Midge Aerobatic Slope Soarer

[Peter Garsden]

Now came the time to drill the holes for the tailplane pivot "Aargh...". Has to be perpendicular, square and tight, otherwise it will wobble and/or fall off mid flight.

I used the pillar drill again, but had to prop up the tail which narrows towards the rear to get it square with some scrap balsa. I also worked up with drills from 2mm, 3mm, then finally 4mm - the o/d of the brass tube which was going to support the pivot.

I had, stupidly, glued the tube into the pivot thinking I could prize apart the sides and squeeze it in, but there is absolutely no chance of doing so. I thus got the superglued tube out of the plastic pivot by pushing it with a round permagrit file - they are so good and useful. I lined up the pivot on the inside and pushed through the brass tube from the outside - worked a treat.

The question is, do I need to use some thin slivers of plywood on the inside because the pivot is very tight - not sure. Maybe some pieces of 1/64" ply?

Obviously the brass tube is presently too long and will have to be dremmeled/filed down

[Peter Garsden]

Colin suggests some hooks and rubber bands to hold the wings together from the inside, so I bent up some old bicycle spoke control rods using my hand wire bender with 20mm length to fit into the wing bearing in mind they are only going into hard balsa and need some purchase

[Peter Garsden]

Here is the 80 gram reinforcement for the tailplane tubes - belt and braces in case of a heavy tail landing.

And some 3/16" square rails for the servo tray to assist adhesion - will use epoxy with milled fibreglass mixed in for strength

[Mark Kettle 1]

Watching with interest Peter.

[Peter Garsden]

Posted by Mark Kettle 1 on 03/11/2017 08:34:52:

Watching with interest Peter.

You and 800 others apparently Mark?

[Peter Garsden]

A further comment worthy of warning - I fixed in the brass tube to retain the carbon rear pegs to support the wing, then found that the drilled hole in the wing was 1mm out, and the peg didn't fit. I shouldn't have relied on the marks on the fuselage and lined it up properly first, or used the Depron template which Colin helpfully provides.

So, I had to open up the hole sideways to make the hole too big, cover both the wing root and fuselage facing with masking tape to stop wing gluing to the fuselage, cover the peg where it inserts into the wing joining tube with Vaseline, mix some epoxy and microballoons, inject the glue into the hole in the wing with handy throw away NHS syringes, then slide the wing into position on the main joining tube and leave to set. Thankfully it worked, but it was a pain. I somehow lost the picture of the pillar drill I use - crane your neck sideways as I can't rotate it so it works.

[Peter Garsden]

Work today on the tailplane pivot and the rudder post. To line up the tailplane pivot, I marked the position of the support rod to drill a hole.

I used a very handy dremmel tool to open out the hole which I drilled and make the curved hole both sides.

[Peter Garsden]

You can see that I decided to line the hole with two squares of 1/32 ply to hold the pivot bearings, held in position with epoxy mixed with milled fibreglass and filed down first.

Once dremmelled the hole was rough and had to be smoothed with some small files

[Peter Garsden]

Next was the elevator pushrod. I used some carbon rod I had left over which had a 4mm hole in the middle. I used some inner Sullivan pushrod tubing to house a threaded studded rod to take the clevis, and glued with epoxy and microballoons the smaller tube into the larger diameter carbon tube. I also used the Sullivan attachments. I soldered the tail pivot clevis as recommended to stop it coming unscrewed with a view to giving the servo end some adjustment.

I decided to create a rudder post with 2 pieces of 3/16 glued together to make 3/8 thickness which I figure witll be enough to take the mylar hinging, which surprisingly is supplied. I used gorilla glue to attach it so as to fill any gaps. You can see in the picture how it oozes out and has to be filled back when dry.

[Peter Garsden]

Colin, helpfully, provides a piece of plastic card to attach the battery and radio to, which fits neatly, in a vertical plane down the inside of the nose, and is trapped by the front wing joining dowel tube.

[Peter Garsden]

There is not much room inside that fuselage. The switch was meant to go at the front of the servo tray but after I installed the tray and the glue dried, I realised there wasn't enough depth for my switch, so I had to fettle an extra piece of 1/16" ply to attach it at the front, being careful to miss the holes where the servo leads come in and the hooks for the rubber band wing holders!

[Peter Garsden]

Then the mini Dubro rudder snake with metal inner had to be installed. What a fiddle trying to get epoxy mixed with milled fibreglass down the side of the fuselage, whilst trying to miss, and failing, the elevator pushrod, then trying to wipe off the extra glue with a Meths soaked dowel!

[Peter Garsden]

There is a light at the end of the tunnel, and I can see a glimmer in the distance. Time to start the covering. Although this is fibreglass and resin, Solarfilm and Oracover adheres well to it.

I decided to do the underneath of the flying surfaces white with red stripes, and the top and fuselage with some left over carbon finish Oracover.. In fact everything is left over covering, the plane is so small.

I have made some carboard templates for some curved trim in fluorescent orange and orange for the edges of the top of the wing and tailplane

Having done a union jack design on my JW and had it peel off, I put some primol on the white to help the red adhere properly. It creates a matt surface and dries almost immediately.

[Chris Barlow]

I like the idea of using the milled gf with epoxy Peter. Will be using that on a future project...

Not long to go now then?

[Peter Garsden]

No indeed so Chris, Milled fibreglass works a treat - better to buy a large bag of it than from model suppliers - a lot cheaper - careful you don't get it on your skin because it itches.

I was reading on the Deluxe Materials website that for glue to work you have to match the viscosity of both materials, and with fibreglass or plastic epoxy doesn't work because it is too flexible and breaks the join.

Am hoping to get the Midge ready for tomorrow morning up the Cloud. That's the plan. Don't know if I will make it - hope so.

[Chris Barlow]

I'll be there about 10am for the Phoenix 2000 maiden so hope to see you up there.

[Peter Garsden]

I put a few hours in yesterday to try and get the Midge ready for a maiden up the Cloud today - the rudder servo is twitching so I have disconnected it. I can fly without a rudder methinks. Must order another one. It was taken out of another model so no wonder.

I have finished it in Oracover carbon film which looks really smart - same as the Jart, but with different trim flashes

The Rudder connected well

I did my usual bury the nose in sand, melt the lead, and produce a plug trick

[Mark Kettle 1]

Nice Peter have a fun flying it.

[Peter Garsden]

Maidened on Sunday in a 20mph wind up Bosley Cloud. How did it fly then?

Well the C of G was too far back - so I added a penny weight to the nose, and it flew better, but the lift was a bit iffy as it kept sweeping round to the North. Thus it dropped out of the sky alarmingly and I had to land it.

The flapperons work well to slow it down

Also my rudder was disconnected because the Tower Pro servo twitches and is faulty, so I am sending it back for a replacement.

It reminds me of the D40 and that is fast - rolls loops, and does all the aerobatics, but I need to test it properly with the correct C of G. You need to fly it fast and it flies VERY fast - not a beginners model at all.

So the verdict is very exciting and fast, and good fun, but verdict deferred until I have got it sorted.

I ran out of Radiator insulation for a bag, so I borrowed a wing bag from the A4 Skyhawk. I managed to lose all the carbon rods and tail joiner rods out of the bag on the way up - FORTUNATELY, I managed to find them about 300 yards back by retracing my steps ("would you Adam and Eve it?" - it was a miracle as they are black carbon rods and 1 x 2mm piece of wire - the Gods were with me.

Keith managed to lose his bright red Fusion way back in the trees. We couldn't find it despite 3 hours of searching but he found it 10 yards from the trees today after another 1 and half hours - Total 4 and half hours searching! Result!

Hopefully video and pictures when I can fly it next with my new Action Cam.

Go online to www.slope-dudes.co.uk and order one NOW.

[Peter Garsden]

I took this picture of the model from underneath but didn't display it - stripes underneath help avoid losing orientation

The glue holding the wires pinged off on the maiden and had to be held on with tape, so I took the glue off, held them down with thick cyano then put some 80 gram cloth over the wire to hold it better.

[Peter Garsden]

Also took some picture of inside the cockpit, first showing the way the rudder is held on with a miniature screw lock with some threadlock holding it.

One can see how the plastic card is held in by the front dowel tube and the switch also the hooks to hold the rubber band securing the wings together

[Peter Garsden]

Finally, just to jazz up the front a bit I put on some solartrim to mock up a spinner

[Peter Garsden]

Another flight today in good lift up at the Gate above Leek. The wind was not that strong. I had 2 flights, and used the thermal setting of 3mm down for the ailerons. It shot up and seemed to fly well.

I am beginning to get the hang of how to fly it. There is quite a lot of expo on the settings - 30% and it smoothed out the elevator.

What I learned most is that the incidence settings (1.5 degrees positive on the wing) means that it pulls out of dives automatically and the dihedral also works out of turns. At least I think that is it. It flew much more smoothly.

One of my landings was awful. I over flew it and it cartwheeled. No damage other than a dislodged wing tube. That is the power of fibreglass and says a lot for Colin's building. All fixed already.

To be honest I didn't expect such a small model to fly in 10mph winds but it did - very well.

Getting to like it a lot more now.

[Peter Garsden]

I have had the impression now that the C of G was too far back, which was making it twitchy so I tested it yesterday and found it to be tail heavy by some margin. I worked out that it needed more lead and measured the amount..

I then took out the receiver and battery tray, only to discover that the lead weight was loose, so no wonder the glider was unstable. I removed the glue and reinserted it, and hey presto it balanced at 55mm back without any extra weight.

I flew it again, today it and it was a lot better.. Less twitchy and much more flyable. The lift was variable dependent upon the dampness in the air and fog.

[Peter Garsden]

Well I have finally worked out why this Midge keeps pulling out of dives all on its own. The All Moving Tailplane had play in it, so in a dive it would pivot up in the force of the wind.

The reason was that I had opened out the hole in the pivot to take the piece of wire at the rear of the tailplane but not for the elevator pushrod which should be tight in its hole. Stupidly I put the pivot in the wrong way round so the large hole with play in it connected to the pushrod which gave too much play.

So I cut a window in the side of the fin and moved the pushrod up into a tight hole closer to the pivot and bingo, all is fine. I then glued the window back in the fin carefully to avoid gluing it to the pivot and applied a covering piece of Oracover.

Works fine and the play has gone - hopefully will be able to test it out this weekend.