Highland Railway Drummond 0-4-4T Passenger Tank

As a rough idea of how the boiler would print


The black horizontal line indicates the layer being printed, the assembly has been tilted by 30 degrees, estimated time to print between 10 and 11 hours (0.05mm layer height). By looking at the layers I believe I could remove the supports for the chimney without adverse effect (will be worth trying). As the top of the dome is just over the top of the boiler the print time isn't extended by much, certainly not as much as the 5 hours to print the domes and chimney seperately. There is also plenty of space around the build plate for smaller items to be printed at the same time.

I still have the tanks to be added to the boiler print, unfortunately the tanks, cab and bunker are too large for the build plate, so will need spliting in two, all will be revealed - eventually.

Now to the chimney and dome print tests.

5 hours to print, a rinse with IPA (not the beer, thats used primarily for the operator - when not required for taxi services that is), then a 4 min wash in the Ultrasonic cleaner using the yellow/green all purpose cleaner (50:50 mix with water) I've used both Tesco and Lidl's own brands and both work great. Finally a rinse in water. I forced the curing with a UV nail polish curer - I will be making my own larger UV box in the future, several 100 sec cures, turning the print to get all sides.
It was then over night to allow to further harden.

The edge of the dome is 0.1 mm thick, so very delicate, and I did manage to chip one of the upside down prints before even trying to remove the supports (shown in pic below), these were printed with the light supports at 30%

First up the upside down prints

I did mange to remove the supports from both models without damaging the rims the dome looks good but the top of the chimney on one of the prints needs attention.

And the normal way up

Again both rims on the domes broke, however the chimneys were ok.

Paul

 

Worked on the tanks and cab sides



Now this is too large for the build plate, so I decided to split them



Giving the cab sides that will fit over the tanks



Tank made up, the extensions are for aligning the handrails to the boiler.



Then join up the boiler and tanks, plus add some additional supports.





And now time to prepare for printing.




Then on to the cab ......

Paul

 

Started on the cab this afternoon, just checking alignment.



The cab back is slightly over size



Now to correct

Paul

 

fixed



Now the cab front and back walls

Paul

 

After 11 hours the print for the tanks and boiler completed - with a few errors, but not bad for a first print

For some reason the tank fillers haven't printed, and the steps on the front of the tank aren't correct.

Paul

 

Found the error - a 0.3 mm gap between the top of the tank and the base of the tank fillers.

I also ammended the supports to provide a support at the outer edge of the tank front steps.

11h 15m later

You can see the support for the tank fron steps

And by using the green resin, the inner frames shows through.

Just waiting for the resin to harden a bit more before trying to remove the supports from the front and splashers.

I have had an idea (dangerous I know) for the cab glazing, but need to do a little bit of testing before all is revealed.

Paul

 

And the cab plus roof



The idea for the glazing is

To put a 0.4mm slot in the wall, then once the cab is painted insert 18mm square glass slide covers to form the clazing - nothing looks like glass like glass



The roof will be held in place with neodymium magnets, and the inside needs to be done next.

Paul

 

Been a while, but a bit more progress made

On the boiler / tank assembly the strengthening was beefed up a little, and a hole for a 8BA / M3 nut to secure the body to the chassis.



The cab is getting there



and there is now a roof as well



and a quick peek at the underside reveals the pockets for the 3mm dia neodyuim magnets used to hold the roof in place. M2 washers will be stuck in to the recesses on the cab body.

Then to create the printfile for the 3D printer. I have started to use ChiTubox V1.5.0 for this, the original AnyCubic software was based on an earlier version of Chitubox, the newer version being far more feature rich, especially with support creation, placement and shape, but I'm still at the learning stage with this software.
Another advantage to the newer version is when used with Anycubic Photon firmware version 4.2.17 upwards supports anti-aliasing smoothing out curved surfaces helping to reduce the stepping effect.

Here is the latest boiler and tank test print



and the Cab body roof test



Estimated print time for both are approx 9 hrs

So feed back will be later in the week

Paul

 

Prints completed, with mixed results

Bad news - I should have spotted the mistake above - there is part of the platform base layer missing



This meant there was nothing supporting the start of the roof

And gave the following print

However the two completed sides fit perfectly in the cab recess, so size wise we are good.

Putting the bits together we get

A little fettling on the join but nothing that isn't easily fixed for the next print.

I will need to do a couple of tests with the Anti-aliasing and print angles, I think I need to increase the angle for the tanks as ther was quite a lot of banding, that wasn't present on previous prints.

A few more pics.

The 8 BA nut fits perfectly in the smoke box

The magnet recesses are a little too tight so will need to be tweaked, just need to find which safe place I put the 2.5mm washers to test the recesses to retain the roof.
Also the gap for the glass inserts are filled so I will need to increase the gap further.

The layer lines are quite visible on the smoke box front

And when I find the 2.5mm washers I will be able to test the fire box retaing nut

Ah well back to the drawing board

Paul

 

Thanks Rob

A fresh print of the cab, with the glazing gap increased to 0.8mm, and a roof print ..... photos to follow

Paul

 

Well as promised here's the pics

Cab and roof

The pockets for the glazing can be easily seen

The glazing I will be using is 18 x 18 mm Microscope cover glasses

And a complete success, the glazing just drops in and can be easily removed. This will allow me to paint the body then add the glazing afterwards.

By using the green resin at this stage it makes seeing the different parts easier for example the side view below shows the solid bunker and side tanks plus the brackets for the washers used to retain the roof.

and finally the rear bunker

Paul

 

Well, a year and a bit later, and I now have a printer capable of printing the whole body in one main piece.

So a couple of hours spent re-aligning and joining the main bits together and we get this



Next up I need to cut away the boiler inside the tank area



Now just need to relocate my drawing to make the foot plate and I think I'll be ready to do a test print.

Paul

 

A little progress on the footplate



The bottom layer of the body extruded by 0.5 mm, then a 0.5mm layer added to the base for the footplate, thus the height from the top of the footplate to the rest of the model is correct.

The protrusions are not part of the model, but once the footplate is completed will provide the holes for the chassis securing screw at the front and the handrails for the cab. I may try a print with the handrails in place, but I think I prefer Brass handrails espceially as the front cab handrail may have the door fitted to it.

I need to beef up the tank sides and put some form of retension for additional weight. So far I intend to place weight in the smokebox, and bunker, with some additional weight in the tanks, but I will some space for the decoder and maybe a speaker (although I don't know what sound file I would use ).

Buffer beams next

Paul

 

and here they are



Lunch time I think

Paul