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Mig 15 Scratchbuild


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43 minutes ago, longshanks said:

Just caught up on your build, truly amazing!

 

Thank you for taking the time to show the techniques you use. it's always good to learn new ideas

 

Kev

New ideas! 😀 Ah you see...Everything old is new again!

All of this stuff pre-dates injection molding by decades.😜

Pleased you're getting something out of it all. I really appreciate the encouragement.

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Stand - Part 2

 

Hello,

 

A lot to discuss in the last few postings and I promise I will get back to the points raised.

 

Firstly though, after 'Stand - Part 1' John-W expressed an interest in the hand-sander I was using and I promised I would post the model number. Well I have looked and can't see a model number, it just says 'Ryobi Palm Sander' and that's all.  Here's a photo in case John's chasing some detail. 

IMG_5011

Along with a bandsaw and an electric drill this is one of the three power-tools that I really would not want to without for this kind of work. There are plenty more excellent tools out there, but I have limited space and so tend to run on a minimum - I consider this part of my minimum kit.

 

Last time we looked at the stand, this was where I was up to; stand 'roughed out' and the aircraft balanced on top, ready to drop off at the slightest gust of wind. The stand currently looks a bit angular and 'blocky' to my eye, so let's round off the sharp edges.

IMG_4577

 

First I just marked out a rough guide as to how much material I wanted to trim from the sharp edge around the base.  No fancy methods required, if you can hold a pencil steadily in the manner shown it's fairly easy to mark sufficiently even guide lines. 

IMG_4693

 

And now carve away the shaded bit between the two relevant guidelines that you can see on this photo.  In this case I'm using MDF which is a good option for some jobs but has it's drawbacks; firstly any cut surface tends to leave a furry edge that needs significant work to clean up, secondly, it's very dusty to work on and I believe that it's dust is not especially healthy stuff to breath, and finally it has a reputation for blunting tools.  Just as a good tailor or upholsterer will not use fabric scissors on paper for fear of blunting them, a good woodworker will not use his or her chisels on MDF. Oh well - I never said I was a good wood-worker, so here I go! :think:

IMG_4694

 

Same deal on the upright stand.

IMG_4695

 

Sand to round the edges off, even them out and make them look a bit more respectable.

IMG_4697

 

I think that this photo tells it's own story really - mark out holes in the right place on the upright and the base and fit some dowels in preparation for joining them.  Note that a drill-press would be very useful here,  but again - I'm running fairly tight for space and don't have one set up, so I just 'eyeballed' these holes.

IMG_4712

 

Scribe the mating surfaces, add glue, and whack the bits together.

IMG_4714

 

Check that the upright really is upright and just gently press and hold it into position if it needs some persuasion.

IMG_4715

 

Looking good!  Just needs some more time for the glue to dry, some plastic wood to conceal the join and a bit more sanding and I will be able to give it a test run...

IMG_4718

 

And here's the result...

IMG_4723

The stand seems to be working quite well.

 

The model is a Kifr C2 that I made when I was in my early high-school days - about 14 years old I think. Dad helped a bit - thanks dad! The model's survived OK, but never had it's own stand before. I should make one for it some time.

 

This model is made in almost exactly the same way as the Mig-15 but is considerably larger. It's based on drawings in Bill Gunston's excellent 'Encyclopedia of World Air Power' from 1980 and hence, to my knowledge is not at any particular recognised modelling scale - I've never actually done the maths but I'm pretty sure it's somewhere between 1/48 and 1/32.

 

I'm still quite proud of it. Hope you like it too! :smile:

 

Best Regards,

Reconcilor

 

 

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Reconciler, 

In albergman's thread about his Lola he mentions using composite decking as a substitute for Renshape. Might be worth looking into. Bound to be less expensive:

 

 

Re: Renshape. I get it from a local company here in Ontario, Canada so that won't help you as I see you're in the US.

If you can't source a free/cheap supply (and it's VERY expensive to buy) I'd suggest you look into composite decking. All the big box stores carry it now and it's not a bad substitute for Renshape. I got a bunch of off-cuts from a neighbour's deck project and screwed/glued them together ....

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Hello Hendie and Sprueloose,

 

Thanks for your comments - both good suggestions on the 'Renshape' front.

 

I'm still dead keen to try this stuff and I think I will take up Hendie's suggestion of approaching the retailer and seeing if he has any customers likely to be able to supply me some off-cuts. To ask for that favour though I think I should really meet him in person, and because his shop is not open Saturdays that will mean I will need to take a bit of time off work (probably a few hours off one afternoon)and work is very busy at the moment. Probably won't get out there until June at the earliest.

 

As for the idea of using composite decking as a substitute for Renshape - well I'm all for having a go. In my estimation Albergman's work is some of the most inspiring on Britmodeller and that Lola is just fantastic (and he got bored and didn't finish it!).  Did you see the pleasure cruiser he's made a few slides below it - unbelievable! So, next time I'm down at the local hardware store I'll check out 'composite decking' and see what's available.

 

It's funny some of the things one can learn on this forum. One of the 'issues' I've been struggling with over my next possible build is getting a thick enough piece of 'liquid ambar' to work on. I've been thinking that maybe I can join two pieces of it together and that that might be OK - and then looking at Albergman's thread he had exactly the same 'problem' stuck two bits of Renshape together and used the join as a permanent centreline always visible regardless of how he carved! This essentially assures symmetry as he can always measure equal distances from it!  Genius!  That's a very simple but very, very practical idea that I will be using for sure on my next build,  in fact it's got my little brain buzzing thinking about all sorts of other related possibilities and I'm now in a 'can't wait for the next project to try this out' state of mind.

 

Best Regards,

Reconcilor

 

 

 

 

 

 

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By the way - just in case anyone can offer any advice at all, I'm still having to write all of these replies on page 2. The 'reply to this thread' tool is still not working on this computer on all subsequent pages. I also cannot quote anyone. I'm a bit worried that if I start another thread for my next project I won't be able to post anything except from my I phone - and that would be a royal PITA.

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One of the links that turned up when I googled sold cut offs. Shipping to Australia is expensive but you'd still be well under the cost for an entire board. I'd say keep searching, you'll find your best option will involve shipping no doubt.

 

Thanks for sharing the Flying Scotsman's work. Beautiful.

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2 hours ago, Reconcilor said:

Well, in case any-ones interested, its definitely an issue with the PC. I'm writing this on a Mac on page 7.

 

In that case, I try deleting all the temporary internet files and clearing your cache as a first step. (Though if you can still post from another page on the same thread, I don't know if that will make any difference.)  This new forum software is definitely buggy.

The other thing I'd look at is any anti-virus to see if there's anything related to the website there, though the point about still being able to post from a different page still applies

 

 

I'm looking forward to the next project already

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Canopy - Part 5  Taking a small Problem and make it bigger

 

Good suggestions concerning sorting out my tech issues Hendie, thanks for that I will give those fixes a try sometime when I'm less pressed for time.

Also great suggestions regards composite decking. I have googled suppliers here in Perth and they are abundant. The stuff looks ideal so will definitely be trying out that idea. But for now, let's see if I can take a small problem and make it bigger - why not?

 

Back to the dreaded canopy.  You might remember I was using this rather rough canopy mold as a template testbed to work out how to fit the canopy onto the fuselage and discovered that, when the canopy was placed accurately, there was a rather significant gap behind the pilot's shoulder.  Unsure about what to do abut this I decided to postpone solving that problem and start working on my plan to secure the bubble.

 

IMG_4624_LI

 

Found this old discount card from a supplier that will remain un-named.

IMG_4629

 

Very, very carefully marked out the outline of the canopy - Hmmmmm...

IMG_4631

 

Cut out the shape and checked that the canopy would 'pop-on' over the top of the new...whatsamacallit... 'Canopy base'?  It actually fitted pretty well and I was happy.

IMG_4635

 

Marked out the hole for the cockpit.  Just look at the research effort that going into this would ya!  :party:

IMG_4637

 

Drill some holes...

IMG_4639

 

Grind out some plastic...

IMG_4640

 

Ah-ha... Now I have a structure that I can essentially just clip the canopy onto (as shown above) and secure with a beading of well-placed canopy glue - sweet!

IMG_4641_LI

 

Only problem is - now the plastic canopy base is flat and it's just made the gap look even bigger - I'm not sure the gap actually is bigger, but it sure looks bigger.

IMG_4643

 

So now for the real crushing irony - the root cause of this whole problem is actually a lack of research on my part.  Now I know that some of you love, love, love research - and good on you if you do. For me it's 'Research - Smeasearch' (I know that there's no such word). Research for me is pretty close to just another word for homework! (Wow - I bet this post isn't going to get many likes!) So I'm highly dependent on the accuracy of the plans that I'm using; chances are if they are wrong I'll be wrong, and I'll have no-one to blame but myself.

 

So the root cause of the problem here is laziness on my part - the plans that I'm using show no detail inside the cockpit. The canopy is rendered as if effectively opaque so they do not show the size, shape or exact location of the cockpit aperture and when I was carving it out I was just making it up and guessing the size and shape. It seems in my haste I guessed wrong.  More homework required.

 

Next time I will be more careful.  Now the obvious solution here is to start again. Carve a new fuselage, this time out of composite decking - chop the wings and tail off this one and re-fit them to the new one. Maybe that's what the next post will be about.

 

Best Regards,

Reconcilor

 

 

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2 hours ago, Reconcilor said:

Now the obvious solution here is to start again.

 

not for me it's not.   Remember cockpits tend not to be slab sided, and almost all of them wrap in to some degree around the actual aperture.  So.... If I was in your position, I'd:

 

1: add a couple of infill blocks into the sides of the current opening

2: sand them back so the fuselage sides are smooth (ignore the cockpit opening for the moment)

3: get a good canopy

4: place aforementioned "good canopy" on the fuselage

5: mark outline of good canopy in the correct position

6: sand, carve, chainsaw, or otherwise open out new infill blocks until they're just shy of the canopy marking

 

There you have a canopy that fits the fuselage and cockpit, and when it's all painted up, no-one will be any the wiser.

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Oh Hendie! If only this was April the first I could have so much fun telling you I've already chopped the wings off. 😜 

 

Don't worry, I'm not actually going to start again. Just dial your BS detector up a few notches when reading my posts. 😄

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The advice of Hendie is very good, I am sure.

 

15 hours ago, hendie said:

not for me it's not.   Remember cockpits tend not to be slab sided, and almost all of them wrap in to some degree around the actual aperture.  So.... If I was in your position, I'd:

 

1: add a couple of infill blocks into the sides of the current opening

2: sand them back so the fuselage sides are smooth (ignore the cockpit opening for the moment)

3: get a good canopy

4: place aforementioned "good canopy" on the fuselage

5: mark outline of good canopy in the correct position

6: sand, carve, chainsaw, or otherwise open out new infill blocks until they're just shy of the canopy marking

BTW - perhaps you know it already - if not here is nice walk-around with detailing:

http://www.milavnarc.com/mig-15_fagot_mig-15bis_at_the_national_museum_of_the_united_states_air_force.html

Do not give up! The model is just for small correction not for starting again :)

Cheers

J-W

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The detail shots also show the top side of the fuselage closing in over the opening so adding shims to the opening will do the job nicely!

 

The paint scheme makes it look distressed, just like the pictures of the real ones abandoned in Eastern Europe...

 

Regards,

Adrian (BS detector now turned up to 11)

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  • 3 weeks later...

Canopy - Part 6 - Taking a big problem and making it smaller

 

Hello,

 

It's been a while since my last posting here, mostly due to life getting in the way - families, holidays, work... you know the kind of thing...

 

Anyway, at my last major posting I suggested that I was about to re-start the entire fuselage and to my delight Hendie seemed to believe me - at least briefly! :penguin:  Suffice to say I am not actually going to build the whole damned fuselage again!  Here's another view of the problem that I have to solve, there's a gap approximately the size of the Grand Canyon either side of the canopy. Hmmmmm...

 

IMG_4643

 

I have decided on fairly simple and rather dodgy fix - but in the interests of time and simplicity it will do.

 

I just cut out two small lengths of 1.5mm evergreen styrene sheet, each a bit longer than the cockpit aperture and smeared a blob of two-part epoxy on the top side of each end of each piece. I then ran a bit more along one edge of the plastic strip.  I then used tweezers and bad language to position each piece of plastic inside the cockpit and along the top of the cockpit wall. As each plastic strip is longer than the aperture the excess plastic at either end sits sit inside the cockpit under the fuselage skin.  I then forced the plastic upwards, using the tweezers, so that the glue on either end attached to the inside of the fuselage skin. I also pressed outward so that the glue on the outside edge gripped onto the outside fuselage wall. I then held the piece in place, manually, for about 10 very boring minutes until the glue gained a secure grip. I should have taken more photos to make the process clearer but that would have required 3 hands!

 

IMG_4650

 

Using glue in this 'upside-down, inside-out' kind of way is not very smart because any bump from above will subject these 'hanging' strips to forces that will tend to push the strip downward and as glue is very weak under tension (as opposed to under compression) the bit of plastic will drop off easily.  Therefore I let the glue cure for 24 hours before gently smothering the plastic strips in perfect plastic putty to smooth out the dodgy work.

 

As you can see in the photo below - the gap is now considerably reduced, not quite eliminated, but now much more manageable.

 

IMG_4653

 

Don't worry about all of the PPP smeared all over - it cleans up very easily with a bit of sandpaper.

 

From here I think I can see my way clear to sorting this canopy business out once-and-for-all and I am getting my 'mojo' back for this project. So expect the posts to start coming a bit quicker in the foreseeable future. I am starting to think that with a good set of military spec binoculars the finish-line might now just be visible in the distance! 

 

Hope you can all sleep easier now knowing that this situation is under control! :D

 

Reconcilor

 

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Canopy - Part 7 - Getting there...

 

At the end of the last post I had got to the point where the cockpit aperture was only very slightly wider than the 'canopy base' for a few mm just behind the pilot's shoulders, but there is a 3D aspect to this problem.   Look at the photo below to see what I mean. On the starboard side of the cockpit you can look right through a gap between the bottom of the orange base and top of the fuselage, that gap is there simply because the orange plastic is flat while the fuselage, when viewed from the front, is circular.

 

IMG_4652

 

So we need to get the base to conform much more closely with the top of the fuselage.  Here's how I've done it - I've never used hot water to assist shaping sheet plastic before, but it turned out to be dead easy. I'll be using this method again.

 

First assemble the tools as shown below. A coffee cup probably isn't really a 'tool' but you know what I mean; perhaps equipment is a better word.

 

IMG_4654

 

Boil a jug of water and pour the water, while still very hot, into the coffee cup. Dunk the piece of plastic into the hot water - not for long; only about as long as you would dunk a chocolate chippie biscuit into hot cocoa.

 

IMG_4658

 

Pull the, now very soft and pliable, piece of plastic out of the water and press it onto the outside of the dowel so that it is forced to mold a gentle curve along it's long axis. In this case the dowel is a much smaller curvature than the top surface of the fuselage, but luckily less than 100% of the curvature was transferred to the plastic.

 

IMG_4660 (2)

 

The resulting contour was a pretty close fit. :smile:

 

IMG_4664

 

Now all I had to do was knock back some of the paint-work and scribe in some cross-hatching so that the soon-to-be-applied araldite would have something to grip.

 

IMG_4671

 

Following a quick spray of primer over the bare plastic (note that it's no longer Woolworth's orange) I used two-part epoxy to glue the 'canopy base' onto the top of the fuselage.  I held it tightly in place with Tamiya tape and let it sit for a few hours. The tape helped enforce the close conformity of the part with the top of the fuselage.

 

IMG_4672

 

Whew! that's looking better. Now I have a sensible looking structure to attach the canopy to. The canopy clips onto the base now, so although glue will still be necessary it won't have to do 100% of the work. 

 

IMG_4681

 

I am happy with the outcome here. You may note that there is still a very small residual gap between the canopy and the fuselage, again just behind the pilot's shoulders, but this should be easily filled. I'm now  confident that I've got most of the 'engineering' associated with the canopy sorted out.

 

Phew! I think I'm getting there...

 

 

Edited by Reconcilor
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6 hours ago, hendie said:

 

either works for me - as long as it's filled !

Somewhere to put that Glenfiddich we were talking about earlier! 😆😁

Edited by Reconcilor
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Hi Reconcilor,

 

Keep with it mate, I admire your tenacity with this project! If you need any Mig -15 photos' , I took a bunch last week just outside of Christchurch at the Ashburton museum, happy to email them to you. BTW - I'm still  sorting out Omaka airshow photos.

 

cheers

Propnut

 



 

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Hi Prop-nut.

 

I had no idea that Ashburton had a Mig15! I love that museum but haven't been since 2014. Do they have a Strikemaster yet? That was their number one acquisition goal when I was last there.

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