3D printing....print your own fighter plane!!

[John Candy]

Quote from a Daily Telegraph article concerning a Tornado fighter flying with BAE parts produced on a 3-D printer at a RAF station!

Researchers at Michigan Technological University are working on a low-cost metal printing machine that could cost consumers less than £1,000.

Think what it may be possible to do with one of those.......print your own loco chassis?
Print a panelled carriage side?

Depends upon quality of output but sounds interesting.

John.

[MikeWilliams]

Is it 1st April already?

Mike

[Andy B]

A metal-printing desktop unit may be a way off yet, but desktop stereolithography is now a reality at a shade over £2000
http://formlabs.com/

One of the Western Thunder members has one - samples shown in this thread

Andy

[MikeWilliams]

Impressive Andy.  I can see many parts that could be made that way with no saw or file in sight.

I was at CMA Moldform this week and discussed rapid prototyping and 3D printing (which is one of their specialities).  I had seen things in television etc about printing metal and wondered how that could work as the only printing I've seen is plastic of various types.

Apparently, though they couldn't show me the process, it involves tiny particles of the chosen metal with an extremely fine coating of resin.  Lasers burn away the areas not required as usual with 3D printing, but the clever bit is that extreme heat then uses the resin as a flux and welds the metal particles together.  You do end up with a true 3D printed solid metal component good enough to solder, machine and even use as bearings.  You can for instance make crankshafts this way which are hollow for weight saving and not needing any coating on the wearing surfaces.  Tomorrow's world really is here today.

On the matter is surface finish, which I believe is still the biggest problem for us modellers, the latest lasers are so small that they move and approach the surface at 90 degrees.  Up till recently the laser was static and the beam moved by mirrors which means the angle of attack varies and the surface suffers.

How long it will be until these improvements are affordable, or even available from local businesses, we'll have to wait and see.

Mike

[Traininvain]

The process is caller laser sintering and was first developed for use on US aircraft carriers to reduce the parts they had to carry to keep the aircraft flying. This article by Boeing explains quite a lot: http://www.boeing.com/news/frontiers/archive/2004/december/ts_sf03.html

and this magazine is well worth looking at: http://www.tctmagazine.com/

Ian

[MikeWilliams]

Thanks Ian - interesting.

Mike

[croned]

Check out the RS components website. They do a 3D printer kit for £495 plus vat. They also do free downloadable software for it as well.

We have a 3D printer in work. It has been used for making up 3D models of intended future products. The layering is quite prominent but with some filler and extra work it can be tidied up quite well. I haven't been able to try it out as its booked out to various jobs. The print rate of these machines is quite slow. Being able to operate 3D CAD helps as well.

[454]

Being able to operate 3D CAD helps as well.

Yes it sure does help as well. From my viewpoint the 3D software is a complete disaster.

The price of software packages is approximately the price of a Gauge 3 loco kit, i.e. several hundred pounds.

OK so someone will tell me you can get it free.
Yes you can, I tried it & the file type that is needed to export the design one has produced by fighting one's way up the learning curve is greyed out. Only the file type created by the free package may be saved & this is not the file type that is required to export to a 3D printer. 

The easiest software that I have used is Sketchup & it is quite easy to use. But really expensive to register.
So I visited Amazon & found Turbocad Deluxe 2D/3D for less than 25 quid. Quick learning curve to generate 2D designs to satisfy a laser print firm. However, the next stage is making the leap from 2D to 3D. Wow, for me it is a non-starter, I might as well start off with a block of wood & carve my 3D whilst sat in front of the telly using my Swiss Army knife. I do not believe I am thick in the head, I just feel that the examples & tutorials are not up to the job. I feel that I ought to give up & study ancient Egyptian hieroglyphics it would seem easier. The annoying part about this is that there seems to be plenty of folks on the www who are proficient & up to speed producing 'professional' results. That is the problem, it seems unless you are a professional designer with access to the training, the business & the kit then unless you have the flare for cryptic software design packages then it costs huge amounts of time to do anything worthwhile with it.

So the questions I would like to ask are:

1) Are there any non-professional designers out there who have climbed the learning curve & produced a 3D print?
2) Are there any users out there of 3D software packages that are both low cost & easy to use, recommendations please?

Professional designers need not respond, but it would be appreciated if someone would present their experience & advice to promote the use of the 3D setups from a practical hobby spare time viewpoint.

Hope this is not a big ask.

Cheers
Dave
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[MikeWilliams]

Dave,

You are not alone.  I've been using 2D AutoCAD for 20 years (not professionally) but a brief tutorial from my former boss (who is also on here!) showed me that it was not so easy in 3D and I've not yet managed to complete a drawing on my own to a suitable standard.  Adding things like rivets onto a curved surface was so hard.

The severe limitations of 3D printing have meant this has not been at the top of my priorities, but with technology improving it soon could be, so I'm interested in any replies too.

Mike

[Andy B]

Professional designers need not respond,

Well, I certainly would not describe myself as a 'professional designer' - more an occasional user of CAD who has had some dealings/use with a number of systems over the years ('DOGS' from PAFEC, 'Bravo' from Applicon/Schlumberger, 'CADDS' from Computervision, 'EMS' from Intergraph, 'Catia' from IBM/Dassault, and most recently AutoCAD and Draftsight). I've not created anything in CAD at work for over 12 years now, and even when I did the regular users would churn out models and drawings at twice my output.
When I first tried using DOGS (about 25 years ago), I just didn't 'get' CAD at all - it took me at least 3 times as long to draw some electronic lines as it did to do it on paper with a pencil, square and compass!
I've seen it similarly when people try to move from 2D to 3D CAD (and, dare I say it, to a certain track design software too!).

For me, getting to grips with 3D CAD is firstly down to getting one's head out of 'drawing' (I note Mike used this term....). Most 3D CAD tutorials don't help here - they dive straight in to the button presses and don't spend any time explaining the 3D design process.

Designs in 3D CAD are more aligned to producing a sculpture - the core is built up in sections using basic cubes and cylinders, then combined with more complex sweeps and extrusions. These are then stuck together (glue), or subtracted from each other (imagine using a form tool). Then we can add fillets, chamfers, (like using milliput or a file) etc.

So to use Dave's frustration analogy - If you wanted to produce your 'widget' from a block of wood using your swiss army knife in front of the telly, how would you do it? Would you start with a cube or a piece of dowel? Would you mark out some profiles on the sides and ends? Would you try to carve the small details from the solid, or add these on once the basic shape is formed?
Another part of this visualisation is to break down apparently complex shapes into several simpler ones. e.g. rivets on curved surfaces - a snap rivet head is just part of a sphere. A pattern of rivets is that same sphere copied and rotated around the centre line of that curved surface.

I've rambled on enough for starters.
So here's a suggestion - start a new thread with a picture (ideally a drawing, but sketch or photo with some dimensions will do) of the thing you'd like to model in 3D (suggest we start with something relatively simple, not a complete loco!!). Then we can use it as an 'interactive' tutorial to work through how the model could be produced. Anyone who has a 3D package can then try it for themselves, and I'll also do it in ACAD and show the main commands used.

I'll leave it for others to discuss software costs and features  - other than to say that you don't need the latest wizz-bang versions for home model building. All my G3 stuff is done using the 2000 version (14 years old).

Andy

[John Baguley]

I've used Autocad for many years but made the jump to 3D a couple of years ago. Best thing I ever did. I use Geomagic Cubify which used to be Alibre Design PE. Not sure of the cost now but £200 ish.

It was a very steep learning curve but I did find the tutorials very helpful. I use it all the time now and can knock out parts pretty quickly. The difficult part is deciding how to build up a part as there are several ways to achieve the same result. I have found that it struggles with complex fillets but you don't need those very often.

Nowadays I wouldn't cut metal until I had designed the loco etc. in 3D first. Many of the designs available are riddled with errors and it's better to find them on the computer than after machining the real thing!

The first major project was a 2½" gauge version of Keith Wilson's Rebuilt Merchant Navy but with the correct motion brackets etc. Haven't touched this one for a bit though.



Another is a new design for a 2½" version of Tornado which the Association is hoping to produce sometime in the future.



I recently picked up a part built Evening Star to the Chris Baron design so I've been drawing up that as well before proceeding any further with it.



I also produced drawings for the safety valve bonnet and safety valve/topfeeds for Kingette and we had those 3D printed. Unfortunately, the printer used was not of good enough quality and the base of the bonnet didn't come out very well. I've no doubt that if we used Shapeways the result would be fine. The bonnet was a nightmare to draw up and caused me no end of head scratching!



Plenty to keep me busy!

John

[John Baguley]

Here's a rather poor photo of the bonnet we had printed and also the safety valve casting that it fits over. One of the members of the Association got it printed at a university and looking at the quality, I would guess that the machine was something akin to a RepRap. The quality of the printing from these is getting better all the time but they've still a long way to go.



John

[John Baguley]

For those interested in 3D printing and CAD there are some very interesting threads on the Model Engineer forum. A couple of people have bought the more expensive 3D printers from RS and Cutwel and show their results.

http://www.model-engineer.co.uk/forums/threads.asp?t=392

http://www.model-engineer.co.uk/forums/threads.asp?t=148

John

[IanT]

I've been a TurboCAD user for some years (now on version D/L 15) - so not right up-to date but more than enough for my needs (and I started out with Version 4). Many people do not like TC but the key (at least for me) was understanding how the 'snaps' worked (or didn't). Since then I've been fairly comfortable with TC 2D although my drawings would not win any prizes!

I've recently tried to generate some 3D objects (mainly from curiosity) and agree with Andy - you almost have to start over in the way you think about things.

I found it relatively easy to make various 'block' units but really struggled when it came to joining my various blocks together in the way I actually wanted. They seemed to have a mind of their own and I ended up with some very odd shapes indeed.  I suspect this ability to 'join' correctly is the key to TC 3D and if I can grasp how it works, it may be somewhat akin to understanding 'snaps' in 2D for me. Although I don't have a driving need for 3D, I would be interested in picking it up - although JB's work looks way beyond my capabilities - now or in the future!

I'm sure Andy has something much simpler in mind?

Regards,

IanT

[454]

Thinking of sticking to 2D only designs 
3D wise I am quickly developing an inferiority complex 

Just getting comfortable in front of telly with Swiss Army knife & a block of balsa.

Dave
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