Mike Chantler

Some print settings while I remember:

One problem I had was that while the foam cores were exactly the right size, the veneered wings are too thick - by errrr... 2 x .8mm veneer. duh! 😮 😞🙄 I was convinced the vac bag was going to crush the cores a bit and in a traditional build this extra thickness would not matter as you'd just build the fuselage on top of the thicker wing. However, the pla is really difficult to sand, so I added a skin in the 3D design and moved the wing up by .8mm. This is fine for the body but means that the fairings of the next section (behind the wing) definitely will not fit and I'm not sure I can be bothered relofting it as its edge rails are both time-consuming compound curves and the loft itself is a bit problematic. So I think I'll maybe print the next section without fairings and then add them traditionally.

Still going - but very slowly! Got chance to print off front two sections (first section in 2 parts). Thinking it is beginning to resemble a griffon engine spit 🙂 Designing the second (blue) section took me several goes due to the cockpit and additional flanges for the bulkhead and servo tray.

Nice 🙂

Lovely build. Curious as to what the G10 is?

Thanks - yes idea is that spinner slides off ballast tube to give access to battery and for loading slugs. Will simply have single countersunk screw to hold in place: Needs bit on front of body to screw into(!) 1mm PLA cross shaped former is just to make sure ballast tube aligns while real former positioned and glued. Will either be liteply or 6mm B&Q foam/carbon sandwich to securely connect front wing dowel to ballast tube. Similar at rear of wing to take stresses of ballast tube vs wing. Time will tell 🙂

Rear and centre sections may still be bread and butter xps depending on weight of 3d prints strong enough to take slope abuse. Above is from devfoam wing, which after a bit of hassle, I found reasonably easy to use 🙂

So after a lot of procrastination I'm finally getting somewhere with my 3d design - still very slow! Spinner in 3mm with holes for battery and carbon reinforcement/ballast tube. Printed off spinner (red) and the rear of section 1 + front of section 2 to see if my flanges etc work: Hand assembled as sanity check: Ballast tube is 18mm x 500 and spinner and exhausts have 2 degrees 'down thrust' otherwise it looks weird 🙂

I built an F86 from an old Ron Collins plan. I was a bit shocked by the price of the balsa so I replaced it all one-for-one with XPS foam sheet and sections, plus some 6mm carbon/foam sandwich in place of liteply formers. Took me quite a while to learn how to use and finish it as a) it dings really easily during construction, and some of the foam glues stay really rubbery which means they don't sand. Next time will cover in brown paper before glassing, and keep the glue very thin and use the stuff that dries hard.

Thanks Simon, enjoying your log and I especially like the wing construction above. I'm building a 46" PSS spit, target 1kg plus so - so suspect I have a lot more weight that I can afford (and need) in the structure than you. Front half of fuselage is 1mm PLA skin with some foam/carbon bulkheads to absorb hill landings in gales. Rear likely XPS with some PLA bits (depends on overall weight!). And it has an 18mm carbon ballast tube running 500mm from the spinner. I like that glue you recommended so will use this for foam-to-foam and foam to carbon - thanks. Suspect your weight will be a fraction of mine(!) and I don't even have a motor lol Designing with Fusion 360, which I have to say is taking me quite a while to learn!

Simon, nice build as always 🙂 Am curious, as I'm doing a mixed carbon/foam/pla build myself, what do you use to glue pla and lwpla to the foam? Do you use the foam glue you mentioned earlier in the thread? And is it CA for pla to pla?

I usually cut the plan into big bits, wing, fuselage etc, and then cover with mylar or some other clear plastic. But a second copy always helps as some how or ever, I always end up partially destroying the original.

Fuselage is ordinary PLA except for carbon ballast tube. Wing is 75g laminating film on hotwired EPS (as I can't get EPP). You have to be carefull with the temperature of the iron!! Spars are double, full-length, 6mm carbon tube (top and bottom). Has hardwood LE and balsa sub TE with correx ailerons. Tips have ply end-caps. Think I'd change TE for thin hardwood, and swap ailerons for hard balsa. Plan and Fusion 360 model on Tim's GitHub pages (url at start I think). My Fusion 360 mods are VERY untidy - would send only via PM as they are a bit embarrassing!!

So having decided to make the fus largely out of foam I've now done a 180 degree about-face, and think I will experiment with 3d print using a 1mm shell and use the carbon ballast tube and some internal carbon reinforcement, in a similar manner to the 60" plank. Just getting a shell for the body took me a while due to my incompetence with the 3d modeller. This now needs cut up and flanged into printer-sized bits, and support added for the ballast tube..

Did manage to get into the hills last Sunday - and it flew well in moderate winds with 1/3 ballast. I forgot about looking for the tail jitter, but as I didn't notice it perhaps moving the fin back has fixed it 🙂 It could do with being a little faster - it's faster than a 45" Wildthing, perhaps slightly slower than a Gulp, and definitely looks slower than a couple of streamlined moths that were up. Wing is quite tatty now - so servo covers and tidy might speed it up a bit and have cut PW51 wing for it which I may fit in a while 🙂 One thing I did like was, despite the fact I like building, was just fitting the 3D print parts together - nice simple assembly when work is eating up your evenings 🙂 🙂