Topic: Great Planes 1/3rd Extra 330L build

Well, after an abscense made up of the weather being too cold to work in the workshop and a week away on a course, I finally got back on the Extra. I decided to crack on and try finish the canopy.......total disaster.

It started well enough by making a frame up....



which was then held in position on the fuselage...



The plan was then to glue the canopy in place in situ but this proved impossible as I needed to clamp the canopy to the frame, so I took the frame off the fuselage and glued, then clamped the canopy in place. This worked well but when I offered the complete assembly to the fuselage it would not fit with the frame appearing to have warped. I had no choice but to try and remove the frame but the inevitable happened and I split the canopy in several places....

Sooooo...options.

I looked on the Great Planes website and they do list the canopy in the spares list for discontinued kits, so I have fired an e-mail off to check availability and price. Another option, which I had considered doing a while back, is to covert the model to a single seat version which has a much smaller canopy. I could just carve one out either balsa or blue foam or Wendell Hostetler in the USA do a canopy for a very similar size version, which I may be able to adapt. Not sure which way to go yet, I'll think on it while I await the reply from Great Planes.

Still plenty I can be getting on with so back soon.....

Hi Brookes

An alternative to glueing the canopy on would be to hold it in place with a number of small screws. You'd have to glue mounting blocks along the bottom edges of the canopy rails, along with some appropriately shaped blocks around the front and rear areas, but I'm sure it would do it ok...... Modelfixings servo mounting screws would certainly be good for this job.

You could screw the canopy in place while you have it clamped in situ, then remove the canopy and undo the clamps to remove the frame. Then re-attach the canopy to the frame. You have dowel fixings already at the front, but you'd need a fairly robust latch catch type arrangement at the rear if you didn't want to lose it in flight Brookes.

It's a bit late now I know Brookes, but my personal preference is always to hold a canopy on with small screws rather than glue if possible.

P.S. Don't Glen's Models do some Extras around this size? Might be worth trying him for a lid. Just a thought.......

If you are not bothered about a pilot / some detail in cokpit then I'd fashion a solid canopy and spray it black.

Looking forward to the covering process. 

If you are not bothered about a pilot / some detail in cokpit then I'd fashion a solid canopy and spray it black.

Looking forward to the covering process. 

Dom

It was always the plan to spray it.....I did toy with the idea of detailing the cockpit but this was only ever going to be a semi scale effort.

Hi Brookes

An alternative to glueing the canopy on would be to hold it in place with a number of small screws. You'd have to glue mounting blocks along the bottom edges of the canopy rails, along with some appropriately shaped blocks around the front and rear areas, but I'm sure it would do it ok...... Modelfixings servo mounting screws would certainly be good for this job.

You could screw the canopy in place while you have it clamped in situ, then remove the canopy and undo the clamps to remove the frame. Then re-attach the canopy to the frame. You have dowel fixings already at the front, but you'd need a fairly robust latch catch type arrangement at the rear if you didn't want to lose it in flight Brookes.

It's a bit late now I know Brookes, but my personal preference is always to hold a canopy on with small screws rather than glue if possible.

P.S. Don't Glen's Models do some Extras around this size? Might be worth trying him for a lid. Just a thought.......

Yeah, I hear what you're saying Brian. As discussed in a previous post, I had planned to additionally secure the canopy with screws but I don't think screws alone would have done the job. To be honest, the shape of the canopy wasn't brilliant when compared to the frame it needed to attach to, which is why I ended up having to clamp it while I glued it. I think that is why it ended up warped because I had for force the canopy on to the frame in places. I guess if I had used screws, I would have need them spaced every inch or so.

One thing I wish I'd done, is to take your suggestion and secured the corners with screws before removing it from the model which would have given me a datum........but there you go, hind sight is a wonderful thing....

Great call about Glens Models by the way. I'd forgot about them; I'll give them a call tomorrow......

OK....so after yesterdays traumas, I was a bit nervous about the next job, trimming and fitting the cowling. However, faint heart, fair maidens etc, so I took the plunge.

First off, I roughly cut a hole for the prop shaft, the air exit holes and mounted the cowl, taping it place before marking out the positions of the mounting screws. The spinner was fitted to ensure prop clearance.



Next the holes were drilled and the screws fitted.



The cowling was then removed and the cooling holes enlarged and tidied up.



Finally the cowl was refitted to check clearances...



You can see from this shot the effect of the offset on the engine.



I was a bit disappointed that with such a large offset required by the plans that the cowl wasn't moulded to reflect this, however it is only really noticable from underneath and I'm pretty pleased with the overall fit of the cowl, so I'm not going to loose any sleep over it.

More soon.....

The sidethrust does appear more noticeable when the fuselage is inverted Brookes, but I wouldn't worry. And yes, I'd have thought the cowl ought to have been moulded to allow for at least some sidethrust. That is a little disappointing. I see you'd already offset the engine on the firewall, so there's little else you could do.

Regarding the canopy, if a suitable replacement can't be found there is always blue foam. Once hacked/sanded to shape, a couple of coats of epoxy wing finishing resin should help durability.

Hi again Brookes

I just looked at Glen's site, and he does do a 35% Extra 330S (106 inch span), although it appears to be a single seat variant not the two seater you have. At least the canopy could be made to fit at a pinch though, by possibly adding some additional decking where the front seat passenger would sit. It would give you another option if you were stuck.

See here.....   http://www.glensmodels.com/2005.htm

Regarding the canopy, if a suitable replacement can't be found there is always blue foam. Once hacked/sanded to shape, a couple of coats of epoxy wing finishing resin should help durability.

Yes, blue foam was my first thought if I go down that route.

Hi again Brookes

I just looked at Glen's site, and he does do a 35% Extra 330S (106 inch span), although it appears to be a single seat variant not the two seater you have. At least the canopy could be made to fit at a pinch though, by possibly adding some additional decking where the front seat passenger would sit. It would give you another option if you were stuck.

If I do end up having to make one, which I may do anyway regardless of the results of my enquiry to Great Planes, I would go down the single seat route. I'll give Glens a call tomorrow and see what they say.

Ian

While the engine was mounted, I decided to take advantage and complete a few items on the front end. I started by finding a place to mount the ignition module and glueing the lower cover onto the engine mounting box.



Then I flipped her over and made up the removable cover for the top....the slot in the front is to clear the top mounting bolt.



When I got the silencer, although the tube from the exhaust outlet to the expansion chamber is quite substantial, I had concerns that I might have vibration problems due to the long moment arm to the expansion chamber. To eliminate this I decided to make up a mounting bracket......



....and with the silencer in place....



I have decided to go ahead and make up a single seat canopy but I need some wood and blue foam for this which I can't get until the weekend, so next job is to start bolting in some servos and hardware to try get some idea of how far the balance point is out...

Back soon.....

Tonight I went ahead a bolted some of the hardware in place starting with the rudder and elevator servos and the tail wheel assembly...



....followed by the cowl, spinner and the landing gear.....



At this point I did a check of the balance point which is just forward of the main wing tube and.......it was pretty much spot on... Obviously I need to add the wings and canopy and double check but I shouldn't be too far out.

While it was assembled I couldn't resist a photo call..... The handsome chap in the photo is me and to give you an idea of the size, I am 6 foot tall...



Back soon....  

Why don't you use the old canopy suitably supported to make a plaster of paris (or similar) plug and get a new canopy vac formed ? Their will be someone local with a vac former .For example your local secondary school tech department will  probably have one.

Alan

Why don't you use the old canopy suitably supported to make a plaster of paris (or similar) plug and get a new canopy vac formed ? Their will be someone local with a vac former .For example your local secondary school tech department will  probably have one.

Alan

Hi Alan

Yeah, I guess I could and If was desperate to keep it as a two seat version, its something I may have considered. However, I am quite happy to convert to a single seat version which will be a lot less work than the process you describe.

Ian

OK.....decision made....I'm going for a single seat canopy and so to that end I have made up a frame....



...and from another angle....



More soon...

More progress on the replacement canopy....remaining formers made up, fitted and stringers glued in place.....



The canopy frame was then removed....



Next job was to come up with some method of retaining the canopy. I took the lead from the plans and used the suggested positions of the rear of the canopy below the frame. I made up some mounting plates from 1/4 ply, drilled the holes and pushed in and epoxied some captive nuts.





The fuselage was reinforced with some 1/8 lite ply discs and backing plates which were then drilled and counter bored to accept the mounting bolts.



Tomorrow night I will do the other side......

A friend of mine used four IKEA type fsteners to hold down a similar canopy.  He just made a hole in the fuselage that captured the turning bit and placed the spike thing on the bottom of the canopy.  Te best thing about this, he says, is that he never loses the bolts to hold down the canopy. 

Any more progress? if not we want to know why not.    

Any more progress? if not we want to know why not.    

No progress of late for a couple of reasons....

1.    Been too cold in the garage this last couple of weeks and I'm a complete wimp when it comes to cold...

2.    I've been studying for an exam which if I pass will result in a £5k pay rise and although I like to keep my viewers happy, I have to prioritise!!!

Hopefully back on it this week.

All the best with exam result.

Agree with you re too cold for working outdoors.

We invented centrally heated garages for exactly that reason here in Iceland -- plus we have ultra cheap hot water coming out of the ground that we do not have to heat up 

We invented centrally heated garages for exactly that reason here in Iceland -- plus we have ultra cheap hot water coming out of the ground that we do not have to heat up 

(Attachment Link)

Do the ladies come free as well........

Do the ladies come free as well........

I'm afraid not, they are the most expensive luxury you can find 

Well after a month off the build due to exams (passed - kerching!!) and a recent, near fatal bout of man flu, I finally got back out in the garage for an hour tonight...

I started by cutting a cardboard template to get the right shape for the base of the canopy.....



I will use this again for the shape of the foam block for the canopy. Next I cut the shape out of lite ply and removed the centre for lightness.....



...and that's it for tonight. Yes, I know its not much and it looks as though I have fitted a toilet seat but I should be able to start planking tomorrow....

Looking good Brookes. I have 50p here says you get this right first time........

Looking good Brookes. I have 50p here says you get this right first time........

.....you're on!!

So with the frame bolted back into place, I attempted to put the first piece of 4 inch, 3/32nd sheeting on. By taking my time, using lots of water, steady trimming around the canopy area and using a mixture of medium & thin cyano, I managed to make a pretty neat job......



There is a slight gap at the front lower edge due to the way the sheeting sits but that can be tidied up later when the masking tape has  been removed.



Total time for the one piece....about 1 1/2 hours....

More soon

Looking good! 

Here's a thought Brookes. Lash up another set of formers for the cockpit to replicate those you've already assembled on the fus. Temporarily fix your block of blue foam to it and hack/carve/sand into shape. That way you'll not be doing it in situ on the fus, with the associated risk of dings and abrasions on that nice sheeting you've just stuck in place.........

Looking good! 

Here's a thought Brookes. Lash up another set of formers for the cockpit to replicate those you've already assembled on the fus. Temporarily fix your block of blue foam to it and hack/carve/sand into shape. That way you'll not be doing it in situ on the fus, with the associated risk of dings and abrasions on that nice sheeting you've just stuck in place.........

mmmmm.......simple......but genius......I like it

No problem, pay at the door on the way out...........

P.S. It isn't really genius Brookes, just bitter experience and a tub of lightweight filler.

Ok.....some more progress over the weekend and tonight.

First job was to finish off the decking planking...all in all, it went pretty smoothly



I then tided up the joint lines where it met the fuselage and sanded it to the correct profile...



Finally I cut a profile shape for the foam that I will use to make the canopy .....apologies for the Carp photo, but you get the idea..



I need to study some photos of the full size to make sure this is about the right shape....more soon.....
 

Yep, get the idea.    Not 100% sure on the template shape though. I'm not an Extra expert, but somehow it doesn't look just quite right. A touch more bulbous at the front perhaps, with a slight increase in length/straightening of the canopy line directly over the pilot's head? Of course I could be completely wrong Brookes! It's bad to tell when you only have photos to refer to. You need a 3 view maybe?

Nice neat sheeting on what was the cockpit Brookes.

Ok, after a bit of an absence due to a ridiculous work load, I've managed a bit more this last week. Not much in the way of photos due to camera memory card issues but I'm finally getting there......



Still a bit of filling and tinkering with the final shape, but not far off.

One question......when I complete it, what's the best finish to put on it? Its too much of a compound shape for glass cloth but can I just use glass resin to seal it and give it a hard shell?

Any thoughts?     

Hi Brookes

I'd go with a few coats of P113 (or whatever it's called). I think Ripmax also supply something similar made by Deluxe Materials. A careful rubbing down between coats and it'll look 100%. 

I will shortly be moving on to covering and finishing the model, starting with the wings but first I need to run the wiring for and trial fit the servos....



I am using two servos for the ailerons.......



Next job will be to start applying the Solartex......back soon..

Made a start on the covering and got the wings and tail done but I've been struggling to keep interest in the project and find myself being drawn to other activities. To that end I have put the model and its engine up for sale on e-bay, item numbers 110866844797 and 110866851213 if anyone wants to take it on and finish it.

If anybody is interested and wants to do a deal outside of ebay, drop me a PM.

Regards

Ian