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Old Aug 26, 2012, 03:26 AM
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Malanda, QLD Australia
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Spent a couple of pleasant hours today finishing the radiator. It was just eye-balled from a selection of photos, no precise dimensions. There's some variation in the position and even the number of pipes and hoses- I guess some had a catch-tank for coolant expansion and some presumably just lost it overboard.

In the past I've tended to use balsa for details like this, with odd bits of wire and metal tube. Styrene is nice to work with and the results are good but it's rather heavy! Next time I'll be using thinner plastic.

The large tube represents the cool water return to the engine and the aileron servo wires will go through it (hopefully they will fit!) into the top of the cowling. The smaller pipe with the 90-degree joint is the hot water feed to the top of the radiator.

Both these pipes have rubber sections, I'm thinking either heat-shrink tube or paper masking tape to represent the rubber. Very satisfying this, even though it doesn't make for very quick progress!
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Old Oct 03, 2012, 06:45 AM
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Malanda, QLD Australia
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Here is the radiator mounted on its little shelf. The prototypical arrangement is needed for scale effect and it's also quite a good way to mount the radiator securely. The aileron servo wires will just about fit through the tube- using common + and - wires was an option but I think I got away with it this time...

Next, the small door/air outlet thing on the right side of the cowl. I built it up from plastic. There should be a pair of catches or hinges on the front edge- which I may get around to making...

Last, the spinner part-way through being glassed. Nothing new here but I'll briefly describe how it's made.The backplate is a disc of 1.5mm ply. The spinner base is a disc of 0.4mm ply, to which I glued a piece of foam. A 3mm bolt holds the two ply discs together and the whole thing is mounted in a suitable drill (a Dremel held horizontally in a pillar-drill attachment in my case) to be turned to shape. My turning tools are pieces of foam with various grades of sandpaper glued to them. The spinner is held to the backplate with a pair of small self-tappers which also helped to keep everything together while turning.

The backplate is then separated and the foam spinner covered with glass cloth. I used some small off-cuts I had lying around so I'm not sure exactly.the weight of the cloth. Probably a couple of layers of 0.7oz and a layer of 1.4oz. It will be tough enough since I intend to leave as much foam as possible in there.
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Old Oct 03, 2012, 07:59 AM
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Norfolk, England
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Shouldn't have as much trouble balancing that as Steve had with his Morane spinner.
Details are looking good mate.

Pete
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Old Oct 03, 2012, 07:11 PM
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Malanda, QLD Australia
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The spinner should be OK since it weighs very little. It doesn't vibrate when mounted in the drill but you never know! Slight hold-up while I get some rattle-can primer/surfacer, not so keen on epoxy/microballoons for these small spinners as I never seem to get them round again after the filler is applied...
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Old Oct 03, 2012, 08:35 PM
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Great looking build mate, very neat work.

Cheers
Craig
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Old Oct 04, 2012, 04:35 AM
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Malanda, QLD Australia
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Thanks for the nice comments about the details. The WACO isn't over burdened with external bits and pieces but there's enough to keep it interesting.

I've attached a couple of photos of the spinner- at the moment the prop-shaft is just jammed into the foam in the nose of the spinner. I'll have to cut 5-6mm off the shaft.

I miscalculated with the position of the spinner retaining screws. They're too close to the centre so the motor will have to be removed to fit the spinner. No problem as access to the motor mount is easy.

Tomorrow I'll cut the end off the shaft, bolt it all together and give it a run. No point going forward if it vibrates or runs out badly.

There are a very few WACO 9 videos on YouTube but those that are available are interesting. I hope mine climbs a bit better than this!!!
That's what you get with 90hp hauling nearly a ton of biplane I suppose.

Waco 9 at NWC Reunion (0 min 22 sec)
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Old Oct 04, 2012, 10:04 AM
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Australia, WA, Ellenbrook
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oh, i don't know mate, that takeoff really was beautiful, i just love watching those old aircraft in action where the pilot has to feel for every once of lift available to get the poor things flying. so much better than modern planes with enough power to tear themselves off of the ground!

Cheers
Craig
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Old Oct 04, 2012, 06:19 PM
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Malanda, QLD Australia
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It was a nice take-off for sure, I just thought the climb rate was a bit nerve-wracking! Having just watched another 9 taking off I think the pilot must have been holding it down for some reason though.
Should be interesting to try replicating the long ground run with the model...

Cheers
Rich
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Old Oct 05, 2012, 03:53 AM
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Malanda, QLD Australia
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I bolted up the spinner for a test-run. No problems- I wasn't expecting anything drastic but the screws that retain the spinner are 12mm from the centre and they could easily cause some vibration.

Next up are the wheel covers. I can make them from balsa but I may turn a master and try vac-forming them since 4 identical parts are needed. The plane I've chosen to replicate had exposed wire wheels but at this stage, after 9 months (sorry Pete!), I'm taking the easiest way out!
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Old Oct 05, 2012, 11:45 PM
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Malanda, QLD Australia
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The wheel covers aren't going so well so I had a go at the cowl humps instead.
It would have made sense to build them in when the cowl was being carved but at the time I was entertaining ideas of making them from sheet plastic.

Very simple, bits of 6.5m balsa sanded to fit on the cowl and faired in with lightweight filler.
I could have waited to post a photo of the finished humps but there's nothing else to do while I wait 20 minutes between applications of filler!
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Old Oct 12, 2012, 02:38 AM
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Malanda, QLD Australia
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Painting is underway and the wheels are more or less done. They are covered in tissue, doped until I got sick of it (about 5 coats I would think) and painted with Humbrol MetalCote 'polished aluminium'. Pretty good stuff this, it's fairly tough and can be buffed a bit to bring out the shine.

The idea was to have some contrast between the aluminium wheels and the silver doped fabric on the airframe. I think it worked out OK. The rest of the airframe is painted silver but another coat is needed on the top wing. It could have used a couple more coats of dope to get a really smooth surface but I was starting to think about the weight.
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Old Oct 13, 2012, 09:53 PM
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Malanda, QLD Australia
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Here's the fuselage painted. There's just a bit of brush-painting to do on the struts.
The wings are getting yet another coat of silver, hopefully the last!
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Old Oct 18, 2012, 07:30 PM
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Malanda, QLD Australia
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A photo and some stats- I love stats even if they're fairly useless!

First the photo. The radiator is glued in place because it's trapped on its mounting by the top wing. The big pipe is wrapped with paper masking tape for the rubber section, the small one is a piece of soft brass tube with pieces of black heat-shrink tube to represent the rubber hoses. It's heavy but I tried plastic tube and it just didn't work out.The hose clamps are 18A fuse wire. The brass paint on the radiator seems a bit bright but it matches the brass pipe very closely so it's got to be right, hasn't it!

Everything is painted and the servos are all in the model so I had a weigh-in to prepare me for any bad news at the ready-to-fly stage...

The painted airframe with servos but no other equipment weighs 323g.

If I add the motor, Rx, ESC and battery the weight comes to 558g (19.7oz). Allowing for some extra details, control cables, and maybe a bit of nose-weight for balance I hope to bring it in under 600g.
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Old Oct 18, 2012, 11:52 PM
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Looks great bud, nice weight too. should float along nicely

Cheers
Craig
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Old Oct 19, 2012, 04:23 AM
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Malanda, QLD Australia
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Hi Craig, thanks! I'm trying to get a balance between detail and a nice paint job on one hand, and weight on the other.

Not much left to do- the engine is just about done but it needs painting, and I haven't started on the exhausts yet. The windscreen on the front cockpit must be fitted before the top wing goes on so I'm working on that now.

Looking at photos it seems the Waco 9 windscreens were simply curved pieces of Perspex attached with three brackets. Seems like the easiest way to attach the screens and make it look scale is to do the same. I've made up some brackets from brass shim and glued them to a piece of clear plastic with canopy glue. That seems to be almost strong enough but I'll be drilling them and gluing something, maybe cut-off pins, through to make them stronger still.

So far I've only done a test piece. It's taking time but the results are worth it. Nothing looks less convincing than a windscreen with no visible means of support!
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