SHORT SOLENT MARK IV – 2014 WINTER BUILD

[Papa]

Far too much negativity. Come on you guys you're better than that.


Say something nice and positive with lots of hope and joy.


jack.

[piker]

Spring is almost here!  Just 8 more months!   

BTW, yesterday was Blue Monday   

[battlestu]

BTW, yesterday was Blue Monday   

did they play New Order all day long

http://www.youtube.com/watch?v=FYH8DsU2WCk

Greg

[wollins]

Keel getting there ... bulk heads (1/8 balsa sheet) and temporary stringer (the actual keel stringer will be spruce) dry fitted for alignment purposes before I commit to glue!   She should be on her "feet" by tomorrow. 

C.

[wollins]

Progress has been slower than expected but isn't that always the case?    Anyways I decided to go with 1/32 aircraft ply for sheeting the hull/keel.  (I did 1/16 with my CL-415) Since this plane will be flying 90% of the time off land, I need something stronger than the balsa sheeted hull/keel the plans called for, yet something relatively light.

The other reason I went with 1/32 this time is that my hull/keel is much deeper/sharper on this plane which means more severe compound curves near the nose and at the step. As it is I had to do those sections one piece at a time to get the curves right.  That's what took the majority of time, but now that's over so the rest of it should be much faster to do.

I feel good and bad (to a much lesser extent) about how it's coming out. I feel good because I know it'll look awesome how I've done it, but I feel kinda bad cause since I wanted to go super scale here I should have put more curvature in the framing of the bottom of the fuse back of the step because the full size has quite a dramatic "flair" in that area. Oh well. I missed that one.   

One of the things I did deliberately compromise on is the dept of the keel/hull.  You'll notice that the full size's is about 14.28% of the fuse at that spot. (in the pic) Mine is only 10.28%.  That's because I've found with my limited experience with flying a heavy flying boat off grass is the deeper the hull/keel, the harder it is for the plane to get moving. If the hull/keel is deeper it tends to "furrow" into the ground more than say a shallow bottomed one. But I must admit on one hand I kinda regret not building in the full 14%.    Funny though the plans call for it being 1.5cm high (at that spot) and even though mine is double that at 3cm, it's still not scale! lol!

Colin

[wollins]

Done. 

[Papa]

Looks great.


jack.

[piker]

Yes!  Beautiful work!


Keep going.  Spring is almost here!   

[wollins]

Never mind Spring ... month end (when I'm supposed to completely finish the structure of this fuse) is coming fast.  I have an estimated 43 hours worth of work to do in seven days if I'm to make that goal. Gonna burn some midnight oil in the coming week, that's for sure.

C.

[wollins]

Making some progress. Windows installed. One passenger trial fitted.

C.

[battlestu]

very cool ... but why is pilot sitting back there

[wollins]

when Im done with him he wont look like a pilot. Besides those are Beats headphones! lol!

[wollins]

I'm gonna attempt to make a vacuum former so I can pull this canopy but I have some questions. I've read about different styles (mainly the one hole vrs multi hole platen styles) and for the sake of simplicity I want to try the one hole version. My questions are:


1. How big should the platen be relative to the plug? For instance if my plug is 6 inches by 5 inches ... how much "excess" platen should there be? Is there some formula to this?

2. How high should the risers be between my plug and the platen? Is there some formula to this also?

3. How much bigger than the plug should my plastic be? (My plug is a simple canopy plug of 6" wide x 5" long x 2.5" high)

4. What release agent to use to release my canopy from my plug? (I've heard some use baby powder?)

Thanks!


Colin

[Papa]

I don't know about formulae but I used the perforated MDF as a base for mine.


I used 1/4" spacers so I would get a "tuck under" of about 1/8". This I would cut and sand off for a close fit.


Mine is 12" x 12" and it is too small. It causes crinkles in the film at base of curves that are too close to the edge. I think for a plug your size I would go 18" x 18". I drilled 1/16" holes every inch to create a matrix on a perforated platform. My thinking was to have uniform suction all over the base. I used window sealing foam on the base and attached the film with screws and duct tape to an oak frame, 1/4" x 1/2".


I heated the frame in an oven on two bricks to stop the film from contacting the racks when it sagged. I wrapped the bricks in aluminum foil to avoid any awkward conversations with the management. I used 375 degrees as my setting and the film sags pretty quickly. I had it hooked to a 5 Hp shop vac which was running and I used oven mitts to grab the frame. I lined it up as best I could and just pushed it into place and hoped for the best. It all happens very fast.


I just sprayed the plug with automotive top coat and lightly sanded it with a wet sanding, when it was dry. I did not use a release agent and the mold did not stick to the plug.


Jack.

[wollins]

I used 375 degrees as my setting and the film sags pretty quickly.

Thanks Jack! Just the info I needed. One more thing ... what thickness plastic did you use?  I'm intend to use this .3mm one from HK, just wondering if that would be ok.

C