Building my 1/3 Dimona motor glider

[DennisB]

I have been working on a 1/3 scale Delro Dimona motor glider for the past year or so and am still at it. In May I came across this new (new for me) sandpaper and sanding blocks at my local automotive paint supply store ( Finish Master, I understand they are nationwide ) only recently they have offered this product and I like it a lot. I decided to paint the wings on the Dimona ( they are Obeechi over white foam with carbon and glass sandwich ) so I was faced with a lot of block sanding. the beauty of these sanding rolls is they are adhesive backed but not too sticky. They come in almost infinite amount of grits, for my needs 220, 320 and 400 would do. Finish Master also offered several sanding blocks to compliment the sanding rolls, the photos should explain. I am using PolyPrimer which is polyester based but once dry it sands superbly and does not shrink over time. The sanding rolls to tend to load up quite a bit, that's why I keep a shop vac by my side to vacuum the dust and the residue on the sanding blocks. I have to say the wings went MUCH faster than expected, my wife was going to be out of town for two weeks so I had planned to use those two weeks to have the wings sanded and final prepped for paint. Turns out it took me two days! Nice!! I will be posting more of build of the Dimona very soon. It's been a real learning experience, much more than any other model I can think of.

[Steve P]

Great information. Looking forward to the build!

[lenb]

Hi Dennis.
I would love more detail on exactly how you finished the wings. I will be assembling a couple Rosenthal planes this winter and will need to do the same process. I'm looking for a perfect glass finish and I know thats what you will have.
Did you glass the wings first or go straight to primer?

Thanks for the tips on sanding blocks, great stuff.

[DennisB]

Len, I decided no glass, many told me there would be too much weight gain since the glass would require more filling of epoxy/primer. I used a slurry of West Systems epoxy mixed with West 410 Microlight filler, I mixed the filler in to a point where it would spread nicely, you need to try a few times till you get a good spreading mix. I actually used an old credit card as my squeegee and mashed the stuff into the obeechi as evenly and as thin as possible, The credit card method allowed me to get really close to the work and mash it in really well, I did about 18 inch by 4 inch lengthwise sections and block sanded it out and repeated. I then went ahead with spraying the PolyPrimer, and more block sanding. Be sure to wear a mask or respirator because there is a ton of dust, and have the shop vac at your side to suck up the dust and suck the residue from the sand paper as well. Its a lot of grunt work and a big mess but I got it done thanks to the big sanding block in the photos and the sanding rolls. I did use the 220 grit throughout the slurry sanding process and first coat of primer, I moved to 320 grit for the subsequent coats of primer, moving to 400 and even 600 for final blocking of the wings. I have a 3 inch dual action sander I got from Griots Garage, I'll post some info on this fantastic tool that I use for small spots on my cars and sanding and polishing after I paint model wings.

[DennisB]

A few teaser photos of the cockpit finally coming together, just got the instrument panels from Noll in Germany

[DennisB]

I wanted to "possibly" have my canopy open, close and lock in a scale manner but wasn't sure if it would be worth the time and hassle, what I "at least" wanted was the scale detail of the mechanism, as it turns out I got the geometry right and it works just like the fullsize, with the red handles unlocking internal sliding pins at the rear, at the front I cheated a bit and have the locking pin hidden under the hatch used to check the oil in the cowl. I am guessing at least 200 hours of work went into just the canopy frame. Once the clear canopy is attached the sliding vent windows on each side provide access the red locking levers. It sure helps having extreme close up photos of the fullsize mechanism. It was a lot of work but the challenge of the job was something I had to take on.

[lenb]

Geez Dennis, you never cease to amaze me. Did you sew the seat pads and control stick boots yourself? Nice work...

[Xroadie]

Looks great Dennis!

What are the specs...I know its 1/3...but what are the dimensions and what will the power plant be?

Pete

[Swiss1]

Nice work on the canopy Dennis.

Jeremy and Ben
SCCAAA TT TN

[DennisB]

The seat cushions were made by Dan Fitzgerald who makes really nice wing bags for models including the E Flite Blanik. I somehow talked him into making them after I sent the pattern. Pete, I am using a Hacker A60 with 2 6s 5000 Lipos teamed up for 12s power. The model is approximately 5.4 meter span. Much more info coming soon, and lots of pictures as well, this model really forced me to put on my thinking cap, much more than any other I can think of.

[DennisB]

I have been pretty lazy with progress, the model is ready for final painting now, but I took a detour and did the long anticipated recovering of my 1/3 Grunau Baby, used Natural Solartex and brushed on several coats of Varathane from Home Depot. I don't usually do the brushing process but wanted to try what Fred China does, works great and looks superb. I hop e to get back to the Dimona after Christmas.