1/24 Hawker Fury Biplane

[brahman104]

Wow! Nice work on the legs Jim This has got to be a record for one of the fastest scratch builds around, but it's certainly not impacting on the quality....

 

Craig

[airscale]

 

 

 

 

that is really quite an achievement Jim - looks superb and basically created out of thin air

 

hats off to you, an enthralling build I am enjoying every second of

 

Peter

[Jim Barry]

Craig, Thanks.  I'm in awe of all you have done to date and think of our projects  as similarly ‘reaching' beyond our comfort zones  and having a blast doing it.  The speed of the project is perhaps unusual.  I think I'm afraid if I go too slow, I'll stall.  One day (soon) I'll have the confidence to slow down. The full blown scratch build is still beyond my attention span. 

 

High praise, Peter. Thanks. So glad you like it.  It was not just thin air here. There have been a number of beers behind me too! 

 

 

Yesterday I also got around to trying my new panel bolt solutions, some scale washers for 1/24 sports cars from Hiroboy (Thanks Bernd (109) for that tip!) .  It's just the perfect bling for the panels I think. Tiniest damn part I've ever worked with, I think. 

 

[Jim Barry]

Work on the lower wings tonight. Added a little video if you want to see the embossing process in action.  

 

Switched glues to bond the sheet to the core  from Testors (thin)  Plastic Cement to 5 Min Epoxy. The Plastic cement was a bit harsh as you all may know, it melts plastic as part of its bonding process. It left small scars on the upper wing that I could fill in OK. With the epoxy.. No scars/warping! I love 5 min epoxy quite a bit; so workable for the time you need to work a part into place and then BOOM lock down. 

 

Tomorrow should allow for the final wrap around the top. Another super nice thing about biplanes for the scratch builder is the wing root is rather simple. Monoplanes, generally,  have to have that part OVERBUILT to keep the wings from ripping off. Biplanes..not so much (or at all really) . It's an interesting transition to monoplanes that was hampered by the weight a monoplane wing created with all its fussy cantilever support. No (practical) engine could develop the power to make it all work better than a biplane. Then came the Liquid cooled V-12s and the P&W Wasp and Wright Cyclone which delivered the goods.  The Fury was sort of interesting as it hosted the engine (the Rolls Royce Kestrel) that was exactly the thing that basically ended the biplane fighter.  

 

 

 

[Jim Barry]

 Control surfaces lightly glued for now for inspection and just thinking things through. Oops!  gotta fix that gap on the port side elevator. I have not been that busy with the Fury lately instead taking some time to learn the 3D design and print world so that I have all my options open for future projects. I took to Fusion 360 with a reasonable success. Test (P&W R-2800 cylinder in 1/24)  sent off to a few different print services and soon enough,  I guess I'll get a little more feel for that side of our hobby. It kind of seems too good to be true to be able to craft some things like this so I kind of expect some bumps ahead. 

 

 

 

Edited May 5, 2017 by Jim Barry

[Jim Barry]

I got some feedback on my desire to have my  cylinder printed. According to Shapeways, the fins,  aka  "unsupported walls"  are too thin to survive the manufacturing process. They sent a  form letter and 3d rendering of the suspect parts  and go on to explain a bit about how the process works and why it would fail despite their best efforts which were pretty impressive (support wax that is melted away etc). As a total beginner, I do not know what standing I have to doubt them, but I do (mostly because I do not want to hear this!).  They do allow me to request a print at my own risk and cost and I might just take them up on that. It could give me a true understanding of what they mean by "failing".   Though disappointed a little by this setback,  I am learning and that's progress.  

Edited May 5, 2017 by Jim Barry

[fozzy]

Hi Jim

 

I am glad you are in the process of learning this new skill......slightly jealous... but I have to say rather you than me!...I wouldn't know where to start with all that CAD stuff!  ....I think I'll stick to the "old fashion" route of suck it and see!...if it doesn't look right then start again!

 

Good luck mate!

[Jim Barry]

Martin, Thanks for the send off. Let's see where this goes.  I too have been jealous of others who ride this wave  and have had feelings (perhaps from envy)  that 3D print solutions  are cheating and butting into a world where hand craftsmanship matters. However, reading closely about how the masters have been tackling the art of  SB, they have been known to send out a lot of their tiny bits (like gun sights!) to a photo etch service.  So I caved thinking this is just the 3D version of having someone cut your etch (of which I was jealous too). I still have to R&D the part and do the digital 3D file, so there's not lack of sweat (even if this does work). I'm also restricting the efforts to stuff I just can't practically do so things like the rocker arms are still some of my work ahead. I can do that! 

[Hubert Boillot]

It all depends on the printing process, Jim, and there are more than one.

 

However, in general terms, 3D-printing is done layer by layer, and whilst a limited overhang of the next layer over the one underneath may be possible, it is generally not possible, as you can't just add a layer supported on thin air...

 

To avoid this pitfall, there are some tricks like changing the orientation of the part, or, with the printers processing software, adding in some places supporting rods which you will later cut-off.

 

When doing printing trials on finned cylinders for a radial engine (a Wright J6-9) I had to add some of these supports. The key is to design them in such a way that they can be removed easily without ruining the details that matter, and trying to have as few as possible.

 

Hubert

[Jim Barry]

Thanks for weighing in Hubert. Good ideas there.  I think I'm coming around to things as I poke at them.  It's interesting in my research of others trying to create a 1/24 P&W radial engine I come up with a hit on Peters F7F here (and other forums). He too explores 3D solutions for the first time (2015)  but ends up manually doing the pistons in the end. No explanation why. I see some nice 3D renderings that looked really doable since the complex fins on the exhaust port  do not cut nearly as deeply as mine. He did the wheels/tires and the engine block in 3D print.

 

Must keep this low boil for now. As interesting as it is, it's distracting from the Fury attention. Must keep pushing there.

[Jim Barry]

I just could not leave it alone tonight. I did a redesign with thicker walls and in someways more realistic as the left intake valve is actually not finned.  I learned a bit more about some shapes I needed for this and they worked pretty well: some better than others. Print feedback was green lights!  I'll go to print with this and see what I get. 

 

[Joe66]

It all depends on the printing process, Jim, and there are more than one.

However, in general terms, 3D-printing is done layer by layer, and whilst a limited overhang of the next layer over the one underneath may be possible, it is generally not possible, as you can't just add a layer supported on thin air...

To avoid this pitfall, there are some tricks like changing the orientation of the part, or, with the printers processing software, adding in some places supporting rods which you will later cut-off.

When doing printing trials on finned cylinders for a radial engine (a Wright J6-9) I had to add some of these supports. The key is to design them in such a way that they can be removed easily without ruining the details that matter, and trying to have as few as possible.

Hubert

 

Hubert,

 

Not entirely true about the overhangs ! It depends on the equipment being used to do the print ! Many of the printers today use 2 or more materials, One being a material for the part, the other being a support material that is either rinsed or blown away after. One way around this could be the orientation of the part, as you say, but it really helps to know the specs and limitations of the printer before drafting a file and setting up artwork.

 

If an overhang is a small point, and not a continuous thing ( like this cooling fin ) it is also possible to add a removeable support post.

 

I run into this a lot, because while the printer I'm using can do really fine resolution with few if any 'step lines' in it, it is a single resin component printer so overhangs need to be avoided if possible and supported if not.

 

As for the thickness of something like a cooling fin, it may well be too thin for the 'z' axis or layer print capability of the printer.

 

Joe

[Joe66]

Here we go...found this video ( from 2015 even ) that shows what I mean about soluable support material......

 

[Jim Barry]

Thanks Joe!

 

Yes, Shapeways says they use a wax support material. They put your print in an oven and it melts away. Some solvent then washes any extra off. 

Regarding print axis. I do have the choice here, but Shapeways suggests their engineers can perhaps figure it out best since they know the machines. If printed as pictured, I'm thinking my new design has much less overhang. 

[Hubert Boillot]

Hubert,

 

Not entirely true about the overhangs ! It depends on the equipment being used to do the print ! Many of the printers today use 2 or more materials, One being a material for the part, the other being a support material that is either rinsed or blown away after. One way around this could be the orientation of the part, as you say, but it really helps to know the specs and limitations of the printer before drafting a file and setting up artwork.

 

If an overhang is a small point, and not a continuous thing ( like this cooling fin ) it is also possible to add a removeable support post.

 

I run into this a lot, because while the printer I'm using can do really fine resolution with few if any 'step lines' in it, it is a single resin component printer so overhangs need to be avoided if possible and supported if not.

 

As for the thickness of something like a cooling fin, it may well be too thin for the 'z' axis or layer print capability of the printer.

 

Joe

Absolutely true, Joe. Hence my opening remark about the many different processes.

 

In looking for a 3D printer, one if my key critetion was a small enough Z-axis movement to avoid the layering effect, and good X-axis and Y-axis resolution. I did not find a wax-type machine that had those, but then I was not considering 6-digits priced machines.

 

I have printed fins 0.2 mm thick with my machine, Below that they were mechanically too fragile. Up to a point, a limited overhang with a single UV-curing resin was possible without supporting rods. But the accumulated thickness was key to that: too thin fins, and they would just collapse during the printing. Or be sucked-in by the viscosity of the uncured resin.

 

Looking forward to see your print result, Jim. Sorry for the hijack.

 

Hubert

Edited May 6, 2017 by MostlyRacers