Topic: Sequoia Systems Greenfinch234 Build

Following that a frantic rub down with some 60 grit followed by a couple of finer grades and they've taken shape nicely

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Mine have come out quite a bit narrower than Sequoia intend but I like 'em, so there

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This is just a kind of 'rough shaping' for now, I'll finish them up a lot nicer before I cover, or paint them. Haven't decided which way to go on that score yet. I built a Gee Bee Z from Jamara recently and managed the spats on that with profilm and they turned out quite nice so might do the same thing with these.

Whilst my sanding head was on this afternoon I gave the fuz a quick going over too which I wanted to do before fitting the stringers. That done I could finally fit them, here's how they look...

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You can also see epoxy glass lug sticking out at the bottom of the rear fuselage, this is the one mentioned earlier that the vee struts bolt too.

Now that's all done I decided to bolt everything back together, for no other reason than that I simply couldn't resist a butchers'

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A look at the stab struts. The trunnions mounted in the tailplane halves are just pushed in for the mo 'cause I don't want to glue them in until I've covered it. Gives you an idea how they'll look though. I've also shaped the tail feathers today as you can see, PHEW, big sanding session today!!

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Another quick one so you can see the spats properly...

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Think this bird needs some wings now folks, I've been looking forward to this bit for AGES 

TTFN,

Greg

Evening folks,

Been a bit busy these last few days helping a friend who's building a new rally cross race car for next season. Made the fatal error of sounding confident about fibre glassing and got roped in to mould the ducting for the rear mounted radiator, fun, but it's taken me away from the greenfinch

Anyway I have managed to get a bit done so i'll fill you in. Here's a shot of the first parts required for one wing panel, note these are the FIRST parts, there's a fair few more as the wing progresses what with balsa sheeting, ailerons, wingtips etc. to come later.

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The pointy bit in the middle is the main spar web, nice innit!! you can see on the right the two epoxy glass joiners that will eventually slot into the fuse and hold the wing on.

First job is to bush the two aileron hinges that are built into the back end of two of the ribs, usual procedure of pushing a length of 2mm tubing into the hole, drop of cyano and slice off flush...

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Strangely pleasing 

These carry the usual 1mm wire, which runs the full length of the aileron before coming out at the wing root. there is a slot in the fuselage side that takes the end of the wire so that it can be left slightly proud of the wing root for easy removal

Next up the ribs are slotted down on to the main spar web. These fit with the usual accuracy and slot home with a satisfying 'thunk'

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The leading edge goes in next and slots in from the front of the ribs, going all the way back to the spar web

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The photo makes it look like the edges are 'frilly', they're not, super smooth as usual 

The rear spar web goes on next. There's a bit of twisting of ribs here as the web needs to slot over the aileron hinges before it can slot down through the ribs to either side. Doesn't pose a problem though as the structure is not glued at all yet

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The main and rear spar lower 'caps' go on now, along with the rear spar upper cap. These make the spars into an 'I' beam and will be strong. Clever design again though as the rear spar caps also act as shrouds for the aileron. Coupled with the fact that the ailerons have a round leading edge means that they are gapless, and therefore should be very efficient.

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You can see a piece of the ubiquitous 2mm tubing has been inserted through the first three ribs. This carries the aileron hinge wire through to where it needs to be.

S'all I've got for now folks,

See you again soon,

Greg

Hi Greg,

Inspired by your nonpareil build thread, I've finally ordered my own Greenfinch. I've got an electrocuted Sig Hog Bipe on the building board at the moment, but that's almost ready to fly.

I built a "real" TEAM MiniMax a few years ago, but I reckon the Greenfinch will be a more satisfying build!

Keep up the posts 

Paul,

Nice one

It really is enjoyable and I hope you enjoy it as much as I have. Let us know how the hog flies!!

Just googled 'nonpareil', THANKS  

Keep us up to date as to how your finch goes,

Greg

Greg,
Just a quick note to say that I now have my own Greenfinch kit safely in "the shed" and will be returning to the start of this thread to learn how you have made such excellent work on yours.
Paul

Paul,

Thank you for the compliments, glad to hear you're Finch arrived safely. I doubt you'll need any help as the instructions are pretty comprehensive but if you do hit a snag don't hesitate to post a question here or PM me. Roger from Sequoia is also very keen to help if need be so just bung him an e-mail or give him a call. Hope you enjoy it as much as I have.

Ok folks not much to report as I've been pretty snowed under this week, no pun intended 

The diagonal ribs are next in and will make the wing panel very torsionally stiff when it's all glued together. Incidentally in case I haven't already mentioned it this bird is constructed in a fairly unconventional manner, i.e. instead of gluing each part in as you go whole assemblies are slotted together and then 'superphatic' thin resin is dotted along the joints before being brushed in. Works a treat and is really quite therapeutic, just gotta watch that no joints are missed.

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You can see a step where the upper and lower trailing edge panels don't quite meet at the back. This is eventually filled with balsa parts that are then sanded to section, I'm assuming this is done so that you don't end up with a double thickness ply trailing edge which might look a little clunky. The main spar will also receive an upper flange in time, the instructions state that the wingtip has to go on first though so that's what i'll do....

Here are the required parts...

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The balsa strips sitting outside of the main tip panel are doublers that will strengthen the tip. The instructions also urge that cyano is used to bond them on so that the tip is as hard as possible and more 'ding proof'

The tip panel and the ribs are assembled together on to the wing panel and look like this...

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The triangular ribs just need a chamfer on their inboard edge so that they align properly. The tip panel is then moistened at the forward inboard edge so that it can curve up to meet the ply leading edge and then glued in place.

Apart from the doublers that just about completes the tip but before I can fit them the main spar flange mentioned earlier has to go on as it extends all the way to the tip. I'll be doing that next but for now, that's all I've got.

See y'all again soon,

Greg

Morning all!

Made a little more progress last night so here goes...

You can see the top main spar flange is now fitted, had to get the needle files out in order to make a level bed for it to sit into as a couple of the diagonal ribs were a touch proud. My fault as the instructions do tell you to ensure they are spot on as they are fitted. Trouble was they 'looked' pretty good until the flange was offered in where it sat slightly above the top surface in a couple of places. Not a big deal though, quick whizz through with a file had 'em sorted and it's lovely and flat now along its length.

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Also added the tip doublers at this stage and gave them a preliminary sand to level them with the tops of the tip ribs.

The wing panel is now amazingly stiff and incredibly light, hard to believe it's made almost entirely from plywood!!

As with all the flying surfaces on this model the wing panels have a ply 'facing rib' that gives a nice hard face where the wings join and this was added next followed by the epoxy glass wing joiners

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You can see in the foward joiner that there are three small holes in the section that will push into the fuselage. You'll probably recall from back when the fuze first went together that there are slots in the ply wing tongue boxes. A carbon rod passes through these slots and through one of the holes in the tongue itself. When both wings are fitted the two carbon spigots are bungied together with rubber bands and thus hold the wings on while providing crash proofing.

The notch you can just see in the top inboard edge of each joiner is there to remind you that it is the 'top' because although at first glance the tongues look straight there is actually one degree of dihedral in the lower wings and obviously gluing them in upside down would make 'em a little droopy!!

Not something someone of my calibre would miss of course 

The remainder of the inboard upper and lower sheeting parts are added in now that the joiner tongues have been bonded in, followed by my favourite feature of these wings, those lovely riblets!

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Think this is deffo going to have to be a predominantly translucent covering job folks, I want everyone to be able to see into these wings!!

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Might just be my eyes but the wing looks a bit 'wavy' along the leading edge and spar in this pic, it's not though it's straight as a die in the flesh. Some kind of optical illusion no doubt.

Not much more to do on this panel now, just gotta fit the balsa trailing edge infills and the interplane strut mount and it'll be ready for an aileron.

Back as soon as I can,

TTFN,

Greg

Loving this kit it looks so right 

Might just be my eyes but the wing looks a bit 'wavy' along the leading edge and spar in this pic, it's not though it's straight as a die in the flesh. Some kind of optical illusion no doubt.

No, it's not an optical illusion - it just looks like one

Looks a lovely kit.  I might even be tempted myself if it were about twice the size.  34" is a bit teeny for my old eyes.

Geoff

No, it's not an optical illusion - it just looks like one

  Nice one Geoff!!

Looks a lovely kit.  I might even be tempted myself if it were about twice the size.  34" is a bit teeny for my old eyes.

Geoff

Yes you're not the first person to express this view, and you're right she is very small, pretty perfect for me though 'cause I'm not exactly overburdened with room at the moment!! I got an e-mail from Roger at Sequoia yesterday as he'd seen I was at the riblet fitting stage and wanted to offer a tip that he'd thought of, so I asked him how progress was being made with the larger versions of the Greenfinch. He told me that he is just finishing a prototype of another style of Finch(Monoplane) and then he'll be getting on to the big finches (60 and 90 inch I believe but don't quote me on it!!) He also mentioned a while back that he had designed the Greenfinch to be scaleable and therefore the bigger birds shouldn't take too long to develop, apart from the fact that they may feature built up tail feathers in the same vein as the mainplanes on this one.

All the best,

Greg

Afternoon all,

While the leading edge riblets were drying I thought I'd crack on with the interplane strut socket. This is laminated together from the parts you see below...

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The resulting part is then offered in to the wing and its upper surface profiled to that of the adjoining rib. You can see below that the silicon fuel tube is inserted into the oval holes and forms a friction 'socket' that the epoxy glass tongues on the interplane struts will push into.

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The silicon tube is bonded into the socket before a ply capping piece is added over the top. As you can see the holes in the capping piece are smaller than the tube which will mean it can't pull out.

The assembly is then bonded in to the wing, here's how it looks.

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Next job was to make up the two laminations that form the balsa leading edge fillet just forward of the underside riblets.

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I also installed the trailing edge fillers which are just made from scrap balsa, and then left it clamped up to dry overnight.

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Hopefully I'll get some time tonight to shape all this then it's just the aileron servo bay to install and this panel will be finished!! Then I just gotta build another three

Catch you all later,

Greg

Morning all,

Bit more progress...

The leading and trailing edges have been sanded to section so on to the aileron servo bay, just a couple of parts needed and these form a bay with a screwed in hatch that the servo mounts to...

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I forgot to get a photo of what it looks like now they're installed but you'll be able to see it all in later shots. The option is given in the instructions to glue or tape the servo in place if the model is going to be electric powered, however there are pre-cut servo mounts included with the kit that are primarily for use when IC power is chosen. I'm gonna use those even though I'm going electric, it would seem silly not to considering they're already cut out for me, and this model will be worth about £600 by the time it's finished and I don't want to rely on a bit of sticky tape!!

Ok so the last job on this wing panel is to make the aileron...

Here's the required parts.

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The spar web took on a slight bow when released from the sheet which hasn't happened on any other parts, however it won't be a problem as it will be locked straight when installed by the tabs along its length.

The aileron is constructed by first inserting the ribs upwards onto the spar web before the upper and lower skins are clicked into place. The balsa two part ribs are then installed to finish off the ends. 

You're all wondering what ALET means right? Stands for Aileron Leading Edge Template and it is used to cut the paper leading edge sections that wrap around the little 5mm balsa segments you can see at the top of the pic.

Last job to do before assembly is to bush the control horn holes with the 2mm tubing and we're ready to go..

Here's how it looks once we've got that far...

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The slot you can see just outboard of the control horn carries the aluminium strut that joins the upper and lower ailerons, which pivots in the rearmost two bushes.

The little 5mm segments that were in the previous post are arranged along the leading edge to provide support for the paper fairing. Before they are installed though a length of the oft used 2mm tube is inserted all the way through the holes in the leading edge of the ribs and then trimmed away where the two hinge brackets mounted in the wing enter.

Now that the hinge tube is in place the aileron can be trial fitted in the wing. Had to do it just for an idea how it looks!!

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You can just see the 1mm hinge pin which extends just past the outboard hinge. this carries all the way through to the wing root where a small length is bent to enable it to be pulled out should the ailreon need removing at any stage.

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The hinge has so little friction that the aileron droops under it's own weight, which is a good sign

Once the leading edge is installed there will be almost no gap either!!

I like this plane 

See you later,

Greg

Hi Greg.

             Thank you so much for this detailed thread. I first saw this plane in the QAEF article, and it looks to be the most perfect antithesis to the ARTF pre-covered aircraft that have become the norm nowadays, whilst still encompassing the use of technology that has transformed this hobby. I have been surprised though at the lack of excitement about this plane -  the few threads that I have seen basically shooting it down as 'way too expensive' for what it is. I hope these doubters have seen your thread and now understand how subjective the cost is. Sure you can buy a much larger pre-covered airframe and kit it out for the price of the kit, but the Sequoia is WOW!! Every part is just quality, and I am getting that you are achieving  more satisfaction from this build than you could put a price on. Don't get me wrong ARTF's are fantastic (I would not have got back into this hobby a couple of years ago without them) but I find the little amount of assembly required to be a bit of an empty experience.

Anyway, I am back after a 30 year break from the hobby (golly, how things have changed - where do you put the crystals in the DX7? ) and I have just ordered the 46" spitfire plan and bits from Tony Nijhuis to get that particular warbird out of my system, so the house is goin to be a bit dusty for a while . Then I will be saving my pocket money to join what seems to be a small group of very satisfied owners of the greenfinch 234.

Once again thank you for using your time to publish this thread, and also thank you to Roger for what is a beautiful piece of engineering. I look forward to seeing the complete airframe, and reading successful flight reports,

cheers, Simon

For those of us who are less gifted (or fastidious) builders than Greg, may I add a couple of observations?

Firstly - when you are dealing with a mixture of ply and soft balsa, do remember that the balsa is far more frangible than the ply. The latter can take quite a bit of pressure when fitting components, but the balsa can't. The fuselage is particularly vulnerable when the front formers have been fitted and the two balsa sides have yet to be gathered together with the aft former sub-assembly. Yes, I am a little clumsy, but that's because I'm old.

Secondly - if you accidentally prick yourself with the point of a Swann Morton blade (easily done ... if you're clumsy), try not to bleed all over your handiwork. 

Other than that, this model is an absolute joy to build. It will punish sloppiness and richly reward forward planning, care and patience.  Respect to Sequoia and the talented Mr Moffatt.

Hi everyone,

Been away from the building board for a few days having been forced to drink mucho mucho beer in the name of christmas, it's a hard life an' all that

@mightypeesh

Thank you for your lovely comments, glad to hear you're back at it I too have the DX7 and it's a great TX for the price, don't think I'd like to trust this little beauty on 35 meg!! I've heard very good things about the Nijhuis Spitfires and I hope you enjoy the build. You are quite correct in that ARTF's have a fantastic place in the overall scene, but nothing will ever quite replace that feeling that one gets when maidening the airframe that's been on the workbench for the preceeding few months, think it's known as brown adrenalin!!

Please keep us updated on the progress of the spit, believe it or not I've never actually built a Spitfire but will. I actually have the 1/6 scale drawings by Paul Monforton which I am considering using to scratch build a MkIX. If you've never seen those drawings then I recommend a look, they are out of this world!! he also has a book out on the same subject and utilising both one could build a real Spitfire, they're that good!!

Once again thank you for the compliments, look forward to hearing that you've joined the Greenfinch club!!

Greg

@paulellis

For those of us who are less gifted (or fastidious) builders than Greg,

Thank you Paul, Though a lot of the pics in the thread are pretty 'soft focus' if you know what I mean 

You're quite right and care is needed with the balsa parts, it's pretty easy to get blase when handling the ply parts 'cause they're so strong. Believe me I've done it, you just can't see the repairs 

Thanks again and keep at it, it gets really fun when you start on the wings!!

Greg.

Right then better show you what I've been up to...

The 5mm balsa leading edge formers have been added along with the trailing edge filler piece, which you can see poking out at the end of the trailing edge as it hasn't been sanded in yet.

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Once the leading edge formers have dried they are sanded back to the ply ribs to give the correct section. I also shaped the trailing edge at this time.
 

Next up are the paper covers that form the leading edge.

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This job really is a case of practice makes perfect, the first one took me ages and eventually went in the bin, second try was a bit better and by the time I reached the other end of the aileron they were going on pretty easily. Reckon by the time I get to the fourth aileron I might actually be happy with one!!

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What I've found for those guys that are building one is that the template ALET can be used as a kind of 'squeegee' to smooth the paper onto the formers before again using it to press the paper into the join with the ply skin. This worked well for me as before doing this I was getting bulges in the paper between the formers. Roger recommends using masking tape to hold them in position and I'm sure that will work well, I have to admit that I've run out which is why I had to resort to other methods. I'm sure everyone will find their own best practice.

Just a couple of shots now to show you how the aileron looks back in the wing. You can see that the gap is pretty small and is consistant across the entire range of movement.

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It actually moves over a much greater range than that but these are the best positions I could get with it balanced on the input horn!!

Nice design eh!!

Right that's one wing finished apart from covering, I might be away a while now whilst I build the other three wing panels but i'll keep you updated of anything that's different. might also post a coupla shots as each wing panel is finished so that you can see them on the aircraft.

Ciao for now,

Greg

Best day of the Greenfinch build so far ... finished a perfect pair of spats.  That's the first time I've scratch-built wheel pants (as opposed to using ABS moulded or glass fibre) since I made a pair in 1958 (aged 12)  for a C/L Midget Mustang 

Love those ailerons, Greg. I'll approach that bit with some trepidation 

Just finished the upper wing centre section on mine.  It looks remarkably like yours, Greg, so I must be getting into the groove at last!

I can't believe how well it all fits together. It's absolutely 100% zero tolerance - every part just clicks into place with so slop, play or gap. I don't have a digital camera, so no photos yet - but you've all seen Greg's, so no point in duplicating     Frankly, I don't care how long this build takes - I'm just having too much fun .

I'm going to paint mine high gloss midnight blue with white lettering, prob. bogus G-**** registration, and probably a maroon and gold cheat line (like on my old Jag!).

The only problem so far was breaking the all wheel mounts (cos I bent them the wrong way. duh!), but the gallant Mr Moffatt was there at hand and has sent a replacement pair.  Best ever customer service

Hi Paul,

Wow you sure are cracking on!! you'll have yours in the air before me at this rate!!

Yes I remember feeling really chuffed when I'd finished my upper centre section, though the main wing panels are even better!!

Your colour scheme sounds really nice, I've pretty much decided on a modern sport scheme on mine as I want the wings to be translucent. I'm also probably gonna give her a british registration, how does G-REGS sound 

Keep at it, I'll be back as soon as I've got something new to show everyone.

Regards,

Greg

P.S you'll have to get a shiny new digital camera for christmas 'cause I want to see your finch when she has her plumage on (just don't make it look better than mine or else!!) 

Hi Greg. Started my Greenfinch on 22nd March 2010. All construction now finished, just started on the covering. OK. Could have built it quicker but it's such a dream to put together so why rush it?
I only had one small problem and that was with the motor mount. Roger recommends the use of epoxy resin for this, all went well BUT, fingers well smothered with the stuff!
Living here in southern Spain, unable to find meth; spirit that I have cleaned up with in the past.
What to do? Well, what else but use neat vodka. It really did do the job well and here, it's very cheap. Word of warning, however. Don't lick your fingers!!
Thanks for a superb post & pictures, will keep watching.
Regards. Brian.

Greg,

What power train are you planning to fit to your 'Finch?  I'm a bit of a newcomer to eclectic flight and I need to curb my historical tendency to over-power. For my current crop of electric-powered aircraft I have always sought and followed the advice of wiser heads than mine 

Greg -

I also found that some of the sub-assemblies I've completed were tending to get marked and even slightly "dinged" during trial fittings - and just general handling, so I've decided that, much as I'd like to see the aircraft complete in its bare bones, it is safer to cover and prime bits as they roll off the assembly line. 

Which begs the question - how do you keep your looking pristine all through the build?

Hi Brian and welcome to the unofficial Greenfinch owners club!!

Good to hear your build has gone well. I don't think I could trust myself with that particular method of epoxy removal, I think I would probably still be there several hours later, still epoxy clad but unable to walk!!

What sort of colour scheme have you decided on? Would love to see some pics of your Finch when she's covered if you have the time to upload some.

Kind regards,

Greg.


Paul,

I've just ordered the electrics for mine funnily enough, I opted for a Hacker A30-16M motor with an Overlander 40A ESC which should just about do it. I don't like to fit speed controllers that have too much 'headroom' as they call it because I feel it is inefficient and just makes the controller work harder, even at full throttle.

The Hacker should pull about 33A max so a headroom of 7A should be enough (It's a theory that has held up well in the past and I haven't smoked any speedos yet!!)

This is obviously a rather 'smoking' set up though as you can imagine and I've gone for this because I want my finch to have loads of vertical performance. The Greenfinch drawings show a JP EnErg C28-20-890 motor and I think this would be a sensible bet if you don't want to overpower your bird.

Roger could you chime in please if I've made a mistake with my setup or if the advice I've given Paul is misinformed (most of my electric experience is in Heli's and there are undoubtably differences between the two). I based my setup on the fact that 150W per pound would give good performance. I've also gone for an 11x5.5 prop which should give plenty of 'pull' without overspeeding the aircraft.

All the best,

Greg

Paul,

Sorry just seen your second post. The only advice I can give on keeping things 'ding' free really is to keep the building area VERY tidy and keep tools and anything else that might drop on the parts well away.

The parts that I have already made live on my building board overnight (the building board itself has to live on top of a cupboard at night 'cause I'm building in the kitchen at the mo) and then are moved off to a worktop when I'm building to keep them away from the building area.

As you can imagine then the various bits and bobs do get quite a lot of handling so I have to be gentle with them, and it may be that I have to move them all the time that makes me so wary of dinging them. So far everything remains looking as good as new (fingers crossed).

If you are suffering dings it might well be worth storing the completed assemblies somewhere safe until you're ready to paint, though I do find that seeing the finished parts every day motivates me to push on!!

Keep at it!

Greg

Hi Greg. Started my Greenfinch on 22nd March 2010. All construction now finished, just started on the covering. OK. Could have built it quicker but it's such a dream to put together so why rush it?
I only had one small problem and that was with the motor mount. Roger recommends the use of epoxy resin for this, all went well BUT, fingers well smothered with the stuff!
Living here in southern Spain, unable to find meth; spirit that I have cleaned up with in the past.
What to do? Well, what else but use neat vodka. It really did do the job well and here, it's very cheap. Word of warning, however. Don't lick your fingers!!
Thanks for a superb post & pictures, will keep watching.
Regards. Brian.

We used to use a meths camping stove when we were cycletouring in Northern Spain/France and the stuff you need is called, in French, alcool (don't know the Spanish).  It's colourless as the French, and no doubt the Spanish, see no need to colour it artificially.  It worked just as well as the meths we'd smuggled on the aeroplane from home.

Geoff