February 26, 2021 at 4:40 pm #1223
While the Triang Big Big MK2 coaches are reasonably accurate they are shorter than British Rail MK2 coaches should be. Also more realistic ready to run O gauge coaches from the likes of Heljan are expensive starting at about £170 for a BR MK1 with the Mk2 coming in at over £230 when they are available in 2022!
My plan is to have a go at converting some Big Big coaches in to something more accurate.
I found some plans at https://www.networksoutheast.net/coaching.html and comparing to the Triang coaches you can see it’s missing a door and window in length and the existing windows are also further apart than they should be.
There is also someone on eBay selling 3d printed upgrade items for Big Big coaches (and Hymeks – another story) which should come in very useful.
There are 3 ways I’ve seen other people doing this.
1. Cut a coach in half and insert a section cut from another coach consisting of the missing door and window. Whilst the easiest this ends up with the coach being longer than the correct scale length.
2. Cut the train up into multiple sections with one window per section (adding the extra window and door) and re-glue it all back together to get the correct length filling all the gaps with filler. You then sand the whole coach down removing all the raised window surrounds which you then replace with acid etched metal ones. This looks better, but because the coach bodies are about 4mm thick the window surrounds come out at about 6 inches thick if it they were full size.
3. You’ve guessed it, the method I’m trying. Cut the train in half at the right point to add the extra window and door and make it the right scale length ignoring where any existing windows end up. Then cut out the complete white coloured window areas between the doors and replace with thinner plastcard with window holes cut in the correct places, fill, sand and attach the acid etched window frames.
Sounds easy so here we go!
After a lot of adjusting the length and sanding to get it straight it came out like this. I checked it on a piece of glass to ensure it was flat with the edge against a spirit level to make sure it wasn’t banana shaped.
Glued it together with Slaters MEK-PAK polystyrene cement which because it is a solvent melts the surfaces together and unlike superglue doesn’t stick your fingers together. Apparently you can also make a liquid filler out of it by dissolving offcuts of plastic in it. I was actually really impressed with how strong the guide joint has ended up.
Then attacked it with a multitool using the borders of the white area as a guide.
Looks better after a bit of filing and sanding.
Cutting plasticard inserts, laying out the new windows and cutting the holes.March 4, 2021 at 10:37 pm #1235
So I cut some 1mm thick plasticard panels to fit the gaps and then marked out the window holes by drawing around the window frames that I got from https://www.jandmhughesogauge.com
March 4, 2021 at 10:41 pm #1236
Then trial fitted…
…before scoring around the outside of the windows between the lines the hole so that the frame will overlap both the window hole and the glazing. Then cut an x using a Dremel so the remaining plastic could be snapped off.
After some more filing glued in permanently using the polystyrene cement leaving slightly proud along the bottom edge due to a slight wasting of the body below the windows. Filler will hopefully then fill the gap to give a smooth line up the side of the body.
March 4, 2021 at 10:47 pm #1238
Apply some filler
March 4, 2021 at 10:49 pm #1239
This is after about 4 cycles of sanding and filling.
You may have noticed I’ve also filled the holes in the roof with plasticard, squared off the tops of the end doors and opened up the small windows. It doesn’t matter that this window is still in the original thick body as it is the toilet and will be opaque white so you won’t see that thickness.
Maybe rain guttering and other details.March 12, 2021 at 12:00 pm #1240
These arrived the other day!March 13, 2021 at 12:05 am #1242
Forgot to take a picture, but put a coat of grey on and it really showed up the imperfections, but did remember to take a picture part way through several cycles of filler primer and sanding.
…and this is what it looks like once it’s finally smooth with 2mm acetate sheet cut to fit all the windows and temporarily wedged in the gaps. They will be permanently fixed from the inside behind the frames once all the painting is completed.
and because it hasn’t been seen before the inside looks like this,September 1, 2021 at 10:42 pm #1272EdwardParticipant
A lot of care and attention has gone into this conversion. If there are any updates on your progress I’d love to see them.
EdwardSeptember 17, 2021 at 8:44 pm #1274
There has indeed been progress, I really need to be the odd update or 2 !!
RichardSeptember 17, 2021 at 8:50 pm #1275
Right then… it’s been a while so here goes!
Sprayed with filler primer and sanded a few times.September 17, 2021 at 8:53 pm #1276
Hmm think I have got confused in my postings previously and posted that last update before. Actually theres’s white a few replicated updates for some reason.September 17, 2021 at 8:58 pm #1277
Right the an update I haven’t already done before then.
Glued on some rain gutters made from square section plasticard by using a steel rule as a guide to get it on straight.September 17, 2021 at 9:05 pm #1278
After the rain gutters were fitted and after checking some fuzzy pictures on the Internet and of some 00 gauge models marked out where the roof panel weld joins should be. They seem to have ben at each window pillar and then half way along each window. This was made from the smallest section plasticard strip I could find.September 17, 2021 at 9:09 pm #1279
Next came the windows.
The steel rule came in handy again for getting them straight.
Stuck them on with superglue which with so little overlap on the edges was a nit of a nightmare with them repeatedly falling off which eventually improved after a few layers of top coat paint to help hold them on (Yes I have now got as far as some paint) They should stay attached even better once the glazing is glued in as well.September 17, 2021 at 9:34 pm #1281
I forgot to say that with the weld lined for the roof panels it was quite variable as to how prominent they were. Apparently they got better at welding them over time and on later coaches they are much less prominent. because of this and how thick even the smallest plasticard is several other modellers doing this haven’t put the weld lines on. As I’m doing an earlier MK2a coach they would have been more prominent so I’ve put them on anyway, but then sanded the plasticard strips back to almost nothing to reduce their prominence.
- You must be logged in to reply to this topic.