Puffin RCM-Pelikan Grace 2.66M Build Thread

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[MooSey]

When I started sloping last summer I happened to be at Westbury Whitehorse with little lift. My (overweight) X-it was barely maintaining altitude. I heard a swoosh and looked up. A big T tailed moulded F3J glider was clearly having no such trouble whilst looping over my head! From that moment I've always had a soft spot for big T tails.

so last xmas my wife finally gave in and bought me a glider instead of the usual crap. what did I want? Well had to be a big T tail for those lazy summer  evenings really did'nt it. where do you get such a beast for xmas present type money?
Let your fingers take you to puffin Models.
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http://www.puffinmodels.com/

John does a range from RCM-Pelikan or Reichard of which both cater for the larger span glider in the budget class. Being European many are considered motor gliders but the Pelikan range provide the noses intact.
here's the blurb accompanying the model:-
"Grace, or the Puffin inspired third version of Elegant benefits from all the detail improvements found in the current Elegant kits, so it includes the same high quality epoxy glass fuselage, the wing spars are also spruce with hard balsa spar webs, and the 2.66m two piece wings are joined using a steel I beam joiner. Both Grace and Elegant use the SD 7037 wing section. Elegant remains an excellent thermal soarer, but the reduced dihedral and larger ailerons of Grace make it more suited to slope soaring and gentle aerobatics between thermal soaring sessions.2

I'll mention some of the construction during the build, but suffice to say I wanted it because it is no more (or less) a light wind sloper. it should fly from the gentlest of breeze to 15mph with ease and more so with care. whilst it's not going to roar up and down the edge snapping off rolls it will hopefully live up to it's name. Graceful.

So onto the build.
(apologies for the yellow tone photos. it's the hanger lighting)

You can see the box did'nt fit under my xmas tree! It did prop up to one side though
I will just mention I ordered the model over the phone. I had a long chat with John who gave advice and within 24hrs the box was on my doorstep. You cannot really ask for more. Top quality service.



This box came in another box. No damage to contents and everything well protected, bagged and taped. Since the grace can also be a motor glider there is a lot of parts that will be redundant for me. the accessory pack is very complete. However some items I chose to replace out of personal choice. I replaced wing control rods and clevices with M2 metal versions as the originals had strange clevices that required the pin to be inserted. I also had to add an internal snake as one was too short. (looked like they had been cut wrong as one was short and t'other way overlength). Im sure John would have provided me with a correct one but I was in the model shop so.......
 
The instructions read as a translation. they are perfectly understandable but you might need to read them twice to get the full picture. They manage to convey alot of info in few words.

I started with the best bit. The wings.
The wings come in 4 sections. You join them to give you two halves which use a steel bar wing joiner. They are built up wings employing a sheeted D box section at the LE and full length spar. The spar is 2 spruce strips with webs. The inboard half wing section uses CF tows embedded into the spruce section.

When I first opened the box the covering was superb. No wrinkles or bubbles anywhere. I'd since stored it at work in a hanger. I suspect the lower temps were the culprit but after a few weeks wrinkles appeared. To be honest with a built up wing I would expect to have to finish the filming.

The wing joining procedure is easy enough. The kit has two ply spar joiners with a polyhedral angle set in. The end ribs of both sections to be joined are cut to match the polyhedral angle.
The spar box is capped by the end rib on both halves so you need to employ a sharp knife to access it.



Make sure you match both sides.
The ply joiner then sits nicely in the spar box.



The two wing halves are then married together by simply using a little 30 min epoxy on the rib ends and ply joiner.
I did both wings and employed big catelogues to make sure both wings matched.
Masking tape is helpful here to stop epoxy going all over the nice film.



Here we are. A nice neat wing join. The instructions state that a bit of wide tape over the join will increase strength. I sealed the gap with some spare profilm and then added a bit of tape to the join.



I have read (from an American distributor) that the ply wing joiner is not required. Your choice but It's no trouble to fit.
The instructions do not mention a set polyhedral angle for the wing tips. There is latitude to have a fairly wide variation. The choice is yours dependent upon intended flying style I guess. I set mine how they wanted to lay naturally.

[MooSey]

The next job is to set the washout angle into the wingtips.
Again the instructions do not specify an exact angle or dimension. The fact that the wingtips match is stressed.
I laid my tips out side by side to see what I had from stock.



Note the starboard wing has less washout. I sighted down the LE to check both wings for uniformity and decided the starboard wing to be most correct with regards to a useful washout. I used a heatgun and gently twisted the tip structure of the port wing past the desired angle. Release after a 30 sec of heat and repeat until it matches the starboard wing.



I suspect only flight testing will reveal if the washout angles are correct. I'd hate to get it wrong and suffer a tipstall on a landing pattern.
Certainly I made sure the tip incidence was visually less than the inner wing section for safety.

[MooSey]

Before I fitted the radio gear into the wings I decided it may be wise to sort out the fuz attachment and servo connector apertures.
The wing fixes by means of a steel bar which passes thru the fuz and locates snugly in each wing root sparbox. The fuz wing saddle has moulding recesses for all holes required so it's just a case of check and cut then file to fit.



A brass receiver box is epoxied into the wing when you have achieved the correct fitment of the joiner.
The kit supplies you with two wooden incidence dowels to ensure correct wing alignment upon fit. Wing security is then a matter of the flight lift forces taking care of it.................
Just for my own sake I decided to fit fore and aft incidence pegs. I had some carbon tube to hand so used that. The wing roots are dot marked for location so I epoxied the cf tubes in each side. I also fitted matching brass receiver tubes into the fuz.  I arranged it so each wing had two cf pegs which passed into the fuz and met in the middle. This gave no chance of incorrect incidence and a bit of reinforcement local to the wing saddle.
Wing security was then a case of old fashioned tape.





Here are the fuz mounted receiver tubes and sleeve.
Note the cf tows around the saddle.
The fuz is a light layup and is a bit squashy near the canopy opening. Considering the electric version has a large ply battery tray in this area I decided to omitt that but use a light layer of glass fibre and cf tow to provide a bit more strength. Combined with the wing cross tubes it's now much more solid.



Now the wing mounting and servo cable openings were complete it was time to get the wing looms done in preparation for radio.
The actual layout with regards to wing looms gave me a bit of a headache. As you have seen in previous pics there are two fuz apertures which match up to the wing servo cable runs. Each servo has it's own run (made of a plastic tube) which exits the wing root fore and aft of the joiner. This arrangement rules out any self automating single connector solutions such as MPX green or greys. The thought of just using normal 3 pin servo connectors without a means of locking does bear thinking about. A trawl here revealed that Ashlock connectors were what I needed and indeed they were!




So to prevent having to thread your cables thru and fiddle with the receiver each time you rigged up I made a set of short leads from Rx to fuz wing saddle and corresponding wing runs. The Ashlock connectors are terminated so you cannot cross connect from say port ail to stbd flap etc. I also put little idents on because im a bit sad like that!



Clearly in order to terminate the servo cables I had to have the servos laid in! So thats the next job in order to complete the wing.
As I've mentioned the servo cables run down plastic tube channels which makes things nice and easy. This is when you find out if your wing join was square and the aileron run is'nt blocked Needless to say when you first join the wings pop a bit of grease into the cable run to prevent epoxy blocking it.
With the servos taped in and the cables terminated you can now check everything works and do some coarse radio tuning. eg setting reverses etc.
Heres a servo bay ready to accept it's new occupant.



For the flap servos I used the recommended HS81MG's as i had some in stock. Not my favourite servo but adequate. I chose to secure them with cubitts mounts which are in fact utterly ace if they fit your particular build.
The instructions suggest you use the double sided sticky pads. Out of curiosity I tried one but found the servo wobbled around on top. No no then.



For the aileron servos I fitted HS65's. These are below spec according to recommendation. However in my book they are far superior to 81's. Considering the ailerons are low torque control surfaces I suspect they will be perfect.
Cubitts mounts don't fit 65 size servos so you'll have to employ your own mounting method. I simply epoxied them in after rigging etc.
As I mentioned at the start I chose to replace the stock control rods with M2 metal rods and clevices. You can see an installation in a previous pic. The horns supplied are suitable for purpose and fit nicely.
Note the flaps are bottom driven. I have no experience yet of flap linkage but understand this geometry can cause slop. It's not a racing glider and the linkages feel fine to me. I'll come back to the actual set up and rigging later.

I guess that leaves the wings pretty much complete apart from final rigging and set up.
Onto the fuz then for the home run.

[MooSey]

Sorry for delays. Im having troubles with my pesky pc.
The build is complete and I had a wonderful maiden today so I've just got to document the rest of the build and hopefully get a video.

[mr ed]

Nice one. Looks a great bird for summer winds.

[MooSey]

Righto. Im back so onwards.
The tail.

The horizontal stab is fitted first. A simple spruce bearer is glued inside the tail mount and drilled to accomodate anchor nuts. The stab is drilled and fitted with metal mountings to match.
The stab is just flat balsa section, not built up. The elevator is a strip affair with plenty of throw. A small horn is ca'd on. There is scope to make a nicer built up section stab if you want. I'll wait till mine breaks or warps as the supplied job is fit for purpose just not as lovely as built up offerings go.........



The elevator horn is attached to a snake. This is secured to the fin/rudder spar. To make the stabilizer easy to remove a simple 90 deg bend is all that is required being cut overlength.



The rudder is a built up affair and nicely done. This is attached via mylar hinges to the fin/rudder spar. Itself supplied ready shaped. All that needs doing is a check fit and fettle followed with epoxy. The rudder hinges simply glue into the precut fin slots. Mine went together well. The elevator snake as mentioned is secured to the top of the fin spar.



Behold the mighty T-tail



Worth mentioning that my stab did not sit squarely upon it's perch. I used insulating tape to build up levels to achieve squareness. I currently tweaking this as a flight trim aid. The incidence appears fine.

[MooSey]

Oh yes. The rudder snake has no exit fairing as standard. The one you see is a fairing I purchased to make it all nice and tickety boo.

[Mudflap]

A nice tidy build MooSey, I've ordered a Elegant, same fus I believe, looking forward to building it, should be here tomorrow

Mat

[Woodstock]

Good one, Moo .  How about some full-length, full-frontal portraits ?

Chris

[MooSey]

Still got more to document. I was rudely interrupted by guests for supper

[MooSey]

Now the pointy end. This is a pure sloper (and rightly so!) so no need to go butchering the nose off. The kit does include instructios and motor mount if you want to go electric.

A picture speaks a thousand words so heres the radio fit.



The supplied radio tray is precut for servos and switch.I mounted it as far forward as possible. The Rx is snuggly resting in a block of neoprene type foam. It's actually a sanding block that comes in a micro mesh plastic/perspex polishing kit. Perfect for the job.
Battery is  a 2700maH 4 cell brick. I did'nt weigh the amount but a little ballast is needed in the nose to aqquire the c of g.
The canopy is held on with a sprung catch affair that's easy enough to mount.
I rather enjoyed the radio fit. Its very spacious as seen so you can make a nice neat job. Note also the foam bulkhead separating the wiring looms and workmanlike wing mount area.

And here's the finished glider.



Aspect ratio and flying controls

[MooSey]

Now the flying part.

Here it gets embarrassing on my part...... She's actually had two maidens
First time out post build. Freshly charged batteries and a light NW. I headed to the NW slope at Whitesheet. Strangely when I got there the wind dropped. I rigged her and took some photos.
Wind dropped further to but a breath upon my face.
Hell thought I! I've got wingspan which makes her an antigravity machine. I've seen Pete Cubitt fly here in such condtions!
So I shoved off.
Oooh, tail heavy (initially i had c of g at suggested aft cos normally instructions are limp wristed here) twitchy in pitch. Big roll to port. And sinking.
Turned her back and managed a slope landing.
bu**er. Bit of tweaking and trimming. Stupidly I decided for another launch.
Off she went. Trim stbd, trim trim trim level, still twitchy in pitch. And then came the sink............... If you are familiar with Whitesheet NW slope you'll know there is a dead 'ard old dead tree slap on it. Covered in thorns and brambles too. The Grace had pasted over the tree threshold before the sink. The decision now was to make a bottom of the slope land out or risk a tip stall and bring her back. Being a t**t I turned her for home. Dip the nose for speed and she turned in nice ready for a run in and final flare and turn. That glider looks big by the tree I thought. Must be my perception because I have'nt had a glider with as large a span as this before................ Im sure shes over it though.................Thwock
Yep into said dead tree of Mordor and then amongst the thorns for good measure.
F$#k. I said aloud and rightly so for being a knob.
The rescue mission returned a casualty with a big hole in the port LE, two broken servos and numerous gouges in the lovely film.
Luckily the the main spar was unscathed. Since I was busy I gave her to my pops to repair. He did the sheeting and ribs on the wing and I finished off the cosmetics and servo gears etc.
Lesson learnt.
No matter how keen you are never rush a maiden unless conditions are right. I'll put that down to experience. I have only been flying since last summer so a certain enthusiasm can be excused.

Maiden "The return"

After the repairs were carried out I was slightly more cautious and decided wind on the slope might help a little. A 15mph+ on the SW of Whitesheet
was perfect. A club member launched for me and up she went.
If you've never flown a bigger glider you're in for a treat. After a little trimming she went up and up. I had reset the c of g so pitch was good now. Roll was regal although with coupled flaps and snapflap she'll haul round smartly. Loops are classicly executed and wingovers with flypasts are what it's all about. Full TE camber results in mucho climb although does result in much less roll authority due to limited downthrows on the 'rons.
This is the first glider I've had with crow. All I can say is "sweet"
The best description of her flying is her namesake really. Im glad i fitted a large Rx battery, this is one that is just a pleasure to fly. Not a F3F rocket, not a 60" screamer, not a mad acrobat, just an enjoyable classic relaxing bird that eats the sky without asking for anything in return.

Conclusion.

It's difficult to comment on it's value now we see so many offerings of similar span fresh from China. In comparison it's not a laser cut copycat clone. It's built in Europe by hand and nicely done. The instructions are adequate although you need to be able to read between the lines and apply some aeromodel sense in places. The kit is comprehensive although many will choose to replace parts with their own choice as i did.
The fact that it's a built up wing carries some penalty in setting up and trimming. It's no drama. You just need to measure and balance everything and slowly tweak it to your liking over time. I guess it's more like the more old fashioned kits rather than the modern perfectly made ARTF and moulded examles.
I love the classic lines, built up wing and T-tail. She's the perfect girl to fly for relaxing and enjoying a few hours at the slope.
I wholeheartedly recommend her for what she is. Don't expect an acme pop out the box ready to fly kit. Do expect to spend some time assembling and balancing. Don't expect to find fibreglass with the strength of a canoe hull and paint 2" thick. It's built to a price and I reckon all in all it's a fair price for the returns.
She's a keeper for me 

[yellowblue]

Nice one...I think you made the right choice in your first big bird, you will have learnt more with this about flying (Your first maiden) than if you had gone straight onto a moldie. Hope you have many hours of fun with it.
 

[MooSey]

Now for sale.
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HERE

Need funds for nice F3 mouldy

[Big Un]

Flew your Grace today Mike - She is delightful - Grace is a very apt name.
Lovely eveing for some gentle soaring apart from a westerly wind and a low setting sun!
But looking forward to the next time I get here airbourne

Hope you get you mouldie.

Cheers

Paul

[MooSey]

Paul thats great news
How was the trim? As I mentioned trimming the tail stab was an ongoing process.
Delightful is'nt she.

I've since been turning my Mini Blade into a hooligan machine and have ordered a Javelin 3m mouldie from Sloperacer.

Hope you get many hours of pleasure from her.