Apache Aviation Monocoupe 90A Build

[Former Member]

[This posting has been removed]

[Dave Garrett 1]

Hi Everyone.

Sorry its a been a long time since the my last post. Not a great deal of progress to report either. Other shorter term projects getting in the way.( DB Spots & Scale Corben Baby Ace & Sig 4 Star 20E)

Now Back to the Monocoupe.

After fitting all the lite-ply formers & balsa cross members, the rear fuselage has stiffened up remarkably. My earlier concerns about the structure been a bit light are now gone.

The next stage was to fit CNC cut contour strips to the front end of the fuselage. The lack of identification of the CNC again caused problems. It was not obvious from the plan which parts were required from the balsa sheet or where they fitted. After a bit of head scratching & trial fitting of the pieces on the fuselage, I worked out where each one fitted. I hope I've got it right. The contour pieces have to be rebated into the vertical spacers by 1/16". I'm sure its OK, but cutting into the spacers does not feel right..

After the contour strips, 3/32" Sq & 1/8* sq spruce stringers are fitted to the sides, top & bottom. When fitting the stringers, I discovered that cyno adhesive is much better at sticking aeromodeller to Monocoupe than spuce to Monocoupe.

Just a couple of small jobs before the front & rear fuselage sections are joined.

That's all for now

Cheers

Dave

[Dave Garrett 1]

Hi Everybody

I have made some progress on the Monocoupe over the festive break.

The last job on the rear fuselage section is to build the rear window frames and fit scalloped infill pieces between the stringers at the front end. The next picture show the results after rough shaping. I will sand to the final shape after the front & rear sectioned are joined.

I have noticed I have made a bit of a mistake about the wing strut mounts on the front fuselage section. The plan shows the strut mounts glued to the top surface of the cabin floor. Unfortunately, I installed the battery in this location Donut!

To overcome this problem, I decided to fix them on the bottom of the cabin floor. This would have meant the wing strut locating face being 1/4" lower than it should. Too big an error for comfort. I added 1/8" ply spacers on the outboard end of strut mounts to half this error.

The build manual instructs you to fit the strut mounts at a latter stage. After the fuselage sections are joined, the area under the cabin floor is sheeted over. This will make it almost impossible to fit the strut mounts at this stage. I decided there was no option but to fit them now. I know this will make the undercarriage fillets & covering more difficult than it would have been. I also added a couple of small screw for extra security. Before the fuselage sections are joined I took the opportunity to cut a hole in the cabin floor for engine clearance. Again this would be difficult after the lower sheeting is fitted.

During the dry run of joining the front & rear cabin sections, I noticed there were unacceptably large gaps at the sides. When the former was glued to the front of the rear section, the clamps caused the edges to curl up slightly by approx 1/!16". I glued strips of 1/16" balsa to the sides of the front face of the former. When the glue had set, I sanded the front face flat with my 12" permagrit block.

At last the front & rear sections are joined. Only a few small gaps. Although not perfect I am well happy with the result. It's beginning to look like a Monocoupe.

Hopefully, progress can proceed a little quicker now, One of the albatrosses is off my back. The baby ace is finished

However, Santa has brought another potential albatross

That it for now

Regards

Dave

[FastFlyer Smyth]

Very nice build Dave.

[Dave Garrett 1]

Thanks for the comment FastFlyer

Happy new year everyone. I managed to do a little more on the Monocoupe in the last few days of the holiday. Unfortunately it's back to work today

After joining the fuselage section, the next job is to fit the elevator & rudder outer control tubes through pre-cut holes in the rear formers. The inner control tube to the rudder closed loop bellcrank is also fitted at this stage.

As I thought it would be difficult to install the elevator, rudder & throttle servos after the fuselage structure under the cabin floor was built, I decided to fit them now. I linked the receiver to my transmitted to allow me to check the three servos worked before fitting. I also hooked up the rudder servo to the inner control rod.

The next job was to build & install the main undercarriage. The main undercarriage legs are pre-bent from aluminium sheet. 2 springs are already fitted in the centre section for the suspension arms. The wheel axles & suspensions arm brackets are temporary fitted. The suspension arms are made from a threaded rod & a metal clevis. The clevis is attached to the axle bracket & the rod is looped through the spring. The spring is stretched to pre-tension the undercarriage. The undercarriage is then fitted to the underside of the fuselage with cap screws & shake proof washers. The screws were installed with loctite, and done up as tight as I dared. I also ran some cyno into the captive nuts after tightening. As there is no access after the bottom structure is complete, they must not come loose.

The fuselage structure under the cabin floor is next. First 3/8" balsa central keel piece & formers are fitted. After the glue the edges are sanded to blend with the general profiles.

The lower structure is completed by sheeting & planking over the formers. the centre is sheeted with a single 3" wide 1/8" thick balsa. Slots are cut to clear the undercarriage suspension arms.

The side are planked with 3/8" x 1/8" strip balsa. I have started this job & hope to complete it this weekend.

That;s all for now

Regards

Dave

[Former Member]

[This posting has been removed]

[Dave Garrett 1]

Thanks Percy

Hopefully it will fly this summer (if it ever comes)

Not a great deal of progress the last week. Major failure of tumble dryer & shower has caused a bit of grief. Mrs G seems to think these are much more important than the Monocoupe. I can't quite see it myself!

I have completed the planking of the front lower fuselage section. Planking is another first for me. Not a frightening as I first thought. I am reasonably happy with the result. The following picture shows the result after trimming & rough sanding. I added thin ply doublers to tidy up the suspension arm exit holes.

The last job on the basic fuselage is to temporary install the pre-assembled tail wheel assembly. I will keep it attached until the covering stage as it will hopefully help protect the rear fuselage from accidental damage.

And finally we have a completed fuselage

Compared with some of the builds on this site, the monocoupe's fuselage is not that complex. But for me, this is by far the most difficult & time consuming model I have undertaken. I am enjoying the build. For comparison, in the background is the fuselage of my Sig 4-Star 20, no more than 5 hours work.

Next stage is the tail feathers & than the wings.

Cheers

Dave

[Tony Bennett]

lovely workmanship and a nice looking model.

[Danny Fenton]

Looking really good Dave, nice neat joints

Cheers

Danny

[Malcolm Blake 1]

Many years ago when attending a scale day at Old Warden my wife bought for me an Apache Aviation Gamma Racer kit. This was based on a Howard Hughes aircraft.

The wings have been assembled to bare frame state but nothing else done yet, am still busy building my Lysander.

Does anyone know anything about the Gamma Racer apart from the statement that it will fly 200 mph when fitted with a 70 four stroke.

[Dave Garrett 1]

Hi Everybody

Thanks for the kind words of encouragement.

Sorry, not a great deal more done on the Monocoupe. The good news is I have completed my 4 Star 20 EP

Back to the Monocoupe. After the fuselage, the tail feathers. surprisingly, for this type of model the tail flying surfaces are made from solid she balsa. The stabilizer is 3/8* thick balsa, The fin, rudder & elevators are 1/4" balsa. The first stage is to butt join separate cnc cut piece to make the fin, rudder & stabilizer. Simples, even Mrs G could manage that

CNC cut 3/8" balsa strips are added to the bottom of the fin & shaped to form a fillet with the stabilizer. The fin & rudder are then dry hinged prior to shaping to aerofoil section. A slot is cut in the rudder for the closed loop control horn (fitted after covering). A brass ferrule is added to the fin for bracing wires.

The stabilizer & elevators dry hinged. Bit of a blunder made here. Managed to hinge one elevator half the wrong way round (thick section outboard). Donut! . Fillled up old slots with glue & re-cut in correct place. Rigging ferrules are also added

The elevator halves are joined by a flattened 1/4" dowel. A CNC cut elevator horn is fist glued to the centre of the dowel. A slot is filed in the stabilizer TE to clear horn.

The stabilizer & elevators are then shaped to an aerofoil section.

To allow the elevator to move to the correct travel, clearance has to be filed into the fuselage. The elevator inner control tube was connected up to ensure full & free movement.

The last job on the tail feathers is to add thin card strips to all the surfaces to replicate the ribs after covering. This is probably going to be my only concession to scale detailing on this project. I spent most of the weekend cutting 2mm wide strips of card and carefully gluing them in place with thinned PVA glue. There was 48 pieces, I know, I counted them!!!. Hopefully it will be worth it

The next stage is the wings. I have cut out all the parts for the port wing. I will start framing tomorrow night.

That's all for now, I'm now off to watch Yeovil Town FC lose again

Cheers Dave

[David Tweddle]

Getting there well done Dave looking good.

David

[Dave Garrett 1]

Thanks Dave

Have made a start on the port wing.

The wing is typical of modern self jigging CNC kits. The wing ribs are positioned by slotting them into 2 spar webs. the ribs and spar webs are cleanly CNC cut from 3/32" light ply. They are suitably lightened with cut-outs. The 2 main spars are 1/4" sq balsa & are fitted to the front face of the forward spar web. There are only another 4 1/8" sq balsa spars behind the rear spar. The ailerons & flaps are built integral with the wing & separated later. The picture below shows the the major components laid out with the lower balsa main spar glued to the front spar web.

The next picture is the result of an evenings work. The front spar web is spaced off the building board with alignment tabs. It is pinned into position over the plan. The alignment tabs have holes pre-drilled for the T-pins. The root rib is jigged & glued the the end of the spar web at right angles. The rear spar web is added & pinned to the board. Like the front spar web it is is spaced off the board with tabs. The remainder of ribs just slot into place. A 1/8" ply plate is slotted between 2 inner ribs for the wing bolts. The wing ribs have alignment tabs at the TE. All the pieces assembled very accurately with no problems. Only a few strokes with a needle file were required on the odd slot. I am veery happy with the result so far.

Before the final full length rib is fitted, a sub-rib is fitted to the inboard side at the TE. This sub-rib forms the aileron end cap, & is spaced off the main rib with scrap 1/16" balsa. The last 2 ribs are jointed together with short CNC cut spars.

The last full length rib is then glued in place, followed by the joined tips ribs which are but joined to the ends of the spar webs. The second 1/4" sq balsa spar is then added. A CNC cut light ply core is slotted into the LE of the outer ribs to form the tip profile. You have spotted my deliberate mistake. I omitted to remove the last cut-out from the front spar web . The structure is a bit weak the moment to risk removing it. When the wing sheeting is added I will have ago then, or just forget about it

The 2 1/8" sq upper balsa spars are added, followed by the 1/8" x 1/2" balsa sub LE. The spars are spaced either side of wing aileron/flap separation cuts.

The TE of the outer ribs are sanded at angle matching the wing tip profile. A piece of 1/8" x 1/4" balsa is glued to end of these ribs to form the tip profile. A 1/4" CNC balsa doubler is added to the front tip profile ply core. A 1/4" CNC cut balsa piece completes the wing tip. The build manual makes no mention of pinning down the TE rib tabs. In fact it would be difficult to do as they are very short. I glued 1/16" balsa strips to the tabs, to allow me to pin them down & keep them on the straight & narrow. The pins will be outside the TE sheeting.

So far I am very satisfied with the result

That's all for now, The next stage is the wing sheeting & rib cap strips.

Cheers

Dave

[Dave Garrett 1]

Hi Everybody

A quick progress update on the port wing.

After planing & sanding the sub-LE, main spar & wing tip components to blend with the profiles of the ribs & spar webs, the full length 1/16" LE & TE sheeting is added. No problems were encountered.

The wing bolts are recessed into the wing & the heads are hidden by small hatches. Before the root end sheeting is added, 2 small ribs are added either side of the hole in the wing bolt plate to support the hatch.

The final job before the wing is removed from the board is adding the rib cap strips. An additional piece of sheeting is added behind the servo bay to support a dummy aileron control rod. This will simulate the closed loop system used on the aircraft. Another scale concession . The last photo is the wing just before it was removed from the board.

That;s all for now

Cheers

Dave

[Dave Garrett 1]

Hi Everybody

More progress on the port wing.

After removing wing from building board, all the spar web & rib alignment tabs are removed.

The aileron & flap control horns are CNC cut from 2mm thick Tufnol sheet.The horns are supported inside the control surfaces with 3/8" balsa sub-ribs. Before the sub ribs are fitted to the wing, a 2mm wide slot is filed in the center to accept the horns.

The sub-ribs are then glued to the underside of the top sheeting. The 2 1/8" square balsa lower rear spars are then added. The control horn slots are transferred through the top sheeting.

A 3/8" balsa filler block is fitted under the wing bolt plate. CNC cut light-ply component are added for the rear walls of the flap & aileron servo bays. 1/8" ply gussets are fitted in the corners of the servo bays to accept the hatch attachment screws. Ply plates with M3 captive nuts are added for attaching the wing struts.

After sanding to shape the sub LE, wing tip strips & ends of the ribs, all the lower sheeting is added. The slots for the control horns are also transferred through the lower sheeting.

Square light-ply pieces are added to form hard points for wing strut attachments.The light-ply servo hatches are temporally fitted after pilot drilling corner gussets. The wing tips are completed by wrapping 3 laminations if 1/16" x 1/2! strips around the complete tip profile. The next picture shows the first lamination fitted.

Considering the relatively light construction of the wing, it is now amazingly stiff. Worrying for nothing again!

That's all for now

Cheers

Dave

[Dave Garrett 1]

Hi everyone

Finally the port wing is finished. Apparently , you now have to make another one

After the 2nd & 3rd wing tip laminations are added, the lower rib cap strips are added.

The LE sheeting is then scalloped behind the wing spars. That was a bit of fun. To make the job simpler, I decided to make a couple of templates. The outer ribs are spaced further apart than the inner ribs. I raided Mrs G crockery cupboard to find suitable plates, saucers or bowls with approximately the right radii. I placed the selected crocks over pieces of scrap light ply & drew round the edge. They were then cut & sanded to shape. (If Mrs G reads this I'm in deep trouble!) The template shapes were than transferred to the wing sheeting & then cut out using a Dremel sanding drum.

The wing tip laminations are then trimmed flush with the parallel section of the TE & LE. Full length balsa LE & TE strips can then be glued into position. After the glue had cured, the LE, TE and wing tips are planed & rough sanded to their final shape. The last job is to install paper tubes to carry the servo wires. The kit even included sheet paper for the task.

I will wait until the starboard wing is completed up to this stage before I separate the flaps & ailerons.

I have a half day tomorrow to take Mrs G Senior (mum) to hospital. Hopefully I should have some time left to allow me to frame up the starboard wing.

It will take me a couple of weeks to build the other wing, so probably no updates for a while.

Cheers

Dave

[Dave Garrett 1]

Hi Everyone

I can't believe it has been over a month since my last post.

Over the last month, I have been steadily working on the starboard wing. I have also been working on other projects. The weather has improved & I have been able to get some flying in. I have also lost a week due to man flu (much worse than female flu). All these things has resulted in slower than expected progress on the Monocoupe.

However, we finally have a completed starboard wing.

The next stage is to separate the ailerons & flaps from the wing.

Hopefully there won't be such a large time gap to the next update

Cheers

Dave

[Pete B]

...and a very nice job you've made of that one, too, Dave

This really is a builder's model, isn't it?

Lurking with interest....

Pete

[John F]

Your work is very nice Dave, quite neat and with lovely attention to detail. Liking the scalloped TE's very much.