Tony Nijhuis Concorde build

Merry Christmas every one. So my Christmas build starts. It is the Tony Nijhuis Concorde with 4 50mm FMS edf's. I bought the short kit, plans and vac forms to get a quick start. I will use my dwindling stock of balsa for the sheeting. Tony does a nice set of build photos to guide you through the build.

First up is the wings. No major dramas here. Just packing under the leading edge, slot the ribs into place, check alignment and drip some thin CA into each joint. Repeat for the other side.

looking good Ralph! Not keen on using cyno on balsa joints myself, I know it's quick but it does make a brittle joint.

I agree Paul and normally I would use aliphatic but as this will be a gentle flyer, after all it is a passenger jet, it wont be subjected to much abuse! The sheeting is glued with aliphatic. I read a post somewhere about applying sheeting. The guy suggested putting glue on the formers / ribs. Laying the sheeting on, lifting the sheeting off adding some more glue on both the sheeting and formers / ribs, then let it dry. Once dry put the sheeting on, line it up then run a covering iron set on low heat across the sheeting pressing down and moving slowly. The heat softens the glue which then goes rigid when the heat goes. No need for pins or clamps. So I tied it and it does work but I still needed some pins and clamps. More practice required but a useful exercise.

Cracked on again today with the build after I changed brake pads on my car. Wasn't happy with the old pads, bad brake fade under heavy braking so went up a grade to some road/track day pads. Seems to have made a positive difference. Anyway, I put the top sheeting on each wing, added the fuselage formers and put some longerons in. Built the nose section. Took quite a bit of time to make sure everything was straight and the wings were sitting on the build tabs so no twists. Started installing the wiring and servo extensions.

Coming along nicely Ralph, I've heard that dodge about ironing sheeting on, must give it a go.
Road n track pads won't help.with fade, just give more "feel" ( I like EBC green stuff pads) sounds like your due a fluid change tbh, brake fluid is hydroscopic.

I've fitted EBC Red. Seems to have improved it. Yes, I do need a fluid change. The car is in for a service next month so will have it done then.

As with all your builds that looks very nice Ralph. What is the estimated all up weight & how much thrust do the EDF's produce ?

Hi Klippy. The brakes were bled this time last year but it is due a complete fluid change. I know that sinking feeling when you hit the brakes and not a lot happens. Spent many years rallying and learnt the Scandinavian flick very quickly to get the cars to slow down. Not so easy in my current 4 wheel drive car on tarmac!

Anyway, on with the build. Crash, it will weight around 5lbs, Tony Nijhuis recons 4.85lbs (2.2kg). The FMS fans on 4S give about 700g thrust, so just over 1:1 power to thrust.

Today was sheeting the underside of the wings and fuselage. I preformed the fuselage sheet over a plans tube I had that was a close diameter to the fuselage. Just apply water to one side, clamp around the tube and bake until dry! On the plans Tony shows the fuse sheeting goes from the front of the wing to the rear. I am worried that the nose section join at this point is a potential stress point as none of the longerons run through into the nose. The nose worries me as that carries the front nose leg. So I decided to run the sheeting just (about 50mm) forward and aft of the front and rear formers to spread the load into the sheeting.









Cut and trimmed the vacuum forms for the nose.



Added a plastic strip to join the two halves together. This gives a supported joint and is easy to fill.

Evening. Completed the sheeting and did a little sanding, again!



Played around with the nose vac forms. Got the cockpit one on by installing a dummy former to support it. Installed the snake to lower and lift the nose. The main nose cone needed some fettling. It wasn't the right profile to go over the cockpit section, need adjusting to make it more oval in cross section. So applied a little heat to manipulate it and wham it distorted!! Must have been the built up stresses from the vac forming process. Well thats my excuse. So spent over an hour trying to get it straightened out with less heat and lots of forming with bits of wood to force it intro shape. Its ok but I think i'll buy another one. First I'll take another look at it it the morning and see before I do order a new one.





Made the control surfaces and epoxied them onto the torque rod that goes over the engine nacelle. Used a piece of ally angle to to get the alignment.



I'm still waiting for my EDF units to arrive. So that will limit me installing the nacelles. Anyway I can still build and cover them then glue them on later. Getting close to the covering stage. I'm going to cover it in white solarfilm or oracover, whatever I have in the drawer.

Impressive!
Quite correct Ralph
Vac forming leaves considerable stresses in the plastic. Only with a moulding process where all the material remains fully plastic until the final shape is obtained will the residual stresses be eliminated or at least very substantially reduced.

Wow a drooping nose!
Of course to be true scale the 'drooping' is a two stage process. The canopy shield first, then the nose.

I like that a lot Ralph! looking great.

Good progress again today. Cut the battery hatch. Tony's design only calls for one hatch but as the receiver is just behind the battery I decided to cut a second one for convenience.



Needed some servo covers and was about to design some on Fusion but thought I would check on Thingiverse. I found these, www.thingiverse.com/thing:2901556 and printed a pair. Really nice design and the designer included the drawings in his files so you can see the size of the covers. He does two sizes. That saved a lot of time.



Decided to make a start to the engine nacelles. Quite simple construction. Tony used his normal method for rounded corners, he uses large triangle section into each corner then sand away most of it. I don't have the EDF units yet, they are on a slow boat from China for the third time. First time they never arrived after 6 weeks so got a refund. Then they shipped again and they were returned to the supplier from Chinese customs for a security issue. So third time they have been shipped and are hopefully on their way. So without the EDF's I have built the nacelles off the plane straight off the plan. Using the Dremel (what would we do without one of these??) I managed to get a nice internal radius to the triangle section. Overall quite pleased.

Interested in how you got such a nice, even internal radius on the nacelles Ralph?

Hi ST, easy, skill, patience and years of practice!!

Actually none of the above! I used a dremel with a flexi shaft and 12mm drum sander. I marked a centre line on the triangle section, created a trough with the drum sander following the line then flared the edges of the trough out. Final finish was by hand using Mirka sanding pads. The Mirka sanding pads are one of the best tools that has been recommended to me. I dont use sandpaper anymore just Mirka pads. They last ages and with the vacuum attachment reduce sawdust to manageable levels. I got mine from Axminster Tools.

www.axminstertools.com/mirka-dust-free-s...branet-sheets-101148

Expensive to start with but like any professional tool worth its weight. I bought this kit about 5 years ago and only used about a dozen abrasive pads and I build a lot. Either they dont wear out or i'm tighter than the proverbial ducks bum under water, or both!!