[wingtipper]

Awe inspiring mate looks fantastic . Love the way you make things . Its great to see how it all comes together .

[secant0give]

Thanks Frank,

The wing on this plane so thin that even micro servos stick out through the bottom surface. I haven’t flown it with the new fairings on yet, but it should make for a reasonable reduction in drag.
The previous fairings were laid up in the mould, covered with cling film, then a sponge was put on top and a weight on top of the sponge to hold the layup against the mould. It would have been easier if I used a few layers of much lighter cloth, but I have heaps of 6oz that I wanted to use up. The sponge conformes to the shape of the inside of the fairing and holds the cloth and resin nicely against the internal corners of the mould. Epoxy doesn't stick to cling film so that separated the sponge from the inside of the fairing and was easily removed after it cured. The section that goes over the linkage is separate piece, made from the RareBear linkage fairing.



While I'm waiting for the paint to really harden up on the plug for fuse, I've dragged out my old vaccum pump, changed the oil in it and tested it out moulding some more servo fairings. This time I vac bagged them into the mould. The bag is just a clip lock bag and since it's made of similar material to cling wrap it doesn't adhere to the lay-up either. The strip across the two moulds inside the bag is a wick to let the air out. It's made from a piece of cotton cloth folded up in a strip of Peel ply. Peel ply forms a porous layer that will release from the layup. It will just peel off the inside of the fairing before I pull it out of the mould. If I didn’t put a wick in there I don’t think it would have sucked right down into the shape of the mould.

Here’s a pic of the Lay-up, one layer of white paper on the outside and then one layer of 6oz glass, cut from 6oz tape. The paper is cut from the corners so it will take the shape of the mould with out wrinkeling. The resin I used was Hobby king 30min epoxy so it's pretty thick and it's not so easy to wet out the cloth. But it has the advantage that it is easy to mix in small ammounts and is cheep. Although it's a 30 min epoxy it's not stiff enough to take out of the mould for about 12 hours and is still a bit plyable even then, but cures nice and very crisp after a couple of days.

   

Here it is in the bag

   

Here’s my ancient Vacuum pump.

   

[smuzz]

Nice work!
It will be interesting to see Mk II flying alongside the prototype - I'll bet there is a noticeable difference.

[secant0give]

Nice work!
It will be interesting to see Mk II flying alongside the prototype - I'll bet there is a noticeable difference.

I'm hoping to measure a difference in speed of 20-30 Ks, the fuse will be a fairer, more slippery shape and the new wing is going to be better as well. I'm going to make the wings by Vac bagging almost exactly the same layup onto the foam cores. Vac bagging it will make the wing a much nicer smoother job and I'm also going to paint the skins before I lay them up. The wing should come out of the bag just about finished. This will save the work of covering it in Iron on film and it should have a very nice smooth surface. The tips will still need to be made up and covered tho' but it's not a huge job to do that.
I may even make a mould to do the wing tips later but I'll see how it goes like this for start. There's another method of making the tips all in one peice with foam core, I may have a go at this too. Plenty of things to try, composites are pretty versatile materials for building things.

Here’s a picture of the wing skins, they are made from 1mm thick pollyethelene sheet and just cut out with a straight edge and an exacto knife. It’s cheap and easy material to work with $25 for a 6’X4’ sheet. Another great thing about this is that epoxy doesn’t stick to it so it will release nicely from the surface of the wing once it’s cured.

   

[secant0give]

A few more laps around the mulberry bush.

Wax on........Wax off..........Wax on..........Wax off...........Wax on.........Wax off................Wax on........Wax off..........Wax on........Wax off..........Wax on........Wax off..........

   
Wax on........Wax off..........Wax on..........Wax off...........Wax on.........Wax off................Wax on........Wax off..........Wax on........Wax off..........Wax on........Wax off..........

   

The vac Bagged fairings came out ok but still could be a little better. This time I've tried painting them in the mould then laying them up. I didn't put the paper in this time just the one layer of 6oz cloth. I'm not sure if the paint is going to be dry enough. Hopefully it stays with the epoxy and not on the mould.
Lucky I used PVA as well as wax on the mould.

   

Here they are in the bag. I thought I'd try it without a wick this time as well and it seems to be working OK. They will probably be a little resin rich tho by the look of them.

   

[gbanger]

Looks incredibly labour intensive mate, how much do you think you will be selling the finished product for?

[secant0give]

Once the moulds are all done its not that time consuming to do
Should be able to make a fuse moulding and wing in fairly short order and it will be up to the builder to cut out the tail group and do most of the fitting
It won't be bind and fly
And I'm not doing it to make money.
If you buy one you have to make a commitement to come along and race it that's the bottom line it's just that simple

[gbanger]

You didn't answer my question buddy, and I know you aren't doing it to get rick quickley, so what's the bottom line to purchase one of these "Jasomites" ... and yes I am happy to accept royalties for naming rights.... that is unless you change it of course you sneeky bugger!

[secant0give]

I'm not sure yet Gazz, depends on how many I make, A bit more than a rarebear and less than anything else that's being raced.

I haven't thought it all out but I'm guessing The all up cost to get one in the air using the same parts as my prototype should be around or a little over $200 that would include motor ESC servos receiver, prop and of course the airframe kit as well. batteries not included, but they are just 1300 4S Nanos and you'd want 3 of them. The cost would go up from there if you use better servos dearer ESC or motor. But the deal is you have to race it.

There will be a bit of a build involved but nothing difficult, pretty much make and do the tail group, fit the wings to the fuse mount the servos put the linkages on the control surfaces, that sort of thing, pretty standard stuff the rest should be done.

I havn't made even the mould for the fuse yet so it all still a way off.

edit.....The Lipos are 1300 4s not 1600 4S flight time is 2 mins at Max throttle with 4.5 X 4.5 prop

[secant0give]

here's how the fairings came out after being painted in the mould

Not too bad but I think it will be better using lacquer rather than enamel so I'm off to get some this afternoon.

   

[secant0give]

I managed to get quite a bit more done tonight.

The mould for the front hatch is finished and curing nicely. Hopefully it will look nice when I separate it from the plug on Monday.

Heres the plug
   

And here it is with the mould formed around it, the reason it's wrapped in cling film is that this mould is made from polyester resin. Some polyester resins unlike epoxys doesn't cure completely where they are exposed to air. Inside it would be OK but the surface stays tacky for a long time and that's annoying. So by wrapping it in cling film it cures right to the skin.

   


I was able to get some Lacquer from Super Cheap Auto, re-waxed and PVA'd the fairing moulds and sprayed them ready to lay up again.

   

I also got the fuse plug set up in the parting board.

Here it is, the parting board cut out to take the fuse plug

   

Then a piece of ply is attached with 4 screws to the bottom of the parting board it can later be removed and the plug pushed out from the back.

The edges of the parting board were chamfered so an easy sanding epoxy bog that forms the part line would have something to bond too.

   

Plasticine was used to support the plug so that the top face of the parting board lines up with the centre of the fuselage plug. A couple of blobs of epoxy bog were also
Put in between the plasticine to form pillars that will support the core a bit more sturdily for when the glass is being stippled on top to form the mould.



   

A bog made from West systems micro sphere blend was applied between the chamfered edge of the parting board and the plug. Hopefully when the plug is removed and this bog is sanded flush with the board it will create an almost perfect parting line………..Well that’s the theory  We shall see how we go.

   

[secant0give]

A bit of a disappointing result, that’s the last time I’ll use enamel to paint a plug !!
Despite being very well waxed and having a good coat of PVA the enamel reacted with the gel coat and pulled some of the paint off the plug.
The Hatch mould is usable but the finish on it is marred and I’ll have to make another one.
Here’s a pic of the plug after it came out of the mould.

   

Here’s the mould after I’ve done a bit of work on it to pretty it up.

   

The Fuselage didn’t fare much better It was stuck hard to the parting board despite having more than 10 coats of Wax and a good coat of PVA as well.
The paint on the fuse plug didn’t react as badly to the epoxy bog as the paint on the hatch plug did to the polyester tooling gel. But it still stuck in places and tore off the paint layer.
I had to cut the parting board in half to get plug out of it.Here’s a pic of the fuse plug

   

Looks like I’ll be stripping the enamel off the plugs and repainting them with 2 pack polyurethane.
Afew more laps around the mullberry bush :I
Oh well …………………….that’s areomodeling

[wingtipper]

such a shame mate . knowing you though the finished product normally comes out better than 1st planned , so i'm sure MKII will be a better than planned result .

[secant0give]

Well see how we go I've got stripper on it now and the paint is comming off layer by layer.......Slowly

I've got some new two part polyester stuff to spray it with. According the to guys at Newplex this is the go, it's called Reface. It's an all in one hi bulid filler self priming and can be buffed to a high finish.

[gbanger]

I hope you don't mean "Nuplex" Jason... if you are purchasing products from them you are in lots of trouble......




just kidding mate, my X wife is the CEO.

[secant0give]

I mean the mob that used to be FGI for years at Brookveil

Have you had some bad experience with them Gazz ?
I've used their R180 Epoxy system a few times in the past and found it to be pretty good
The tooling gel I got from them certainly went off nice and hard and was great to work with.

The other polyester resin and the white gel coat I got from FMS just across the road from the field it works good too.

Is there something I should know ??

[gbanger]

[quote='secant0give' pid='21266' dateline='1372075033']
I mean the mob that used to be FGI for years at Brookveil

Have you had some bad experience with them Gazz ?
I've used their R180 Epoxy system a few times in the past and found it to be pretty good
The tooling gel I got from them certainly went off nice and hard and was great to work with.

The other polyester resin and the white gel coat I got from FMS just across the road from the field it works good too.

Is there something I should know ??


No mate... my X wife is the CEO.

[secant0give]

[quote='secant0give' pid='21266' dateline='1372075033']
I mean the mob that used to be FGI for years at Brookveil

Have you had some bad experience with them Gazz ?
I've used their R180 Epoxy system a few times in the past and found it to be pretty good
The tooling gel I got from them certainly went off nice and hard and was great to work with.

The other polyester resin and the white gel coat I got from FMS just across the road from the field it works good too.

Is there something I should know ??


No mate... my X wife is the CEO.

Then I'll make your's out of West Systems epoxy

[secant0give]

Here's the plugs stripped back to bare timber ready for another few laps around the mulberry bush.

   

   

[secant0give]

I’m quite impressed with “Upol reface” It was a bit of a bugger to spray but I was using a 1.2 mm spray gun and a 2mm minimum is recommended.
It went on reasonably well, didn’t sag or run at all even tho’ I put it on plenty thick in places. Cleaning up the gun was easy enough, actually most of it just fell off the gun parts after I put them in a tin soaking in acetone. Much nicer than poly urethane which is a bugger to clean.

   

It was touch dry after an hour and a half but still quite soft yesterday afternoon, this morning it was rock hard. It seems quite nice to sand and with the right gun and a bit of practice I’m sure you could put just one coat on a timber plug, sand, polish and buff it and you’d be away. It looks like it adheres to the timber very well too. We’ll see how it goes I guess.

Here's the fuse after a bit of sanding


   

[secant0give]

Still waiting for the new paint gun to arrive so in the mean time decided to do some work on the wing.
I was not sure whether the 1mm thick polyethylene sheet would take the compound curved shape needed to form the wing tip.
If could make the wing and the wing tip all in the one piece It would save quite a bit of work and make things quicker and smoother.

Not wanting to bugger up a set of, otherwise perfect cores, trying to find out one way or the other. I decided to make a test piece of just the wing tip and to incorporate a short section of aileron hinge. The episode with the fuse pug sticking must have made me a little more cautious than usual normally I’d just barge ahead and do the whole wing spars and all. But it could easily be waisted effort if something goes wrong. A test peice would be a quick way to restore some confidence with a good result, should everything go well.

There are a couple of other things I wanted to test out with the wing lay up, I’ve done Vac Bagged wings before but using a different layup. I wanted to try painting straight onto the waxed plastic without using PVA and I also wanted to try making a skin hinge for the ailerons which I’ve never done before. I decided that I’d spray two colours against the plastic then primer over that then put some 1 0z cloth over the primer. The other glass, to form the hinge and to go around the leading edge was cut at 45% to the weave. For that I used some 3oz cloth and held it to the core with a light mist of super 77 spray adhesive.

The 1 0z glass was wetted onto the painted plastic skins and once wet through blotted off with hand towel to remove the excess resin. I’d never tried this before and was quite surprised when the handtowel lifted easily leaving the damp glass cloth neatly behind. I wanted to remove as much excess resin as I could in order to keep the weight down . I then wet out the glass that I 77ed onto the core and blotted it in the same way. The core was then put inside the skins and into the bag and suked down.



The way I’ve done vac bagged wings in the past was to put brown paper against the plastic skins and wet all the glass onto the paper with a brush before sandwiching it onto the core and putting it into the bag. That method made nice strong wings, most of which I still have, but I always thought there was a fair bit of excess resin adding weight where it wasn’t needed.



Here’s some pics of the test piece firstly just with the skins on the core and put in the bag with no glass or resin to see if it would form to the shape of the wing tip which it does nicely

   
   

Here’s a pic of the skins and the core with cloth on, ready for resin.
I shopuld also mention that the skins are held together with sticky tape on the inside (sticky side out) at the leading edge of the skins

   

Here’s a pic of the test skins painted red and white, backed with primer, all the glass and resin on and in the bag, hopefully the paint will stay with the layup and not the skins !!

   

And here's the skins for the whole wing cut to size and shaped on the tips

   

[secant0give]

I took the test peice out of the mould this morning and everything went very well !!
The paint stayed on the wing, it released super easily from the plastic sheets, the surface finish is quite nice and the skin hinge works perfictly.

Here's a couple of pics of it just out of the bag, note the LE neads a bit of sanding

   

   

And here it is with the leading edge touched up and the hinge joint cut out.

   

One thing I will do differently next time is that I will tape the trailing edges of the plastic sheets together on the outside of the sheets, I was hoping that by taping on the inside at the leading edge it would form the leading edge without the need for sanding. But as it turns out it actually makes it more of a job and it leaves a tape mark on the wing skin which is also undesirable.

So the go for painting in the mould is the go useing lacquer on first then Lacquer primer and it’s sticks to the layup nicely !!

I tried the same method on the hatch mould with a hand layup, not Vac bagged and it worked great too !!
Just a shame about the finish on the mould, a legacy from finishing the plug in enamel. But certainly a usable part. So I’m quite happy with that !!

Here's a pic

   

[secant0give]

A little bit more done early this morning.
The Wing core’s edges have been rounded and faired down into the tip shape. Three cuts have been put into both cores to take 3 strips of 1.5mm plywood.
The plywood has been carefully shaped so it is dead flush with foam core. Elevators have been marked out so I can position the hinge material in the right place.

Here’s the core, its sitting on the off cuts, kept nicely supported while working on them

   

I sprayed the core lightly with No77 just around the leading edge and over the top of the plywood strips and ailerons to hold the extra glass firmly in place while I worked on it.
A strip of 4oz cloth about an inch wide, cut on the bias (45% to the weave) was rolled around the leading edge. The No 77 holds it there surprisingly well !! The same sized pieces of Uni-directional glass, as I used on the previous wing, were fixed directly over the plywood strips. No brown paper this time as the finished wing will have 1Oz cloth all over, just under the paint.

The inside of the plastic sheets were painted the usual Red white blue for the top of the wing and then yellow for the bottom. On the back of that Was sprayed a light coat of primer.
Then with the primer still just a touch tacky I laid the plastic sheets, paint side down on some on some 1OZ cloth and cut around the edges of the sheets. The slightly tacky primer held the light cloth against the plastic sheets nicely while I flipped them over and taped the trailing edges together. Tapeing the sheets together at the TE helps them stay nicely aligned. Then they were brushed with West Systems Epoxy and blotted them off with toilet paper to remove any excess resin.

The glass that was held to the core with No77 was also carefully wetted out with epoxy, blotted then whole lot was sandwiched between the plastic sheets, slipped into the Bag and sucked down.

The wing is supported underneath and above, by the off cuts from the foam cores. These are outside the bag, with some weights on top, to hold the whole thing nice and straight while the epoxy cures.

Here’s a pic of the wing in the bag

   

The cord around the edge of the bag is a wick to let the air out, it helps keep the Vacuum even across the bag. There is a small piece of cloth under the Vacuum fitting to make sure the air can get out easily and it acts as a bit of a filter for the poor old pump as well.

Here it is, as it sits for 10 hours or so waiting to cure.

   

[secant0give]

It looks good, I’m very happy with the result, I think it will make a great wing !!
It tipped the scales at 126 grams which is not bad considering the ailerons are already hinged and there’s no covering to go on
A little weight will come off the bare wing as the training edge needs to be trimmed and there’s a little sanding to be done on the LE and the ailerons need to be cut free.

Then the weight that needs to go on, is the dowels to hold it to the fuse and two 5g servos, their linkages, fairing and control horns. I think it will end up lighter than the prototype wing which weighs in at 180 grams all finished.

Here’s some pics of it, just out of the bag this morning.

   

   

[secant0give]

Finally a chance to test out the prototype with aileron servo and linkage fairings in place.

Managed to squeese a little more speed out of it with Doppler analysis of speed on the second last pass giving 225 Klicks. Every little bit counts

Here's a quick clip

http://www.youtube.com/watch?v=IoYZmOQpmLw%

[wingtipper]

JEEZ that thing goes hard mate . well done .

[secant0give]

Thanks 'tipper !!

It really needs a fairing to blend the top surface of the wing in with the shape of the fuse.
this fairing will simply be bonded to the top of the wing. It will be made of a thing moulded shell of epoxy and glass fibre.

The bottom surface of the fairing has to match the curve of the top of the wing so if it's already moulded with it's bottom edge in this shape it will be easy to trim and fit.

Here's the method I used to make the plug. I started with a block of wood all nicely cut square, then traced around the root of one of the foam wing cores to mark the curve on one side of it.
I carefully cut along the curve to produce the shape of the wing on the base for plug then I glued another piece on the front, where the leading edge would be. I had to do this because the bandsaw blade wouldn't take such a sharp corner.

The offcut was cut down in width and will be further carved and sanded to form the shape of the fairing.

here's a pic

   

It’s got the wing profile on the bottom so it can easily be assembeled with the new wing and the existing fusalage to be checked for size

   

Here it is with the new wing, the plug for the new fuse and the newly moulded hatch looking like it's all going to fit together well

   

   

Here is the plug glued together pretty much ready for painting and finishing.

   

[secant0give]

The ailerons hinges are moulded into the skin of the wing, although this sounds complicated it's actually very easy to do. As simple as laying a piece of 4 oz cloth that is cut on the bias (threads at 45 degrees) on the core across where the hinge line will go.
The ailerons are marked out on the finished wing, the ends are cut with a saw and the bottom skin is cut with an exacto knife using a straight edge. A cut is made parrellel to the hinge line to give the ailerons just enough clearance to deflect downwards and the foam core is picked out between the two cuts. then using a steel rule as a guide the hinge is creased, very easy to do and they work perfectly !!

Here's a pic
   

Here's the bottom showing the gap cut in the bottom skin and core

   

[secant0give]

I laid up another wing early this morning. I thought I might Change the colour scheme on this one to Red and yellow on top and black and white on the bottom
It should be reasonably easy to orientate both by the colours and by the design being different top and bottom. There’s nothing like having good orientation at over 200Ks 

Here’s the stencils I used for painting the inside of the top and bottom plastic sheets. I didn't tape them down I didn't want to risk upsetting the wax I put on the sheets so instead I used 8 and 10mm nuts to weight them down

   

   

This close up shows the glass cloth that forms the aileron hinge, It’s temporarily held in place with a light mist of No 77 spray adhesive (made by 3M) When it comes out of the vac-bag it will all be one piece.

   

Here is a photo of the unidirectional glass that will form the span wise reinforcement for the wing. It sits right on top of the 3 pieces of 1.5mm ply that are inserted into the foam core
You can also see the 4oz cloth cut on the bias folded around the LE. It’s very much easier to fold around an edge if it’s cut on the bias. Both are temporarily held on place with good old No 77. When it’s wet out the epoxy just seems to absorb the No77 and you’d never know it was there. Remarkable stuff!!

Dyna 151.JPG Size: 78.43 KB  Downloads: 93

   

I’ve got my Vac pump set up so it’s only pulling about ½ an atmosphere I don’t want to go too low for two reasons firstly I don’t want to overly compress the foam core and secondly some epoxies can release volatiles if the pressure goes too low and this stops them from curing properly. Some epoxies handle vacuum quite well too. But better safe than sorry 

   

Here’s the the wing in the bag top side up

   

And here’s the bottom, the trailing edge gets about 10mm trimmed off it so the black strips will go all the way when it’s finished.

   

[gbanger]

Very nice work Jason, I really like the colour scheme!