3 D Printing 16mm models

[ge_rik]

It looks as if it may need to be done like a kit build. But fantastic effort though, but a bit wasteful on material. If and when I do get a printer I would need to be so careful in not having too much waste I am thinking.

Is it normal to get a lot of waste and when you do. Do you make a lot of adjustments to the program to get less..

Hi Rod
It's one of the challenges of designing your own stuff for 3D printing, trying to workout the best way to draw the design so it will print successfully. Because printers build up the object in layers from the base, you either have to try and avoid overhangs or tell the slicing program to put in supports. The supports are then thrown away after it has printed. The supports are usually quite thin and so don't use up too much filament.

Also, to help the object stick to the print bed, you can add a brim around it which is removed and thrown away after printing. The wider the brim the better it sticks. I left the brims on some of the parts of the beam engine kit I sent you. If an object doesn't stick to the bed properly then it will move during printing and so the part is ruined. The size of the brim can be reduced or a part can be printed without a brim, but it's a risk you take. Reduce the size of brim to cut down on waste, but then risk having the part ruined because it hasn't stuck.

It's all part of the fun....

Rik

[FWLR]

Thanks Rik, I did notice the excess material and had an idea they were to start the printing. They were easy to take off.

I am well on my way the the building of the beam engine, just waiting for some more paint to come....It's a pain when you run out and need to wait for the supplier to send more.

[Trevor Thompson]

So I have been more successful with printing the wagon. Firstly the sides of the body printed flat on the bed:

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That was printed with a raft - which is a bed of filament laid onto the bed before the model is started. It helps with adhesion as well as making it easier to remove from the bed.

I tried the bottom of the body on edge:

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It sort of worked but not as well as I wanted. So I printed it again with the bottom of the rear passenger compartment flat on the bed. More waste but it worked well.

Also I have the 4 wheels printed out:

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The wheels were printed with their inner faces flat to the bed - going to get waste because the spokes are thinner - and the hub is wider than the rest of the wheel. So I am successfully printing it out!

I have started on the suspension, and here is my first attempt at the rear axle printed as one piece:

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It worked but involved cleaning off lots of support material. I have printed it as separate parts, with the springs flat on the bed - which is much more usable. Nice clean prints. More of that tomorrow.

I have also been playing tentatively with makehuman and blender. My early attempts are encouraging:

A first attempt at a driver (5ft 3inch tall) as it was printed:

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and in a suitable position:

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Not good enough yet but it is encouraging me to learn more. The bent leg needs to touch the footplate and the arms need moving. It is interesting to see how easy it is to make figures which are properly proportioned and the correct height this way.

Trevor

[philipy]

The bent leg needs to touch the footplate and the arms need moving. It is interesting to see how easy it is to make figures which are properly proportioned and the correct height this way.

You are doing well, congrats.

FWIW, when I did my diesel driver figure ( the one which both Steve and I printed using different machines) I wanted his hands to touch two different controls and I also had to move his legs slightly. I started by trying to do it by eye which was hopeless, too many 3d position variables. In the end I imported the basic shape of the cab console into blender, then stood the figure in place and moved his limbs to where I wanted them. Doing it like that you can spin it in all directions to check, because what looks Ok from one direction can look totally unatural and distorted from another.

[ge_rik]

Really helpful series of photos, Trevor. Interesting to see the various ways you've tried to get successfully printed sections.

Clever idea to use a 3D drawing of the cab to get the driver's limbs right, Philip. It reminds me of the solution to the fox, chicken and grain, rowing boat problem

Rik

[Trevor Thompson]

I also think it is clever to use the cab to position the figure. I was wondering if that might work. I would also want seated figures for coaches, and sitting them in the coach itself seems like a way forward.

Beats messing about with modelling clay and baking foil! In fact I am wondering if I should have waited to make the quarrymen train until I had all this sorted out? Perhaps not - they do have a certain charm as they are!

Thanks for the link to the video.

An update on the wagonette.

Successfully assembled the wheels axles and suspension. The suspension was a bit fiddly to glue together. The drawbars and fifth wheel were tricky to clean up. Printed as an assembly so lots of support filament to get free:

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I am printing the seats and backrests at the moment. The model is reasonably delicate. Not something you would want to leave out in all weathers . On the other hand it is strong enough to be handled. It is a compromise between beefing it up so much that I loose the delicate appearance of the real thing, and it being so delicate it disintegrates when someone touches it.

I thought this would be something to "dress" the railway with when visitors are coming to run trains, rather than a permanent installation and i think it will fit the bill.

Trevor

[Trevor Thompson]

Oh and its likely to lead to another wagon with a roof on the back section- which is mentioned as an option in the sources where I found the information to make it. And of course the Festiniog had a carriage wagon - and I think I could make a different type of wagon to go on that!

[philipy]

That wagonette is beautiful Trevor, well donenindeed. looking forward to the finished version.

[Peter Butler]

Nice one Trevor, I can see the advantages and benefits of printing something as detailed as this over the production of flat wall sections for the station building, which might be easier and cheaper using HIP? Creating the roof sections I fully understand. However, the experiments using the equipment in so many ways will eventually lead to discovering where it is best utilised.
It's all way beyond me but I can appreciate your interest in mastering the system.

[Trevor Thompson]

Peter

In some ways you are correct in that printing the building in sections isn't perfect. But the cost and ease is not as you think. For example once the thing is designed - and it doesn't always take that long to draw it - it just prints away while I do something else. Sitting at the computer in the dark evenings designing things while Dinah sits on the sofa next to me reading a book is far less antisocial than if I were out in the workshop all evening making things. Of course the printer is busy printing the next section of whatever I'm making while I sit in the house.

As for cost, the building took about £30 worth of filament. There has to be an allowance for maintenance of the printer added in, but I don't think I could have bought enough HIP sheet to make it for that price. That is a big building and it would have cost whatever materials were used.

I particularly value being able to make individual items that are not available off the shelf. You cannot buy that station building, bridge, the fencing, or the coal wagons as kits. Nor is that Kerr Stuart Diesel available as a kit. But I can still make them!

You are correct in that I enjoy the challenge of doing it this way, and the software can be particularly challenging of course.

Bear in mind that this isn't the only thing I am doing, even though its now too wet to extend the railway, I am still building live steam locos and I have a mound of track to make.

Trevor

[FWLR]

Your wagonette is brilliant Trevor. It's fantastically made and I guess for only pennies. The wheels are extremely well done.

Have you thought about the tack for the horse or are you just going to cut some material for it.

[Trevor Thompson]

Firstly let me show you the finished wagonette:

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The rear door is meant to be sloping down at an angle - the rear face isn't upright - it slopes at the same angle.

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The detailing was not easy to print because much of it is so delicate. This is what worked best: The drivers backrest was printed upside down as a separate section. The passenger seat was printed with the end armrests attached, and sticking upwards. The passenger backrest was printed with the mudguard and the two support frames in one piece with the inner face of the backrest on the bed and the mudguard sticking up in the air.

The horse was just a test to find the correct type of horse and the correct size - and to check it would print. It was printed upside down by the way.

As for the harnessing or tack - I am about to create it and add it to she horse before re-printing the horse. Some of it will have to be added later - but the basics should be possible in sketchup. Well lets see how it works out!

Trevor

[philipy]

Lovely work.

[Andrew]

Love the wagonette, perfect!

Looking forward to the FR carriage truck too...

Andrew.

[ge_rik]

Exquisite!
And thanks for the background info on how it was printed

Rik

[SimonWood]

The wagonette is really nice - if it is now strong enough to survive handling despite its delicate appearance then you've certainly hit a good balance that gets you very close to the scale and intricacy of the real thing!

[FWLR]

Great printing Trevor. It's a master class in 3D printing...

[Trevor Thompson]

I have now drawn up the horses "tack", or at least an approximation to it. This is what I am currently printing:

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and in case you are wondering how I created it:

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The elements are basic circles pulled to give thickness and then distorted to make them elliptical. They are then superimposed on the horse so that the centre of the circle is inside the horse. After that it was just a matter of cutting away some parts of each element and distorting others.

Perhaps the cleverest bit is the collar. That is a combination of making a circle, turning it into an ellipse, and then pulling for 1 mm. Change the size and pull again. repeating that to make the basic shape. Making the top thinner was done by grabbing one of the ellipsis and rotating it to make the top thinner. Then repeating that with the next ellipse. Finally the whole thing was treated using the soften/smooth edges window.

Trevor

[FWLR]

Nice Trevor...

[Trevor Thompson]

So the result of the overnight print (7.5 hours by the way):

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I printed it upside down because this is how I have achieved success with horses in the past. You can see if you look carefully a light line on the horses neck and another parallel on his "chest". It is where the print has shrunk during the printing process. I will try a higher extruder temperature next time. The problem with printing them this way up is that the roughest parts of the finished item are on the top where they are so obvious.

And with the support filament removed and a bit of a clean up:

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There are some errors. Firstly the harness around the horses chest has a gap just in front of the girth. Secondly the collar is at an angle. Very difficult to control how you rotate a curved component. I will fix these errors and try again - perhaps the right way up to see what happens.

Trevor