Ton has cut the sections to the inside of the fuselage and then take off thickness of balsa or ply skin so that when the window panels are laid on this 'inner skin' the plastic will form up to the inside of the real fuselage. Personally I would be use either 0.3 or 0.5 PETG, at 0.5 thickness the windows would be very rigid but still light, don't forget to trim the ply/balsa windows by 1.5 times the thickness of the PETG all round so that the radius of the PETG (after the forming) has enough room to sit nicely inside the 'frame'...Just thinking ahead Danny, Have we allowed enough on the window cut outs to 'feather' the fiberglass skin into the window openings for a smooth finish and still have room enough ? Marty

Hi Danny and Ton, I almost bought Rhino myself some time ago, a lot cheaper than AutoCAD, but at the time I had several versions of AutoCAD, Turbo Cad, ArchiCad, blah blah under my belt, then I changed jobs from building design to working for Council, had to learn 13 new software packages that year and to be honest I couldn't at that time see the benefit of yet another Cad learn - maybe I will have to remedy that - looks like I might have to down load the trial version..... Anyway, onwards and upwards Danny, keep up the good work and remember Santa is on his way hey hey ... Marty

Hey Ton, what is that software you're using? Marty

Hi Danny, no postcard - message in a bottle LOL, for thought and planning..... you need to make the side ribs for the cabin less 2 mm, form up an new side frame and layup the new 2mm dummy skin, which is now (outside) a plug matching the inside of the cabin wall, I am sure that Ton can send an alignment template for the cut out sections of window less say 0.5 mm all round and cut the window panels in 1.5 mm sheet then fix onto the plug using the template, now when you vac the new window 0.3mm clear or black, it will fit almost flush minus say 0.2 mm inside the outer skin, I am sure Ton could model that up in about 3 minutes including the strong ply stringers top bottom and middle (nice and strong for the Vac as is the 2 mm dummy skin, Marty

Danny & Ton, could always sand down a block of hard balsa for the tip - na! - just kidding, unfortunately being down here we don't get the freebies, or I would have subscribed when the building jig was up for grabs..... I do admire your sense of art - the colour scheme you so patiently applied when clamping the fuz was to say the least impeccable LOL, mine are big black so-and-so's... Didn't you use a stringer behind the side panel join, or did you misalign the bottom panels to the stringer? Could be a good detail or notation to utilize for the final plan. I also like using 2 mm, as it is firmer to work with and still sands back to about 1.6 finish if you're not too harsh, so there is still enough meet for the glass to hang on without going concave between the bulkheads.... now outside to bash some Australian Hardwood into shape on my deck or I won't live til Xmas.....Marty Edited By Pete B - Moderator on 19/12/2013 09:55:52

Hi Danny, you are getting close - how about a few 'exploded' shots, showing the 'whole model' as is so we can all see exactly where you are at - doesn't need to be pretty, I'd send you a few more clamps - but Santa might beat me there - just remember it is not a case of not having enough anything else - it's a case of not having enough space to store all the stuff and still have enough space to work. My double car garage is full to the eye balls LOL Marty

Hi Danny, firstly a big thank you to Nick for the information, another point for the ailerons being so 'awkwardly' hinged is that although this aircraft had a 'never exceed speed of 240 knots', that is still quite fast. I am not sure at what speed control surface buffeting cuts in but having the pivot point so far back would probably offset any induced buffeting by way of counter balance (amount of aileron in front of the pivot point) also counter by a balance of the air pressure on the forward area of the surface...now readers please don't mistake what I am saying here for the sort of buffeting from a higher performance military craft, this aircraft was an at the time high performance civilian commuter, so any buffeting from the ailerons that could cause discomfort to a passenger would have been designed out, especially when the other benefits as identified by Nick also come into play, of course the last part which would have been carefully considered by the designer is that the force needed to be exerted on the control surface by the pilot is also further reduced by the balance of air pressure on the surface which would make it more comfortable for the pilot as well. As far as my tuppence goes, I probably would have designed the 'hinge' as 'a single rod running through the aileron with a z bend to (the appropriate center point that you calculated) a bearing fixed into a cleat each end, a cleat similar to a control horn soldered midway to the rod would be located to a bearing soldered onto a rod located similar to the detail in the photo (above) for the flap ... ok so the detail would not be perfect but far simpler to model and the same outcome as your design and the rod passing through the aileron would stop any warping of the aileron.. Back to you Danny Marty