Fat Fighter Me109

[Graham Davies 3]

Hi All,

 

For those that have not come across foam sheets, foamboard, and the various  derivatives, I've been experimenting with these materials since the great Balsa shortage. It's proved hugely rewarding and the possibilities are equally huge. My preference for practical scale models is more than satisfied, and the results are great, but also extremely cheap.

 

My latest project is inspired by the Fat Fighters seen here:

 

 

 

I found some rough plans for the Me109 here:

 

https://numavig.com/plans/Messerschmitt-Bf-109-cartoon/

 

My usual foamboard approach is to start with 3 views and use the outline as an approximate plan. For this, I have pretty much followed this design. Similar to how I use a 3 view, I print a copy and then work out my preferred size. In this case, around 35" span, and then create a 'scaling factor'. A bit of measurement from the drawing and an afternoon with the calculator gives me a load of dimensions which I then use to create the shapes:

 

Chosen material for this build is laminate floor insulation from B&Q. 3, 6 and 9mm are available. I am using 3 and 6mm.

 

 

It's a lot more brittle than the core of foamboard, but more than useable. I started by cutting the wing outlines. The lower is exact, the upper is made by drawing around the trailing edge, and then pushing the profile forward by 10mm to make a broader chord to accomodate the airfoil.

 

 

The upper sheet is then curled. I tried to curl it by dragging over the desk edge, but it cracks! It needs a bit of heat from the gun, and a bit of patience. 

 

The airfoil is created by using 3 spars, each of 2 thicknesses of foam. I created the root dimensions from the drawing and projected the taper so the tips meet, but cut them about 50mm short of the tips as they become too thin to be any use. All gluing is UHU Por used as a contact adhesive. Great glue, very fast, but a tube doesn't last long.

 The lower panels are joined, and a 1/32" ply dihedral brace added

 

Then I glued the upper skins, lining up at the trailing edge

 

I then spent a bit of time carefully curling the leading edge sheeting to get it to meet as much as possible, although my intention is always to add a leading edge. Once they are suitably curled you will find the upper skin overhangs the lower. I then added 2 laminations of foam glued to the inside of the upper skin and the edge of the lower skin. This gives a nice chunk of material to sand to shape.

 

That's the wing mostly complete. I will cut out the ailerons when I get ready to fit the servos, and face the edges with foam at the time. Servos will be fitted to the inside of the upper skin with hot glue; quick and easy (as long as you remember to centre the servo first!). The wing weighs 3.5 ounces at 35" span. Time taken (ignoring the time to create the dimensions) is 1 1/2 hours

 

Fuselage is underway. This is a relatively simple framework, over which a 3mm skin will be formed.

 

 

Cutting the shapes took a while, but overall this took me 2 hours. The skinning may present a few challenges....

 

Finally, a quick shot of the fuselage frame offered up to the wing to get an idea of cuteness,,,

 

More to follow

 

Graham

[martin collins 1]

Very well explained Graham, looks like we have a few more people joining the Merry band of foam builders, should be some fascinating builds coming in 23 and hopefully a good group of people to have a fly in at Buckminster in the summer.

[perttime]

In USA, parkflyerplastics sells plastic parts and plans for many designs in this style. A bit smaller, as I recall.

[Lima Hotel Foxtrot]

Intriguing. Some of those models in the video look challenging to fly - that F-104 has virtually no wing area (!) - but those are some great designs and the concept has gone straight onto the To Do List.

 

Is there much of a weight difference between the Diall flooring foam and, say, HobbyCraft Foamboard or regular Depron?

[martin collins 1]

Dial flooring foam or their insulation foam (found in different areas of B&Q) are  forms of depron and very light, HobbyCraft foam board has a paper covering on either side and is heavier but much stronger so ideal for the structural parts, the paper can be removed with your heat iron to soften the glue bonding it, thus saving weight but loosing some of the structural strength.

[Lima Hotel Foxtrot]

 

53 minutes ago, martin collins 1 said:

Dial flooring foam or their insulation foam (found in different areas of B&Q) are  forms of depron and very light, HobbyCraft foam board has a paper covering on either side and is heavier but much stronger so ideal for the structural parts, the paper can be removed with your heat iron to soften the glue bonding it, thus saving weight but loosing some of the structural strength.

Yup. Perhaps I should have been more detailed: When I weighed Westfoam foamboard from HobbyCraft in 100cm sq pieces, the average weight was 6g, 4 of which was the paper backing (removed in the tests via a light steam over a boiling kettle).

 

What I'm asking is if there is a major weight difference between foamboard and this Diall sheet, which may be very close to the Depron I can get in my LMS, but may not be as good when forming curves without heating due to it's above reported brittle nature.

[Graham Davies 3]

Good question LMH. I suspect the Diall flooring is lighter than foamboard core, but that's just a guess. I've never used actual Depron, so can't comment on the differences. I'm so far enjoying using the Diall stuff, and it's certainly producing a light airframe.

[Graham Davies 3]

6 hours ago, Lima Hotel Foxtrot said:

Intriguing. Some of those models in the video look challenging to fly - that F-104 has virtually no wing area (!) - but those are some great designs and the concept has gone straight onto the To Do List.

 

Is there much of a weight difference between the Diall flooring foam and, say, HobbyCraft Foamboard or regular Depron?

 

I agree that some don't look like a relaxing proposition! I elected to scale up a bit as I think the weight difference will be minimal and the extra area will mean a lower loading and mean the model can be slowed up a little. My model is 35" span although with the fus in place, there's not much wing remaining!

[Graham Davies 3]

A bit more done today.

 

Finished of the frame of the fuselage and laminated the front formers. I added a disc of 1/16" ply to the motor former, and similar behind. I am using a little 2830 motor and will hold it in with small woodscrews. The laminations provide a load of support and will make the front end nice and sturdy to avoid handling damage. 

 

 

 

One 'thinking ahead headache' related to fitting the rudder and elevator servos. The tailplane is very high on the ME, so I needed to think about where to put the servos, and how to get at them to set the model up. I elected to fit them behind the wing, but accessible through the bottom of the fus. I will sheet this area last once everything is hooked up. I added some 6mm foam doublers and then hot glued the servos to these after wrapping them in masking tape. This will give the traditionalists the heebie jeebies, but works well on these little models. You can just about see the servos in the 1st pic. I'm using up some cheap tower pro 9g servos (actually samples from a potential supplier!).

 

I've then moved onto sheeting with 3mm sheet. Not too difficult, but needs to be done in a few hits to be able to apply POR and get it set so it can be impacted. I used the flat sections of the formers and got the sheet attached before moving to the curved sections. It's reasonable and a bit of sanding will make it good.

 

I've offered up the wing to get a feel. Not much wing left once the fus sucks it all up!

 

Today's effort was 1 1/2 hours.

 

Graham

 

 

 

 

 

[martin collins 1]

Looks like a WW2 Link trainer! 😅

[Graham Davies 3]

Now there's a great scale subject. 

 

How about this:

 

 

Do you think it will be eligible for scale comps?

 

😀

[Peter Miller]

I am not sure that I would risk pointing my new lens at that!!!!

[Graham Davies 3]

You're going to need to go wide angle for the Chubby!

[Graham Davies 3]

Today's progress:

 

Added the tailplane. Made a fin and added a strip of 1/32" ply to the tailplane to prevent accidental damage, or a 'folding'...

 

The assembled tailplane is fitted to the fus with a couple of cocktail sticks to support it. Once fully dried I will add a strip of foam each side to make the tail end a little stiffer.

 

Next was the spinner.... 

It's not easy to find ultra-lightweight spinners at 140mm diameter. So this is made from foam. This stuff came free with my freezer,,,

There's a great tutorial making use of XPS here:

 

A really neat idea making use of a bottle and cap to make a 2 piece spinner.

 

There is a tutorial on the flitetest youtube channel, but I can't recommend it. They suggest final spacing with the prop in place. No chance I will be doing that...

 

Anyways, mine came out well. One point, I suggest reversing your drill to prevent the screw constantly loosening.

 

And today's cuteness shot:

 

I need to check my sums for the tailplane as it looks a bit big. He says Ironically...

 

Anyways, that was 1 1/2 hours today and mostly because making the spinner was a new technique.

 

The evils of work return tomorrow, so progress will slow now. Shame as it's nearly done!

 

Graham

 

 

 

 

[Keith Billinge]

Nice work!
I have the kit for the Fatty Corsair from the German company.......Erm I must get round to building it.

 

LINK To Scale Park Flyer DE

 

K B

[Peter Miller]

ER....I wonder what a fatty Gee Bee would look like!!??

[Shaun Walsh]

1 hour ago, Peter Miller said:

ER....I wonder what a fatty Gee Bee would look like!!??

Morbidly obese?

[Graham Davies 3]

Things moved slowly for a few weeks, but I decided yesterday to push on and get her finished. A load of little jobs to do:

• Close the rear lower fuselage
• Fit the pilot (Snoopy) and make a canopy
• Make a battery hatch
• Paint...

With the 'quick and dirtiest' of 'quick and dirty' paint jobs, it has at least an air of Me109-ness about it.

 

Balances fine with a 1500 3S pack and weighs just under 1 pound 8 Ounces.

 

As today was a sunny, still day, it was a good opportunity to maiden..

 

It went without any sort of issue. An easy hand launch and a few clicks of elevator was followed by a pleasant and uneventful flight and a gentle landing.

 

Graham

 

[Peter Miller]

I have just had a report from the club secretary and how well it flew. Amazing

 

Have you managed to get the mud off your boots and the dogs feet 

[martin collins 1]

Looks great Graham, just the markings to apply now as it has flown, Porky Spit next for dog fights?

[Graham Davies 3]

3 hours ago, Peter Miller said:

I have just had a report from the club secretary and how well it flew. Amazing

 

Have you managed to get the mud off your boots and the dogs feet 

Mostly! It was properly claggy today!

[Graham Davies 3]

2 hours ago, martin collins 1 said:

Looks great Graham, just the markings to apply now as it has flown, Porky Spit next for dog fights?

Cheers Martin,

 

Yes, I'll 'pretty it up' when my enthusiasm returns! Definitely up for a dogfight. Although once I get Dick Dastardly's biplane up and running you won't stand a chance. 20mm cannons vs. a giant baseball bat swung by a robot arm? No contest...

[Graham Davies 3]

A great day in the sun today. So it would have been rude not to have a few flights with the Fat Me109. 

 

Thanks to Peter Miller for these great photos

 

Graham

 

 

[martin collins 1]

Looks great in that tight bank Graham.

[GrumpyGnome]

Cute!

Edited February 5, 2023 by GrumpyGnome