Cutting neat holes in foam for lipos

[pk-surfing]

I've nearly got my big wing ready for LOS maiden and I needed to cut some deep long holes in the foam to take the 2no 4000mah 3S lipos I am using.

The wing is 57mm thick (2 1/4") and my lipos are 50mm (2"), I wanted a neat rectangular deep slot so the lipos fit nice, cutting with a knife and pulling bits of foam out with pliers wasn't going to be neat enough for what I wanted.

I found a piece of thick wire and bent it to the outline shape of the lipo, I bent it to the depth I wanted and also made a side 'lip' in the wire to act as a depth stop that would slide over a steel ruler I taped to the wing along where I wanted the slot.

I then took the soldering end out of my gun type soldering iron and tightened my shaped wire into it, press the trigger and the wire gets hot !

It worked perfectly, have a look at the photos I've just taken.

PK

"click on each photo to see an enlarged version"

[6lennn]

im lovin this as i was wondering how to do this on my zephyrII

and by chance i have a similar soldering iron thats been sat gathering dust for the best part of 10 years

what wire was it, would a coat hanger do???

[FPVSteve]

Superb idea Paul, great tip

[dogzilla]

Yup this technique is awesome!

You can bend various shapes out for different jobs. I'm not sure what the best sort of wire is but I've even used coat hanger LOL. I imagine some sort of copper would be best.

[pk-surfing]

I was looking to strip a bit of copper earth wire out of some thick 'twin and earth' cable but my eye caught some thick garden tie wire (galv steel I think) so I used that.

It 2mm dia so too slack in the clamp ends of the iron so I added a short length of 1mm copper wire in to let the clamps tighten, if I hadn't been in too much of a rush tonight I would prob have doubled back 10mm at each end and maybe tapped it with a hammer to get a nice fold then that would have been a good fit in the iron.

As the iron uses low voltage (high current) at the bits you can touch I just gave it a quick switch on for 5 secs first to check it heated up ok.

[Funky Diver]

Nice!  Thats every kind of clever, and a simple idea too. Just a shame I don't have one of those soldering irons, guess I can look out for one though

I hve one that I picked up at Lidl for less than a tenner.  Been using it for years for various stuff, cutting fabric (cordura), soldering and same as this.

One of these

[dogzilla]

iChargers have a foam cut option too if you have one of those.

[papa_lazerous]

iChargers have a foam cut option too if you have one of those.

Yup got a 3010b  never thought of that!

[6lennn]

Hey PK

or anyone for that matter

How did you know where to put the batteries considering its critical to get the cog right

I will be doing the same to my zephyrII when I get around to it and dont know exactly where to cut?

[pk-surfing]

I get everything connected up, servos, control rods, receiver and aerials, OSD, GPS, bec, ESC's, camera, Vtx, lights etc laid out on the wing and taped down with masking tape.

I have two mapping pins with ball heads pushed and glued in underneath at the Cof G point so I can feel them when doing a balance check, then I just move the lipos around (heaviest item) so that the balance is just right and they are oriented how I want them.

I then lay down some masking tape on the laminate to outline the lipo positions and that's it !

I like to build lightness into the stuff I fly and hate the idea of having to add dead weight anywhere to get the C of G where it needs to be.

The only time I add weight is maybe out near one wing tip if I find the lateral balance of the plane is off.

PK

[Dizzy]

That style of gun uses induction heating so any wire will work  :D

nice one Pk  ;)

dizzy