Simple Cub... With a TWIST

[Vimana89]

I just rinse out a milk jug cut the top and bottom off and then slice it into flat sheets to use.

A 6 pint jug yealds enough 'flat ' plastic to make the belly cover in one piece but I now use skimmed milk and they only sell it in 4 pint jugs vs 6 print jugs for semi and full fat annoyingly so I have to make my belly strip in two or three lengths.

I score the plastic in a diamond pattern to give the glue something to grip as milk jug is HDPE and then I just hot glue it to the underside of the plane.

It makes the belly indestructible for landings I land on hard mud and even gravel and bare foam gets trashed on just grass let alone hard ground.

Below is my VERY well used daily cub, it's got a couple of hundred hours on that plane and you can see the scrapes in the paint but the plastic is holding out fine.

Also below is a new build of a GPS cub which I haven't finished yet and haven't painted the plastic yet and you can see what I've done a bit clearer.

although the rest of the fuse is already painted, I always put the plastic on after and blow over it, painting the fuse first makes a stronger surface on the foam under the plastic and stops it pulling the paper soon the foam when it flexes on hard landings.

I put it on all belly landing planes now, the plane lasts and lasts and as I've pointed out in an earlier post, in a crash the nose will crumple but the belly plastic limits how far back the damage goes and will flex in a crash absorbing the force instead of just transferring it further down the fuse. View attachment 139510 View attachment 139511

This is a sweet mod. I fly mostly in a gritty desert lot across my street, and hand launch/belly land everything. The bottom of the nose box on my V Sliver delta(and the one on a plane I'm building for the FTFC20 challenge) design has a similar curve and flat surface which make contact with the ground and get pretty scuffed up. I've just been using a strip of heavy duty packing tape to do the same job, and it holds up alright, but not as good as this would.

 

[PoorManRC]

That does seem like a good belly landing mod... ESPECIALLY where WE live!

 

[BATTLEAXE]

I just rinse out a milk jug cut the top and bottom off and then slice it into flat sheets to use.

A 6 pint jug yealds enough 'flat ' plastic to make the belly cover in one piece but I now use skimmed milk and they only sell it in 4 pint jugs vs 6 print jugs for semi and full fat annoyingly so I have to make my belly strip in two or three lengths.

I score the plastic in a diamond pattern to give the glue something to grip as milk jug is HDPE and then I just hot glue it to the underside of the plane.

It makes the belly indestructible for landings I land on hard mud and even gravel and bare foam gets trashed on just grass let alone hard ground.

Below is my VERY well used daily cub, it's got a couple of hundred hours on that plane and you can see the scrapes in the paint but the plastic is holding out fine.

Also below is a new build of a GPS cub which I haven't finished yet and haven't painted the plastic yet and you can see what I've done a bit clearer.

although the rest of the fuse is already painted, I always put the plastic on after and blow over it, painting the fuse first makes a stronger surface on the foam under the plastic and stops it pulling the paper soon the foam when it flexes on hard landings.

I put it on all belly landing planes now, the plane lasts and lasts and as I've pointed out in an earlier post, in a crash the nose will crumple but the belly plastic limits how far back the damage goes and will flex in a crash absorbing the force instead of just transferring it further down the fuse. View attachment 139510 View attachment 139511

Looks just as clean as the foam alone but has personality in it's experience lol. I'm gonna use this one if you don't mind... unless you have a patent on it . Thx man

 

[Steve Fox]

Looks just as clean as the foam alone but has personality in it's experience lol. I'm gonna use this one if you don't mind... unless you have a patent on it . Thx man

Glad people like the idea
Everyone needs milk jug plastic on belly landers, makes them so tough and they last for ages, ive not had a milk jug base wear though yet!
a bare foam bottom gets chewed up in just a few flights landing on just grass, this laughs in the face of concrete, hard mud and gravel ha ha

another thing that works out quite well is the plastic makes the plane skid along more easily, you are much less likely to flip over and just slide to a controlled stop.

 

[cranialrectosis]

Brilliant mod there @Steve Fox. Elegant solution, IMO.

 

[Vimana89]

I can also picture disposable plastic plates for parties and BBQ working to cut pieces from like a milk jug

 

[Steve Fox]

I can also picture disposable plastic plates for parties and BBQ working to cut pieces from like a milk jug

The thing about disposable plates is they are made of a brittle plastic, the HDPE that milk jugs are made of is tough as bricks

 

[Vimana89]

The thing about disposable plates its they are made of a brittle plastic, the HDPE that milk jugs are made of is tough as bricks

Yeah good point the plates are flimsier and brittle. They would work in a pinch but wouldn't hold up as long or to as rough of an impact.

 

[BATTLEAXE]

The thing about disposable plates is they are made of a brittle plastic, the HDPE that milk jugs are made of is tough as bricks

So I cut out some skid plates from the milk jugs for the Spitfire as it is a belly lander and your right, it is slippery plastic. Question though, how did you adhere the plastic to the FB?

 

[Steve Fox]

So I cut out some skid plates from the milk jugs for the Spitfire as it is a belly lander and your right, it is slippery plastic. Question though, how did you adhere the plastic to the FB?

I carefully score a diamond pattern into the side to be glued with a very sharp blade.

Go careful so not to cut too deep and weaken it and also go at it with the blade at an angle so you score a lip under the surface rather than just scoring surface lines, that lip gives a strong mechanical bond with the glue.

I use the same scoring technique on my aluminium firewalls when epoxying them to power pods

 

[BATTLEAXE]

I carefully score a diamond pattern into the side t be glued with a very sharp blade.

Go careful so not to cut too deep and weaken it and also go at it with the blade at an angle so you score a lip under the surface rather than just scoring surface lines, that lip gives a strong mechanical bond with the glue.

So it was HG to bond it then?

 

[Steve Fox]

So it was HG to bond it then?

Yes, I use hot glue, it's flexible and won't break up under the constant impacts from landing.
it can cool pretty fast against the plastic, if I don't manage to spread the glue out before its cooled and set I use a heat gun to gently heat the plastic till the glue goes soft again and use a card or similar to run along the plastic which spreads out the hot glue underneath.

 

[BATTLEAXE]

Yes, I use hot glue, it's flexible and won't break up under the constant impacts from landing.
it can cool pretty fast against the plastic, if I don't manage to spread the glue out before its cooled and set I use a heat gun to gently heat the plastic till the glue goes soft again and use a card or similar to run along the plastic which spreads out the hot glue underneath.

I did the spray adhesive thing and it was easy to apply but I'm not to sure how long it will last. I used this idea on my Spitfire because it's a belly lander and I already have packing tape covering the bottom and I forgot about the scoring the plastic thing so it's adhesion is questionable, I pulled on a corner of the plastic just to test it and it peeled up easier then I thought, maybe cuz it had nothing to soak into. If it falls off I'll worry about it then, and do it right. Thanks again

 

[Steve Fox]

I did the spray adhesive thing and it was easy to apply but I'm not to sure how long it will last. I used this idea on my Spitfire because it's a belly lander and I already have packing tape covering the bottom and I forgot about the scoring the plastic thing so it's adhesion is questionable, I pulled on a corner of the plastic just to test it and it peeled up easier then I thought, maybe cuz it had nothing to soak into. If it falls off I'll worry about it then, and do it right. Thanks again

another thing i use it for is on the leading and trailing edge of the wing where the rubber bands pass over, it stops the bands cutting into the foam

Below is the wing on my very well used daily flyer which is flying on a wing i rushed as a replacement after chopping the previous one in half on power lines, i literally showed it the spray can and said that will do as i wanted the plane flying the next day and didn't care what it looked like ha ha
that replacement wing is also patched in places, i abuse that plane lol

also a pic of the regular job i do on my wings, the one that is built for my gps cub which has not flown yet.

both have the plastic on the leading and trailing edges that im talking about.

 

[BATTLEAXE]

Yea

another thing i use it for is on the leading and trailing edge of the wing where the rubber bands pass over, it stops the bands cutting into the foam

Below is the wing on my very well used daily flyer which is flying on a wing i rushed as a replacement after chopping the previous one in half on power lines, i literally showed it the spray can and said that will do as i wanted the plane flying the next day and didn't care what it looked like ha ha
that replacement wing is also patched in places, i abuse that plane lol

also a pic of the regular job i do on my wings, the one that is built for my gps cub which has not flown yet.

both have the plastic on the leading and trailing edges that im talking about. View attachment 139793 View attachment 139794 [/QUOTE
Yea i do the TE with the bbq skewer but that looks like it blends in better. I havent had to do that on the LE yet, planes dont last that long for me lol. Looks good.

I'll try it on the Spit as a skid plate for now and go from there. I did make up a cool window scheme on my Shrubsmacker with the aluminum tape. Shiny reflective windows. First time i used it on a plane. Works good. I can see why people would skin their planes with it.

 

[Steve Fox]

Yea

The daily cub is a workhorse, i really dont care what it looks like, its patched in several places including the whole tail having been reattached after i tore it off just before the horizontal stab and it was hanging by the pushrods lol

This battered plane is what i do cloud surfing with ha ha

you can repair foam board planes almost infinitely, and have them flying the next day after a serious mishap, i love it

 

[BATTLEAXE]

The daily cub is a workhorse, i really dont care what it looks like, its patched in several places including the whole tail having been reattached after i tore it off just before the horizontal stab and it was hanging by the pushrods lol

This battered plane is what i do cloud surfing with ha ha

you can repair foam board planes almost infinitely, and have them flying the next day after a serious mishap, i love it View attachment 139797 View attachment 139798

Nice, I would have built a new wing already lol, but that's just how I roll. The fix on the tail is almost flawless, you should have been a plastic surgeon. I like the white control system you have goin on, painted?

 

[Steve Fox]

Nice, I would have built a new wing already lol, but that's just how I roll. The fix on the tail is almost flawless, you should have been a plastic surgeon. I like the white control system you have goin on, painted?

That's already a replacement wing, not long after I built it because I sliced the previous one in half, I put I big cut in that one lol.

I just cut out then damage in a a strip the same width as foam board is thick, glued in some foam board and trimmed it down.

I've been known to patch in sections of wing like 4" square and on the shaped part of the wing too, I just cut out the damage and make new sections rather than buil whole new wings or fuse body's.

I don't see the point in building a new wing unless it's absolutely needed from being damaged so bad that it's not worth patching, if I build a new wing it's only a matter of time before I trash it anyway cos I take lots of risks when I fly and regularly clip things from deliberately flying too close to stuff.

When I'm flying fpv at 5000-6000ft , nether I or anyone else can even see the plane so as long as it physically fly's ok, it really does not matter to me how tatty it looks and seeing as this particular build has a couple of hundred hours flight on it it's actually doing ok, it's the longest running cub I've had so far.

My current daily flyer is cub MK4, the gps one is the fifth build

The nose has been replaced 3 times on that cub now, I've got pretty efficient at lopping it off and fitting a new one .

The rear linkage is white from the tail getting sprayed with it in place after I tore off half of the horizontal stab on a power line.
I kept flying that day with it only having half of it till I'd used up all my battery's, it hardly affected it's flight at all amazingly.
I've also flown on only one working aileron before as well, that just makes the plane feel 'numb' but still has enough control to fly

 

[BATTLEAXE]

I could use some more experience with repairs. I see what you mean though. I don't think I'll be flying at 5000 ft. Was it you that posted high altitude video the other day?

 

[Steve Fox]

I could use some more experience with repairs. I see what you mean though. I don't think I'll be flying at 5000 ft. Was it you that posted high altitude video the other day?

Obviously it only applies to planes built with hot glue but it's pretty easy to to repairs.
I use a heat gun (a hair dryer will work just as well), place the heat source at a distance and slowly heat the area you need to strip down.
If you go slow and allow the heat to work it's way deep into the glue you can soften it enough to pull the damaged parts without affecting the rest of the plane.
If you don't go slow and try heating too fast and too close you will bubble the foam.

If you look in the pics, just before the vertical stab there is a dig in the fuse at the top edge, it shows that both images are the same plane and both the horizontal and vertical stabs are different in both pics, in the repaired pic they have proper hinges and shows that it's not just the tail before getting damaged and you can see the removed parts on the desk as well

All crashes are repairable, I even had a plane run over by a car once and repaired the fuse lol.