Well, it must be summer already as I started carving canopy out of block of wood. See previous episodes.
It’s time to do some vacuum molding. Theory is simple. Heat plastic using frame, slap it on top of mold with base perforated with holes to allow suction to pull plastic down.
That’s theory. In practice it means several try’s and fails. But eventually I found better settings. I was forced to order new sheets from stockist (5 large sheets in total (1.5×2.5m or something..), that means plenty of plastic). With smaller canopies it seems that 0.5mm stuff is optimal, but anything bigger really needs 0.75mm. I am using PET-G and APET sheets from local ETRA-shop. Which is really professional shop for all kinds of industrial stuff. I am using brands Vivak and NudePetG (funny…).
Anyway – now I have plenty of L-70 Vinka & PIK-16c Vasama canopies. Along with PIK-18 Sytky cowlings. Actually I have 3 vac boxes for different size molds. You might notice that biggest one needs double vacuums to do the trick. Actually that vac box is designed with oven size as an guide. It really is the biggest one which I can make without resorting to more exotic stuff.
Next step is to finetune PIK-15 Hinu (1.5m) canopy and cowling and do at least 4 sets of those. Also I need new batch of my really pro aileron covers.
Then next steps with canopy stuff. Finalized 1/3 PIK-16c Vasama canopy and PIK-18 Sytky cowling. Then did initial work for finalizing Valmet Vinka L-70 Miltrainer canopy. Incidentally, that same canopy is utilized in Redigo L-90 and PIK-23 Suhinu. I guess that Finnish aviation ‘industry’ is so small that we are experienced recyclers of designs. The good news is that I will be able to do several models with one canopy effort. Still needs final sanding etc.
Ps : I added commenting features to this blog. And now with spam filtering etc. functions. It will be interesting to see how much Vuitton bags and UGG-stuff I will see in comments. Last time it was totally horrendous.
This summer has been rather long and .. it’s time to get back to building. Time to finalize Vasama canopy. Canopy form is ready, but the front and rear parts that allow vacuum moulding to work were missing. Not anymore. Used soft balsa to make them. Still some sanding needed to finalize stuff but it is quite ready.
Sadly no plastic so cannot do moulds today.
Oops.. I just forgot to add one thing. This will be drawn to 1:6.67 size, due the nice feature of this design. It shares canopy with L-70 Vinka. As an lazy person I really do not want to make second canopy mold for this plane. So to save time and effort it will be same size as my previous project.
Canopy mould of L-70 Vinka kit. Not finalized, but getting there.