Cutting wing cores - people in the know

[jase]

guys, i'm looking at purchasing a transformer so i can start cutting my own wing cores.

i've been looking on ebay at the following transformer and though i have sent the seller a few questions, i thought i would ask here to get your technical know how if this is what i should be getting.

cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=120441515651

basically i want something to regulate the power going through the wire for my wire cutter without connecting directly to a 12v battery (which i think would be rather dangerous).

thoughts.

[sean]

Hi Jase,

That looks like it would work well, although it does say it requires a 15V AC input so I'm guessing it wouldn't work with a battery as power source. You could buy a 15V 5amp AC power source from Jaycar.

[jirvin4505]

Jase - not sure what you are using for information?

Most common simple hotwire supply is a transformer $20 from Dick Smith and a light dimmer from Bunnings $5.00 (guess). I recently sent AVB details plus links - don't have them here with me.

I have built 10 or so hotwire power supplies (keep giving them away) by ratting out the transformer from a discarded amplifyer 100watts and driving them with a light dimmer.

have you done a search on rcgroups for hot wire power supply - lots of info.

For me i could never get a 12v battery to work with the better quality wire.

cheers jeff

[jirvin4505]

A transformer needs an AC supply to work - the variac would not work with a 12v DC (battery) input.

cheers Jeff

[jase]

ok, so if i do the dick smith job... which transformer do i get..

i do have a 12v battery charger, but it's very basic and doesn't have anyway to adjust the power settings.... could i just add the light dimmer to this and be in business?

[thevon]

Jeff/ Jase I went to Dick Smith and Jaycar asking for a 24 volt, 3 to 5 amp power supply and they didn't have anything that looked like it would suit. I'm not an electrically gifted person so I don't really understand what is best. I'm still a bit confused but Sean has offered to give me his old AC one so I think that will get me going. But if someone does know of an off -the shelf unit that would do the job, it would be good to know where to get it as this seems to be a common question.

[sean]

This is the one I bought:

www.jaycar.com.au/productView.asp?ID=MM2015&CATID=19&form=CAT&SUBCATID=411

Hooked it up to a light dimmer and it works a treat. Not sure if that much power is strictly needed but it doesn't hurt!

[Garth]

Had been thinking about cutting some wing cores for a while now, so mikey100 and i spent a day or so thinking about it.

Computer power supply x1
bow x1
switch x1 (to turn on or off)
Mike had the wire.
THATS IT.

cost $3 for some speaker wire 3m (Dad had lots of power supply's) they are $32 anyway

Vac bagging is next this is were jeff comes into it.

HAD A GO TODAY




Thanks again Mike for the help and the spare bits.

[jase]

nice job. have you seen my latest efforts in my jart build thread.

the last vertical stab cut i did came out near perfect.. i was using tapered wings so i secured 1 end of the wire to the end of a table.

were you using ni-chrome wire as your cutting wire. it's far better than 7 strand.

what length of wire were u able to heat with the computer power supply. i'm getting about 25inches max from a motorbike battery and 0.6 ni chrome.

[Garth]

Not sure what the wire is, Mike had it. The wire and the bow is about 900mm long. Im going to make another bow over the weekend 1200mm long to see how that goes. If you have an old computer just take the ps out of it and join the green and any black wire together so you will have power. The yellow wire is 12v.

Happy Days

Garth

[chamm37]

I will be playing with this sort of stuff really soon. I am going to be making a Supra ;D So i will need to make a bow and everything like that. Would you be able to post up some pics of the bow and power supply please Garth


Thanks mate,
Chris

[mikey100]

Chris...making a Supra. WOW...thats one cool plane. Where did you manage to get the moulds for the fus, wings and tail-feathers? I've done quite a bit of glassing over the years; kayaks, sailboards, surfboards, model yachts, etc, but a Supra is a MAJOR project! Didn't think the wings were foam core on the ones I say recently. Tell us more!

[chamm37]

You don't need any of that Mikey ;D You make everything yourself. You don't get moulds or anything. The tail is blue foam glassed, Wing and horizontal stab is the same as well ;D It will be a major project and i am still a real beginner to fiberglassing and everything along those lines so it will be a big learning curve for me. My grandfather is helping me as well but we are in the dark a little bit. My grandfather has done all the stuff you have done with building boats and stuff but year. Once i pay you off i will be starting it You are welcome to build one as well and we could do like a mini group build and see if anybody else wants to build one as well. Shane Spoor is currently building one but i am not sure where he is. I really want to build one ;D ;D ;D You in on building one as well mikey

Here is a link to the site where it has the instructions and stuff
charlesriverrc.org/articles/supra/supra.htm


Regards,
Chris

[mikey100]

Chris, sounds like a big job. The 2 Supras I saw recently belonged to Brian and Paul. They were up from Newcastle way.( I bought my Pike Superior from Paul). The planes flew amazingly, but I was under the impression that they were bought commercially airstrike.com.au/Daves%20Toys%20Gliders.htm and not home-made. Good luck with it.

[sean]

Hey Mike,

There are two different types of Supra - the bagged wing home made version and the expensive moulded version... The bagged one came before the moulded one.

Defiinitely a big job to build one! Very ambitious for a first project. The wings are bagged but you still need to mould the fuse.

Sean.