Smooth Operator designed by Pete Tindall

[David Hayward.]

12 minutes ago, Geoff S said:

I remember these from several years back (10+?).  It looks to be a very well designed and produced kit that will result in a stunning model.  You're making a neat job.  Are the aileron servo mounts precut?

Yes they are, if you look back at image 20, you will see as supplied the servo cutout is oval, so just requires cutting square and fitting balsa to form the box.

 

[Jonathan M]

15 hours ago, Geoff S said:

I remember these from several years back (10+?).  It looks to be a very well designed and produced kit that will result in a stunning model.  You're making a neat job.  Are the aileron servo mounts precut?

 

I agree with Geoff.  Your presentation is also clear and concise, so a pleasure to follow.

[David Foley]

Just saw the video on your build, very well done. I noticed on photo No.2 above a pattern plane in the back round,

Aerostar ? maybe.

[David Hayward.]

25 minutes ago, David Foley said:

Just saw the video on your build, very well done. I noticed on photo No.2 above a pattern plane in the back round,

Aerostar ? maybe.

I have a hangar one kits Calypso on the bench which you can probably see in some shots, which is waiting to be covered but I think I'll finish the S.O now I've got into it.

[David Hayward.]

 

Wing tips don’t normally cause me any problems but the kit was supplied with two pretty chunky wing tips which were not long enough to span the chord of the wing and aileron – image 28-b.

 

 

Making another pair of wing tips a suitable length would not be a problem, but I wondered if I was missing something, so spoke with David at Balsa Cabin, who was a little confused himself to begin with, but concluded that the wing tips were not required. The Smooth Operator is based on a CAP 222 which does not have wing tips as such, the wing and aileron just finish flush at the end. Having said all of that I felt I wanted to provide some degree of protection to the ends of the wings and ailerons, which are quite vulnerable being just veneered foam, so added 15mm wide end caps – image 28.

 

 

At this point I randomly decided it was time to fit the canopy which fits the preformed shape of the front and rear decks very nicely – image 30.

 

Next up was fitting three servo’s across the fuselage on supplied ply rails and mounting switch onto a piece of lite ply. I fitted 2mm piano wire pushrods to each elevator supported through sections of snake outer at two points along the fuselage and smaller diameter tubes at the point where the rods exit the fuselage. Rudder closed loop system also installed at this time – images 31,32. The open structure of the fuselage certainly made this all very easy to do.

 

 

 

 

[Masher]

Nice to see the details on this build. One question: I like the dual elevator pushrods method but how do you get round them poking through when doing the covering? Obviously the 'Y' arrangement is a build in solution so can't be pulled out of the way when covering ... or?

Thanks

[David Hayward.]

7 minutes ago, Masher said:

Nice to see the details on this build. One question: I like the dual elevator pushrods method but how do you get round them poking through when doing the covering? Obviously the 'Y' arrangement is a build in solution so can't be pulled out of the way when covering ... or?

Thanks

With reference to image 32 the pushrod guide tubes on each side just about exit through the fuselage side, providing enough surface for the covering to stick. When covering I will cut a small slit in the material at the point where the rod exits and slide it into position. Same technique for the rudder closed loop tubes. Hope this helps.

[Masher]

Yes it does, thanks 

[David Hayward.]

 

 

 

 

 

After much deliberation I have decided to go for a 91 size engine despite having an SC 120 FS looking for a home. I think a 91 will have ample power for this model combined with my very moderate skill level. I found an OS 91FS Surpass on ebay for a good price, which I have now had a chance to check over and run up in my test stand; all seems fine.

 

Time to get it in the model. Now the only detail I have for positioning the engine is actually the engine cowl, nothing in the instructions and no plan to refer to, however, the cowl has a mould line running horizontally around its perimeter. This line locates the vertical height of the engine on the firewall, so nothing more required really – image 33.

 

Instructions recommend 2-3 degrees of side thrust and 1 degree of down thrust. I opted for 2.5 degrees side thrust and 1 degree of down thrust. In order to calculate the necessary spacing to achieve the required side & down thrust plus the offset to ensure the crankshaft exits at the centre of the cowl I have produced an Excel ‘tool’ that calculates this for me. A link here to download a copy should this be of interest; note it works best on a PC or laptop, not so good on tablet or phone. https://www.cadmac.co.uk/index_htm_files/Engine%20Mount%20Spacing%20and%20Offset%20Calculator%20-%20Final-v2.xlsx

 

Image 34 shows the engine mount in place, plus blocks fitted for engine cowl fixings; top fixing for cowl actually goes into the engine mount.

 

With the engine in place I then set about cutting holes in the fairing with careful measurement to hopefully ensure they came out in the right places – image 35.

 

 

[Jonathan M]

I'm impressed that you went for an engine at the bottom end of the size range, which should be more than enough to fly smoothly using the full throttle range and the model's own kinetic energy.

 

Useful offset tool too!

 

I see you infilled the lightening-holes in the sides above the wing.  I couldn't work out why they were needed there in the first place.

[David Hayward.]

10 minutes ago, Jonathan M said:

I'm impressed that you went for an engine at the bottom end of the size range, which should be more than enough to fly smoothly using the full throttle range and the model's own kinetic energy.

 

Useful offset tool too!

 

I see you infilled the lightening-holes in the sides above the wing.  I couldn't work out why they were needed there in the first place.

Yes I feel a 91 will be fine for me and having done a preliminary check on balance with the 91, the extra weight of the 120 (almost 12oz heavier) would have made it more difficult to get the CG as specified.

[David Hayward.]

Well with construction pretty much complete its time to check the CG. Instructions advise this should be 6” back from the mid-point leading edge, so with that marked on the wing and some card providing protection to the veneer – image 36.

 

Model inverted and placed on CG stand; it balanced about 3mm in front of the marked position, so by the time its covered it will probably be spot on. Very happy I went for the OS 91 as the SC 120 was about 12oz heavier and would have meant weight in the tail to balance – image 37.

 

And model now ready for covering and decoration – image 38.

 

[David Hayward.]

Covering, painting and trim now complete, (that was almost 6 days of my life), the model weighs in at 7½ lb, so with the 91 up front should be fine. A very simple design, nothing elaborate,  I used Solarfilm Supershrink Polyester, Dark Blue (underside of wings), and White over the entire model apart from the cockpit and cowl which are painted with Guild Dark Blue. Also gave the cowl a couple of coats of clear fuel proofer.

 

The lettering is from Tribal Signs and is individual self adhesive vinyl letters supplied on a ‘carrier’ tape, to your spec, size, font etc and then once fixed in position, backing tape removed; very easy to do and not expensive. The club logo was printed onto clear vinyl self adhesive sheets using a standard ink jet printer; sheets were sourced from QP Media Ltd. After printing left to dry for 24 hours and then sprayed with gloss fuel proofer, then left for a few days somewhere warm, before applying to the model.

 

Just final setup and checks to do and then to the flying field. I’ll give a report, possibly video on how that goes.

 

 

 

 

Edited February 15 by David Hayward.

[Jonathan M]

 Wow!

[David Foley]

Well done. Good luck with Test flight.

[toto]

Very nice kit and a great video to follow along too as well. ..... looks superb.

 

Toto

[Cuban8]

Very nice build and covering job...............but please, get shot of the dolly and replace with a decent pilot figure😭

[Don Fry]

1 hour ago, Cuban8 said:

Very nice build and covering job...............but please, get shot of the dolly and replace with a decent pilot figure😭

Think you need Spec-savers, Cuban. I think the lady is clothed.

[toto]

I like the foam veneered wings. Taking some of the build out of the equation. Maybe a good choice on the way to a full build option.

 

I'm assuming this could be converted for electric flight .

 

Toto

[David Hayward.]

16 minutes ago, toto said:

I like the foam veneered wings. Taking some of the build out of the equation. Maybe a good choice on the way to a full build option.

 

I'm assuming this could be converted for electric flight .

 

Toto

Generally I prefer built up wings for a number of reasons, however, on this ocassion I was looking specifically for a quick build project, being aerobatic and suitable for 4 stroke i.c. I came across this on the Balsa Cabin website and it fitted the bill perfectly. With regard to conversion to electric, I'm not best qualified to say as I only fly i.c., but one challenge I imagine maybe providing easy access to the battery, however, I'm sure the electric boys would find a way.

[toto]

Detaching the bottom of the fuselage looks like one of the trickiest parts. Maybe I'm not quite understanding how you get access to that part.

 

Other than that, there are not too many scary bits.

 

Toto

[David Hayward.]

3 minutes ago, toto said:

Detaching the bottom of the fuselage looks like one of the trickiest parts. Maybe I'm not quite understanding how you get access to that part.

 

Other than that, there are not too many scary bits.

 

Toto

I think the most likely route would be a mod to the top foam veneered decking.

[Richard Ashworth]

I’m in the final stages of making one - electric, 1200W. Top hatch is easy - just razor saw cut a middle section out and ply face all four cut edges, a couple of bamboo pins at the front and a sprung hatch pin at the rear. Slight angle on the rear cut, to make inserting and removing the hatch easier. The cockpit sides are easily adjusted to fit the “new” gap between front and rear decks. 

The biggest challenge I had was getting a single battery plate piece of 3mm ply (with cutouts for cooling and battery straps) to fit. The fuz sides narrow both front to back and top to bottom. Solved with rails on both fuz sides deep enough for 5000 6S battery and a piece of card as a template slowly cut down size. Ply tray cut to template and final adjustment then epoxy front and both sides. Its probably the most solid front on any of my builds!

There are minimal instructions with the kit, no plan, brief written overview with throws & CofG, some general sketches for facings on veneered parts and a bundle of A4 photos some of which are confusing as they show both pre and post what looks like a 2005 minor design change on rear former and wing bolt/bolts.

I would agree it’s an easy IC build for an experienced builder but even after six previous leccy kit builds including conversions, I have done a lot of head scratching and learned quite a few new (old) construction techniques. I have to admit I felt a tad overfaced for a while at the start. I am putting a reg no on the wing F-JGFI. French CAP origins and thanks to a friend - Just Go For It!

Biggest oops, on one aileron I got giddy, wanted to progress quickly, and put the leading edge facing on BEFORE I had built the bolt horn into the wing (photo 15th Jan no 22). Easily remedied by cutting out about 4 cm of facing, fitting the horn and splicing in a new piece of facing. Think twice etc.

No build photos but will post a pic when complete - simple colour scheme, bright red fuz, white with red aileron and tip wings.

 

[David Hayward.]

Thanks for posting Richard, interesting to hear about your experience. I found some of the pictures confusing as well, but once you get get your head round the unconventional wing fixing, all straightforward. Look forward to seeing you pictures.

[toto]

I would like one after seeing what looks like a straight forward build with well made parts. No hassle of building the wing which caused me issues with my previous attempt at what was a relatively straight forward build. The sky 40.

 

The only thing that stopped me ordering it was the lack of clear instructions for conversion to leccy otherwise it would have been gathering more dust with the others Ihave. It looks like a sensible progression from assembling foamies to full on balsa kits.

 

David's is a very inspiring example.

 

Toto

Edited February 22 by toto