Things I found in storage - Trainer Foam conversion and Build

[SteveOBHave]

Yeah - that is pretty much the way I approach these things - except for the wings the plane is just boxes and cylinders. Spinner is just a warped cone and the wings are an extruded spline (airfoil shaped line). It's places like the intakes and around the tail where the geometry can get messy and you end up having to finesse it vertex by vertex. I'm thinking that bigger wheels would go down nicely since I'll likely be flying it off grass.

 

[colorex]

Hmm - sounds like 3DS Max is a bit different though. I'll try it someday.

 

[SteveOBHave]

I think only in as much as it can be a very organic process - I tend to do everything by eye rather than operate around specific dimensions. I use a reference image sometimes but more often it's just going by the feel of the thing.

 

[colorex]

I think only in as much as it can be a very organic process - I tend to do everything by eye rather than operate around specific dimensions. I use a reference image sometimes but more often it's just going by the feel of the thing.

I tend to use measurements enough that I can replicate the design from zero...

 

[SteveOBHave]

Not a bad idea that. I have been treating the process as a 'get ideas on paper' exercise. I have a few tucked away for when my ability will allow for the builds. They're a little more ambitious than these two builds.

In the interim it appears that this wee bundle of joy found its way into my order from HK... No idea how that happened

 

[Bollie]

Thats so cool, first time I've read this whole thread, my envy levels are high to be able to have access to a workshop like that.
The AXN's are great, get a 30A ESC in there and throw a 6x5 prop and they are even better. Another mod I just did to mine was to extend the ailerons by 10mm, gives the plane a better roll rate when doing combat.

Thanks for the Thread I really enjoyed the read.

 

[SteveOBHave]

Cheers Bollie. Heading down to the hangers this weekend so hopefully I can get some serious time in on these. I've got vacuum bagging gear on order, but still need to buy the glass and resin. I also still need to build the curing oven because it's a bit cold at the moment for ambient temperature glassing.

 

[SteveOBHave]

This weekend was a very productive one, well productive from my perspective. First order of the weekend was to sort out the vertical and horizontal control surfaces. The process for this is much the same as for the wings. 2 end templates and hot wireing.

Endplates

Using scrap from the fuselage and wing foam blocks.

All cut out - I decided that I preferred a nice transition between the vertical stab and the tail boom so I ended up cutting off part of the leading edge and gluing a bit extra on - I think it looks a bit smoother. Horizontals were waaaay too big1

I glued the spinner on the front to get an idea of how to approach the finessing of the nose and to also see if I had the lines of the nose right - Not too bad I think? Kinda got the racey profile I was going for. It was beer o'clock by this stage so she got put away and I was going to pick it up again the next morning.

 

[SteveOBHave]

Next Morning!

We got up and flew the AXN Floater and the trainer that we have (the little Cessna in the background of the first photo) - excellent wee plane the AXN - absolute joy to fly and certainly something to fill in the waiting time with. I'm looking forward to summer to see if I can get it to thermal.

Finessed the horizontal surfaces - added a nice transition and a bit of a sweep, and also put a nice radius on the wingtips.

Ended up doing a bit of work on the nose as well - I'm not sure if it's finished yet. I'm going for a bit of a scale look without adhering to a classic fuselage profile.

The next trick with the plane is really going to be filling and then getting it prepped for glassing so I think I've done as much as I can till some more supplies arrive. I think I have two options, one is to do the fuselage in a fiberglass sock and then attach the vertical after the event. I'm thinking that I'll use the lost foam technique. The main downside of this is that I won't really have any way of re-creating the fuselage again if either I or someone else wants one. C'est la vie. The other way is to possibly vacuum bag after the two are glued and the transitions filled. I guess it going to be a case of researching the options...

Putting the plane to the side I decided that it was time to get my hands dirty with some glassing. I need some pretty sturdy main landing gear so I set to making a mold for what I hope will be a nice bow style.

I grabbed some of my fathers glass scraps and some epoxy that he had spare - the day was really cold (about 5C or 41F) so it's not ideal conditions for glassing without a heater, oven or a warm room. Still I wanted to have a go. Going through a bunch of stuff he had sitting in storage I came across some interesting little bits and pieces.

Pulse jet anyone?

Here's the completed mold, peel ply and glass all laid out ready to go

Glass all wetted out - we had to keep a heat gun at the ready to keep the epoxy wetting through - it really wasn't ideal conditions. Two layers of 90 degree opposing grain glass then 9 layers of uni directional followed by another two of 90 degree opposing.

Laid into the mold...

...and compressed. Till next weekend on that one

Alltogether a very productive weekend It's an extremely cool process and I'm really looking forward to getting this beast into the air!

 

[SteveOBHave]

Some of you guys were curious about the planes in the hanger so I've taken a couple of photos and I'll endeavour to give some explanations as well.

This is my motor glider in progress... there is an RC Cessna trainer behind and to the left and one of my top secret designs tucked away behind a sheet of foam board. The other plane is just a little something that my Father is almost done building...

Ok all joking aside.

First up - The playground:

First plane: VariEze

The VariEze is a little hotrod of a plane built entirely out of composites, so bluefoam, fiberglass and not much else. It's designed by one of the greats of aeronautical engineering, Mr Burt Rutan who is probably better know for Spaceship One and also designing and build the Voyager that flew around the world non stop with Gena Yeager and Dick Rutan as crew. It's a pretty impressive aircraft in it's own right and not only because of it's looks. It has a 100HP engine in it and will cruise at about 165mph with a top speed of around 200mph. It has a range of around 850 miles which was pretty impressive for the day, especially when you compare it to something like a Cessna 152 which has only 440 miles range and a max speed of 126mph, but had a much more powerful engine.

The VariEze had some drawbacks in the design, not the least being that it lands 'hot' or pretty quickly. As a homebuilt and having different pilots with different skill levels, Rutan wanted to build a plane that was both a performer and safe. The VariEze also has no storage space and can only carry two small to medium sized people, anyone of around 80kgs and over and it's essentially a single seater. It will carry 700pounds empty weight, so will 27 gallons of gas in it and two medium sized people, you're right on the limit which is not ideal in a small plane.

So - looks fantastic in the air and, even almost 40 years later is still an impressive plane.

The next progression from the VariEze for Burt Rutan was the LongEze. Larger than the Vari, it was built to address all the shortfalls of it's smaller sibling. It is a much less touchy plane to fly and although slightly slower (cruise speed of 144mph and top speed of 185mph) it has a vastly improved range of 2010 Miles (compared to the 850 Miles of the Vari). It could conceivably fly from one side of Australia to the other on one tank, or from Australia to New Zealand... I wouldn't consider it because it would mean sitting in the thing for 10hrs and I can't hold on for that long...

LongEze - it's a matter of months away from it's maiden

And you thought wiring an FPV plane was bad...

Obligitory brrrrrm noises here...

The other fun things?

One Rotoway Executive Chopper

Other things that you can't see
One Quickie:

One Solitaire Motor Glider

Both are also Rutan planes... you might see a trend here...

The others are an RV4, a Glassair and a Glastar but these are owned by other people so I can't give you more than cheeky glimpses at them!

I saved the best for last though...

This is the lawnmower

It's currently grounded due to starter issues but even if it would start it doesn't having any blades to mow anything with. It's range is classified as is it's top speed. I'll leave you to gaze in wonderment at its sleek lines and powerful stance... looks fast just sitting there doesn't it...

 

[colorex]

I like this thread

 

[Carbon]

I like this thread

I have to agree with you now that a pulse jet is involved...

 

[Tritium]

SteveOBhave you have every Rutan plane I ever wanted and a pulsejet too. WAY TOO COOL .

Thurmond

 

[SteveOBHave]

Haha - unfortunately composites and pulse jets don't mix Way too much heat from the pulse jet.

 

[Tritium]

Haha - unfortunately composites and pulse jets don't mix Way too much heat from the pulse jet.

I knew that but I have wanted a pulsejet since they used to be offered by Johnson Smith Co. on the back of my comic books for $9.99. (45 years or so ago)

Thurmond

 

[SteveOBHave]

Woohoo - bagging stuff arrived, next I need 18g glass and some epoxy, a porcupine roller and a fairly large insulated box to use as an oven! And maybe a couple of fan heaters...

Once I get this process down I've got a few plans that I want to get underway, not the least a 2m flying wing. I get far too much jealousy from the Zypher 2 bunch - they look like a huge amount of fun!

 

[colorex]

I have no idea what that is for.

 

[SteveOBHave]

Heh, I will try to explain.

Normal technique for fibreglass skinning of a foam core is to finish the foam as cleanly as possible, then layout the glass over the foam core and wet it with epoxy resin. This creates a hard shell that you would normally use a filler and copious amounts of sanding to create a smooth finish to finally paint.

The drawback of this technique is twofold - first it's a long and boring process of sanding a substance that is very bad to inhale and damn hard. Second it tends to be heavier than needed with no real added strength advantage. Not really the thing that you want with something as weight sensitive as RC planes.

This is the finish you would normally have to work with - of course the finess of the glass wave changes the roughness of the finish. To get a smooth finish all these ridges need to be filled.

Vacuum bagging does exactly what the name suggests. You still do a wet layout with glass and resin but once this is done you sandwich the wetted core in a perforated but non porus fabric, then a 'wicking' fabric or tissue and then finally in a bag. The bag is sealed and then a vacuum pump attached and this evacuates the majority of the air from the inside. External air pressure being equal it presses down evenly on all sides of the glassed core and because it is surrounded by a nice smooth fabric that has small holes in it, the excess resin bleeds out and is absorbed by the wicking fabric. After the epoxy has cured it is removed from the bag and the smooth fabric is peeled off the glass leaving a very smooth surface which required little or no finishing before painting. It weighs considerably less than the standard glassed part and is in some cases stronger.

Picture of a wing in a bag:

Something close to the finish I'd aspire to:

I hope this makes some sense?

 

[lobstermash]

That's beautiful!

 

[SteveOBHave]

It's certainly a good example of the process - That is for a DLG or a discus launch glider - something I'd like to get into one day as there is less waiting for batteries to charge and I really enjoy the challenge of keeping a plane in the air for as long as possible with the engine off. Of course the real advantage is that you have minimal work when it comes to painting and having a beautiful plane is half the joy for me. (in my mind at least )