28 Sqn Westland Wapiti (1/48) scratch 'n' print

[Pinback]

On 3/19/2021 at 4:09 AM, hendie said:

put the bullet path between the cylinders

  Wow! Learning all sorts on the Wapiti! Loving your build Hendie

[Dave Swindell]

On 18/03/2021 at 20:07, hendie said:

spoken like a true engineer

A true engineer wouldn't have been wasting coin of the realm to make adjustments - he has a hammer and knows how to use it!

[perdu]

My dad, an armourer on Gladiators, would almost certainly have packed the height with a folded Players Navy Cut packet.

 

I wish he was still around to chat anecdotally, about maybe when he and a mate with interrupter experience from the Gladiators were loaned to a (Polish?) squadron of Mustang MK1 owners to teach their armourers how not to shoot their props off over the Wash.

 

He'd certainly have been able to tell us about Woppity's gun.

 

😲

 

[hendie]

23 hours ago, derekS said:

Hi,

 Me again.The guns are available from Miniworld,ref Mina4862 in 1/48 Good photo on Hannants web site.

As the set is for the Flycatcher it includes 2 guns,LH & RH feed.

 Your progress so far is stunning.

Best wishes,

Derek S

 

I think I'll have a go at printing them myself before forking out modeling funds

 

2 hours ago, Dave Swindell said:

A true engineer wouldn't have been wasting coin of the realm to make adjustments - he has a hammer and knows how to use it!

 

Dave, Dave... terminology please.   It's a precision adjustment tool

 

As threatened a few days ago, I took Friday off work and started on the Wapiti ands coffee early in the morning.

This session I had intended to work out how to assemble the "kit" but as I started down that wormhole I realized that internal features were going to have a significant impact on how the  assembly sequence was going to go, plus some features may change how the entire assembly is broken down.

Easy on first - pilot seat and cushion. I'm keeping the cushion separate to make painting easier.

 

 

 

Some, all, or none of this may change going forward.  Yesterdays session was more about getting all the internal detail worked out so I can make any final adjustments to the fuselage. I was more concerned with making sure I had captured the detail rather than how well is it designed for printing.

Some of the work may have to be broken down further in order to have a chance of surviving the print process successfully.  Some of this work looks a bit kludgy and overscale but there are times we have to make allowances for scale effect.  

The trays on this foot pedal assembly are only 2.5mm wide. Everything looks beefy but printing may be a challenge for some areas.

 

I have chosen to break down the assembly using the lower wing center section to double up as the cockpit floor.

 

 

Wing assembly will be aided by the usual tab and slot method

 

 

Bulkhead between the the cockpit and the gunners station

 

I have only come across one photo of a Wapiti (may even have been a Wallace) interior and that was almost indecipherable, I purchased a modelers licence to make things up as I went along in the hope they they sort of looked right. 

There's still some more detail to add, but any detailing left is fairly minor (famous last words) .  I am designing this as a "kit" but haven't really put any thought into scratch building aspects yet. I may well throw away some of the printed parts and scratch build my own versions - who knows?

Cockpit view froward

 

 

and cockpit view aft

 

 

I know what you're all thinking... how much will be seen?

 

 

About this much in one direction

 

 

and this much in the other

 

 

and that's if the upper wing doesn't get in the way.

Can't forget the gunners pit can we?  I gave him some basic framework 

 

which, if everything works as intended - and I know that's a long shot, then the rear frame should just slot inside the rear fuselage, which in turn can be butted up against the front fuselage (with the aid of some locators that I haven't bothered about as of yt)

 

then in a moment of madness I added some more detail to the gunners pit. I know they carried a camera so will need a sliding floor hatch for the camera, and I've also read reference to a sliding floor section for the bomb aimer position. Add in a folding seat

 

 

and there's a whole bunch of stuff we'll never see again! - including the camera I added at the rearmost part of the floor.   I believe there's also some radios etc that live in that area?

 

 

I got sort of carried away yesterday and constructed that gunners pit with almost no thought to the printing process.  I'll now need to sit back and have a think about that.  It's probably possible to print the thing in its entirety, but it may make more sense from and assembly, or a painting standpoint to break it down further.

 

Lastly, another question for the hive based on this shot

 

 

Since I have no hard dimensions for anything in the interior, I have been estimating sizes of features. Does the size and relationship of the cockpit components look about right to you? Is the instrument panel too tall ?

I was surprised when I placed the Wapiti next to the Audax at how large the Wapiti actually was in comparison, and in looking at photos,  Wapiti aircrew either have very small heads or the aircraft is a big beast. 

Therefore, does it look like I have the interior scaled for a 1/48 human?

 

[perdu]

Knees

Do you think his knees will fit below the i.p when his heels are sliding along the heel board?

 

Truly awe inspiring stuff H, wow.

[giemme]

I think Bill has a fair point, Alan.

 

For the rest, I just remain in awe of your work    

 

Ciao 

[hendie]

45 minutes ago, perdu said:

Knees

Do you think his knees will fit below the i.p when his heels are sliding along the heel board?

 

Truly awe inspiring stuff H, wow.

 

those were my thoughts Bill.  Here's a shot of a Wallace which I am going to assume (dangerous I know) is very close to the Wapiti.

 

 

the bottom edge of the control panel is not much higher than the seat, and the foot trays/pedals are about a seat pans height below the bottom of the seat.  Based on that I think I have the main components in the right position relative to each other, but without having a hard dimension to work to, it's all guesstimates. 

Going by this photo, and the seat to pedals position, it appears that the pilot had his legs almost straight out in front of him?

 

1 minute ago, giemme said:

I think Bill has a fair point, Alan.

 

so... remove some of the bottom end of the instrument panel?

[perdu]

1 hour ago, hendie said:

 

those were my thoughts Bill.  Here's a shot of a Wallace which I am going to assume (dangerous I know) is very close to the Wapiti.

 

 

the bottom edge of the control panel is not much higher than the seat, and the foot trays/pedals are about a seat pans height below the bottom of the seat.  Based on that I think I have the main components in the right position relative to each other, but without having a hard dimension to work to, it's all guesstimates. 

Going by this photo, and the seat to pedals position, it appears that the pilot had his legs almost straight out in front of him?

 

 

so... remove some of the bottom end of the instrument panel?

No-o-o

 

Looking at the result of your research here I would say leave it and print them as is.

I only queried it as a result of my oft seen scale creep., which this build is precluding.

 

With the scratchbuilt-by-printer methods from the future that you are bringing (with your fellow pioneers) into our dark ages I am certain it will be all good inside the cockpit.

 

Go for it Alan, get in there.

[Ex-FAAWAFU]

16 hours ago, hendie said:

so... remove some of the bottom end of the instrument panel?

How long have you known @CedB?  Remove the pilot’s legs, of course

[Brandy]

I think you have it pretty accurate Alan. I've never had my knees under the panel in any aircraft I've flown, they are normally about level with, and slightly aft of, the bottom edge. Legs will be fairly straight, allowing for full rudder deflection with still a slight bend at the knee to make it easier to maintain full pressure if needed.

Hope that helps!

 

Ian

[Marklo]

The proportions look pretty close to the Wallace photo to me. It’s well known that British airplanes are notorious for bad ergonomics anyway. 

[hendie]

Another test print session under the belt yesterday. The print finished around 9pm last night so I gave them a quick rinse and left them until this morning to have a good look.

I was primarily interested in seeing how my breakdown for assembly worked and in particular, the quality of the seams.  Upon a cursory inspection everything looked good.

For this print I ran:  Front and rear fuselage halves, lower wing center section,  exhaust collector ring, cockpit bulkhead, undercarriage leg, and Jupiter engine casing.

 

 

I'm also using the wing section as the cockpit floor.  This allows for assembly of the internal components from the underside and rear of the cockpit - nice and simple.

On the forward fuselage I'd made a few changes including adding a mount for the engine.

 

 

which worked perfectly.  That was a nice start to the day.

 

 

The wing centre section looked really good with very fine trailing edges.  The down side to this is that they will be susceptible to mishandling and be easily damaged.  I did take note of @TheBaron's observation and each part was washed separately to minimise the chance of damage with all the parts swooshing about in a bag of IPA.  The translucency shows up just how fine those edges are.  

 

 

I did have one issue with the wing section though - for whatever reason, the rib taps on one side did not print     That points to an issue with the STL file.  Print wise however, I'm really pleased with this and the rib tapes issue will be easy to sort out.

I tried to capture the sharpness of the trailing edge in this shot - rather unsuccessfully it has to be said.

 

 

But the big question was how did the wing section mate up to the fuselage? 

(also added some rigging holes at the wing root and between the cabane strut mount points.  I just hope I have the wing root points in the right location as I couldn't find any photos showing the location points clearly, so it's part guesswork)

 

 

I'll take that as a win!  Very pleased with that I am.   I'll add location pins and whatnot later.  I wanted to make sure the join was going to work first.

I have tried to land the join seams on panel lines but it was inevitable that I wouldn't be able to manage that for everything - such as this panel on the underside. I don't think that will take a lot of work to clean up.  I did think about making that panel separate, but that brings with it a whole bunch of other issues, so I think I can live with this quality of seam.

 

 

After the last test print where I lost parts of the undercarriage leg near the axle, I thickened up the entire leg by about 0.25mm. I'm glad to say that visually, it doesn't appear to have a negative impact, but what I did find in this print is that the hole for the brass rod did not survive the entire length of the leg, and the hole was blocked from about halfway down.  That's the reason for doing these tst prints though isn't it?  To find any underlying problems before committing to final design. 

I think I understand the cause though:  In the last print some of the side wall gave way early in the print and the hole was successful the entire length of the leg.  That leads me to believe that with this design and combination of hole diameter/length and resin viscosity, that what is happening internally is that a small vacuum is being created which prevents the resin from draining out and light bleed etc. is causing partial cure of the resin retained within the hole.  The fix will be relatively straightforward - I just need to add another "hole" from the end of the existing channel and exit it through towards the axle (where it will be hidden when assembled). Hopefully, that vent will prevent the vacuum from happening and allow the resin to drain out as the print progresses.

My method for attaching the legs to the airframe looks like a good choice though, and should provide a strong structure. 

 

 

Now to the rear fuselage.  You'll remember that last time I didn't provide enough supports and the print broke away at a few corners leaving unsightly gaps.  

I thought I would try a different approach this time - with resin printing, obtaining flat surfaces is normally straightforward, except when those flat surfaces are parallel to and facing towards the build plate. In those instances you need to apply supports to that face and inevitably, resin lies on top of the flat surface, gets partially cured and results in an undulating surface.  It's not the end of the world and a bit of sanding cleans it up. Printing flat surfaces in the vertical plane, or an angled plane eliminates that issue and gives great results.  It's just that sometimes, that cannot be avoided.

It should be noted that I'm not great at sanding perfectly level and always end up with some degree of curve on the surface. Hence, my new attempt here.

Instead of trying to print that flat surface directly, I offset the boundary line and extruded a small block about 1.5mm deep ( the ledge/flange on the end of the fuselage in this shot below).   I could then add as many supports as I liked to that support ledge without caring about how flat it was on the support side.

 

 

What that ledge now provided me with was a nice flat guide for me to take my razor saw and gently cut around the line where the fuselage and the flange met.  With a bit of care and taking my time I managed to separate the flange from the rear fuselage.

Did it work?

 

 

That looks like a decent seam to me.   Another win

 

The cockpit bulkhead worked.  It's always somewhat surprising when you've been working on a computer screen for a while then you end up with that same object in your hands.  On the computer screen, that seat adjustment housing looked very overscale and industrial, yet when printed, it looks much better, being a lot finer than it appears on screen.

 

 

with the added bonus that the bulkhead slots nicely into the rear of the fuselage.

 

 

 

Coming to the last part of the test print, the collector ring turned out better this time with all legs of the exhaust printing correctly.

 

 

 

 

One of the other changes that I made but didn't mention earlier was regarding those strengthening flutes along the fuselage:  I reduced the height of those flutes from 0.1mm to 0.06mm and they are not as pronounced and less obtrusive.  

I think I'll keep that change.  I added this shot so you can see the comparison but it's very difficult to tell the difference.

 

 

Overall things are progressing very well with the Wapiti.  Taking a days vacation on Friday to concentrate on it made a big difference to the amount of work I accomplished versus taking the odd hour here and there, and working through lunch breaks.

At this rate, we may have a kit before Xmas!

 

 

 

 

 

 

[John Masters]

You see...28 Squadron...all I will be doing for 19 Squadron is using existing kits, most of which are not accurate enough for the rivet counters.  You?  You're actually building the kit itself then assembling it.  Incredible!  There should be a whole different forum for magicians like you...

[giemme]

Wow, successful test print, to say the least!  

 

Ciao

[perdu]

13 hours ago, hendie said:

I did think about making that panel separate, but that brings with it a whole bunch of other issues, so I think I can live with this quality of seam.

Would it be possible to make the panel as an extension of the front fuselage entity and allow the hole for the overlap on the centre section piece?

I suppose that is what you are talking about here...

 

I am not doubting you by the way Alan just trying to see what limitations this alchemy brings, really is akin to sorcery to we wee folks.

[CedB]

More stunning designs and even some resin! 

 

Great work hendie  

[corsaircorp]

Impressive Wapity....

I better not think about buying all these tools...

No no CC, Not until you retire.... Tsss

It is REALLY tempting, creating your own kit and build it...

Kinda like of an ultimate dream for any modeller...

Great great Job !! Congrats...

Sincerely.

CC

[Ex-FAAWAFU]

Superb.  Inspiring.

[Brandy]

More excellent progress. More importantly, for me at least, thanks for sharing the thinking behind what you're doing. It makes it much easier to see some of the problems I've had and possible solutions.

 

Ian

[hendie]

On 3/26/2021 at 4:51 AM, CedB said:

More stunning designs and even some resin!

Great work hendie  

 

thanks Ced, more resin in this weeks episode

 

On 3/26/2021 at 7:17 AM, corsaircorp said:

Impressive Wapity....

I better not think about buying all these tools...

No no CC, Not until you retire.... Tsss

It is REALLY tempting, creating your own kit and build it...

Kinda like of an ultimate dream for any modeller...

Great great Job !! Congrats...

Sincerely.

CC

 

oh come on CC, you know you just want to jump in there and get your feet wet don't you?

 

On 3/26/2021 at 7:50 AM, Ex-FAAWAFU said:

Superb.  Inspiring.

 

Thanks Crisp - I expect to be seeing the same coming from your corner soon

 

On 3/26/2021 at 9:35 AM, Brandy said:

More excellent progress. More importantly, for me at least, thanks for sharing the thinking behind what you're doing. It makes it much easier to see some of the problems I've had and possible solutions.

 

Ian

 

glad to have been of assistance Ian - never be afraid to ask if you need any help

 

I managed to get a couple of printing sessions run this weekend after spending a few hours updating the model.  Some old, some new,mostly in a hard to photograph shade of grey.

Print session 1 yielded this little assortment

 

 

First up being the lower wing center section, this time around with a few additions

 

 

In the wings I have created some slots at each end to accept these little locating tabs to help with alignment and the joining operation

 

 

Around 300 mm wingspan give or take.

 

 

The slots/tab features work though I think I can tighten the tolerance a little bit.  I may also look at adding some additional locating features in there too.  Every little bit helps.

I'm still not sure if I am happy with the wing tips - for the very same reasons Bill pointed out earlier.  I may have one last go at trying to rectify the shape and get it closer to that "flat line" appearance, but I may have to admit that my skills just aren't up to the job.  We'll see.

 

Test fit of the Y branch at the rear of the cylinder.  It's going to be fun assembling this little bundle of resin: 9 cylinders, 9 Y branches, 1 engine casing, and the exhaust system is an additional 5 (?) separate parts. A little project in itself.

 

 

Last out of the bath for this print run was the rear fuselage floor.  Almost there but not quite.  If you look closely you can see that some of the structure has broken during the printing process.

To be honest I am surprised that it printed at all given how thin it was, but it was worth a try to see how it turned out.  I also didn't pay enough attention when adding supports and one or two of them were too close to the structure.  All easily fixable and a few modification for the next time and I'm confident it will be a success.

 

 

Session number two.

 

 

I won't bore you with the bits you've all seen before

 

A camera?

 

 

which will sit at the back end of the rear floor in an area you'll never ever, ever be able to see

 

 

Pilots seat and seat back padding

 

 

Oxygen bottles and some exhaust bits

 

 

Oxygen bottle rack

 

 

with a couple of bottles stuck in.  There should have been three, but one somehow decided not to print

 

 

Floor trays and rudder pedals

 

 

which all gets assembled into this little lot.  My photographs really don't do these parts justice.  It's difficult to believe just how fine they are without seeing them in the flash as it were.

The inside wall to inside wall dimension of this fuselage section below is only about 20mm or so. The foot trays are 3, maybe 3.5 mm wide

 

 

same gubbinses, different view

 

 

The design is now for the most part complete. I have the parts breakdown figured out. Now it's just a matter of going back over everything and making those final few tweaks, such as adding location features, and adjusting for fit between components etc.  It's a shame work gets in the way sometimes.

 

Crud!   I still have the airscrew to attempt.  I guess that's gong to be this weeks big job then.

 

 

 

[giemme]

Impressive!    

 

Almost ready for paint, right?

 

    

 

Ciao

[Heather Kay]

This is very impressive work indeed. 

 

One question, though, for an inquiring mind. Is there a reason for not printing the engine in one piece, or at least cylinders with the detail pipework in situ? 
 

 

[perdu]

30 minutes ago, Heather Kay said:

One question, though, for an inquiring mind. Is there a reason for not printing the engine in one piece, or at least cylinders with the detail pipework in situ? 

Give the modelmaker something to do apart from just painting?

 

Isn't this stuff fabulous huh?

[Heather Kay]

43 minutes ago, perdu said:

Give the modelmaker something to do apart from just painting?

I suppose there is that. Something, something, the journey, something. 
 

It is amazing stuff, ‘tis true. I don’t have the nous for it any more, but if I was 20 years younger I’d be all over it.

[Brandy]

That print looks pretty good to put it mildly. How do you get multiple pieces on a shared base?

 

Ian