3 D Printing 16mm models

[Trevor Thompson]

The latest components printed and assembled:

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I have had issues printing the spectacle plate. Sketchup only identifies "nested object" issues in the inspector subroutine, so it should be OK. The slicing software loads it and it shows all the correct features. However when it slices it it fills the spectacles and the hole for battery access. I ended up chain drilling and filing them out.

I am now printing the cab detail. The radiator, a prominent feature in the cab, is here:

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and the reverse face:

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The back is a bit rough. The result of having to remove the printing supports and rub a file ofer it. This reverse face will hardly be visible anyway so I am not concerned about that.

[philipy]

I have had issues printing the spectacle plate. Sketchup only identifies "nested object" issues in the inspector subroutine, so it should be OK. The slicing software loads it and it shows all the correct features. However when it slices it it fills the spectacles and the hole for battery access.

Never put a grouped or component object through Solid Inspector and expect to get anything meaningful, it always just shows it as a nested object and doesn't look inside the group. You have to 'explode' it first ( and multiple explodes if you've grouped other groups together) and then when you've repaired things to get everything shiny, then you can regroup it.

[Trevor Thompson]

Thanks for the tip.

There were a couple of reversed faces in 2 separate components, and the spectacles needed to have their "faces intersected" Prints OK now.

Trevor

[philipy]

There were a couple of reversed faces in 2 separate components, and the spectacles needed to have their "faces intersected" Prints OK now.

Glad you've got it sorted. It fooled me for quite a while a couple of years ago, before I realised what was happening and it was also part the the problem that Rik was having with his window frames a couple of weeks ago.

[Trevor Thompson]

4415 is now finished as in all the parts are printed and assembled. I await the arrival of rechargeable batteries and a radio receiver. So in the meantime it is being painted. Much easier to see the result when it isn't black!

So it has had a primer coat, a "round" coat of duck egg blue matt enamel. After 24 hours I rubbed the surface lightly with a glass fibre pen, and gave it another generous coat of paint - this time matt green. I will rub it down again and then paint it with a final 2 coats of grey.

So the photos:

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and finally with the roof in place. The roof is interesting as a printing problem. I have successfully printed it, but there are a couple of cracks in the edges where it is thin. Easily filled and not affecting the structural strength - in that it doesn't want to split down the crack. However not perfect. The filling is visible.

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And while thinking about surface finish on my printed models I have a photo of the Ashbury 4 wheel coaches also in the process of being printed. Some surface blemishes are still visible but they will disappear after another couple of coats of paint have been applied:

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Trevor

[ge_rik]

Looking Good, Trevor.
I notice that earlier you said you don't need to do any rubbing down before painting. Have you found that ABS gives a better finish than PLA?

Rik

[ge_rik]

My efforts are nowhere up the the quality and standard of Trevor and Philip - maybe because my printer cost only £80 - or maybe because I'm not so skilled at setting up up properly. Prints which are mostly along the X and Y axis are acceptable

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So these ends and sides of my luggage van have turned out quite well. I've added a bit of detail with plasticard

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And mounted everything on the ubiquitous HLW chassis

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Almost finished ...

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Whereas these ridge tiles which were printed upright and so mostly along the Z axis are heavily ribbed

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I think it's because the frame of my printer is made from 4mm ply and so, even though I've added extra framework to try and stabilise it, it flexes a bit.. However, once installed, the ridge tiles seem OK

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Rik

[Trevor Thompson]

Rik

I don't do any rubbing down normally. For example the coach has not been rubbed down at all - and won't need anything more than another coat of paint. I think I printed that on the high resolution setting. However the sides of the 4415 are not as smooth as I have been able to get other components. I suspect that I printed them using the standard resolution. If you look closely at the flat panels of 4415 you will see that they are not actually perfect. I will give them some attention to lower the raised marks.

I much prefer to cover any slight surface irregularities with paint - rather than removing plastic. It is amazing how a few fairly thick layers will improve the surface. I am spraying the paint using an airbrush so it is fairly thin, and I spray until the paint is just about to run. I need good light to do it though. So a few thick coats don't actually build up a very thick paint film

[Trevor Thompson]

PS I don't think it makes any difference whether I use PLA or ABS. I only prefer ABS because can be bonded with Acetone - which I had in the garage.

[Trevor Thompson]

Rik

I have been thinking about this overnight!

I think that the wagon and the tiles are pretty brilliant considering that you have produced them on such a low cost printer. You would not know how the tiles were made.

I have 2 questions:

Firstly what do you use to glue the wagon components together - they are PLA I think?

Secondly how are you going to finish (paint) the wagon?

Looking forward to photos of the wagon when its painted.

Trevor

[philipy]

Rik


Firstly what do you use to glue the wagon components together - they are PLA I think?

I'll just jump in here for info, I use Plasticweld to glue both PLA and ABS ( and HIPS ) .

[ge_rik]

Firstly what do you use to glue the wagon components together - they are PLA I think?

I use Vitalbond thick super glue (CA). It has the advantage that I can use an activator spray with it to make the bond almost instantaneous - a great advantage for things such as the ridge tiles and some of the fitments on the beam engine

Secondly how are you going to finish (paint) the wagon?

It will be given a couple of coats of Halfords grey primer and then have the metalwork picked out in black acrylic - my standard goods livery.

In fact the van got its primer coats today.

Rik

[Trevor Thompson]

Thanks for the gluing info. I might just try PLA again. It is probably more forgiving to print with.

An update on 4415. Just finished painting it. A week to dry then the lettering and varnish. Of course I have yet to fit the radio control and batteries. So photos:

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[ge_rik]

I've now finished titivating and painting the van.

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As you can see, it's quite a small model - I don't think the CDR luggage vans were quite this small, but I wanted it to look right proportionally.

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The 3D prints were 'bare-bones' so I added the detailing later using plasticard (see above).

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I'm quite pleased with how it turned out.

Rik

[ge_rik]

I decided to tinker with the drawings and have now added the extra detailing as part of the print.

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I've not done any tidying - this is how it has come off the printer.

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I've now printed sufficient parts to make another van.

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From my experience, curved roofs are a bit of a struggle for 3D printers. On the original model I used strips of 1.5mm plasticard as planks covered with a 0.5mm layer of plasticard. I opted for interlocking planks for version 2 of the van.

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They could be covered with plasticard, paper or fabric. I'll decided when I get to it.

Rik

[ge_rik]

And, of course, my source of ready to roll chassis has dried-up - ie the Hartland Loco Works mini-wagons.

So, I decided to design my own version based on the dimensions of the HLW chassis.

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However, I've never been happy with the solebars, so I redesigned them to look more UK-based.

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The can be fitted with Bachmann metal wheels as with the HLW wagons

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Either the usual 32mm wheels

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Or the smaller 24mm (?) wheels

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The smaller wheels looked better on the luggage van BTW

Rik

[tom_tom_go]

The smaller wheels look right to me Rik.

[Trevor Thompson]

Rik

I think that the components are very good - from such a low cost printer.

I am still getting some marks on the surface of my prints. If you look closely at the photos of the model of 4415 you can see them. It looks like I cant keep the dust out of the wet paint! With all of these things it depends upon what you want, and I think the advantages of making things this way outweighs the surface imperfections (particularly if you are looking at them from 2 foot away).

Trevor

[Trevor Thompson]

I am now working on a bridge to span the railway at the new station which is based on that at Tan -y - Bylch.

There is a photo in the Spponer Album showing that the footbridge carrying the footpath over the station was present in the 1870's, but it is very difficult to make much out. So I am going to assume that it was something similar to the current one:

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The site where it is to fit is here:

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and the exact place is over the diamond crossing:

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The only bit which doesn't work for this site is the back end because the bank beyond the bridge far end is much higher than the real site. So I have repeated the staircases at the far end rather than let the footpath disappear into a blank wall. So this is the plan:

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I have started printing it in sections. However the first part has repeatedly come unstuck from the bed. So I have used something I got from Utube. Filled a bottle with acetone and bits of ABS. Then washed the bed with the mixture. It doesn't half improve the bond to the bed - but it is now difficult to get off the bed after its printed!

[Trevor Thompson]

I am also finishing the Ashbury 4 wheelers. They have just received their final coats of paint. On one side anyway. I have airbrushed them on their sides so I can apply a coat of thinned paint which is thick enough for it to run if the coach was sitting on its wheels. This is the paint immediately after application:

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I will show you another when it has dried. I particularly wanted to make externally panelled coaches on a printer to get the regular shape of the panelling. It makes the coach much easier to finish when you come to the lining. And yes I apply the full two colour lining as per the original. I also hand paint the Ffestiniog Railway crest. Here is one I made in the traditional way from plywood:

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And the real thing so you can see what the lining should look like:

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trevor