Jump to content
 

2mm Coach Experiments


Recommended Posts

Having ascertained that even FUD isn't really good enough for 2mm work, and is also rather too pricy I had a bit of a rethink.

 

This is a shell in the cheap polished plastic which gives a nice smooth surface if there is no real detail, combined with matching etched parts. From kit of parts to assembled as in the third image is about 30 mins. It uses Dapol bogies and has provision for fitting coach lighting. Still need to work on the roof as I'm not sure I can get the rainstrips on it and use polished without disaster occurring.

 

The precision of the process is pretty impressive, the etched and printed sets of parts are within about 0.2mm of each other.

 

Alan

post-6740-0-64546100-1331073802_thumb.jpg

post-6740-0-56695500-1331073816_thumb.jpg

post-6740-0-33439300-1331073832_thumb.jpg

Link to post
Share on other sites

That looks very impressive indeed. Any chance of some GWR coaches (using Dapol Collet bogies perhaps)? I would love some of the 1930s suburban or cross-country stock. Anything western is good in fact.

Link to post
Share on other sites

  • RMweb Gold

Alan,

 

That looks really interesting - Gresley suburbans, yes please. Are the body sides etched and Is it therefore possible for you to mark and us to put on door and grab handles etc? Is this the beginning of a range?

 

best wishes,

 

Alastair

Link to post
Share on other sites

I've not tackled pre holing the etched sides for grab handles. Thats really a thing for the etches but would be very very hard to do because the etches are two pieces and I think people would go slightly insane trying to line up 0.33mm holes between the two layers. For a single layer coach it would be easy enough. Any etch holes with plastic behind won't be a problem as a 0.33mm drill will go into it happily.

 

+Karhedron - at the moment I can't do most of the GWR coaches. The coach generating tools I've been writing aren't yet smart enough to handle the complex end profiles. I have a few things I need to teach them to do the Gresley suburban brake ends and push/pull conversions including the change of body profile mid coach. That one really makes the roof tabs interesting. I want to get those kind of things right before I start adding other types of complexity to the tools.

 

So more likely I'll be feeding it flat ended pregrouping vehicles for a while yet then maybe those with a flat profile and slight curve inwards to the bottom. Walk first, run later.

 

It's also going to depend where the technology goes and how soon until we get cheap smooth detail material that can do the sides. At that point the fact it's a generator tool makes it far more fun. For example one day it'll be trivial to let users select 'battery box arrangement' or even once the materials are up to it which seats to have people printed into and on old coaches in BR days to select which panels you want the original woodwork sheeted over in steel.

 

Alan

Link to post
Share on other sites

Interesting technique, and a very nice looking model (GWR would be even better, but I am willing to wait for further developments...).

 

Writing a "coach generator tool" sounds like an excellent idea to me - once you have put in the (admittedly substantial) effort to write and debug it, adapting it for different models should be trivial by comparison with adapting/redrawing existing plans by hand.

 

Unfortunately I am interested in early GWR with the elaborate livery of the Dean era - knowing that I can draw this much more accurately on the computer than I can paint it by hand, I suspect printed vinyl sides onto a clear plastic shell would suit me better, as I think the improvement in accuracy of positioning of the variously coloured thin lines would outweigh the loss of relief for the panelling.

 

Look forward to seeing how this technique develops.

 

David

Link to post
Share on other sites

I was thinking you just mark the outer part, the etch and we drill? Am I misunderstanding the process involved?

 

Thats easy enough to do yes and would work just like any other multi-layer etch you drilled through using guide marks/holes in the top layer.

 

+Gingerbread: One trick I found useful is to print vinyl, stick the vinyl onto really thin clear plastic sheet, pick off any window residue etc then cut the entire unit out, varnish it and stick it to a coach shell as you would an etch. Just take care on glue choice if you do - plastic glues go through the thin plastic, superglue fogs it. I built my BP&GV GWR bits that way.

Link to post
Share on other sites

+Karhedron - at the moment I can't do most of the GWR coaches. The coach generating tools I've been writing aren't yet smart enough to handle the complex end profiles. I have a few things I need to teach them to do the Gresley suburban brake ends and push/pull conversions including the change of body profile mid coach. That one really makes the roof tabs interesting. I want to get those kind of things right before I start adding other types of complexity to the tools.

 

So more likely I'll be feeding it flat ended pregrouping vehicles for a while yet then maybe those with a flat profile and slight curve inwards to the bottom. Walk first, run later.

Would that rule out toplight stock do you think? Flat ended, not much of a tumblehome. The Dapol bogies are not 100% accurate for these but are still pretty close.

 

http://www.tractionads.co.uk/assets/images/W2447W_Toplight_Coach__mess_van__a.jpg

Link to post
Share on other sites

 

I wouldn't want one that looked like that!

 

Since this thread has gone a little bit wish list: I would be most interested to have either dreadnoughts or concertina stock. AFAIK they are the only neglected areas in GWR coaching stock development in our scale at present and in the past.

Link to post
Share on other sites

BillBedford: thanks for pointing out what should be blindingly obvious and wasn't. Ok I'll look at handle holes 8)

 

Toplights might be doable but if/when I get around to GWR stock it'll probably be the BP&GV low roof coaches.

 

Concertina type stock adds a huge pile of complexity, you need to compute side walls for all the indents and figure how to merge them with the interior spans. You need to pray that the windows are > 6inch from the transition or the wall thickness gets you. Lots of horrors and I suspect someone will just have to do then in FUD or future material the hard way.

 

There is a very large world of flat ended (or flat with tumbleunder) stock simply not present in N, and the bits on my desk right now to test and prove the tool beyond Gresley coaches (and thus find the bugs it doesn't show up) are not GWR, but pre-group.

 

As an aside one of the other things I want to try is to see if I can use it to make shells to go with random sides/end bits from folks like Allen Doherty so I can build their stuff easily too.

Link to post
Share on other sites

Since this thread has gone a little bit wish list: I would be most interested to have either dreadnoughts or concertina stock. AFAIK they are the only neglected areas in GWR coaching stock development in our scale at present and in the past.

 

I don't want to completely hijack Alan's thread and turn it into a GWR coach discussion thread, but it's worth making a couple of points here:

  1. I agree - they are a little modern for me, but I would probably be interested in one or two dreadnoughts and concertinas
  2. You are overlooking the first half of the GWR's history - coverage from 1890 to 1940 is pretty good, but as I recall 1840 to 1890 has approximately three coaches available in N/2mm, one each from Etched Pixels, Worsley Works and Mousa Models, so I think there is scope for adding rather more of the early coaches (which probably also applies to the non-GWR part of the railway world too...).

David

Link to post
Share on other sites

Toplights might be doable but if/when I get around to GWR stock it'll probably be the BP&GV low roof coaches.

 

I think it's only fair that you make what you would like to see most, rather than what any of the rest of us would like you to model.

Link to post
Share on other sites

I've been teaching it a couple of new tricks. it now knows how to do roof detail that is oriented across or along the roof. So it can do ridges, water tanks, some of the Gresley roof details etc. It can't yet do arbitary paths like the curved rainstrips. That's a good deal more complicated.

 

Starting to try some pre-group designs on it I also had to teach it how to do inset doors for the guards compartment on the Barry brake coach. That actually turns out to be one of those cases where one door and many doors are the same problem, so it can now in theory draw coaches with arbitary numbers of inset doors.

 

Inset door

Link to post
Share on other sites

Still debugging curved ends. They turn out to be a bit more complicated than I'd expected. In addition it seems various evil real world designers use a different curve/shape on the roof end than the bodyshell end (eg SR EMU stock)

 

Simple curved ends now work and it happily spat out the parts for the GWR bogie bullion van. I've also taught it how to draw coaches with a bogie one end only and a mounting bar the other. Can't think what LNER stock that might be useful for ;)

Link to post
Share on other sites

I wouldn't want one that looked like that!

 

Since this thread has gone a little bit wish list: I would be most interested to have either dreadnoughts or concertina stock. AFAIK they are the only neglected areas in GWR coaching stock development in our scale at present and in the past.

 

Well the framework code seems to be solid enough to handle this now. I really don't have time to be doing concertina stock etches, research and all the stuff that goes with it but if you want them enough Rich and you'll sit and do all the etches and end profiles and figure out if any windows are too close (the tool will do FUD as well its just going to cost more) and find some interior diagrams then we can probably figure something out between us to produce them.

 

Alan

Link to post
Share on other sites

Well the framework code seems to be solid enough to handle this now. I really don't have time to be doing concertina stock etches, research and all the stuff that goes with it but if you want them enough Rich and you'll sit and do all the etches and end profiles and figure out if any windows are too close (the tool will do FUD as well its just going to cost more) and find some interior diagrams then we can probably figure something out between us to produce them.

 

Alan

 

Alan,

 

I will bear this in mind for the future. In the meantime I will send you a PM about something else I would like to do first.

Link to post
Share on other sites

  • 2 weeks later...

gresley4.jpg

 

Next bits arrived. This one is currently on the wrong bogies as I printed it for Farish type bogies and I've run out of NGS ones. I've also printed another test coach with Dapol bogies, but I'm still not happy with the mounting for that. More work needed there.

 

The other bits see to be sorted, including various minor sizing glitches, correcting the vac cylinder locations and the like. The brake showed up a new bug in the roof code I didn't spot until assembling but that was fixable with a file and will get fixed in software next attempt.

 

I've also printed some Gresley buffers in FUD which have come out nicely, the GWR bullion van to test curved ends, some Dapol coupling adapters to use the Dapol bogies in these coaches and mount couplings on the bogies, and a piece of dual gauge baulk track (which is what the coach is sitting on).

 

The track is a little flexible. I think to use it beyond display you'd need to put in a short section of matching brass profile every so often and solder the rail to that for strength.

 

Alan

Link to post
Share on other sites

Archived

This topic is now archived and is closed to further replies.


×
×
  • Create New...