Clock for those MOBs

For those MOBs (Midnight Oil Burners) out there I have added the nifty looking clock on the right. My wrist watch stopped working at 10:10pm last night while I was layng up the spars in the F18 and when I eventually noticed something was wrong it was past midnight already.....! Paul, I need a replacement watch!!! Time surely flies when you're having fun. The trick is getting into bed without waking the better half.

The clock will help old Prepatation Piet to know when to go to bed as I see he has fallen into the habit of blogging at 3:30 am! Somebody will have to feed him some Red Bulls at the upcoming PSS Fest to keep him awake ;o)

F18 Build - Part 4

I did not have a huge amount of time tonight but managed to lay up the top spars into the wing. I decided to use 12K tows for this as it is less "ropey" than the 60K tows I have and it is easier to get the epoxy to properly penetrate the carbon strands without making one moer-of-a-mess ;o)

First step is to decide how many tows to use. As I have always used spruce spars in the past in all my slope models I had no clue as to how many is enough. I just cut some small pieces and stacked them together until I got to about what I thought "looked" strong enough. Based on the "long-term" Allegro build I am also busy with, which used 4 layers of uni-directional carbon to get to the prescribed 0.7mm thickness I opted for six of the 12K tows. In hindsight If I had enought time I would have opted to use the same technique to make pre-pregnated strips (as described here) from UD carbon and just epoxy them in afterwards.

The depth of the groove was just right as the 1.5mm balsa cap I put on top stood just proud of the wing top surface.

The last bit of epoxy mix was thickened to a syruppy consistence slurry with microballoons and used as a filler to close up the tiny gaps. A maxed-out useless credit card took care of the excess epoxy to prevent too much sanding afterwards. To prevent the wing "negatives" sticking to this beautiful piece of handiwork I cut two narrow strips of Mylar which I put over the spars.

And the last task of the evening before I get some much needed sleep was to weigh the whole setup down. This is where those old UPS sealed lead-acid batteries come in very handy. Tomorrow evening I do the bottom spars.

F18 Build - Part 3

Time to get some work done on the wings. I made a small t-piece sanding bar from some 8mm wide spruce stock (just the right width for the 12K carbon tows I want to use as spars) to which I glued some 80 grit sandpaper.

Using a straight edge the sanding bar makes light work of the task and in less than 30 minutes I had some perfect grooves, top and bottom, ready to accept the carbon tows.

Before I start epoxying the spars in I wanted to join the wings so the spars can be continuous across the join. Seeing as the joing will draw it's strength from the carbon spars, glass wing skin, trailing and leading edge balsa stock the join can be done with plain old Alcolin cold glue. From previous experience I have found if you use epoxy for this join, you battle to cut through this join when routing your aileron servo wires.

While the wing join was setting some more shaping of the fuselage followed. It is getting to the point where I am almost happy with the result.

The top aft section is going to have to wait until I've made the root templates for the fins. I need to "picture" how the fins are going to blend in with the fuselage.

Adding some detail to the intakes.

Gert Nieuwoudt's PSS Mig 7

One of the models that will be at the ETB PSS Fest is this Mig 7 made from Correx being built by Gert. I have seen one of these fly at Volksies before and it didn't do bad at all. For those that are interested I have a 1Mb zip file that contains the plans and instructions or you can find it here. Some alternatives also made from correx are available here. Most of the models are powered aircraft but can easily be converted to slopies, especially the Corospit and Corostang.

F18 Build - Part 2

And this is where you start kicking up a snow storm....! Shaping/sanding the polystyrene indoors is a sure way of getting on the wrong side of the "law" at home so I do mine outside. 80 grit paper takes care of everything that does not look like F18 and a finer grit gets it nice and smooth. Here the nose has been sanded to its basic shape and the canopy marked out.

Some more shaping and it is starting to look more and more like a Hornet by the minute.

To do the full size plane justice I am trying to get most of the contours as close as possible to the "real thing" that I can with this technique.

The result I am looking for is to have it slightly better than just stand-off scale. The only area where I am cheating a bit is on the wing. Here I've played a bit with the scale and aspect ratio to, hopefully, get a model that is a bit more versatile and does not need a galeforce wind to fly. I can never resist the urge to do a mockup prop to get an early idea what the end result is going to be.

ETB PSS Fest - F18 Project Part 1

It's been AGES since I posted on the blog and this opportunity is as good as any resume posting. With the upcoming ETB PSS Fest in October I had to decide on a project to put together. To me the choice was easy, I have always wanted another F18 Hornet. Here's what the previous one looked like that I got from Paul.

With the help of Paul we quickly bashed out all the foamy bits. The fuse is from 20dv foam and the wings from 24dv. Somewhere in there is an F18 hiding away.....

Ahh! There it is.... With the templates already having been made with the previous model it saved me a lot of time behind the drawing board and behind the workbench. Now someone must just invent a foam cutter that can do all the compound curves as well ;o) Mind you, I saw some awesome CNC machines at last week's Electra Mining Show at Nasrec that could pretty well do the trick. Pity about the price tags on these marvels of technology :o(

Allegro Lite Build Part 7

I've added another two layers of 160g glass to the fuselage tonight and while that is curing I started with a dry run of the two tip panels components. Quite intensive labour having to very delicately sand the correct angles to the cross grain shearwebs so they butt up to the ribs at the correct sweep. Everything seems to fit nicely according to the plan.

Below is a closeup of the carry through strips I made previously. Next I'll probably get sticky doing the actual building of the tip panels.