CMP Cessna Skylane

[Bernard Petro]

Well done Bob. Congrats - leaves us all green with envy - but nou ja!!!

[Bob Cotsford]

thanks Bernard, it'll be my first ARTF so something I'm looking forward to.

First - many thanks to Magicalia! Christmas has come early this year

So far I've just opened the box and admired the bits - very nicely finished, even down to the corrugations on the control surfaces. Barb type hinges, and lots of them so no worries about the hinge strengths, cf tube pushrods with neat end fittings to take standard spoke type end fittings, all the little bits and pieces look reasonable quality, not what I'd been lead to expect from a mid-range ARTF. It even includes mountings for ic or electric power!

The only thing I've the least concern with are the servo-end pushrod fittings, which are clamp-type - you know the ones that clamp the pushrod wire with a grub screw. They'll probably be replaced with the usual threaded rods and fittings or wire and Z-bends as appropriate.

The wing components include 4 servo mounting 'lids' (what do you call them for mounting the servos in the wing?) with built in exit fairings. Again, the control surfaces have neat corrugations to add atmosphere, the hinge positions are pre-drilled, and appear to have been done accurately. Pivot points of the hinges are to be set into the surfaces which along with shrouded main panels, give a nice scale appearance with no nasty gaps.

For the most part the instructions are easy to understand, being purely diagrammatic with no text, but I've no doubt the few less-clear areas will make sense with all the appropriate parts in my hands. Definitely a case of doing a dry run before final assembly! Apparently something on the tailplane fairing needs sanding with a flate plate sander, but I'm not sure exactly what yet. Perhaps to key it for gluing onm the tailplane halves?

Right now the list to complete seems to be:

Engine - SC65 4st - check!

Servos * 7 - a bit of reorganizing between models - check!

Rx - check!

Battery and switch - ok, we're looking at driving 5 servos full time, with an extra two on flaps on landing, better get a bigger pack in than the 700s I've got now.

Extension leads - two long ones for ailerons, and two shorter ones for flaps, plus two Y-leads to couple aileron and flap pairs - need to order them.

Tools - no problem - soldering iron to remove excess film, a few drill bits and the dremel, and screwdrivers - check!

Adhesives - half a tube of Araldite should be plenty, there's very little needed- check!

I'm nearing completion of a CAP Gladiator, and I have to say that adding up the cost of fittings and finishing materials I've used on that, I really don't know how the Chinese can sell such comprehensive ARTFs at these sorts of prices, never mind cheaper labour - my labour was free!

If anyone's interested I'll tell you more as things progress. Can't promise much in the way of pics though.

[David Ashby - Moderator]

Thanks Bob - it would be nice to see how she goes and how you get on with her - keep us posted.

David.

[Graham Ross]

Nice Model .i would love to win this baby lol

[Bob Cotsford]

assembly has come to a halt - I'm waiting on some Y-leads from Giantcod, with luck they should be in the post tomorrow.

A couple of points i've found - those nice hinges are made of extremely brittle plastic. The warning came as I twisted the last one in the elevators to align it - it snapped. Waggling a few others left me with three broken hinges without trying. Luckily I was using 24 hour Araldite to fit them so I could still pull out the ones I'd already fitted and replace them with Robart ones.

The EZ connectors all seem to be drilled oversize prior to tapping, in fact a couple were so oversize there was no thread at all! I followed my initial instinct and used a combination of swing keepers, solder on adaptors and Z bends instead.

Last bad point(?) - the cowl and spats are extremely thin walled and flexible - so flexible the paint flakes off the cowling quite easily. Once it's screwed onto the front of the plane it's fine though. From the reports I've read on a US forum these models tend to end up tail heavy needing 1/2 - 1 lb of ballast - in which case a heavier moulding for the cowl would be an advantage. I'll try to get the model assembled to check where it balances later tonight!

Now for the good bits - everything is incredably accurate, even down to the dimples for drilling the tailpane incidence pegs. Centreline and thrustlines are clearly moulded into the engine bulkhead making lining the engine up really easy. Servo trays are built in, so it's just a matter of screwing in a set of standard servos and adjusting the pushrods to suit.  The fuel tank looks a good quality item with steel washers either side of the bung to ensure a good seal - how many times have I had the more common plastic washers distort before a decent seal occurs?

Cabin glazing is marked with trim lines - absolutely dead on. Even the 3d moulded windscreen fits perfectly against the fuselage. I fitted them with a polyurethane contact adhesive sold for attaching replacement soles on shoes, it seems to have done the job with no staining anywhere.

The SC65FS exhaust fits straight into the moulded cutaway in the nose, it's just a pity so much cylinder head is exposed - can't win them all can you.

More as it happens! 

[Bob Cotsford]

well, first I stuck it on the scales - 3.2Kg before balancing! That's a tad over 7lb, CMP give a range of 2.95-3.1Kg, optimistic to say the least seeing as you have little control over the final weight.

Ok, so CofG range is given as being between 68 and 73mm back from the root LE - that's another 200gm of church roof on the engine bearers to get within that range, giving an AUW of 3.4Kg or 7 1/2lb. With a root chord of 250mm, that will be on the 30% point so should be safe enough.

Roll on the weekend to see how she goes!

I've just reread my previous post - re the glazing, the mouldings are supplied in need of trimming, the trim lines I referred to being the  moulded cutting lines.  Trimming to these lines resulted in a perfect fit within the cabin leaving a maximum gluing area.  the windscreen has a white frame painted on the outside - trim to the line, glue it in place and the join is automatically hidden.

My expectations for this model were coloured by comments I'd read about artf's where glued joints weren't and parts were held together by the covering - nothing like that on this model as far as I can see - all the fuselage internal supports appear to have good sized fillets bonding them to the epoxy moulding.  So far so good.

[David Ashby - Moderator]

Cor....you don't hang about Bob ....good luck for the maiden

Any chance of a piccy?

I've just moved the thread across to models and accessories....

[Bob Cotsford]

David,

I've got the camera batteries on charge, so I'll try to assemble it in the garden so you can see how it looks. All that's left is to actually attach the lead to the engine bearers, secure the tank and battery and fit the lower strut fixing, so I'm still optimistic for a maiden this weekend, weather permitting.

Believe me, things don't usually go together this quickly - comes of having all the decisions made for you by the manufactorer. In comparison, I've been humming and harring over the Gladiator struts and u/c leg fairings for weeks while fiddling with little things like hiding the remote glow connector and filler.

If I'd used 5 minute epoxy instead of 24 hour, it would have been ready to fly last weekend!

Is there a limit on file size for the gallery/ I should really go and look, but as you are asking for pics...

[David Ashby - Moderator]

Not if you use photobucket.com which resizes them when you bring them across. 3mb per album otherwise Bob - about 12 pics at 250kb each.

You said this is your first ARTF - has it tempted you to the 'dark side'  so to speak or will this be your last?

[Bob Cotsford]

It certainly hasn't put me off them David, but I still enjoy turning a bunch of twigs into an airplane - if only briefly before completing the conversion to matchsticks!

I think I'd be more tempted by  by an ARTF pattern or sport model if I found myself with nothing near airworthy, after this initiation.  I am very impressed with the sheer value for money (esp. when it's free!) compared to something like the CAP Gladiator.  The kits are £189, I've spent around £50-60 on tex, trim and paint, compared to £120 for a nicely finished character scale Cessna.

[David Ashby - Moderator]

Yup you're right Bob. I've looked at many ARTFs and though that I couldn't make this for the money....that's not the only consideration of course.

[Bob Cotsford]

right, lets give it a go:

 

[Bob Cotsford]

and inside:

 

[al johnson]

looks great,  its going to give  some lucky person many hours of enjoyment this summer!

[Bob Cotsford]

finally this weekend I got a chance to get down to the field with the Skylane.

At 7 1/2lb all up and 65" span, I was a little curious how it would perform with CMP's recommended engine range - 40 to 50 2 st, 50-63 4st.  I'd put an SC FS65 4 st up front, along with 1/2lb of ballast.

At the field I fitted the wings, 4 servo connectors and 6 3mm screws and it was ready to go.   For the first attempt I fitted a 12*6 prop.  Range check ok, everything moving in the right direction so off she goes.

Waddling like a sick duck, even downhill there was never a hope of getting up to flying speed.  An attempt to turn round and taxi back tripped the model up - curious, as the field isn't that rough.

Once I got the model back it was obvious why it wasn't going anywhere, the nosewheel was twisted sideways and the leg bent back, pushing the spat into the ground.  I assumed it happened on turning round, but I was wrong.  On the second attempt, I got the same result, but this time I saw it happen - after a couple of yards the noseleg just folded back, acting like an anchor.  The noseleg is a really soft material, no way would it ever survive a landing if it couldn't cope with taxying across a grass field! 

Next step is to find a sturdier noseleg and a set of 3" wheels, throw the spats back in the box, and try again.  I still can't help feeling this model will need at least a .60 2st or .got90 4st to cope with grass sites though. 

[Former Member]

[This posting has been removed]

[Bob Cotsford]

3" wheels all round and a Radio Active 8swg noseleg substituted for the original noodle unit, and off to the field.  Ok it still takes a loooong ground run with a  decent breeze but fly it does.  Actuall, once free of the ground, the 65 4st seemed the ideal size for pottering round or mild aerobatics - rolls are quite axial, loops big and lazy, stall turns look good, but using the recommended maximum throw on the elevator can easily get you into tip-stalling behaviour if you're heavy-handed.  The stall was quite benign, and dropping the flaps fully (45 degrees or so) gives a steep approach or really slow straight and level.  20 degrees of flap definitely helps reduce the take-off run.

The only drawback with the model for me, is that it isn't built for grass strips - bowling greens would be ok, but not farmers fields.  It's too heavy, so when it trips up on the inevitable grass tufts it's got a lot of energy driving it forward. The fibreglass undercarriage legs feel a bit squidgy after 4 landings, and the ali wing joiner tube has developed a bit of a bow, so this model will be reserved for the other club site I use, which has a much better surface.  I'm just glad I left the cowl off for the first flights as I'm pretty sure it wouldn't have survived the trips over the noseleg.