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Deskpilot

A short story, then a long journey

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Hi Riley, not a lot to report actually. See my Rotax 503 rebuild thread. Pistons ready to be refitted but it'll have to wait until after Christmas. My wife had a fall yesterday and is hospitalized for about a week. A quiet Christmas for me except for 2 visits per day. Just put the pork roast on, sausage rolls just come out of the oven, my single mate across the road has the beer in.............we'll be right don't you worry. Have a nice celebration old friend and remember, no drinking and flying. Cheers.

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Hi Riley, not a lot to report actually. See my Rotax 503 rebuild thread. Pistons ready to be refitted but it'll have to wait until after Christmas. My wife had a fall yesterday and is hospitalized for about a week. A quiet Christmas for me except for 2 visits per day. Just put the pork roast on, sausage rolls just come out of the oven, my single mate across the road has the beer in.............we'll be right don't you worry. Have a nice celebration old friend and remember, no drinking and flying. Cheers.

 

Pity about your better half spending the holiday period in hospital but then, at least she'll be out in a week or so. There are plenty of unfortunates in hospital who won't ever get home for another Xmas. No worries about drinking & flying. I'll have my usual daily libation at 'beer o'clock' at home but flying is not on the menu as the local country shire pulls a 'paddock & machinery ban' every year on Xmas day, boxing day and new year's day to give the local volunteer bushfire boys some small hopes of an un-interupted time with family. Obviously it doesn't always work. Enjoy your pork roast, sausage rolls and the mate's beer. cheers

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Never mind Doug, at least it's making some progress. Just think, when it's finished, you may have to change your forum name.

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Did 45 mins in my faithful old T300 with my wife showing the first signs of wanting to "feel the controls". The air was still and warm and we spent the time at 1,000ft doing gentle figure 8's. A new friend on the field took his silver doped Avid Flyer out and we were horrified at the way the colour blended in to the country side below swallowing him quickly into the background clutter. We found it easier track his location by the shadow profile on the earth than the physical aircraft. We chose yellow and red for the coverings deliberately to avoid this. This aside the flying was great.

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Almost a matching pair as a loan car sits in my garage. Smashed my Falcon into a wall (wide sandals covered throttle and brake simultaneously). I reckon the number plate should be on another make of car.1208095513_Almostamatchingpair.thumb.JPG.f92a0202fb2084a6cf19f18cfd32979a.JPG

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New update. Putting aside my frustration with the 503, I took a wing structure off the back wall of my garage with a view to furthering my plan to create a folding wing assembly.  Didn't get too far but did discover it's a T83 with the 29ft wing-span and not the 25ft T84. With a serial number of 1016 inside the wing covers, that makes it the 16th build of the 46 completed.

 

Useful bit of knowledge but, anyone have an image, or can draw a sketch as to where the tension wires go. I've worked most out but there's one on the rear spar going in towards the fuselage similar to the forward one(external to the skin) but this lug points up as if to go to a king post!!!!  the lug may have been rotated during the fold process so I'm not sure. I thought it might go diagonally across to the wing to the opposite spar mounting bolt but the wire seems too short for that(only by a centimeter)

 

TIA.

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Latest update and a question.

Yesterday I put my plane into flying configuration (level) and roughly calibrated my fuel sight tube.

 

 

DSCF5504.thumb.JPG.6a7a1741b1c9a84376cd55d2d8a17c15.JPG Decanting the fuel (petrol only) turned out harder than I thought and I lost a few liters to the pergola floor. I won't be lighting a candle out there for a few days.

 

My next job is to refit a control stick/column. Due to changes to the seat, I need to put in about a 2-2.5 inch offset to allow me to pull it fully rearwards without impinging on my stomach. The material to be bent is 22.5 diam x 1.5 wall thickness.

Can anyone tell me how to bend it without splits? A local plumber says it can't be done without heat.

FWIW, I'm redesigning my throttle control which will sit atop the control stick. My first effort had a weak spot and cracked when I tightened the mounting clamp. Also, I want to incorporate a PTT button.

 

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Later this week I will be fitting the engine to the air-frame and perhaps testing it with a prop fitted.

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Later this week I will be fitting the engine to the air-frame and perhaps testing it with a prop fitted.

 

Nothing like a bit of engine noise to get the motivation going :plane:

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Hi Doug, I would get the joy stick fabricated by a good tig welder in 4140 tube

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Ah, now it's looking more like a hairy plane :plane:

 

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Only problem is, that muffler never came off the plane. The rear location bracket is way out of position. To make it fit I'll have to drill out the rivet on the boom and move the mounting bracket to fit the muffler.

Still trying to source a 1 mtr square piece of poly-carbonate sheet at 1.5 mm thick. Local price has been quoted at $130. Bex tells me it's $13 in china, but how to transport it. I think I'll be going with the 1 mm

stuff at about $40.

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Love the way it balances on one wheel like that, be great for wheel rut landings in rough paddocks, just be sure if you move the muffler or the bracket that there isn't a doubler inside the boom, there is a bit of weight and vibration in the muffler and if you move it there may not be the thickness to repop

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OK, time for a long over due update.

 

Muffler fitment problem still unresolved. No doubler in the tube for the present setup so moving the mount will be no problem if I have to. Still can't figure out how there could possibly be a 4.5 cm discrepancy in the mount holes..

 

Control stick and top mounted, roller throttle, still unresolved. My stick broke after using too much force to get the throttle to work. Nice idea, but not enough leverage. I also broke the 3D printed throttle body. Wrong material used, I guess. I wanted something different and less 'snaggy' things in the cockpit but tried and tested wins out this time I think.

 

So, what to do next.

 

I decided to have another go at covering my fin and skeg only this time, I thought I'd go for a much cheaper material than the Lycra I initially used. I also decided to have some form of firm backing on which to press as I force the resin into the weave. This led to purchasing a sheet of insulation foam from Bunnings and cutting it to fit inside the framework. First thing I didn't like was that the board is 30 mm thick and the tube diameter is 20 mm. I don't have a hot wire knife as yet so re-shaping it was going to be a problem.

 

1839323714_002FittedwithBunningsfoam.thumb.JPG.9f3634a92d8991e35299c15145860e5f.JPG This weighed in at 5.78 lbs (2.6 kg's)and I thought it might be too heavy so I took a tip from a couple of home builders in the states who have used spray foam to complete their roof insulation (www.youtube.com/channel/UChhBsM9K_Bc9a_YTK7UUlnQ) Anyway, this is how it is going.

 

Spray foam expands about X3 and needs to be confined so I purchased some white board and a load of clamps. Now, in order that the foam didn't stick to the board, I first wrapped the frame in Clingfilm and then clamped on the front and back boards, the front one having access holes. I burnt matching holes through the film with a pointed soldering iron.

 

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Now comes the fun part. Just how much foam does one squirt inside. Oh well, trial and error time. After all said and done , nothing ventured, nothing gained. I thought it was going well after spraying in the evening, but next morning..........

 

08OMG-overfill.thumb.JPG.a7d11e895830938d24f9d001c235a3cc.JPG Over done it me thinks. Time to clean it up a bit. Ah, just remembered, foam needs moisture to fill out and set so I squirted a small amount of water mist into each aperture before filling with foam.

 

The film worked well and the boards came off easily. However, the coverage didn't go too well but will be usable I think. So press on.

 

DSCF5652.thumb.JPG.084e7e1e184ba993cfe94e933e6b6f81.JPG This final image is after I had reworked the foam some what. The main problem was that the boards, clamps and stiffening batons clamped across the fin fill, did not prevent the boards bowing outwards and thus ending up thicker than the tube by about 4 mm both sides. By taking to it with a fine cut saw, a small Surform rasp and glass paper, I took off all the high points. Filled some voids and then taped over the tubes so that the resin doesn't stick to the tubes. You never know if this lot has to be removed at some future time. BTW, Instead of c/film on the fin, I just sprayed my boards with cooking oil. Worked well and didn't effect the foam at all.

 

Now I'm going to keep you all hanging as I choose a cheaper material (Lycra is about $35 per meter), and work out a better way to mix resin and harder. I've decided that I won't be repeating this process on the other flying surfaces (filling with foam, that is) but will try another idea and a lighter hand to boot.

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Check to see that the engine is mounted properly. It is offset in one direction to allow for the effect of the prop wash. If you have mounted the engine with the offset in the wrong sense it will mean that the muffler mount is out of whack.

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OK, engine problem solved. I mounted my mounting plate upside down and put the trust line in the opposite direction Methusala, check the offsets on the mounting holes (see my rough lines)

 

1930068561_mountoffsets.thumb.jpg.62cb0958caf3410d4f71764e28cf825f.jpg

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Rotating the mount plate is proving to be harder than I thought. Being on my own, lifting the engine off the plane was a no-go so, with the aid of a couple of cargo straps, I just raised it enough to get at the nuts. When I lowered it back onto the cross members, I found that they were also out of wack so I'm now figuring out where I went wrong with those. You'd think that they would be identical but not so.

 

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OK, so the planes's back in the garage as I was getting frustrated seeing it sitting under the pergola and not getting worked on. Therefore I now have a couple of questions for you and a call for help.

Q1. Does anyone know what profile the Thruster wing is or is based on?

Q2. Have any of you experience with Gurney flaps and would they improve the flight characteristics of a Thruster? 

 

Plea for help. Can anyone make me control stick as per my plan below. I can't find anyone local who can bend thin walled alloy tube without kinking or splitting it. I'm now out of tube. Full remuneration for time and effort provided it doesn't break the bank, so to say.

 

Control stick.jpg

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Deskpilot, you should be able to bend the alloy tube by plugging one end with a custom-made wooden plug, filling it with fine, free-running sand, then plugging the other end with a wooden plug, until there's no air space left inside the tube.

Then, place it in a bender, ensuring the tubing is a good neat fit in the former. There are different-sized formers and benders for thick-walled and thin walled tubing. It may be necessary to wrap some thin material around the tubing to ensure a tight fit.

It's important to ensure that the former is dead smooth in its surface finish, any roughness in the surface finish of the former will assist in creating buckles/wrinkles in the tubing.

Hot forming is of little benefit with most aluminium, cold forming will get similar results to hot forming, unless the aluminium has been heat treated. Other metals such as copper and iron respond better to hot forming.

A 3" radius is a very tight radius for 22.5mm aluminium tubing, you will most likely be unable to prevent some wrinkling at that radius.

Is the 22.5mm measurement, the actual O.D. of the tubing, not a "nominal" O.D.?

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Thanks for your reply onetrack. I know how to bend using sand as a mandrel but it doesn't always work. It's harder than one thinks to get the sand packed tight enough. I don't have access to a bender and have resorted to plumbers in my area. Most just say it can't be done without splitting the tube (being Aluminium) As for the diameter, might be out of round 22mm, if that's a standard size. 

 

There is one other option. A nicely welded version and I'm not a welder.

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Desk pilot, you could go 25od by 3mm wall, I think it would bend ok then press the bottom part  (or all of it)  down to 22mm if needed to fit the brackets. You would have a cool oval shaped strong joystick. 

Edited by Thruster88
Added more info

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