3D Printing in 2mm Scale

[TomE]

Thought I’d give these a go, see how they came out. Not too bad it seems! 
 

 

Tom. 

Edited May 22, 2020 by TomE

[eldavo]

I think I'm getting somewhere.  Beefed up the thickness of the parts as suggested by TomE and also greatly increased the support structures as he seems to do.  Looks a much better print.

 

 

This is a Midland D379 meat van body the only other bit of NPCS Midland stock I have currently.  I have a bunch of Clayton arc roof coaches along with bogeys and some freight stock I might try printing at this scale.

 

Cheers

Dave

 

[Yorkshire Square]

On their way to shop 1 some time next week, the production run of FPLs:

 

 

You'll notice that the Midland one has been tweaked to include the locking stretcher and the detector cam. The other two have been developed on the same basis. As the "bog standard" FPL sits on the sole plate, I've incorporated that into the print. These will be sold at £1.20 per pair.

[TomE]

1 hour ago, eldavo said:

I think I'm getting somewhere.  Beefed up the thickness of the parts as suggested by TomE and also greatly increased the support structures as he seems to do.  Looks a much better print.

 

 

This is a Midland D379 meat van body the only other bit of NPCS Midland stock I have currently.  I have a bunch of Clayton arc roof coaches along with bogeys and some freight stock I might try printing at this scale.

 

Cheers

Dave

 

Looks great Dave! 
 

Tom. 

[TomE]

I gave the griddle test body a quick blast of Malachite green from a Railmatch rattle can (once I found one that still worked!) so I could get an idea of how it will look, and also to test out how the glazing fits. I need to clean out the openings better but it's not too bad. 

 

 

I'm still not happy with the door outlines. I've got an idea on how to tackle them without needing them on the CAD.......stay tuned! 

 

Tom.  

 

 

[MikeTrice]

That looks brilliant. The door openings look good as well in the photo.

[TomE]

Thanks Mike. The door outlines are a bit 'wine gummy' for my liking, and where I've had to sand the body to remove some print lines they become even more so. They also print more defined on one side than the other, but because of the way the bodies have to be orientated to get both halves on the print plate you get half defined and half not on each side. I also had problems getting the join looking good, even though it ran down a door seam. You'd have a mighty draft with the size of the gap! 

 

My plan is to remove them all together, which will make surface finishing much better, and then use very thin strips of tape to represent the raised section you get either side of the door on the real thing. I've done this before on a BG and it looks ok, so fingers crossed it works here! I guess that's the joy of owning your own printer though, you can experiment to your hearts content! 

 

Cheers, 

 

Tom.  

[RBE]

Look great that Tom. I would be more than happy that my printer had done that. I generally am happy its not a distorted mess tbh.

[Yorkshire Square]

First try out of the FPL and detector on an old Easitrac point. The rod from the detector are 0.2mm each and are pretty much welded together. I think I'll produce the detector with printed rods, but if I were using them myself, I'd be inclined to use fine wire for that element. 

[TomE]

Sorry, more griddle! 

 

I wasn't happy with the depth of the windows in the recess, it give the glazing a somewhat Replica OO Mk.1 look! It seems it should be simple enough to get the glazing flush though with some careful cutting, and hopefully some etched frames will finish it off nicely. 

 

The B4 has developed a little bit of a curve to it which might be just visible in the photo, but I removed this from it's supports on the same day it was printed so hopefully those which have been sat on the window ledge for the past few days in addition to the usual UV cure won't do this. 

 

 

Time to crack on with the final body now! 

 

Tom.  

 

[TomE]

Whilst the final parts for the Griddle are printing I’ve made a start on the next Mk.1 needed that isn’t available RTR, a BFK. 
 

This time I’ve created a generic blank shell composed of 4 separate bodies to make it easier to mirror parts that can be mirrored. 
 

 

This will be an interesting one to finish as it’s in lined maroon livery, which means  yellow/black/yellow stripes.....in 2mm.......

 

 

Tom. 

[Caley Jim]

2 hours ago, TomE said:

..... 

This will be an interesting one to finish as it’s in lined maroon livery, which means  yellow/black/yellow stripes.....in 2mm.......

Draw a broad Yellow line with a bow pen and then a thin black one down the middle. 

 

Jim 

[TomE]

17 minutes ago, Caley Jim said:

Draw a broad Yellow line with a bow pen and then a thin black one down the middle. 

 

Jim 

 

Never used a bow pen before Jim. Maybe now's the time to start practicing!

 

Tom. 

[Atso]

For my first C1, I went with the technique Tim used for the boiler bands on his P2. I sprayed the out colour onto a sheet of clear deca sheet and then, once dry, used a bow pen to rule the center black line. Once that had dried, I used a new no. 10 (the curved one) scalpel blade and a ruler to carefully cut just outside of the black lines. It took a few attempts to get enough acceptable decals but I found this easier than trying to rule all three lines consistently directly onto the model. The corners still needed to be painted in with a fine brush though - not something you'll need to do on your coach.

 

Below is the result of using that technique.

 

 

[Caley Jim]

I use a similar technique, but using sellotape and a tile, which I've described elsewhere.  Basically stick a strip (or two) of sellotape onto a tile, paint that with a generous coat of the 'outer' colour, then draw the centre line.  Once dry cut down either side with a scalpel and you can carefully peel the strip of paint off the sellotape.  You have to do all this within a few days, while the base layer of paint is still flexible and hasn't gone hard and brittle.  Fixing in place is by dipping in thinned varnish and teasing into place with a couple of cocktail sticks.

 

Jim

[eldavo]

Best of luck with that Tom. At least it's a straight line.  I'm still practicing with the bow pen and it's a challenge in 7mm let alone 2mm.  I know why I don't model pre grouping in 2mm!  Very cruel close up.

 

 

Cheers

Dave

 

[eldavo]

After several days of frustration and failed prints due to software problems I've managed to get a few more experimantal prints all rescaled from CAD models designed for 7mm models.

 

First up a rather obscure prototype, a Midland railway bunker coal wagon.  Amazingly the printer managed to produce this but due to the thickness of the coal boxes it's almost impossible to handle without breaking.  To make this a practical proposition I would have to beef up the walls of the coal boxes significantly and also make some of the detail a bit more prominent.

 

 

Next up is a Midland D502 Clayton arc roof brake third coach.  This is built up from individual partitions and, as the Midland didn't go in for a lot of variation in it's carriages, you can bolt together combinations of partition modules to build up a large selection of stock.  The print is not perfect but apart from a couple of holes, probably due to crud in my resin vat, it aint bad.

 

 

There is an odd dip in the tumblehome of the sides which needs investigating.  This has also appeared in my 7mm prints so this may be some kind of aberration in the STL file.  Hmm.  The model includes the interior.

 

 

I need to refine the suppport platform as I'm tending to damage the model removing it.  I would also need to beef up some of the solebar sections.

 

 

All interesting stuff but something of a distraction from my 7mm interests.

 

Cheers

Dave

 

[TomE]

Nice work Dave! I don't envy you with all that panelling though! 

 

I managed to find a supply of the Farish 6.3mm dia coach wheels however this has brought about a problem:

 

On the left, the wheelset from a Farish B4 fitted to a Mk.1 I used to draw up the bogie CAD. On the right, a wheelset from the spares bag. 

 

 

Dammit Bachmann!!!

 

The extra length of the pinpoints means they would be sticking out of ends of the axle boxes, so now I'm going to have to carefully file them down. 

 

Sigh. 

 

Tom.  

Edited June 3, 2020 by TomE

[RBE]

Interesting that. All my wheels are like the right hand one.

[Yorkshire Square]

1 hour ago, TomE said:

 

Dammit Bachmann!!!

 

 

One of the drawbacks of N Gauge. There is no such word as "standards" in Bachmann's dictionary... 

[Caley Jim]

As far as I understand, never having worked in N-gauge, there is no such thing as 'standards' at all! 

 

Jim

[Chris Higgs]

4 hours ago, Caley Jim said:

As far as I understand, never having worked in N-gauge, there is no such thing as 'standards' at all! 

 

Jim

 

British N maybe. Our American cousins will be able to supply you NMRA standards for N, and I think Bachmann do follow one of these standards for their wheel profile. But the length of a pinpoint axle is not likely to appear in any standard.

 

As I recall, my Farish Mk1s with B4 bogies do have the shorter axle. But now I will be obliged to ferret through them all and check!

 

Chris

[Scottish Modeller]

Hi all,  

 

Shorter axles in Farish stock.

 

This is one of the main reasons I have found for poor running.

 

It seems that either previous owners have swapped wheelers about without noticing the difference in length or Bachmann production line don't!

 

I recently bought some new type mk1 coaches that were very stiff when run.

 

Checks revealed that the older type axles had been put into the new type bogies.

 

They don't work this way and furthermore, if the bogies are squeezed to try and make them run, then the bogies won't run when remitted with new type axles due to too much slop.

 

Now trying to get new type bogies and replace the ones that came on the coaches.

 

Thanks

Phil H

Edited June 2, 2020 by Scottish Modeller

[Jim T]

Hi Phil

 

When I get any new N gauge stock the first thing I do now is pop a wheelset out, measure the axle length and record it. That way I know which replacement wheels to order and don't screw up!

 

B4 bogies are a particular problem. The old style ones under the air con mark 2s were 15.2mm, the new ones on later Mark 1s with B4s and on the recent Mk2/2A stock are 14.0mm

 

Jim 

[Izzy]

I believe the one-size-fits-all 15.2 axle length with models being made to suit it started to change around the time the Stanier Blue Riband coaches with correct wheel diameter first arrived. The axle length now being chosen to suit the model. This also seems to be the policy with wagons as well as coaching stock, and has now encompassed locos in that the correct wheel dia is used rather than a standard one. Much better really, just making things more difficult when converting to 2FS.

 

Izzy