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Been a while since I've been on site and your progress does not disappoint - that canopy mould looks perfect.

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6 hours ago, John_W said:

Beatiful finish on the wood. Lovely close grain.

Did you use sealer, or is that bare wood?

Hi John_W,

 

That's bare wood, polished with micro-mesh. Very fine close grain almost no grain at all. Seems to be a bit harder than basswood But still very easy to shape.

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5 hours ago, Vanroon said:

No scraps of that left in the shed. I checked. 

Now for a close-up. 

http://2.bp.blogspot.com/-MkHfCGaa2ZI/Tk9xalbwGMI/AAAAAAAABcU/IKUiJ767dkg/s1600/mig-15_02_of_17.jpg

Note the lip around the cockpit. 

G

 

Come on Van Roon! You know this is hard enough without you putting photos of the real thing up there for everyone to see! 😜

 

Thanks again for your help yesterday.

Edited by Reconcilor

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Canopy - Part 2

 

So far all of this canopy making business has been fine and it's been rather enjoyable carving out a teardrop shaped canopy from a chunk of  high quality wood. In the back of my mind however has been a worrying thought - how am I going to attach this thing to the fuselage? 

 

At the end of 'Canopy - Part 1' I had gone about as far as I possibly could without having any kind of answer to this question so at this point I started to do some more serious thinking about this matter. Here's my attempt at a solution...

 

Grab another piece of liquidambar and shape it into the same compound curve as the top of the fuselage.

 

Here's the 'cross section' view.

IMG_4423

 

Here's the long-section view.

IMG_4425

 

Now I will have to attach the canopy to this 'accurately' contoured piece of wood - so I have carved this shallow rebate of the top of the block where the canopy will sit.

IMG_4432

 

And it sits in there quite nicely.

IMG_4437

 

Now I scoured both surfaces, again you can see the X marks in the base of the canopy, and filled the rebate with a generous dollop of 'liquid nails'.

IMG_4443

 

Then I whacked the two surfaces together and held with a clamp for about 3 hours. Cleaned up the surplus glue that has seeped out of the side of the joint. 'Liquid nails' is well named - although they are only glued together these two blocks are now very securely joined.

IMG_4444

 

Smothered the joint with PPP.

IMG_4445

 

Cut off the surplus wood at the base...

IMG_4447

 

Cleaned the whole thing up with sandpaper,  and got ready to vacform the thing..

 

IMG_4451

 

Now just in case you haven't worked out my  plan here - I'm going to try to vac-form both the canopy and some of the surrounding 'upper-deck' (if that's the correct term?) of the fuselage. The idea is that the surplus plastic around the base of the canopy should match the contour of the fuselage. Therefore I should be able to glue the vac-formed 'upper deck' directly onto the top of the fuselage, and with it the canopy will be securely stuck in place!

 

Let's see if this works... personally, I have my doubts.

 

BTW - if any of you have any better ideas as to how to attach this canopy - please feel free to wade in at this point as I am fairly sure that this is not going to go too well. I am open to any suggestions.

 

 

 

 

 

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Stand - Part 1

 

A very quick update tonight. Have hit a few difficulties with the canopy, mostly due to a lack of forethought and as a result am running a bit low on enthusiasm, especially for difficult and detailed bits. I still want to keep the project moving however, and so have turned my attention to part of the project that's a bit less fiddly and finicky - the stand.

 

I think it's a bit of a shame that stands are not more commonly used for aircraft models. Aeroplanes are supposed to fly and, in my view, modellers should perhaps more often depict them doing so.  

 

This one will need a stand and here's what I've done about it so far...

 

Take a piece of MDF, sneak an appropriate size / shape bowl out of the kitchen (ensure that the wife does not see) use the bowl as a template for marking out an oval of suitable size. Clandestinely return the bowl and then use a bandsaw to cut the oval base of the stand.

IMG_4549

 

Use a hand-held sander to remove the rough edges of the oval.

IMG_4550

 

Find another suitable piece of MDF and design / mark-out the desired shape of the upright. This shape could have been cut with the bandsaw, but by now it was getting late and I didn't want to wake our neighbours with a noisy power tool, so I used a fret saw instead.

IMG_4553

 

Here is the result in it's roughed out form. Nothing actually permanently attached yet - but with a couple of dowels through the base and a bit of PVA this should do OK.

IMG_4555

It looks a bit 'chunky' at the moment but with a bit of appropriate rounding off of the edges with a rasp or a sander I think it'll look a bit more attractive.  MDF is notoriously 'furry' on any cut edge - so this will need to be well-and-truly undercoated and sanded and will end up with a coat of black paint over it.

 

Here's what it looks like so far with everything just sitting there balanced - looks OK!

IMG_4576

 

The model itself is looking a bit battered but that's only because I'm half way through the 'inspect and sand' cycle following the first coat of metallic paint.

IMG_4579

Note how the aircraft is depicted climbing - not diving. A pet hate of my father's is when aircraft are put on stands in a diving attitude. The Spitfire replica at the entrance to Christchurch Airport (New Zealand) is depicted as if about to hit the ground in the next half second; it drives him nuts!  He's even written letters to the editor about it!  So - just in case he sees this, our Mig15 is depicted proudly climbing to meet the capitalist foe.

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12 minutes ago, John_W said:

I like the hand sander, what make is it?

Guessing by the garish yellow/green, I'd say Ryobi.

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Ryobi - nothing flash but it does the trick. Will post the model number for you tomorrow.

 

BTW - That 'like' you just posted is my 300th so thanks for that John-W! I'm pretty sure it was one of your 'likes' that was the first one ever posted on this project so your ongoing interest and support is noted and much appreciated!☑️👍

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5 minutes ago, Jaffajake said:

Guessing by the garish yellow/green, I'd say Ryobi.

Yep! Ryobi - God knows why they set that colour as their corporate standard - but there you go - that's what they picked!

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It obviously works for them. We see the colour and think Ryobi. Good products though. 

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I have a Ryobi cordless drill. Very solid. 

Your project reminds me of building crude balsa wood aircraft aged 8 or so.

I vaguely recall building something that could be mistaken for a Mig 15 with red stars drawn on with felt tip pen.

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Excellent! I too am hoping my model can be mistaken for a Mig 15. 😜

I'm guessing you don't still have your balsa Mig, otherwise it would be compulsory to post photos here. 

I still have a scratchbuilt Spitfire mkXIV, an A4K Skyhawk and a Kfir C2 all built during high school years. One day I think I'll dust them off and post some photos here.

Pleased to hear this project is bringing back some memories for you. 👍😀

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Canopy - Part 3

 

At the end of 'Canopy - Part 2' we left our viewers with this cliffhanger photograph... Buck completed, buried up to it's neck in ball-bearings and about to be smothered with a sheet of hot semi-molten plastic!

 

IMG_4451

Is this the end? Can our hero escape? Find out - in 'Canopy - Part 3...'

 

I've never vac-formed anything before, but my esteemed friend Mr Van-Roon has done quite a bit of it in the past and owns a rather handy machine for just this purpose.

 

If you are not familiar with Vac forming here's a very quick primer... The 'buck' or mold goes into a bed of ball bearings that sit on top of a perforated steel sheet through which a vacuum pump can draw air.

 

A sheet of PETG plastic is mounted securely and tightly into a frame.

 

IMG_4452

 

A heating element is then swivelled into position over the plastic..

IMG_4501

 

The heat causes the plastic first to 'tighten up' and then go a bit floppy and pliable. In the photo below you can see the reflections starting to distort in the plastic sheet.

IMG_4455

 

Once the plastic is pliable the frame holding the plastic sheet is lowered down onto the vacuum unit, the two respective frames form an airtight seal and the 'floppy' plastic is sucked, quite quickly, down around the mold by the vacuum being pulled through the ball-bearings. 

IMG_4460

 

You let the whole lot cool down for a couple of minutes and then withdraw the plastic sheet and remove the mold and...

IMG_4470

Voila! One canopy!

 

Except it really hasn't worked very well at all. Notice how the canopy is far to wide at the base - that's because the suction in this case did get into the corner where the canopy meets the 'upper deck' of the fuselage surface.

 

That's no problem - just drill some holes to let the vacuum in (or let the air out if you prefer).

IMG_4473

 

Sweet!

IMG_4474

 

But of course now there's a problem - my plan for using the 'top deck' to secure the canopy to the fuselage is looking less workable all the time - now the mold is going to have a line of dimples in it right where I want to glue things down.

 

With the drill-holes around the 'skirt' of the canopy the shape molded nicely - but now I have to cut the skirt away and am back to having no secure way of attaching the canopy to the model.

IMG_4493

 

And besides - the canopy proved to be far too large and over-scale.  I had not allowed sufficiently for the thickness of the plastic and the small amount of 'rebound' that the natural elasticity of the plastic causes.

IMG_4500

Don't worry too much about the yellow colour of the plastic as this particular run was always going to be a practice run.

 

But for now - I have two jobs to do:

 

1 - reduce the size of the mold and sharpen up the rear part of the tear-drop that is obviously too fat.

 

2 - come up with a workable way to properly secure this thing to the fuselage.

 

Stay tuned for 'Canopy - Part 4'.

Edited by Reconcilor

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Rather than drill a series of holes around the base, I'd be tempted to "raise" the canopy on a small plinth slightly smaller than what you need for the base of the canopy (if that makes sense).  That will allow the canopy to be sucked under, and into the undercut, and keep the profile clean.  Then, you can't get the buck out until you trim the canopy !

 

You might want to shorten your heating time slightly as there's some discoloration on the one above (says he, knowing it's just an example at this point)

 

Looking forward to Canopy Parts V, VI & VII with baited breath

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Not sure if this will be any use to you but I thought I'd throw it in just on the off chance it would be.  I've experimented with vacuum forming a canopy for my Sabre project and believe I'm pretty close to getting an acceptable example.  I use clay, shaped, baked and polished for my moulds.  The first one had the wrong shape but I think I got it right on the second one.  The webbing occurred because I had the temperature too high and got too much of a droop.  After using the wrong kind of clear plastic, I tried plain white styrene. Much easier to discern the final shape and cheaper than PETG to practice with.  Also try raising the plinth a little, rather than, as Hendie says, drilling the holes, until you are satisfied with the result. .Nifty little rig you've got there.  For dental work?   

 

Looking and learning.

 

Dennis 

 

http://s1088.photobucket.com/user/OldGuy4/media/SNB10243.jpg.html

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Thanks for a look at your plinth this arvo. 

The canopy is approaching fruition by process of elimination. Love that timber. 

Cheerio,

Grant

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Canopy - Part 4 - Following Advice

 

Now it's back to the ongoing saga of this canopy / cockpit.  Thanks for the advice on this everyone, It's been useful, as you will see...

 

DMC - I think that Sabre canopy looks absolutely 'bang-on' and next time will be trying some clay as you have suggested. The main reason is that even with this very good wood there is still some trace of the grain being transferred to the mold each time.  I know you are using clay, but do you think FIMO would be OK? - it's readily available and can be baked in a domestic oven.

 

Anyhow, the whole 'let's mold the top of the fuselage into the canopy' thing didn't really work out and drilling holes in the base only 'sort of' worked. So it was time to follow some good advice and try another approach.

 

Let's get out the fret-saw and start cutting!

IMG_4530

 

Cut away the block on the base down to a narrow 'plinth' just like Hendie suggested.

IMG_4531

 

Clean it up with sandpaper.

IMG_4534

 

Trim and carve down to a size just a whisker below the final size, and be a bit more careful with the shape this time. This was fairly delicate work and for the first time I have used a razor blade for shaping the wood. it went OK too!

IMG_4537

 

Clean it up - and here we go. The holes are still there but they are just leftovers from my last effort, from now on will play absolutely no role in the process.

IMG_4540

 

DMC was wondering if the vac-form rig was for dentistry - I actually have no idea, but I know that Van-Roon bought it over the internet and here's the make if you are interested. I find it really convenient to use and am thinking I will get my own, but I am no expert on vac-forming and have no idea what else is available.

IMG_4591

 

And so, with the new mold and a variety of plastics a process of elimination and trial and error begins. This one had the wrong kind of plastic and, in addition to all of that webbing, the final canopy went all 'scrunchy' - just as if it was made out of shopping bag plastic.

IMG_4595

 

Over time I got a bit better at this- but still nothing perfect. See how this one has gone all cloudy due to too much heat. But at least the shape is right.

IMG_4586

 

There's a fair bit of wastage - but in the end I got two that were OK.

IMG_4597

 

One that looks like this - cloudy but the right shape that I will use this one for all subsequent test fitting and so-forth, and one that might just be the final product if I can't make anything better. I've put that one to one side for safekeeping.

IMG_4625

 

As you can see, I now have a new problem.  I finally have a canopy that's the right size, but when I place it in the correct location (slightly further forward than I had somehow anticipated) the rear half of the canopy is not wide enough to cover the cockpit's aperture.  in addition I am still not really sure how I'm going to attach this.

 

Hmmmmm, Lot's of thinking going on here.

 

Just a final note - if you have not vac-formed before please don't let any of this 'trial and error' put you off. It's actually quite fun and I'm sure that once I have nutted out all of the details this technique will be a valuable addition to my, rather limited, repertoire of skills.

 

Reconcilor...

 

 

Edited by Reconcilor

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Hi Reconciler,

Any polymer clay will work.  I use Super Sculpey and Super Sculpey Firm mixed about 50,50.  I use a pasta machine and roll it out until the colour is uniform.  Clay is great medium to work with.   If you find out after baking that you've made the mould too small you can add more clay and bake it again.  I use liquid Sculpey as a bonding agent.

 

I'm wondering if you might be better off with a flat, perforated platform rather that those ball bearings.  Look at the picture again, you'll see what I mean.  My rig is just a wooden box with a perforated metal sheet and a bit of tubing to plug the vacuum cleaner in.   It works okay now that I have had some practice with it.  If you can carve a Mig out of wood, making your own rig should be a doddle.

 

Any questions feel free to ask.

 

Cheers,

 

Dennsi

 

http://www.polymerclayer.com/baking-polymer-clay.html

 

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Hi Dennis,

thanks for that, will definitely try some form of polymer clay next time around. Have thought about making my own vac-for rig and would probably do so if I needed to make bigger pieces but am not sure I could convince my wife to let my use the oven for heating sheets of plastic.

 

The ball-bearings don't do much except fill the space between the perforated base and the bottom of the job - I think they just provide a simple means of varying the height of the effective base which is necessary in this case because the perforated base is set Quite deep in the machine, a long distance below the starting position of the plastic sheet.

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you could coat the wood with superglue, then polish it back - that should get rid of the grain effect.  You already have the shape right so there's no point in making another.

 

I have one of these vacuum formers - they're intended for the dental market. The same design is marketed by a number of different companies - same machine - different label.  I think I got mine for less than a hundred dollars delivered.

I also stopped using the ball bearings, as the vacuum was so strong, it was sucking the plastic over the bearings and it took me ages to pick the bearings back out of the plastic.

 

For bonding the canopy to the fuselage, you have a couple of different options. Superglue, though you'd need to coat the canopy first to prevent fogging.  Then there's Formula 560, which is marketed as a "canopy glue" - it dries clear, and excess can be wiped away with a damp cotton bud or paper towel.  Then there's 5 minute epoxy though you need to be careful with that. I normally mask around the area where I don't want the glue to stick, then when it's almost, but not quite cured, it's easy to slice away any excess with a sharp blade.  There's also GS Hypo which I used with success on my lysander build, then last but not least there's all those UV glues on the market now intended to be used with your cell phone glass.... apply the glue, then when you're ready, activate the UV light which then cures the glue.  Personally, I'm not sure how successful the last one is, but have read that others have used it with some success.

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Wow! Thanks for that very comprehensive answer. I think I have a workable strategy for attaching the canopy but must admit that I have not yet thought too carefully about which glue to use. Thanks for the input.

 

Will give vac-forming 'sans' ball-bearings a try next time around. As you say, they take forever to pick out of the plastic and when they do pop out they end up all over the floor and roll around the house.

 

 Thanks again for taking the time to share your insights. Will look at that superglue sealing idea also!

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I love this thread and your work is inspiring.

 

I used to be a professional pattern maker. May I recommend, for future projects, a substitute material for wood? It's a filled polymer commercially known as Renshape. I believe it's made (or was, at least) by Ciba-Geigy.

 

Imagine a material available in various densities that range from medium to hard wood yet has no grain. It's beautifully carvable, machinable and can be sealed and polished to a mirror finish quite easily. That's Renshape. Simply lovely stuff.

 

IIRC, my favorite to use was the 450. It looks a bit like grain free cherry wood. Here's a link to the first supplier that popped up when I Googled. Edit to add: you can actually carve/file/sand it to a fine enough edge you could cut yourself on a trailing wing edge.

 

https://www.freemansupply.com/products/machinable-media/renshape-modeling-and-styling-boards/renshape-450-medium-density-modeling-board

Edited by Lowbrow

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Hello Lowbrow,

 

Thanks very much for taking the time to write in and my apologies for being slow to reply - it's been a busy couple of days. I am a bit surprised that a professional pattern-maker would find my humble little Mig-15 'inspiring'. I imagine you could have made this model while sleeping, but I'll take the compliment with thanks.

 

I have heard of Renshape.  Here's where I initially discovered it.

 

http://www.britmodeller.com/forums/index.php?/topic/234991589-scratch-built-triumph-tr6/#comment-2157841

 

'Albergman' does truly wonderful work with this stuff - have a look at his Flying Scotsman (on Britmodeller) for example. I love this guy's work and am absolutely dead keen to try some Renshape for all of the reasons you have stated.  About two months ago I did some research here in Perth to find out if there are any local suppliers and discovered from a local fibreglass, plastics and carbon fibre supplier than no-one imports Renshape into Australia.  Fortunately he has an alternative in stock, 'Racku-tool' board.  Apparently it's essentially the same stuff and having discussed my future plans with the supplier he assures me that it would be ideal. Ideal in all regards, except one - cost!

 

The smallest lot he can sell is a single sheet 1.5m long by 0.75 m wide by 50mm thick, and it's cost?  $580 Australian! He does not sell off-cuts. If I could get 10% of that amount for 10% of the cost (or even 15% of the cost) I would happy to make the outlay, but I feel I can't really justify paying such a large amount for material that I might never use up.

 

So I'm in a bit of a dilemma - on one hand I'm dying to try some and am tempted to just burn the money to have a lifetime supply of the stuff, but on the other hand - $580 for more than I might ever use! Cripes!

 

If you, or anyone else out there, have any thoughts on this matter, especially on where I might be able to get a smaller test sample of the stuff from  I would be very keen to hear. As noted above I'm OK with the fact that the stuff is expensive (gram-for-gram) I just need a smaller volume, at a commensurately smaller price, than the supplier here is able to provide.

 

Thanks again for your contribution to the thread,

Reconcilor

 

 

 

 

 


 

 

 

 

 

 

 

 

 

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