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Pete's Cavallino Rampante Italian Aerobatic Team Sabre

Colourful Italian Ice Cream Sabre

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McG 696911/02/2020 21:02:59
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3019 forum posts
1143 photos

Great progress, Peter. yes

I'm closely following your approach as I still have to attack my tailplanes fitments.

Cheers

Chris

Peter Garsden15/02/2020 14:49:35
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1710 forum posts
1296 photos

I can see light at the end of the tunnel. I must admit that usually fibreglass fuselages are quicker, but in this case, because I have had to fit a number of formers to hang other bits on rather than for strength it has taken longer than usual.

I am only using F1, F4, F7, F9 and F10. I am omitting 2, 4,6, and 8. The problem is that I am having to fit the former whole rather than in halves for the fuselage so I am gluing them together and reinforcing the joint with some 1/32" ply for strength to take the strain when they are shoe horned into the inside of the fuselage. I am also roughing up the inside of the fuselage which is smooth from the parcel tape to provide a good join for the formers.

They are only 1/8 ply so I am adding short stringers to increase the gluing area.

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It is impossible to get the exact shape so fitting has to be done. I use my very handing shaping tool then matching it against the formers and sanding with my disc to the line.

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Amazing how you can use up off cuts, I think from the Skyhawk wing seat doublers.

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The stringers will point forwards as will the reinforcement doublers so you will not see any of this from the wing seat.

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This is F7 (behind the wing), which I have inserted to provide a mounting for my wing seat plate and guidance for my rudder wires. I will be redrawing the wing seat plate to span the fuselage. I am not using the F11 wing set bits because they won't fit into the slots due to the curvature of the fuselage. The wing seat will be quite stiff enough with front and rear formers going in.

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F1 from the rear showing some 1/4 square I have glued in to hold the battery box - there is no keel on my fuselage which would have cradled the box at the front. I will feed in the box after F4 has been glued in.

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F1 from the front - because of the curvature of the fuselage it would go in from the front which would have been easier. I had to push it in from the rear. I then used a syringe full of epoxy mixed with fibreglass powder to fill in the join with the edge of the fuselage and provide a fillet.

Steve McLaren15/02/2020 21:13:02
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241 forum posts
252 photos

Hi Pete.

I thought the many hours of planking was laborious, but this method looks like hard work too. But its good to see someone doing something different. I look forward to seeing the finished result. I'm definitely going to try this method one day!

Peter Garsden21/02/2020 16:11:52
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1710 forum posts
1296 photos

I thought hard about how to secure the wing retaining bolt plate. I didn't want to just glue it to the side of a curved fuselage, which is mainly why I installed F7 so I could butt it onto the side as per the plan. I don't have any ply doublers so I glued in a support of 1/4 x 1/4 to F7 for the rear to sit on and fashioned some pieces of 1/2 balsa for the sides to rest on. I made it so I could slide it in and out.

I made the dowels for the front of the wing. To mark the position I spot glued some short pieces into F5, brushed some black acrylic onto the ends and slid the wing in which marked the hole positions, then drilled them out with ever increasing size drills as usual, then offered the wing up. I had to file away some of the fibreglass seating but it is a good fit.

I was then able to drill holes in the rear trailing edge from top through the wing and then the ply plate in one go. I put one in first, attached the bolt to hold it then drilled the second. Never been able to do that before. More accurate.

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There was a slight bubble in the rear wing seating which I cut away. I cut too much away so have patched it with 2 layers of glass cloth as the foreground shows. Next job is touching up any holes in the fibreglass with filler.

Edited By Peter Garsden on 21/02/2020 16:13:52

Peter Garsden21/02/2020 16:19:03
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1710 forum posts
1296 photos

So to the tailplane. I intentionally left the gluing of the tubes into the tailplane halves so that I could attach the wing, then line up the tailplanes with the fin temporarily slid into position. One everything was lined up, I pinned them into position and left them to dry. I have now filled the holes with some 3mm balsa scrap

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Finally, I glued the front nose intake pieces together, first of all drawing the lining up lines onto the wood to make sure they would sand down correctly.

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To get the right side profile, I made a cardboard template from the plan, which was very helpful.

dirk tinck21/02/2020 23:34:25
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507 forum posts
782 photos

Hi Pete , you're getting there !

Peter Garsden26/02/2020 09:48:27
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1710 forum posts
1296 photos

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In this picture you can see the elevator and rudder servos in situ. I used up some scrap 1/16 sheet. I don't have a lot of 1/4 but have loads of 1/16 so laminated 4 sheets together using cyano then made up some curved supports out of 1/2 and epoxied in the tray once I had cut out some holes for the 1/4 birch hardwood to take the servo support screws.

As I said on another blog I am using the old faithful hitec 85mg for the elevator which has never let me down. The torque is about 3kg so hopefully more than enough for the 4mm carbon rod with a 2mm insert I will be using. It is now priced at over £20. I remember not long ago before Brexit when they would be priced at below £15.

I reckon that the load on the rudder closed loop system I will be using is less, so I am using a KST metal geared which is a bargain at £11 and 2kg of torque - **LINK** KST servos are excellent.

If you look in the picture you can see that I have added a piece of 1/16 ply to take the other closed loop wire. Incidentally it is a lot cheaper if you buy pike fishing trace rather than use a model supplier.

I am away skiing and it is blowing a hooley so using the time to catch up on my blog.

Peter Garsden04/03/2020 19:13:13
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1710 forum posts
1296 photos

Dirk deserves so much credit for inventing all sorts of extras and the hatch under the fin to gain access to the all moving tailplane mechanism is no exception. So, again, I copied Dirk's hatch using 2 pieces of Sullivan snake inner, and a screw with 1/64" ply to provide guides and a home for the screw with a piece of 1.5mm balsa underneath

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It was difficult making holes close to the bottom of the fuselage in F9 to take the plastic inners, but I used a small manual drill I have.

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Peter Garsden04/03/2020 19:13:14
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1710 forum posts
1296 photos

Dirk deserves so much credit for inventing all sorts of extras and the hatch under the fin to gain access to the all moving tailplane mechanism is no exception. So, again, I copied Dirk's hatch using 2 pieces of Sullivan snake inner, and a screw with 1/64" ply to provide guides and a home for the screw with a piece of 1.5mm balsa underneath

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It was difficult making holes close to the bottom of the fuselage in F9 to take the plastic inners, but I used a small manual drill I have.

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John H. Rood05/03/2020 18:32:57
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268 forum posts
387 photos

Pete, your fuselage process reminds me of my MiG-15 1/10th scale that I started but never finished some years ago.

Here I was laying on the first fibreglass strips over the packing-tape-covered pink foam... and yes, Sir -- that same unbelievably godforsaken messy "is-ness" that you encountered from A to Z... foam dust, static cling, resin, gloves, brushes, fiberglass shards, silica dust, the works!

Note the extra strips lying there in the foreground...

 

It was my first attempt at doing anything in fiberglass... and after the resin dried I was dismayed by how dang HEAVY the fibreglass monster seemed to have come out... as in, I likely fell prey to the impulse to add more resin than was needed... something I had set out to AVOID, but maybe it happened anyway?

So... here's how the thing looked during the next step, rough-sanding the now-cured White Whale:

The leftover pizza and gin helped me to cheer up, as did the shiny insides that emerged when I cut the thing in half... turned out that I didn't even need to destroy the foam original plug in the process!

So I can fast-forward to NOW and your Sabre build is a real eye-opener. Lots of info about where and how next to proceed on this MiG-15 someday soon, especially with all these new Sabres out and about.   Love your detailed, info-packed build threads!

Edited By John H. Rood on 05/03/2020 18:47:59

Peter Garsden06/03/2020 09:14:38
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1710 forum posts
1296 photos

Excellent John, very interesting. Nice to see you without a scratch on your face. I have made 2 other fibreglass fuselages - the Tornado and the Alpha Jet, and both come out about the same weight as the balsa equivalents. Not weighed this one yet but it will be interesting to compare. This time I have put more infrastructure into the fuselage which may put the weight up certainly. Should probably have replaced them with balsa rather than ply - too late now.

Peter Garsden07/03/2020 18:01:21
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1710 forum posts
1296 photos

Well I am now doing the very tricky underwing fairings, which are very thin and have to follow compound curves - tricky indeed. The problem is that when balsa gets very thin it rips, unlike fibreglass.

So I used the tried and tested 40 grade sandpaper on the fuselage/wing and sand away until the balsa follows the shape then glue on and fill gaps with epoxy.

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First I did the front former which has the tricky triangular side bit. One then has to sand them hollow to follow the curve of the fuselage and wing. I used 1/2 inch then planed it down. I used a piece of dowel wrapped in wet and dry to get the concave curve effect.

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To make sure I got this the right way round I drew an arrow. In the end I cut it down the middle across the wing as it was easier to fit. This is 6mm.

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Following Dirk's excellent suggestion the rear piece rang the grain across. I made the wing bolt holes oversize, and finally added the rear pieces joined in the middle again to ease fitting. It is now drying to await sanding and planing. Note the cling film to stop the wing sticking in place.

Peter Garsden10/03/2020 09:28:58
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1710 forum posts
1296 photos

Well we are getting there.

Re the underneath fairings. I noticed that both front and back under wing fairings made from 6mm balsa had very fragile ends to them which would break off. I thus packed underneath them with Milliputty (2 pack mix together) and covered both the top and sides with 25gram fibreglass cloth. It is now a lot sturdier. I am still at bit apprehensive about weight but we must await a final weigh in.

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You can see the greenish wedge of putty and the glass fibre over the top.

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And the rear fairing

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I also decided to cover the wing bolt access plate with 25 gram cloth and water based epoxy (resin would have done). I am going to cover the wing and fuselage in heat shrink film (Glosstex by Solarfilm) but when I was unscrewing the wing bolts the screwdriver slipped out and put a ding in the balsa which I have now filled. The edges are also a bit delicate so I thought I would reinforce it. It certainly now is a lot stronger and ding resistant.

 

Edited By Peter Garsden on 10/03/2020 09:38:00

Peter Garsden10/03/2020 09:34:13
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1710 forum posts
1296 photos

I have also made my fin to tail triangular stock fillers ahead of gluing the fin in, principally because one has to sand them down to cope with the 3D complex shapes of the tailplane fairings and the curve of the fin. You can only do this with the fin out of the fuselage with sandpaper on a flat surface. I use coarse 60 grade.

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These are not yet glued in obviously. It is easier to make them in 2 or 3 pieces - other side is in 3 pieces.

And I have made a handy sanding tool, by stealing Dirk's intellectual property, except mine is made of wooden dowel, a piece of ply, and a metal rod glued in with epoxy. I think it will work well.

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Peter Garsden10/03/2020 16:37:18
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1710 forum posts
1296 photos

I decided to cover the fin before gluing it in as it will be difficult enough to get the glue round the convex curves which bridge the join as it is. I lined everything up eg tailplanes before lining up and ensuring the fin is perpendicular before epoxing the fin in position and attaching the front fairing - also covered before gluing in.

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This photo shows the SLEC closed loop horn that I have glued in after roughing up the plastic for adherence. I also added some 1/32" ply surrounds to the slot which the horn fits in for extra strength, otherwise I fear that the horn would rip through the balsa if tugged hard.

dirk tinck10/03/2020 19:45:58
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507 forum posts
782 photos

Wow !the first color on a MB sabre !Congrats Peter !Nice !

Peter Garsden15/03/2020 16:37:51
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1710 forum posts
1296 photos

As I am waiting for my pilot to arrive, I thought I would make some internal cockpit furniture and fit the canopy. Had to use ammonia to bend the 3mm square to shape, then sand off the edges. Cockpit fits fine. Needs painting now. Got some mouldie repairs to do but will be able to do some covering in readiness.

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Have also found an instrument panel

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Edited By Peter Garsden on 15/03/2020 16:40:09

Peter Garsden17/03/2020 17:34:10
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1710 forum posts
1296 photos

Well, I had a little weigh of the fuselage which is finished apart from covering. I then weighed the wing so between them they came out at just over 2.5lbs which is good. I can't see the covering adding a pound so all good I reckon. I did add in the battery for the weigh and receiver. No closed loop system or control rods for flaps and ailerons, nor, indeed did I add the control surfaces. Still good though. I was a bit worried about weight because I should really have remade the formers out of balsa - at least some like F9 and F10 at the tail as I had the strength in the fibreglass and didn't need to double up with the formers, unlike the balsa version. Hey ho!

Peter Garsden17/03/2020 21:07:26
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1710 forum posts
1296 photos

I am whiling away the time adding detail to the cockpit. I was looking at photos and realised that pipes come from the various pieces of machinery to each other and the cockpit.

I had some copper wire (one of those things that will come in handy one day), so I used it as the basis and threaded on black shrink tubing as pipe outers

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Peter Garsden21/03/2020 16:10:15
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1710 forum posts
1296 photos

Isolation and Corona = Good building time - time stolen to do "those jobs you never get round to"

Algebra has never been my strong point.

Still the build goes on despite postponement. I can always test fly the Sabre, get it set up, then store it ready for the event. I know this is against the rules but I am a maverick at hear.

Have covered the wings with a mixture of Solarfilm and Glosstex. The issue is that this version is covered in cream, and I much prefer film to paint, so I hunted for something suitable. Solarfilm have sold out of Cream. Oracover cream is a dirty brown. I sent it back. Glosstex is is a bit heavy but is like plain Solartex with a paint layer already applied. Strange stuff. We will see how much weight it adds on top of the previous 2.5lbs already logged above.15848011392741777769606.jpg

I was planning silicone hinges. I made top hinges for the ailerons and bottom hinges for the flaps. I sanded down the covering, applied Prymol, and syringed in the silicone. I let it go off. Sadly, when the tape came off, it didn't stick, so I pulled it off and went for Blenderm Tape, which I have never used before. It works anyway. A layer top, then fold it over and apply a layer underneath.

I have nearly finished covering the fuselage. the fin and tail are done, but right in the middle, the postman arrived and ..........

Edited By Peter Garsden on 21/03/2020 16:12:38

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