Aero-naut A-10

[Nick Cripps]

It must be heavy balsa, it's flattened your dog ?

[Gary Binnie]

She's either flat or eating. There are two of them, Rodney and Cassandra (Cassie).

 

No further update as I spent the afternoon tidying, doing housework and fixing the hoover (they don't work very well with completely clogged filters!).

 

 

[Gary Binnie]

Lunchtime update:

 

A leisurely start, was looking forward to some sedate rib capping but fell at the first hurdle!

 

The strip supplied is 2 mm but the wing sheeting is 1.5 mm, I felt the step on cutting the first piece.

 

I thought it might be a mistake but the parts list does list it at 2 mm and the sheet at 1.5 mm, perhaps it was supposed to be sanded down?

 

No worries, I just cut some 1.5 mm strip from sheet. I dug out my dad's old X-Acto stripper and knife handle, it's missing the screw and wheel that secure the red plastic strip (that sets the width), I should fix it.

 

The blue one is Master Airscrew brand, it does the job but the blade slips occasionally.

 

[Gary Binnie]

Rib capping strips done, bit of a marathon but I pushed through it!

 

Seems to be a lot of work for a small wing but it's keeping me entertained.

 

Jobs left on the wing are fitting the shaped leading edges, finish the ailerons and install servos, wing tip blocks and centre section plastic fairing.

 

1. Working on the bottom of the wing is a little bit tricky because of the dihedral, I've got it propped up on batteries and using an old foam wing bed.

 

 

 

2. To help with placing the capping strips centrally on the ribs I add a couple of pencil marks at both ends.

 

 

3. Adding lower cap strips, tape on the two servo bay ribs to remind me not to fit strips there.

 

 

 

4. I needed some hard 1.5 mm balsa and this stuff certainly is! Bought from my local model shop who are model railway specialists, I get told off for calling them trains!

 

 

5. Marking to size.

 

 

6. Done, this is exactly per the plan, Aero-naut's idea is to pass a thin snake and wire through it, I will mount a servo and cut a slot for the arm.

 

 

 

 

[Gary Binnie]

Quite a productive day.

 

Wing leading edges fitted and sanded, there is no spare material at all on these, could have almost got away with no sanding on the centre section.

 

Wing bolt holes opened up, wing aligned and marked.

 

Centre section plastic fairing tackled, was easier than I expected.

 

Not sure what to do next so I scribbled some jobs to pick from on the building board.

 

1 and 2. Using the bookshelf and a square block to sand the sheet back to the false leading edges.

 

 

 

3 and 4. Aligning the wing and marking it against the fuselage sides, I took diagonal measurements from both wing tips to the fuselage rear former.

 

 

 

5. I needed the alignment marks to position the cut out part of the centre leading edge, the dowel former sits in here.

 

 

6, 7 and 8. Opened out the wing bolt holes and felt the need to add a thin ply spreader plate to stop the balsa being crushed through over enthusiastic tightening. In many glider designs, particularly slopers, the bolts are designed to shear and save the structure in a bumpy landing but with this design they are purely for holding the wing on with formers trapping the wing fore and aft. 

 

 

 

 

9. Plastic centre section fairing fun! I particularly enjoyed this bit. It can split as I discovered so have to be careful not to cause one. I chain drilled the finger hold recesses first before cutting the base so it was still supported.

 

 

10. Razor saw to take that section out.

 

 

11. Wing bolt holes were drilled then carefully opened up with a prop reamer.

 

 

12. Then a rotary sander bit in the Dremel at a slow speed to prevent melting and avoid over sanding.

 

 

13. Marking the rear end (over length) then razor saw across. There are faint cut lines moulded in.

 

 

 

14. Stopping here for the day.

 

 

 

 

 

Edited March 13, 2021 by Gary Binnie
Stray text

[Gary Binnie]

Today I moved to the forward fuselage.

 

Cut the canopy and nose cone down to just oversize . The canopy is glued on with the help of some balsa strips that increase the area, I'm thinking about converting it to a removable hatch for CG adjustments.

 

I couldn't find the 2.5 mm sheet wood intended for the lower forward fuselage so replaced it with some of my stock and increased to 3.0 mm. It was a tricky operation gluing this on and I didn't have enough clamps so I've ordered some more for future builds.

 

Will let the fuselage dry overnight and should be able to do some nose shaping tomorrow.

 

1, 2 and 3. Nose cone moulding is quite flimsy, the best way forward was to add the Liteply former and then sand down to the cut line. The former was sanded with a chamfer on the edges and pegged in place before applying CA (it was quite 'squirelly'!).

 

     

 

 

 

4. The nose cone had a thin dimpled section that I corrected with some balsa on the inside.

 

 

5. Canopy moulding, cut down to just oversize. The canopy and nose cone are needed to find the profile of the fuselage section.

 

 

6. The forward lower fuselage sides have to be planed and sanded to match the curvature of the formers.

 

 

7. Adding the forward lower sheeting. I always ask myself 'is there anything else to do in here?' before closing up, sometimes there is! Quite a fiddly job and two pairs of hands would have been useful. Because the majority of the joint will be sanded off when rounding I added glue to the inside using runny thin aliphatic resin.

 

The square balsa strip load spreaders on the outside are provided in the kit and shown on the plan, they are called 'Hilf Leiste' (Help Strips). 

 

 

[Gary Binnie]

More fuselage work and a weighing session.

 

The forward fuselage shaped easily, just needs final sanding after gluing the mouldings on, I need to check if cellulose dope affects the plastic.

 

Weighing all the parts came to 895 grammes, that included a second motor, mount and prop that I have to order. Battery is 135 g, receiver and two ESCs around 60 g, covering and finishing 75 g ish.   Nose weight unknown, it might be better to use a larger, heavier battery.  There is a small amount of engine pylon fairing wood not included and a lot of the plastic still needs to be trimmed. The tail assembly feels chunky/heavy at 77 g but hasn't been sanded yet.

 

Total weight guess is 1,165 g so hopefully it will end up under 1,200 g. That compares to Aero-naut's weight of 1,500 g (I assume without undercarriage) and tallies with the battery weight difference of circa 300 g.

 

That works out to a wing loading of 16 oz/sq ft which is the same as my Phase 6.

 

1. Using the centre section fairing to mark the contour line.

 

 

2 and 3. Same at the nose cone.

 

 

 

 

4. A template is provided in case you don't trust your eyes!

 

 

5. Making some hamster bedding.

 

 

6. I've missed some photos of trimming the canopy and fitting a former to it, still thinking about making it a hatch. The rear lower fuselage sheeting needed to be added so I fitted the elevator snake, servo bearers and servo, not sure if I will stick with this arrangement, might upgrade to a carbon inner rod and proper clevises.

 

 

 

7. The wind had died enough to get a photo outside, it's getting there.

 

 

8. Weighing bits and pieces, the tail assembly weighs 77 g at the moment, the fins feel particularly heavy but they haven't been sanded yet.

 

 

9. Weighing the wing with everything except the servos and covering, the tip blocks are very heavy, hard wood but the majority of them is carved away to make Horner tips. 290 g.

 

 

10. Fuselage and one motor, 370 g.

 

[john stones 1 - Moderator]

Oooh nice bench fly Gary, with you on the push rod, don't like those.

[Gary Binnie]

Cheers, I have to do it every now and again to keep the enthusiasm up!

 

Thought I might get away with the short length of snake and cheapo clevises but you're right, I should do better!

 

My first RC model was a Middle Phase, it had these plastic inner/outer snakes on the elevator and rudder and the trim was all over the shop. I replaced it recently and even went mad with digital servos and an optional aileron wing. 

 

The poor snake/horn geometry on the rudder can be seen on the original.

 

Edited March 15, 2021 by Gary Binnie

[Martin Harris - Moderator]

That looks to be a very nice kit Gary and you're making a lovely job of it. Is the wood as good as it looks in the photos?  It only seems like a few days since you started the build but you've made great progress - I should have looked back sooner!

 

I'd second the idea of a cf rod linkage - looks like a nice straight run and should give a lovely slop free result.  I always feel there's a possibility of the screw weakening the plastic pushrod if you tighten it enough to ensure there's no slippage.

 

 

[Gary Binnie]

Cheers, I think I have been working on it non-stop, I would have a break if there was something else to do!

 

Have to say the wood quality is variable, the Liteply is good, warp-free and of the European variety (American Liteply is different). All the die-cutting was excellent apart from the ribs.

 

The wing ribs were cut from very soft and light balsa, ideally should have been harder but it's made a nice light wing. As they were so soft they were 'die-crushed' which left tatty edges.

 

The centre section balsa sheeting (six sheets) was odd, different grades and thicknesses. The dark brown on the upper rear is a sheet from my stock. The outer panel D box sheeting (four sheets) was also different and one panel was unusable because it had bent.

 

Similar with the strip wood, different grades in the same sizes but the instructions do occasionally say 'look for the hardest grade' so perhaps they deliberately picked different grades. The supplied rib capping strip was 0.5 mm thicker than the sheeting it mated to which was confirmed in the parts list. 

 

The strip balsa for the fins was much too hard and heavy but I used it thinking it might get a beating on the slope and quite a lot of it will be sanded off anyway. The fins are not tapered towards the top, which they are on a full-size A-10, some weight can be saved by tapering them and it will look better.

 

If Aero-naut wanted to they could correct the plan (wing drawing), redesign for modern EDF units and shorten the engine pylons to a more scale size (they are over length to use with propellers).  Laser cutting would also be nice, some parts didn't quite fit exactly but I couldn't work out why, latest Aero-naut designs are laser cut. It could probably take light retracts but would need a hard surface to fly from.

 

The instructions are very unclear and need re-writing in both languages. It's still a high quality kit, up there with Graupner and Multiplex (of the same era).

[Gary Binnie]

Lunchtime update.

 

Woke up to the joyous news that the nose cone had fallen on the floor overnight and been picked up by one of the dogs followed 10 minutes later by a phone call advising that we have lost our flying field, I've had better days!!

 

Pushing on through adversity I'm having a day of plastic cutting. Have found a carbon rod to replace the elevator snake inner and some better clevises.

 

1. Plastic part in the centre is a pair of wing fillets, ply parts to the left are their supporting structure and the parts to the right form the core of the engine pylon trailing edge fairings.

 

 

2. I initially thought that the fillet support would join to the side of the fuselage but it glues to the wing seat (shown on the plan top view). This will leave a gap at the front (exaggerated and arrowed). I will fill that with balsa and it's a good thing because that area of the wing seat wasn't a good fit anyway.   I'm super glad that I haven't fixed the wing dowels in yet because their position will need adjusting slightly.

 

 

3. Will look something like this...

 

 

4. These parts form one main undercarriage nacelle, half a wheel is provided for the retracted version. An A-10 can land on these should the gear be stuck up through battle damage.

 

[Gary Binnie]

Mid-afternoon waiting for glue to dry tea break.

 

The gear nacelle pieces are quite tricky shapes to cut and the final trimming will need to use the wing to test the fit.

 

I used my Dremel only, with a diamond cutting wheel and small sanding drum. The smell of melting plastic reminds me of my first full-time job working which was in an injection moulding factory. We made afro combs mostly, I fed the moulding machine hopper with plastic pellets, removed the parts and cut the sprues off with a Stanley knife then stacked them into groups of 10 with a rubber band then placed in a cardboard box that held 1,000.

 

There was another variety of comb with two folding plastic handles that were hinged with hollow rivets, I was promoted to use the foot operated riveting press, happy days.

 

1. Highlighting the cut lines using a non-permanent pen.

 

   

 

2. The two halves share Liteply Part 117 so the final trimming is going to have to be pretty precise.

 

 

3. The hatched area of 117 has to be chamfered to follow the curve of the bottom of the wing.

 

 

4. From the plan I've marked the rear of 116 at 70 mm from the leading edge. Piccie is slightly out of focus,must have sneezed, sorry!!

 

[Gary Binnie]

Have had a break for a couple of days while waiting for the second motor, ESCs and servos.

 

Rigged up a motor test bed today which involved the exciting milestone of programming a new model memory, only four characters in its name which made it easy peasy!

 

I think it would be possible to mount these motors (2830 outrunners) without using the plastic Aero-naut mounts.

 

Both ESCs initialised together and I've run them up to half throttle mounted in a vice, will wait for a good weather day to run them in the garden as I'm a little bit wary of the propeller integrity.

 

Will have to extend the motor wires but I'm not sure quite where the ESCs need to go yet, they might need to be placed forward.  

 

 

[Gary Binnie]

Nice weather today so was able to run the motors to full thrust in the garden.

 

With 6 x 4 two-blade props the total current is just under 12 Amps and power is 130 Watts.

 

There was a reasonable draught behind them but debatable whether it would fly well on that.

 

I've ordered some 6 x 5 three-bladed props and will test again, if the current stays reasonable I will try some smaller ESCs to save weight.

 

 

[Gary Binnie]

Have moved back to the shed now it's warming up.

 

Spent the afternoon doing some odd jobs on the rear fuselage and elevators.

 

1. The tail cone is another plastic moulding, it needs a cut out on each side to pass over the elevator joiner.

 

 

2. New improved carbon elevator drive, cut to length. The grey outer is recycled from my Multiplex Cortina which was converted from snakes to servos for the wing surfaces last year.

 

 

3. A clearance hollow had to be sanded out to allow movement of the drive link. The bolt is 6 BA as I couldn't find an M2.5 bolt long enough, the plastic link is from an aileron torque rod.

 

 

 

4. Preparing to join the elevators, I had chamfered the front face of the spruce joiner to get down travel and it also needed chamfering top and bottom to match the elevators, easier to do before gluing.

 

 

5. Gluing against a straight edge.

 

 

6. Another little job that needed doing was trimming the end of the elevators to the scale outline that's needed for rudder movement. If the optional rudder control is built then the trim line is slightly different and extends in to the tailplane end. The plan also shows the optional bolt on fin arrangement.

 

 

 

7. I've recently taken to hoarding empty cornflake boxes to make templates for odd jobs.

 

 

8. That's the tailplane and elevator virtually done apart from covering, I think I've overdone the clearance to the tail cone but I can correct it using the waste cut off the ends. One thing I've got very good at over the years is correcting mistakes!!

 

[Dwain Dibley.]

Just read thru from the start and what an interesting model. 

Nice, extremely tidy work too. 

D.D.

[Gary Binnie]

Cheers, I've always liked unusual subjects, my dad did too. We built a Lancaster together in the 1970s, not a particularly unusual subject but you don't see many 102" span free flight ones!

 

It 'flew' twice, resulting in damage that was repaired then retired to various lofts including mine.

 

Transmitter for scale.

 

 

 

[Gary Binnie]

Busy day, just working on the ailerons.

 

There are a lot of photos so I'll split it in to two posts.

 

The first job was wiring in the servos and working out where to place them exactly.

 

1. A slot needed to be cut in the sheet for the servo horn, I used my best guess for position.

 

 

2. In this position the horn and drive shaft are nearest the aileron to keep the linkage as short as possible and it's far enough forward not to stick out above the cap strips. The plug has been cut off to pass through the hole in the spar. Cutting plugs off servos voids any warranty so not recommended for expensive servos.

 

 

3. Stripping the insulation and tinning the ends with solder. Servo wires can differ in colour as they do here but they are generally black or brown for negative, red for positive and yellow, orange or white for the signal. I've added short lengths of heatshrink, if they are not far enough away from the tinned ends they shrink before you want them to, such fun! I'm using a cork table mat to protect the model from accidents with the soldering iron or hot blobs of solder.

 

 

4. Covering the joints with heat shrink, then shrunk with a lighter (I have a heat gun but it's not needed for these small wires).

 

 

5.  Pulled the excess cable through, if the servo has to be changed in the future it will be easy to remove.

 

 

6. At the other end I needed to cut the cables to length and add plugs. 

 

 

7. I will mark these up by painting them different colours, my Xtra Wot has the same arrangement and I got them backwards once but spotted it during the pre-flight check. Out of interest F5J gliders use fixed computer D Sub connectors, the flaps and ailerons automatically connect on fitting the wing.

 

 

8. A functional check with a servo tester before moving on, no 'magic smoke' and the slots I cut seem to be about the right length for horn movement.

 

[Danny Fenton]

Looking great Gary.

Another thumbs up on the D subs, i use them on my 85" Chippy for ails and flaps. 11 years on and still solid, or have i jinxed the model now?

 

[Gary Binnie]

The second aileron instalment is woodwork.

 

1 and 2. The ends needed to be closed up, just cut some balsa sheet wedges and glued them in, left over length to make life easier.

 

 

 

3. Next step was to find the horn position using my WH Smith school geometry set! The linkage will be at 90° to the aileron hinge.

 

 

4. Transferring the marks to the aileron.

 

 

5. The ailerons are hollow so any horn will need some kind of reinforcement, the kit arrangement has Liteply plates and large bolts which is a bit OTT for these dinky ailerons.

 

 

6. I had made a balsa wedge when I cut the ailerons free from the wing for this job.

 

 

7 and 8. I rummaged through my spares box for ages looking for control horns, I was sure that I had some park flyer ones but couldn't find them. I used standard SLEC horns in the end, cutting the base off. I'm not sure on the gearing at the moment so these won't be glued in until final assembly.

 

 

 

9 and 10. A nicety was to cut a slot in the balsa wedge so the horn will fall into position (which makes a change from stabbing blindly and popping through the top skin!)

 

 

 

11. Last job for today was to glue on the facing strip making sure that the thick end was uppermost. 

 

 

 

 

[Gary Binnie]

5 minutes ago, Danny Fenton said:

Looking great Gary.

Another thumbs up on the D subs, i use them on my 85" Chippy for ails and flaps. 11 years on and still solid, or have i jinxed the model now?

 

 

Cheers, I have got one glider with four ailerons and two flaps and a mixture of loose D sub and MPX plugs which is a bit of a pain. It's only for sport flying, when I have the patience to put it together. It was designed for brushed motors and large Nicad packs so converting it to geared brushless and lipo caused some head scratching.

 

It's a Vladimir's Graphite, a mixture of parts from three gliders, the tip panels belonged to Chris Moynihan.

 

 

 

[Danny Fenton]

I tried this as an experiment, and surprisingly it has stood the test of time. There is a landing light in one wing panel too, so flaps, ailerons and light. They do have to be well aligned though, or even one side left a little loose so it can self-align.

 

Sorry, digressing, back to you sir ?

Edited March 22, 2021 by Danny Fenton
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[Gary Binnie]

I like to digress occasionally! It's not really off topic though as it's on the subject of getting servo signals in to a detachable wing.

 

I'm a big fan of anything that makes rigging at the field easier and foolproof.

 

Think the DLG flyers use a spring loaded contact system, similar to the system on some car tail gates.

 

Some other ideas:

 

1 and 2. Multiplex five pin connector, one fixed, one loose. Becoming difficult to find. Useful for a tip panel with two servos. To save weight a lot of glider harnesses share power wires. 

 

 

 

3. Standard Multiplex connector, both halves fixed.

 

[Danny Fenton]

Yes same here, I share the power and neg wires just separate signal wires. 

I have just bought some normal servo plugs, but they are 4 pin, going to use them on my Auster which just has an aileron and flap per wing.

Edited March 23, 2021 by Danny Fenton