Garden Railway Forum

Looks great!

I have been preparing ancillary fixtures to go with the station building. I have noticed that the station name boards which I printed over 2 years ago are looking a bit tired. Not the plastic itself - but the white paint I had used to fill in the background. So I have tried something to see if I can get around that for the future.

I have never tried printing in multiple colours before but this seemed like a valid reason to try it. So most of the sign was printed in white filament, and the embossed lettering and the surround printed in black filament:
That was an easy way to get clear crisp lettering! I think that should avoid paint fading - as long as the filament does not fade.

Trevor

They look excellent Trevor.
I've never tried 2 colour printing, although I bought a 2 head machine deliberately so I could, but never really had a need in reality. Unless it is simple black and white like this, most of the coloured filaments are too bright and garish for reality.

I agree about the filament colours being unsuitable for our needs - but in this very limited way I can see the advantage of a two head machine.

Trevor

Won't the print become brittle with exposure to UV? I thought painting was necessary for that reason?

I don't really know - but we will find out!

I suspect that they will last for quite a while. They are made from ABS which is used for all sorts of outdoor fittings in the commercial world - and it is supposed to have good resistance to UV and vandalism! Well we have lots of slugs and toads so vandalism resistance might be quite important.

Of course at the back of my mind is that if one day they are so bad that I want to replace them, it is just a couple of hours printer time and some filament, rather than ages cleaning and repainting.

Trevor

Sorry Trevor, I missed that you are using ABS. I bought a PTEG or PLA - not sure which - kit from a 'commercial' supplier which came with a warning that the finished model building should be painted before being left exposed in the garden.

Some photos of the finished building now that it has been painted:
and
I don't know what colours the Ffestiniog buildings were painted in the 1870's but some light shade somewhere between white and cream seams likely. The colourised photos in the 16mm association Ffestiniog document look cream. So my Tan-y-bwlch building is white and this one cream. So I cant be that far out!

I am pleased with the plank effect on the walls - perhaps they are too far apart but at least the gaps were not filled up with paint. The chimney represents my first attempt at printing the stone and brick effect within the walls - and that has worked. I think the brickwork on the top of the chimney was particularly successful. Note that the bricks are exactly to scale.

Trevor

That's really lovely! I agree, the chimney is particularly good.

In technology terms, I'm about to head about as far as you can go in the other direction, and attempt to make a station building from mud. Well, clay anyway - my wife's just purchased a kiln...

That looks absolutely brilliant, Trevor. The paint job is really effective.

Rik

Yep, I agree, a first class job.
I dont think the plank gaps are overdone. They may be a tad overscale, but they show up and thats what is needed to give the effect and the human eye tends to ignore things like that.

Returning to the forum after quite a few months... somehow with work and DIY my trains have been on the back burner! Anyway, I wanted to dive into this thread because I have discussed this build with Trevor (and now have his prototype!) and seen the model in situ on his line - where it looks fabulous. The build thread is fascinating, Trevor, and the stone and brickwork on the chimney absolutely superb.

Trevor Thompson wrote: ↑Mon Oct 25, 2021 9:25 pm I have never tried printing in multiple colours before but this seemed like a valid reason to try it. So most of the sign was printed in white filament, and the embossed lettering and the surround printed in black filament:

I am really curious about this - I've seen the actual name boards but I hadn't realised the colour was the filament, not paintwork. So - how did you do this - do you have a new filament printer with dual nozzles?

It is actually quite easy to change the filament mid print.

I got the idea after I realised that our printers had the ability to change filament mid print job. I had used it before when I was using up a reel of filament and watching when it got to the last 2 metres left.

When it is printing there is a set of icons along the bottom of the printers screen. The one on the right brings up some options. One is to turn on the light on the extruder, another is to change filament.

Using it at the end of a reel. You just need to leave enough sticking out to be able to pull it out - which means keep on looking at it as it prints. The machine tells you to pause printing first - you just confirm and it does it. It saves wasting filament.

In this case I watched it until it started to print the raised letters. A fine timing - which I have missed more than once. Then I changed filament. Hence the black lettering. I think it is sharper and crisper than I can achieve with paint.

Trevor

Been quietly watching with interest. How did you do the bricks on the chimney? They worked really well..

Trevor Thompson wrote: ↑Thu Dec 23, 2021 9:34 am It is actually quite easy to change the filament mid print.

I got the idea after I realised that our printers had the ability to change filament mid print job. I had used it before when I was using up a reel of filament and watching when it got to the last 2 metres left.

Well this is doubly useful. I've abandoned prints where the filament has run out previously, as I didn't think it's be possible to change successfully. So that's a great thing to know for a start - and that it's easy enough to make it worth doing by choice, to print in two colours like this - excellent. Thanks!

SimonWood wrote: ↑Mon Dec 27, 2021 10:44 am I've abandoned prints where the filament has run out previously, as I didn't think it's be possible to change successfully.

Yes, I can confirm that it is possble to change filament in mid print although you do need to get the 2nd filament all ready, you only have a few seconds to feed it in.
Must admit I never thought of deliberately changing colours that way, though. I did once produce something with about 4 colours in it because it was only a test print and I had a load of odds and sods that were too long to throw away but not enough to use for one item!

philipy wrote: ↑Mon Dec 27, 2021 12:09 pm

SimonWood wrote: ↑Mon Dec 27, 2021 10:44 am I've abandoned prints where the filament has run out previously, as I didn't think it's be possible to change successfully.

Yes, I can confirm that it is possble to change filament in mid print although you do need to get the 2nd filament all ready, you only have a few seconds to feed it in.
Must admit I never thought of deliberately changing colours that way, though. I did once produce something with about 4 colours in it because it was only a test print and I had a load of odds and sods that were too long to throw away but not enough to use for one item!

Its a feature of some printer firmware to support an M600 command for changing filament - or be able to do it from the LCD screen while printing. I don't know if your printers have this feature, but it can be quite useful. The M600 command is put into your gcode file at the point you want to change filaments, e.g. just before the top layer, some slicers can do this for you like PrusaSlicer, or you can open up the gcode file and add the line manually before printing, or just use the LCD menu option at the right time.

The printer pauses, lifts & parks the head, and automatically fully retracts the filament out of the drive gear. It then prompts on the LCD for you to insert the new filament, and then it will purge until you tell it to stop. You can then get rid of the pile of purged filament at the nozzle with tweezers and tell it to carry on with the print. The advantage of the purge is that you get rid of the part of the print where you would have a mix of both filament colours, for example you wouldn't have an area of grey when switching from black to white filament.

sjrixon wrote: ↑Thu Dec 23, 2021 10:07 am Been quietly watching with interest. How did you do the bricks on the chimney? They worked really well..

I measured an old brick - probably victorian - and made a "model" of a brick in sketchup. I then traced the drawing of the building to get the outline of the chimney, in 3 dimensions.

I copied the brick which I saved as a "component" and repeatedly pasted it on top of the chimney, moving the bricks around until I covered the outline. I worked out by trial and error that 2 bricks end to end were about the right size for the side of the chimney, and 2 bricks rotated 90 degrees with a brick between them were the same size.

So I literally placed the bricks in the right places with a slight gap between them - just as I would have if I were building a real chimney from bricks.

Finally I reduced the size of the base outline of the chimney by 10% in width and length - but left the height alone. This left the brick joints exposed as if the grouting was that type which leaves a slight gap between bricks. Exaggerated a bit of course but I wanted to define the edges of the bricks.

The stonework was done a bit differently. I photographed some stone walling and imported the photo into sketchup at the correct size. I then traced the stonework on top of the photo using that "Pen" which allows you to draw lines which follow where the mouse goes. Having a set of stones in outline I copied them and placed them on top of one side of the outline of the chimney. Then I pulled each stone 1mm to create the effect of stones joined by the same type of grouting - and deleted the stones which were outside the basic chimney outline.

I hope that makes it clear!

Trevor.

Perhaps I should add something about "nested objects". I often overlap components - as described above. If you use the Inspector software to identify faults in 3 D models it will identify a "nested objects" fault. If you look up that in the help section it says something about nested objects which ends with "sketchup will correctly export an stl file containing nested objects". So I ignore the warning, and the stl files have always printed correctly.

Thanks Trevor - That really works very well, I like that a lot!

I need to get started in sketchup at some point, just a Tinker Cad user at the moment and often hit the limitations.

I am sure there is no "best" CAD software for our purposes. The 2016 version of Sketchup took me a long time to get used to, but I think I can do most things with it now. To the point where changing to another programme would set me back a long way!

I suspect you can get a long way using tinker cad.

Trevor