Avro 504K, 1/32, Scratchbuild

[Courageous]

Lovely bit of whittling. 

 

Stuart

[TheBaron]

Elegant immaculatery.

This is a continual pleasure to catch up with and learn new skills from Steve.

[Bandsaw Steve]

No Lathe

 

One day I'm going to buy a micro-lathe, not a big woodturning job for making bowls and things, just a little one for exactly this kind of job.  For now though, I don't have one. So I'm just going to have to press on.

Here's the bit I’m going to make, the cowling, here viewed looking along a length of Huon Pine that it's almost exactly the correct width for the job.

 

Huon pine is probably Tasmania's most famous and highly prized timber. I've never used it for anything before but picked this bit up at a woodworking show a couple of years ago. It's another one of these pale coloured 'softwoods' that actually aren't that soft and are just beautiful to work.  According to Wikipedia (and various other sources) a 'Lagarostobos' (Huon Pine) tree is actually a podocarp and not a conifer despite what it's common name suggests.   85% of remaining Huon Pines are protected from the logging industry so their wood is now quite rare and very expensive. It's use is now generally restricted to the construction of 1/32 WW1 rotary engine cowlings. Interestingly enough, one of these trees is the oldest living thing in Australia.

 

Anyhow, it just so happened I had one of these very vicious looking drill bits - I'm sure this type of bit has a proper name but can't think of it right now - that was exactly the 19 mm required to make the hole.

 

Mark the intended centre of the hole with a braddle.

 

Fit the drill's centre into the mark and 'hit it'.  Years and years ago my dad taught me that for holes like this always start the hole with the drill running backwards. This allows the sharp little pointy bits on the edge of the drill to scour out a guide circle and prevents the wood from 'chipping out' around the edge when you start drilling in earnest.  Good advice - it works - do it that way folks. I forgot this time...

 

Here's the result of a few second's drilling.  At this point the aroma is really surprising. It seems that  Huon pine, when cut, has a smell unlike anything else in the world. Not only does it not smell like any wood I've ever smelt before - it doesn't smell like anything else at all! I reckon in a blind smell test I wouldn't have even picked that this was wood. I can't really describe the aroma at all - it was just plain weird.  The wood seems very 'waxy' so I'm guessing that the smell was a result of disturbing some sort of botanical wax?

 

Anyway - putting the aroma to one side for a moment - the hole drilled out beautifully, even without the precautionary 'run the drill backward' step.

 

Spray some glue on and stick the paper cowling pattern on. Make sure that the pattern is properly centred around that hole in the middle, that's what the pencil 'cross-hair' lines are for.

 

Start whittling. Note this time I actually am whittling, using a knife rather than a chisel. I was working on the table top at one of my mate's places and didn't think he'd appreciate me chiselling into his table top. 

 

After a bit of whittling and sanding and so-forth I got to this point. 

 

And then I just carried on whittling out the rounded front of the cowling.

 

Leaving this - which was essentially what I was after.

 

I reckon that's not too bad considering I don't have a lathe.  This is actually going to be a 'buck' for vacforming the cowling, as the cowling needs to be hollow.   Will post my attempt at vac-forming next time round.

 

Till then - stay safe, and if you do have a lathe, keep your fingers out of it!

 

Steve

 

[keefr22]

1 hour ago, Bandsaw Steve said:

if you do have a lathe, keep your fingers out of it!

 

That's the best advice I've read today. However as I don't have a lathe I shall be reckless and ignore it! 

 

I wish t'internet had 'smellovision' as I'm now intriqued as to what Huon pine pongs like! 

 

Enjoying watching this come together Steve, I really used to enjoy woodwork in school, back in medieval times, but haven't done any since (come to think of it, it feels just as long since I've whittled any plastic either, must extract finger!)

 

Keith

 

 

[Redshift]

Cor, thats some accurate whittling! Are you sure you don't have a lathe hidden away somewhere?

[Azgaron]

Well done, Steve! Looks great!

 

Håkan

 

[Courageous]

3 hours ago, Redshift said:

Cor, thats some accurate whittling! Are you sure you don't have a lathe hidden away somewher

My words exactly.

Bloody good show that Steve. 

 

Stuart

[pheonix]

Sorry Steve but I have missed a lot of this recently and have just read through the thread.

 

I completely agree that basswood is one of the best woods that I have ever come across. I too cannot recommend it too highly, and it takes a superb polish.

 

Your woodworking skills are something to marvel at: I have done a little in my time but nothing as complex as this. Congratulations on solving the dihedral problem - perseverance paid off splendidly. The lower wing attachment is also very good indeed - another brilliant solution to a tricky problem. The cowling is staggering - I think that you have a secret lathe and are just not showing it to us!

 

I agree that life would be much easier if we could think of solutions to problems which worked before the third attempt..... My own project is continually presenting me with headaches at the moment and I have not even started on the wings and dihedral! But then why attempt a scratch build if we don't get some form of challenge?

 

I intend to keep a closer eye in future - if life will allow me to.

 

P

[Mick Drover]

That is remarkable work so far Steve.

 

My family and I recently did a lap through Queensland where we visited the QANTAS Founders museum in Longreach. Though no the real thing the replica that they have on display is remarkable. Considering that it was their first aircraft I don't know how they survived. The QANTAS one would be a bit different to yours as it was fitted with a Sunbeam Dyak engine.

 

Again, great work and an excellent display of skills for scratch building.

 

Mick

[Martian]

On ‎17‎/‎07‎/‎2018 at 12:33, Bandsaw Steve said:

Till then - stay safe, and if you do have a lathe, keep your fingers out of it!

Sensible advice but try keeping multiple tentacles out of it!

 

Martian 👽

[bigbadbadge]

Hi Steve.  Just caught up with this thread again. This is fascinating and looks amazing. I had always wondered how people like yourself made such models and am learning a lot.  Although I doubt I will ever be able to masteread the skills needed for such a model.  Cracking work fella it is magical to see it coming together. 

All the best 

Chris 

[Bandsaw Steve]

A Job that didn't suck - despite all the sucking

 

Before I go any further I must thank everyone for their kind and encouraging comments above. 👍 I greatly appreciate the interest and the feedback. I feel duty bound to add however that  @pheonixis clearly lying when he says he's never done anything as complex as this.  Have a poke around this website and have a look at his WW1 pushers and the flying boat he made from scratch in the flying boats and seaplanes group-build.

 

@Mick Drover - I did briefly consider doing the first QANTAS aircraft when first considering this  project and might have gone down that path if it hadn't been for the RAF centenary.  If I'd done the QANTAS 504 I wouldn't have had to vac-form the cowling. 😉

 

So - back to work. First I must finish making the buck.  The Avro 504K subtype was developed specifically to accommodate three different types of rotary engines - a Gnome-Rhone, the Clerget and one other that slips my mind for now.  Apparently during the war an adequate supply of any one of these engines could not be guaranteed. In order to deal with this uncertainty the Avro 504K was given a revised engine mount and cowling that could accommodate any of the three engines. The revised cowling had a gap at the bottom of it, presumably to improve engine cooling. This gives the Avro 504K it's distinctive 'moustached' appearance when viewed from the front.

 

Here I am cutting out the gap in the cowling where the 'moustache' will stick out.

 

And here I’m cleaning out the hole with a chisel.  The chisels is nice and sharp but the shank needs a bit of clean up.

 

For the first time ever I'm going to try vac-forming with opaque plastic. The only prior vac-forming I've ever done was with clear plastic (for the Mig15 project) and it took a long time to find the right plastic for that job. The correct type of plastic is critically important.  Here' I'm going to try some 'bog standard' white Evergreen styrene at 0.5mm thickness.

 

Once again I will be using @Vanroon's excellent little vac-forming machine. Apparently this model was developed for dental work and is readily (and affordably) available on various internet shopping sites.  I'm going to get my own one day but in the meantime I'm going to keep bludging off Vanroon.

 

A very quick primer on Vac-forming for those not familiar.

• Stick the master shape (buck) in the machine as shown with the shape you want to form facing upwards.
• Clamp a sheet of plastic into position in a frame that can be lowered down onto the buck at the appropriate moment.
• Turn on some heaters that are just above the plastic sheet
• Wait for the plastic sheet to start to go soft and sag in the heat.
• Turn on a vacuum pump within the machine
• Lower the frame that holds the plastic sheet down onto the Vacuum chamber
• The moment the frame seals up the vacuum chamber the vacuum will draw the soft, hot, wobbly plastic down over the buck (this happens in less than a second - practically instantly)
• if all has gone well you can turn off the vacuum pump, turn off the heater, get the mold out and admire the shape you have made.

 

So - here's the machine switched on to heat up the plastic. Once the plastic is all saggy I'll hit the 'model' button which turns on a vac pump in the machine and pull the sheet of plastic down onto the vac chamber.

 

And here's the result.  Really encouraging! No webbing - no tearing of the plastic. In fact I reckon this evergreen stuff is about Ideal.

 

Here's what the result looks like from behind in case anyone's interested.

 

Once cut out, the mold looked like this. It was OK but the plastic had been stretched out too far and it was clear that the 0.5mm sheet was too thin to start with. The product - although good in all other regards - was too flimsy.

 

Try again - this time with 1.5mm sheet and with little ball bearings spread around the base so that the plastic won't get drawn down so far and hence stretched so thin.

 

And here it goes! - better!  I thought that the 1.5mm might be too thick for this process, but it was fine.

 

And after a bit of cutting and cleaning we have this...

 

Which currently sits on the front of the aeroplane something like this (if you use a bit of blu-tack to hold it in place).

 

Well - that was fun.

 

Like I say - this round of vac forming was actually pretty easy. The job didn't suck at all, despite all of the sucking that was involved.  🙂

 

Best Regards,

Steve

 

[hendie]

Well, your last post really sucked (sorry - just had to go there - and you knew I would).  Seems like you are moving along at a good pace since I was last here

 

I got one of those machines a while back. Good value for the money.  I haven't had the need to use it for some time but it's good to know it's there and invaluable when needed. I think I used it quite a lot on my Lysander build.

 

[bzn20]

On ‎4‎/‎1‎/‎2018 at 2:38 PM, Bandsaw Steve said:

Wish me luck..

102 ish  years ago my grandad was a Sgt Rigger in the RFC ,he worked on these in the RAF too . He arrived from France in 1916 at Farnborough for training late at night . The orderly Sgt was in one of the hangars working on his 504K so he went to get his Barrack allocation and sign out his bedding from the Orderly Sgt ,who was actually Sgt James McCudden ! He'd stripped his engine down and reassembling  and was  flying it by breakfast time ! My dad worked on a 504 at RAF Halton during Airframe (Rigger) Apprenticeship  43-46 .

 

Good luck BTW ! Looks like a great job in the making.

On ‎4‎/‎4‎/‎2018 at 8:58 PM, Tomoshenko said:

Squadron Leader Neville Duke

What a gentleman he was . I was working on the Optica 1985 and he was one of the Test Pilots and  an absolute pleasure to deal with and we solved a few problems together during the night hours full of rush , panic and chaos leading up to an early morning First Flight deadline  .

 

Edited July 21, 2018 by bzn20

[Courageous]

Good effort with the vacforming.

An observation, your newly formed part seems to have a dimple finish? 

 

Stuart

[pheonix]

First class job with the vacuforming. Personally I stick with the old push-moulding method - cheap and cheerful but effective. I find that 30thou card from Evergreen is ideal for most things and moulding opaque plastic is much easier than moulding clear plastic. I should know as I have made a fair number of both over the years.

 

Looking forward to more on this thread, especially how you will fair in the cowling to the fuselage.

 

Thanks for the compliment re-my Dornier flying boat and other pushers - much appreciated.

 

P

Edited July 21, 2018 by pheonix
additional comment added

[Bandsaw Steve]

 

'who was actually Sgt James McCudden'

 

Man! - that's a story and a half. See, even McCudden had his own Avro 504!

 

My dad worked on a 504 at RAF Halton during Airframe (Rigger) Apprenticeship  43-46 .

 

For me a large part of the appeal of the Avro 504 is the sheer number of people and professions / trades that were involved with the type - this is an excellent example. Interesting to think that in the post WW2 world a pre-WW1 design was still being used as an instructional airframe.

 

'he was one of the Test Pilots'

 

Wow - you met Neville Duke! I seem to remember hearing other glowing references about the man. One of life's true gentlemen by all accounts.

 

'your newly formed part seems to have a dimple finish?'

 

Yes it does I'm afraid.  Not sure how the dimples got there but they were completely absent on the thinner versions. I'm guessing that this might be the only drawback with using the thicker plastic. The part is at least nice and rigid though so I think a dash of filler and a swipe with some sandpaper should see this right.

 

'First class job with the vacuforming.'

 

Thank you - this is only my second time vac-forming. I used to do plunge molding with a candle to heat the plastic, a buck held in a vice, steely nerves and steady hand when I was kid. 😉  About one in ten used to work out OK.

 

Thanks for the interest everyone - will be posting again soon as the project is still advancing at a good clip.

 

Steve

[Ted]

Amazing work carving that mold Steve. I'd call that drill a spade bit.

[Brandy]

Nice result on the vacforming.

 I must admit when I saw the comment that you would be using .5mm I just knew it wasn't going to end well. Not that I've done any vac forming, only crash moulding, but it does stretch and get thinner, as you found out!

 

Ian

[Bandsaw Steve]

59 minutes ago, Ted said:

Amazing work carving that mold Steve. I'd call that drill a spade bit.

That’s it! A spade bit! ♠️ Just goes to show...

I don’t always

’call a spade bit a spade bit ‘ 

cause sometimes I forget to. 🙃

[Matt_]

Loving the progress.  A bit of mixed-media. Nice.

 

Thought I would also update on the Bandsaw Steve Tribute Biplane...

 

 

Needs a tail wheel or skid, but I was starting to be doing it on my own, so we put it aside for a bit.

 

The wheels turn pretty well on the nails (I drilled them and glued the end of the nail into the centre block to make the axle), but the little'un seems pretty annoyed that they don't spin like they're on bearings. Harrumph. 🙄

[Bandsaw Steve]

Love it. Love it. Love it! 💕 

 

Thanks so much for sharing this it’s made my day! 👍

[Bandsaw Steve]

A Change of Plan

 

Well - it's not really a change of plan because I'm essentially making much of this up as I go along.  Earlier on Pheonix made a rather innocuous comment regarding how he was looking forward to seeing 'how I would fair the cowling to the fuselage'. I was troubled by this as I was rather hoping he could tell me!

 

Here's where the last post finished.  Please take special note of the big block of Jarrah right on the front of the fuselage, directly behind the cowling.

 

Yep - that big block right on the end there.  That big block that was an important part of my plan for the whole forward fuselage. Watch closely now...

 

Bang! Gone! Change of plan!

 

On the real Avro 504 the cowling is circular in section - while the fuselage becomes progressively squarer and squarer as one moves to the rear of the cockpit.  So having a great big square block on the front of the model was not very smart.

 

On the real thing the forward most portion of the fuselage was made out of sheet metal which started as a perfect circle but progressively described a flatter and flatter vertical profile on its sidewalls.  On the diagram below at 'Section A' there is a complete circle. However, at 'Section B'  the side walls of the aircraft are much less curved.

 

The bit of paper that I'm holding indicates the sheet metal section that, through a couple of compound curves, accommodates the change.

So I have to carve that slightly complex shape into a block of wood.

 

Here I am marking on the circle at the front...

 

See - a nice circular section...

 

And various bits of random geometry traced on to try to give me some guidance while I hack away.

 

Once the hacking and sanding is complete I have this. A nice circular front to the aircraft at least.

 

But unless this is a side-by side seat trainer it looks like more work will be needed. 😦

 

Carve, hack, chisel away...  This piece also has to taper as the fuselage becomes progressively thinner all the way to the tail.

 

Cut off the bit that I'm after.

 

Sand the back of the piece to have just the right profile at the rear of the sheet metal section of the fuselage, where it joins onto the front of the wood and fabric structure.

 

Draft up the gentle curvature at the rear of the piece and check that it's the right width for the fuselage.

 

And after a bit more chiselling, sanding and swearing we have this...

 

Which I think looks kinda OK.

 

Here's another view of how the project is looking right now. Note that I have cut out the notch between the two elevators so the tailplane looks much more convincing.

 

I am pleased with this - I think it's starting to become identifiable as a 504. In fact I reckon a competent WW1 aircraft spotter might now be able to guess what this is.

Next up we might have a closer look at that cockpit area.

 

Best Regards,

Steve

 

[JohnWS]

That was a lot of carving, but the final product looks awesome.

 

21 minutes ago, Bandsaw Steve said:

... I reckon a competent WW1 aircraft spotter might now be able to guess what this is. ...

Yes sir, it's a 504!  

[Redshift]

Another first class bit of carving there, I am taking copious notes from this masterclass.