These were taken at Oripää airshow summer 2013.
I Started build of Vinka L-70 back in summer 2013. For several bad reasons it got stalled for some time. This has been waiting far too long so let’s get something done. Build log can be located here. It is in RCGroups which is rather good place for this type of plane. I will occasionally update this blog, but actual stuff will be at rcg.
There has been couple other postings of Vinka in this blog. You can find them with tag ‘Vinka’ on right column OR… just press here.
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.
Just an brief comment about the status of Valmet L-70 Vinka -project. I have finalized (at least I think…) initial drafting stage. Things which are still missing are some parts (rudder to be exact) and better positioning of parts etc. And some quality control. My way of working is quite straightforward. I draw quite intesively and then I have to stop project for an while to allow brains re-think some items. After this ‘it’s just cooking there’-phase I will make some quick fixes which are absolutely necessary.
Below you will find latest bitmaps of this 1.44 (1:6.67) creature.
This is exciting. I have been negoating with Patria Aviation and they kindly allowed me to make scale planes (+kits) of their range of military planes and even supported me with providing original factory drawings of L-70 Vinka, L-80 and L-90 Redigo. That last one was eventually re-branded as Aermacchi M-290 Redigo.
Great many thanks for Patria Aviation. I really appreciate the fact that they took effort on supporting us. This is so great.
Also, my old pal HSK’s father was part of part of design team of L-70 Vinka so this has some personal meaning to me also.
This time my goal was to make extremely light parkflyer with 1:6.67 size ending with 1.45m size. I wanted to draw something which is as easy to build as PIK-16 Hinu, but lighter. The scale ratio is exactly same. Eventually this means that my next project L-90 will have same scale. But in L-90 I will make it quite much stronger allowing faster speeds.
Reasoning is simple, L-90 and L-70 share same canopy design and I am quite lazy. I will make one canopy mould and I will use it for both them. …. also same canopy was used in PIK-23 Muhinu…. interesting…
For Vinka (which btw means cold wind in Lappland) I used trusty old Clark Y for wing and again variety of Naca’s to tail. Current stage of project is :
- fuselage is ready in devfus waiting to be 2d’d. I am quite happy with design and 3d-modelling in this project. I managed to iron all normal devfus kinks out and all stringers are nicely done. I even used devfus capabilities to draw canopy frames.
- Wing + foils are ready
- Elevator + everything associated is also ready