3 D Printing 16mm models

A place where discussions are about 3D printing.
Phil.P
Fireman
Fireman
Posts: 430
Joined: Thu Jan 31, 2019 3:28 pm
Location: Staffs. UK

Re: 3 D Printing 16mm models

Post by Phil.P » Tue Aug 03, 2021 2:24 pm

Thank you for replying, Trevor..

My reason for asking about printing detail onto a sheet of material, is that most of the kits I have bought, where panels are printed, fall woefully short of having a decent finish.

They either have marked stripes / ridges, or a hatched pattern.

If I was to purchase a more 'traditional' kit, then flat panels would need a lot less finishing.

If a panel is printed (with rivet detail, say) it can be almost impossible to get a decent finish. - YMMV.

Phil.P

Trevor Thompson
Trainee Driver
Trainee Driver
Posts: 964
Joined: Fri Oct 05, 2018 6:30 pm
Location: South West Wales

Re: 3 D Printing 16mm models

Post by Trevor Thompson » Wed Aug 04, 2021 12:16 pm

Ah now I see what you are trying to find out!

Yes you are right about the difficulty of getting flat surfaces to be perfect when they are printed. However I have never found it to be insurmountable. Let me explain.
IMG_1666.jpg
IMG_1666.jpg (1.48 MiB) Viewed 3373 times
The photo shows two of my Ashbury 4 wheel coaches. The red one is scratch built from plywood. The one in the plum livery is 3 D printed. Can you see any of those marks in the flat sections on the 3 D printed coach? I cant even when I have the real thing in front of me. I think that one has the slightly better finish - perhaps because all of the external framing is square and even (which is difficult to do by hand but easy on a computer).

I did not do any sanding or take any material off to get the finish. I use paint as a filler primer. Specifically I use an airbrush and an oil based paint to fill those imperfections.
In detail:

Coach on its side on a turntable with the side to be painted uppermost
paint thinned until it successfully goes through my airbrush (about 15% thinners in my case)
Spray the side from all 4 sides carefully to cover all of the frame edges
concentrate on each of the flat panels in turn - spraying from side to side until each panel has sufficient paint for it to "pool" making a flat layer
because i am using an oil paint I can keep coming back to specific parts of the side as long as I allow the paint to become "skinned" first.

When I have covered it as thickly as I dare I leave it to dry for 24 hours - then I can start again. It might take 3 goes to get the right finish. Remember that the side I am painting must be upright because I am applying enough paint at each go for it to run.

As to paints. I have successfully used Humbrol and Precision Paints products this way. I don't find acrylic airbrush paints work as well in this way, although I do use lots of acrylic paint on other things. The thinning is important - I want it to firstly go through the air brush and secondly provide a small area of paint on the model - covering about a 1cm diameter area of the model. Then spray it as if it was a full size spray gun and a car I am painting. It then tends to dry as quickly as if I was painting a car.

A last point. I buy things like door furniture - hinges can be printed but handles need to be strong so I favour lost wax castings. Rivets are easy a basic rod shape is softened by painting - but it doesn't look overpainted. I have also successfully incorporated lettering which is easy to get accurate on a computer but at the limit of my ability by hand.
Attachments
IMG_1667.jpg
IMG_1667.jpg (1.46 MiB) Viewed 3373 times

Phil.P
Fireman
Fireman
Posts: 430
Joined: Thu Jan 31, 2019 3:28 pm
Location: Staffs. UK

Re: 3 D Printing 16mm models

Post by Phil.P » Wed Aug 04, 2021 12:38 pm

Trevor,
Thank you, once again, for the detailed reply..

I think I have two problems:

1. The fear of failure. - We see so many well-executed constructions, a mental paralysis stops us from having a go. Let's face it, in the grand scheme of things, it won't *really* matter, if I make a complete dog's dinner of the job.

2. Expectation :
People see a 60+ bloke messing about with model trains, and assume that I have been modelling for years..

3. (yes, I know I said 'two') I am my own worst critic!

Phil.P

User avatar
philipy
Moderator
Moderator
Posts: 5033
Joined: Sun Jan 30, 2011 3:00 pm
Location: South Northants

Re: 3 D Printing 16mm models

Post by philipy » Wed Aug 04, 2021 1:26 pm

Phil.P wrote: Wed Aug 04, 2021 12:38 pm
1. The fear of failure. - We see so many well-executed constructions, a mental paralysis stops us from having a go. Let's face it, in the grand scheme of things, it won't *really* matter, if I make a complete dog's dinner of the job.
Shut your eyes and think of England. i.e just go for it!
We all make mistakes, some are correctable, some simply go in the bin, no shame in it either way.

A random sample from my 3D Print Failures box! Some are true failures of the print process and some are simply prints that I was unhappy about for some reason and re-did. I think you'll find that everyone has a box like this.
DSC_0021.JPG
DSC_0021.JPG (184.58 KiB) Viewed 3362 times
Phil.P wrote: Wed Aug 04, 2021 12:38 pm 2. Expectation :
People see a 60+ bloke messing about with model trains, and assume that I have been modelling for years..
Age is irrelevant and nobody on here will criticise you for having a go, even if it doesn't work. Somewhere,( I can't remember exactly what it is called) there is a thread of epic failures that folks have posted to publicise theirown errors. :shock:
Phil.P wrote: Wed Aug 04, 2021 12:38 pm 3. (yes, I know I said 'two') I am my own worst critic!
Again that applies to most of us... refer back to Point 1 above :lol:
Philip

Trevor Thompson
Trainee Driver
Trainee Driver
Posts: 964
Joined: Fri Oct 05, 2018 6:30 pm
Location: South West Wales

Re: 3 D Printing 16mm models

Post by Trevor Thompson » Wed Aug 04, 2021 2:42 pm

I agree with all of that.

Sometimes you just have to bite the bullet and have a go.

Sometimes having a go leads to epic failures, but often it leads through a series of attempts to something very worth while.

I have a large box of failures as well, but I have quite an array of successes. The successes are the bits you show people! Although you have seen some of my failures on this forum!

Trevor

User avatar
ge_rik
Administrator
Administrator
Posts: 6497
Joined: Sun Oct 25, 2009 10:20 pm
Location: Cheshire
Contact:

Re: 3 D Printing 16mm models

Post by ge_rik » Wed Aug 04, 2021 2:49 pm

It took me eight tries before I got the housing for my Schull and Skibberreen motor block loco right. There are two parts to the block, each taking nine to twelve hours to print. That's not counting the time taken in between to redo the drawings....

All part of life's rich pageantry!

Rik
------------------------
Peckforton Light Railway - Blog Facebook Youtube

Post Reply

Who is online

Users browsing this forum: No registered users and 5 guests