Jump to content

Avro Anson - XIX T.20/21/22/C.21


Recommended Posts

3 minutes ago, cngaero said:

Oh yusssssss 🤣 🤣 🤣 🤣 I'll be watching this with great interest. 

Will it be 1/72 or 1/48? 

 

Chris. 

 

1/48 to start, maybe 1/72 if there is enough genuine interest :)

  • Like 4
Link to post
Share on other sites

The wings are on (temporarily), I may need to scale them slightly depending on the answers to the questions in the thread above, I have also yet to add the large wing fairings.

 

Avro Anson CAD 4

 

  • Like 2
Link to post
Share on other sites

The approximate fairing shape is in place now, it's not right, but it's a start. What I will now do is create multiple guide lines for the multi-section surface to get the correct shape. It's a bit messy where it joins the wing trailing edge, typical of British aerospace engineering, I doubt the profile of the fairing would have been defined (after all, in the 40's/50's there were no CMM's, so it wouldn't be possible to measure the surface), instead, the fairing were most likely rolled to the correct shape by an almost artisan machine operator.

 

Ironically, aerospace engineering is almost coming full circle with composite manufacture. It requires very skilled operators to understand the material and place every piece of fibre by hand. Quite different to a CNC machine (although that also takes a lot of skill to operate, a good ear is required to notice when the chatter becomes unacceptable, the clamps are not tight enough, the tool is about to break, etc, etc).

  • Like 1
Link to post
Share on other sites

I think you are grossly underestimating the skill of a professional designer/draughtsman, to produce a drawing that the skilful shop-floor artisan will follow to produce the curve.  Of course the profile will have been defined as part of the design process.  Aircraft curves were produced to mathematical formulae, not just a suck-and-see random process.

Link to post
Share on other sites
On 30/10/2020 at 23:40, Graham Boak said:

I think you are grossly underestimating the skill of a professional designer/draughtsman, to produce a drawing that the skilful shop-floor artisan will follow to produce the curve.  Of course the profile will have been defined as part of the design process.  Aircraft curves were produced to mathematical formulae, not just a suck-and-see random process.

Oops, I meant a geometric surface profile tolerance, rather than a cross section profile :) Airfix found a similar issue when designing their Spitfire XIV https://www.airfix.com/uk-en/news/workbench/first-2019-new-tooling-announcement

 

The table is used to defined the profile, at a cross section - rather than defining the whole surface, as is done using Geometric Design & Tolerancing in combination with 3D design.

 

A bit of an update, I've got the wings and engines on, after sorting out the issues with the wingspan. I've since added a few fillets here and there as required...

 

Avro Anson CAD 6

 

Before I start the tail surfaces (which are a bit boring to do), I'm going to challenge myself. I was hoping I'd be able to get some 1/48 resin Armstrong Siddeley Cheetah engines.... I was wrong! I'll design one myself :D

 

This will be my first attempt at designing an engine for a model plane, as opposed to "just" an entire model plane. I don't have any drawings to help me however, only images :S

  • Like 3
Link to post
Share on other sites

The centre of the engine is roughly ok, the cylinders are just in there to have something in place, it needs quite a bit of work to look something like a proper cylinder.

 

Cheetah1

 

Cheetah2

 

As long as it looks about right I guess...

  • Like 3
Link to post
Share on other sites

Well this looks more or less correct, I still need to add the pushrods, although these won't be on the printed engine, and will have to be added with wire/stretched sprue.

 

Cheetah3

 

Cheetah4

 

  • Like 5
Link to post
Share on other sites

Engines more or less done... I'm not going to add too much detail to the pushrods as I don't intend to include them on the printed engine (they are too small to print).

 

Cheetah5 Cheetah6

 

  • Like 4
Link to post
Share on other sites

What printer are you using?  I've successfully printed to .2 mm wall thickness on the Anycubic and pretty sure I could go smaller.  I haven't even attempted to push it as I port a lot up onto Shapeways and .3 mm is thinnest they'll accept, so I tend to design everything to their design guides regardless of where I print it.  That being said, I drew the pushrods on the R4360 I'm drawing to .6 mm, again, to accommodate Shapeways (they differentiate between supported and unsupported, .6 mm being the thinnest they'll accept to unsupported, .3 mm for supported):

spacer.png

  • Like 3
Link to post
Share on other sites

@Woodstock74, that's stunning!

 

I'm using an Anycubic Photon, I have been able to print down to 0.2mm, but not reliably! I also intend it with the back of the engine face down, I'm not sure if the unsupported pushrods would print properly.

Link to post
Share on other sites

Yes, good points.  I've drawn the R4360 to be componentized with 28 individual cylinders, engine block, gearbox, and supercharger housing all separate, which gives me many more options for orienting.

Link to post
Share on other sites

Well, that's the fundamental design complete - not bad seeing as I started less than a week ago and I'm only able to work on this before and after work!

 

Avro Anson CAD 8

 

I need to add panel lines to the horizontal tail before adding fillets to the horizontal and vertical tail surfaces. I realise the vertical tail/fuselage join isn't quite correct, but it'll do (the fillet should improve it quite a lot :)

  • Like 5
Link to post
Share on other sites

I'm happy to call the fundamental design complete. There are a few things to do still, the Anson XIX has some sort of intake on the bottom of the cowl that I am to add, I must also sort out the wheel wells.

 

Avro Anson CAD 9

 

Avro Anson CAD 10

 

I realise the Anson should have a very distinctive "rag and tube" look to the rear fuselage... I might give it a go (I don't really know how though)! I've thoroughly enjoyed this design :)

  • Like 5
Link to post
Share on other sites

That's a few people interested in 1/72!

 

Hopefully, it will print fine in 1/72 (the wall thickness will be marginal at 2/3 of a mm), but I'll give it a go :)

 

Propellers, undercarriage and interior still to do...

  • Like 3
Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...