28 Sqn Whirlwind: A highly detailed, shake and bake kit

[perdu]

3 minutes ago, TheBaron said:

5. I've changed my methodology  with the dental vacform and achieve more reliable results now by ignoring the gradual heating that I used to do. Now I let the heater element reach full blast, then raise the petg straight up to the top. You mentioned the sagging process yourself - after the second droop starts, once it reaches about 2cm (quite there in the stalls), drop the petg straight down onto the bucks, simultaneously whipping the heater off to one side whilst turning the vacuum on for about 10 seconds.

Blimeyoriley, that's enough of a palaver to put me off mechanising vaccing forever.

 

Not sure if I will bother now, although the high speed drop onto the buck is vital in my methodology too.

 

My problem is never having some place to dump the hot air blower whilst getting on with the other stuff.

[Fritag]

23 hours ago, hendie said:

The Vokes filter nose intake breather template thing with holes in it appeared to work, though it was a bit of a pig to clean up and remove from the master.  I did a few and got better at it as I progressed

 

Brilliant concept.

 

23 hours ago, hendie said:

I'm bringing the PETG up just a bit less than halfway to the heater and leaving it until I see it sag - somewhere around 15 seconds or so.  I've noticed that it initially sags very quickly, then goes taught again before finally sagging deeper.  I tried forming after the first sag, but the plastic was still way too firm to be able to be pulled over the buck, so now I wait for the second sag.

 

Any advice greatly appreciated (and I've also ordered some 0.02 inch PETG just in case.)

 

Back in the day I was a halfway up and second sag man myself too (just don’t go there).  I might yet be again.   I used to find bubbles quickly formed in the PETG if I left the element to get fully hot and lifted the cage right up.  I generally used 0.5mm or 0.7mm PETG.    Might have been my clumsiness tho’. 

 

 

[RichieW]

A great weekend's work! It might have taken an age to do but adding those little wires was well worth it. Some great vac forming done too, I really must have another bash at using mine. Your results look great to me. That filter, YES!!!! 

 

Richie

[Terry1954]

3 hours ago, TheBaron said:

You'll crack this problem. You always do.

 

And you know what, i have every faith that Tony is correct even though i am struggling to actually understand some bits.....

 

And as for @Fritags observations,  as long as they are legalisticly plausable and indeed have some small basis in law, then i could cautiously consider some form of agreement, i think!

 

Terry

 

 

 

[hendie]

On 7/31/2021 at 3:48 AM, bentwaters81tfw said:

https://www.scalemates.com/kits/res-kit-rs48-0201-h-19-type-2-wheels-set--1273474

https://www.scalemates.com/kits/res-kit-rs48-0200-h-19-type-1-wheels-set--1273473

 

Both sets in stock Sprue Bros.

 

Could you do me a favor please?   Could you measure the Outer diameter of the Wheels and the hubs?  

I want to make sure I'm in the ball park with my wheel set - thanks

[bentwaters81tfw]

Nose wheel hub 4mm dia, tyre 9mm

Main wheel hub 6mm dia,  tyre 11mm

 

@hendie

[hendie]

A minor update before my travels

 

On 8/2/2021 at 4:04 PM, TheBaron said:

Tis a black/bleak art Alan isn't it so kindred solidarity heading your way from this end.

 

It's hard to tell from the photos the exact nature of the imperfections that you mention, so as to the windshield on the helicopter itself I can't quite tell if that's speckles of dust on it, or bubbly bits on the vacform itself.

<snip>

Since making these changes I've been reliably turning out batches of canopies without any of the previous blistering/clouding problems I initially struggled with.

 

I hope some of this helps Alan - apologies for taking up so much of your space with verbose explanations...

 

You'll crack this problem. You always do.

 

 

Thanks for all the info Tony.  Excellent stuff, but I still failed

BTW those were bubbles in the actual window itself, not dust.

 

On 8/2/2021 at 4:10 PM, perdu said:

Blimeyoriley, that's enough of a palaver to put me off mechanising vaccing forever.

 

Not sure if I will bother now, although the high speed drop onto the buck is vital in my methodology too.

 

My problem is never having some place to dump the hot air blower whilst getting on with the other stuff.

 

It's put me off and sucked out most of my mojo this week Bill

 

On 8/2/2021 at 4:52 PM, Fritag said:

 

Brilliant concept.

 

Back in the day I was a halfway up and second sag man myself too (just don’t go there).  I might yet be again.   I used to find bubbles quickly formed in the PETG if I left the element to get fully hot and lifted the cage right up.  I generally used 0.5mm or 0.7mm PETG.    Might have been my clumsiness tho’. 

 

 

I think I'll put vacforming clear canopies into the same bucket as plastering.  There's things I can do and things I can't do.  Plastering and Clear vacforming are at the top of the list. 

 

On 8/2/2021 at 5:10 PM, RichieW said:

A great weekend's work! It might have taken an age to do but adding those little wires was well worth it. Some great vac forming done too, I really must have another bash at using mine. Your results look great to me. That filter, YES!!!! 

 

Richie

 

thanks RIchie

 

On 8/3/2021 at 12:45 PM, bentwaters81tfw said:

Nose wheel hub 4mm dia, tyre 9mm

Main wheel hub 6mm dia,  tyre 11mm

 

@hendie

 

Thanks for that.  According to the drawings I have the mainwheels scale out around 12.5mm in diameter. I'm not sure if the WW had different mainwheels than the H19 but I think I'm going to stick with the larger diameter

 

This week I have been mostly vacforming. Failing miserably too it has to be said.

I had used up most of my stock of 0.03"PETG and had ordered some 0.02" sheet to see if that made any difference.  It didn't.  All in all, I must have vacformed 70 or 80 canopies this week, using every variation of process I could think of.  

 

I did make one interesting discovery this week though. Well, two to be more precise.  The first one being that Tony had it right all along of course. - aluminum powder is a much better medium.  Anyone with any sense - i.e. not me, would have realized that stainless steel is a lot harder than aluminum and will take a lot more polishing to remove any imperfections from the buck and bring a shine to it.  I spent probably at least couple of hours in total polishing the fiberglass/stainless powder buck. - before making a second version and going through all that polishing process again.

 

I realized very quickly after a few attempts that standard casting resin is just not a suitable medium.  The PETG always blistered and had multiple uglies all over it.  Filed away in the never try this again folder.

 

Fiberglass/stainless buck.  Produced consistent results but always with some imperfection visible.  This was like a mottling in the PETG and I wasn't sure if it was the process I was using, the amount of heat, or some other factor.  As mentioned, I spent a while polishing the buck and certainly could not feel or see any imperfections in the surface.  The mottling didn't seem to correlate to the grain structure visible at the surface of the buck.  The same imperfections appeared in the .03 and the .02 sheets, and it didn't matter if I went full blast with the heat or tried to gradually heat up the sheet.  

Conclusion?  I think the grain structure is imparting some texture to the vacform, even though (on the buck itself) I can't detect it by touch, or catch it in the light.

By this time I had already made a second fiberglass/stainless buck and gone though all that polishing process again.  Guess what? Yup, same result. 

 

This led me in desperation to try something... the fiberglass resin was just going to waste, so why didn't I try making a buck from just the resin with no additives?  So I did.

From Left:  Standard casting resin buck.  Fiberglass/stainless buck.  Fiberglass resin only buck

 

 

That allowed me to vacform on both the stainless and resin only buck at the same time.  At least this would eliminate any variation in the process causing defects when comparing the two versions side by side. 

 

 

The important things to note in the above shot are:  On the stainless buck, towards the center of the shot you can see a very slight almost granular texture visible in the vacform. On the fiberglass buck, there are a couple of "patches" visible at the center of the screen towards the bottom.

Once I had removed the bucks and examined the pulls I confirmed two things. 1:  The stainless is imparting the granular texture to the vacform, and 2: Bog standard fiberglass resin such as the stuff you get in car repair kits is a good medium for making bucks. That canopy was much clearer than the stainless version - except where you can see those patches.  When I was polishing the fiberglass buck, there was an imperfection in that area which I polished out.  That resulted in a light depression in that area. As the PETG was formed around the buck, the suction pulled the PETG across that depression and never allowed it to settle in to the depression.  That resulted in what I can only liken to a watermark around that patch area.

 

I tried everything I could think of to eliminate that mark.  I cut vents in as close as possible to the area.  I even drilled a number of .5mm holes along the center of the buck where the frame would go. Nope, nothing worked.  I even tried plunge molding on the vacformer to see if I could eliminate the suction effect. Nope. Same result every time.

 

 

So far, this is about the best canopy I've managed to produce.

 

 

It's debatable whether it's marginally better (or worse) than the kit part.

 

 

A dip in whatever Klear substitute I have appears to reduce, but not eliminate the effect.  I think it could be argued that the kit part is actually clearer, but has more distortion at the curves.

 

 

I've now spent over a week and many $'s in PETG trying to tame this beast with limited (and debatable) success, and the mojo has definitely taken a bit of a beating and decided to hop off on a vacation leaving me staring at a bucketful of PETG scrap.

The good news is that I am away on business all of next week so I fully expect to find little mojo sitting patiently for me in the basement when I return.   The bad news is that I am heading to Chicago (shudder) which is currently a rampant hotspot of COVID transmission.  The other up side is that I get to visit (if it's still open) what I would consider the best Indian/Nepalese restaurant I have encountered in the US so far. Yes, that place where I unsuspectingly ate a large slice of Naga cili thinking it wouldn't be much different than a Jalapeno.  Then thought I was going to die.

I'll be more careful this time

 

After all this abject failure I was a bit worn out.  I can't really continue with the WW until I have a windscreen attached and faired in so this was holding me up.  I took the best dozen or so attempts and gave them all a dook in the magic clear stuff and set them aside to dry.  I'll take a look at them when I get back next weekend and simply select the best of what I have and continue forth.  The de'il be damned and all that.

 

Then, just as I was packing up for today I had an epiphany 

 

I've been doing this all wrong, and approaching it from the wrong angle.  What a duffus I've been. Idiot!

 

PETG? Clear Stuff? pah! who needs clear stuff?     There's a much simpler method guaranteed to reap results.

 

To paraphrase some childhood heros of mine... We don't need no steenkin' clear stuff 

 

 

Those of us of a certain vintage will no doubt remember those little cars and other assorted vehicles and wotnots that were imported back in the 60's. 

 

Police cars, Fire Engines, Taxis, Rocket ships and all sorts. They all had nice interiors and drivers/pilots/astronauts etc.  They didn't have clear stuff did they? Oh no, they didn't waste weeks of their life failing miserably on the vacforming front - they had a foolproof method.

 

All I have to do is copy that... Job done!

 

 

Look - I can even get a pseudo 3D effect if done right

 

 

Okay, I'll admit - I'll have to work on my figure painting skills a bit before it will meet spec but I think, with the right brushwork, this could be a goer!

 

 

 

 

 

 

 

 

 

 

[Pete in Lincs]

The moustache on that Jockey is not to scale. Another failure.

Sorry to hear your tale of woe. I know you'll sort it in the end.

Meantime, stay safe on your travels, and come back soon.

[LorenSharp]

I would almost say that the gent with the  'stash reminds me of our dear @general melchett ready to take to the skies for God and Country.

[hendie]

General Melchett looks like Mickey Dolenz?

[LorenSharp]

3 minutes ago, hendie said:

General Melchett looks like Mickey Dolenz?

 On his better days.

[perdu]

 

General Melchett looks like Mickey Dolenz?

 

Your great problem is that you havent met the General

 

We just possibly might have..

 

PETg?

 

have you considered my clear stuff of choice?

 

Acetate?

 

I buy it by the A? sheet, cut down to A4 for me*

 

I have less/fewer/not as many moulding problems with the far less 'active' acetate.

 

Why not have some of that available when you return from Trek Chicago?

 

 

*I should know the numbers?

 

I am standing still, not a stationer.

[Head in the clouds.]

10 hours ago, hendie said:

Look - I can even get a pseudo 3D effect if done right

Pixar await your CV application.....and Disney are not far behind 😆

 

That was a marathon of vac-forming and a lesson in determination for us all. I am sorry but cannot offer any advice or 'get out of jail' cards as my experience in such matters is very limited but the rest and distraction of work may give clarity and a solution.

 

Onwards an upwards old bean👍😁

[perdu]

Now this merits further investigation.

 

Why on earth is Darling allowing Melchie access to the driving stick?

 

This cannot possibly end well.

 

Was the Whirly well known for decent flying characteristics whilst in the inverted flight platform?

 

 

The front window.

 

Cant you just discard the overly complex machinery and pull stretch a piece of clear plastic over the buck by hand, like wot I do?

 

Add extra material to the buck, polish and pull

Cut the moulded thing of beauty (when done) to size, move on.

 

 

Not sure what happened to the photo of the finished screen, gremlins fed water after I've been down the pub methinks.

[LorenSharp]

14 hours ago, perdu said:

 

General Melchett looks like Mickey Dolenz?

 

Your great problem is that you havent met the General

 

We just possibly might have..

 

PETg?

 

have you considered my clear stuff of choice?

 

Acetate?

 

I buy it by the A? sheet, cut down to A4 for me*

 

I have less/fewer/not as many moulding problems with the far less 'active' acetate.

 

Why not have some of that available when you return from Trek Chicago?

 

 

*I should know the numbers?

 

I am standing still, not a stationer.

I was actually referring to the amazing photographic likeness of Herr General on the forward windscreen But if one were to almost squint ones eye completely shut and turn head cockeyed and sufficient quantities of Baldrick home brew, Dolentz could almost pass for the General. But Dolentz would definitely have to wear lifts in his shoes.,and have extra "padding"

[hendie]

22 hours ago, perdu said:

have you considered my clear stuff of choice?

 

Acetate?

 

Bill, I did not, but will certainly bear that in  mind for the future.

 

12 hours ago, perdu said:

Cant you just discard the overly complex machinery and pull stretch a piece of clear plastic over the buck by hand, like wot I do?

 

Already tried that Bill, though in an inverse sort of way

 

 

same result.

 

I examined the dipped windscreens this morning and lo and behold, there were a couple of windows that passed muster.  The first one I messed up while filing to size - it was only 0.02" thick and was a bit flimsy to be honest.  The next candidate at 0.03" went a lot better.  

This is the sad victim after being molested by my fair mittens while filing to shape - the Fyle came in very useful for this as this material doesn't take to filing very well. 

 

 

With the victim now chosen and the sacrifice begun I was about to start sticking the thing on when I remembered that I had the 4 vertical bars to add inside the window.  Of course, being a home brewed vacform, I had no guidelines for the frame, which meant I didn't know how long the bars/rods should be, therefore I had to mask up to get the general layout.  Tamiya tape was my weapon of choice.

 

 

Resting in place to check the "frame".  I feel it should have been easier to mask this blighter since it wasn't stuck in place but it did not feel that way - it was still a bit of a pig.

 

 

Join the dots...

 

 

Fill in the gaps, then remove the tape that was standing in for the frame.  I realise that the windows should probably be a bit longer, but I gave allowed 1mm border all around the windscreen to give myself some breathing room while fairing the window into the fuselage. 

 

 

Support bars added from enamel wire.  E6k to attach the bars at the bottom, then the tiniest spot of cyano at the top once the E6k had cured enough to hold things in place.  I can pretty much guarantee that they are not straight/vertical/parallel/spaced right or whatever, but they're done now and staying that way. Any misalignment shouldn't be too noticeable on the final show. (he hopes)

 

 

Once I had masked the windscreen it was impossible to tell how clean it was after all my grubby handling so I cleaned it up as best I could prior to the bar sticking. I'm sure there will be a finger print for prime time viewing at the final reveal.  I've never been lucky with getting crystal clear canopies on a finished build.

 

With all that done it was time for the window to go home to its final resting place.  Cyano was used for this as I had to forcibly spread the windscreen to meet the edges and it was still a bit narrow.  Drops of cyano at the corners, then once I was sure it was fixed, cyano was run along the seams as a final joiner and filler.

 

 

Milestone.  That's what I'm calling it.

There are definitely going to be some steps between the fuselage and the window but I'll do my best to minimise them where possible.   Mr. Dissolved Putty has been applied around all the seams and left to cure, so I have that to look forward to on my return from Covid ravaged Chicago.

 

Did I remember to add a spot of black paint on the IP cowling where I had rubbed the paint off while all that test fitting was going on?  Of course not.

 

 

 

 

 

[Terry1954]

Another great update. Love that masking in steps approach to getting the frames defined. Have stored that in the memory banks under "extremely useful tips".

 

Good luck in Chicago. Spent some time there myself way back during a few enjoyable work visits, when times were better. Loved the place. Ate some of the best steaks I've ever had the pleasure of encountering!

 

Terry

[RichieW]

Onwards and upwards. All ready to crack on with on your return.

 

Don't chillis have antiviral properties? A few of those naga chillis might be just the ticket.  😁

 

Richie

[Space Ranger]

4 hours ago, RichieW said:

Onwards and upwards. All ready to crack on with on your return.

 

Don't chillis have antiviral properties? A few of those naga chillis might be just the ticket.  😁

 

Richie

I recommend Hatch green chiles from New Mexico. Probably not as hot as those naga whatchamacallits, but delicious, especially when use as a basis for chile rellenos.*

 

*Slightly spicy chiles (Hatch or Anaheim) stuffed with Mexican cheese, rolled in flour and beaten egg, and pan-fried until golden brown. Yum, yum!

[giemme]

Well, I'm back from my hols and had quite  catch-up on this, Alan. 

 

Excellent job on the filter, and glad to see you were able to pull out an appropriate windscreen (it looks miles better than the kit part to me, BTW) 

 

Still a bit disappointed by the lack of paint, but I'm confident your trips will boost your coloring enthusiasm 😉 

 

Ciao 

[heloman1]

On 8/3/2021 at 6:35 PM, hendie said:

 

Could you do me a favor please?   Could you measure the Outer diameter of the Wheels and the hubs?  

I want to make sure I'm in the ball park with my wheel set - thanks

Hi Alan, many thanks for the heads-up re the hub/wheel sets. Now all we need is a main rotorhead! (I'm getting lazy!)

 

Colin

[heloman1]

Great work with the windscreen Alan, the idea of the circles for the corners is most ingenious a must try.

I've been using K&S Buterite  (?) clear plastic sheet for my vac-forming it works well but will try the PEGT.

 

I have another word for our lexicon of modelling terminology. Gremlinology: The study and dealing with gremlins!

 

Colin

[Brandy]

We, of course, never doubted that you would find a suitable windscreen in your stash of trial bits. A huge improvement over the kit part once again.

 

Have fun in Chicago!

 

Ian

[Fritag]

Glad there was a windscreen that passed the hendie QC in the end.  It really goes without saying that most of the ones that failed the hendie QC would’ve been perfectly acceptable to the rest of the modelling world.  Smart masking too - just casual throwaway hendie inventiveness that…

 

Have to say that I find PETg pretty horrid stuff to work with come to think of it. Even once you’ve got a nice canopy it’s difficult to get the perfect shape because it doesn’t really like being sanded; and as for trying to polish out any accidental nick or scuff…..  P’raps I should listen to Bill and try acetate.  P’raps I should always listen to Bill?

 

With Bill’s advice in mind I did get 3 seemingly perfect results one after t’other last night, stretching candle-heated 0.5mm PETg over a resin buck of the rear (fixed) canopy section of a spitfire.  No bubbling and no discolouration of the PETg on contact with the resin buck.  But then it’s only a very small and simple shape and the PETg only needed gentle heating, more to bend it around the buck than to stretch over it.  Still it probably does show that PETg can work ok with a resin buck in limited circumstances.  It was still a PITA to trim to fit afterwards mind.

 

As others have said, enjoy Chicago.  I’ve been there a couple of times and really enjoyed it…except for the ghastly Chicago-style pizza that is (apologies to all as love it - my failing no doubt ).

 

 

 

 

[perdu]

3 hours ago, Fritag said:

 P’raps I should always listen to Bill?

Ah well..

 

but...

 

 

er...

 

 

 

 

Perhaps I should, guess who scored another Airfix HAS22 last week, arriving later this one?

 

Where's me Micromesh?