I thought that these would be much better under the Lima 72'6" carriages as the Lima cars do not track too well due to the lack of vertical play in the centre axle. I have for years run these bogies without the centre axle to try to overcome this issue. As a case in point I was running a pair of the Lima cars and the same bogie on the same car came off in a number of places on the layout where others don't derail. I feel that the bogie may be a bit warped or that the wheels were hitting the Kadee coupler box..
So after several designs and 3D prints on my filament printer to get the dimensions right I had working bogie centres mounted on the offending carriage.
After this I realised that I could do much the same and design a Kadee coupler mount for the ends on the carriage.
The coupler mount took 6 designs mainly working out the correct height for the coupler.
Here are a few photos to show the process of modifying the Lima bogie mount and installing the new bogie mount and the coupler mount.
Please note that the Eureka Models 3AF bogie has the mounting hole offset towards the front of the bogie, this is to reduce the possibility of the wheels hitting the Kade coupler box. As anyone knows who has done this with the Lima bogie it certainly restricts the swing of the bogie. The Eureka bogie improves this issue greatly.
The small raised walls of the existing Lima car bogie mounts need to be removed down to the large smooth surface (see photo). This is easily achieved with a pair of transistor nippers which are like side cutters but they a flat on one side of the jaws. After removing as much of the short walls as possible then use a hand motor tool or file to smooth off the remaining pad. Only the front portion of the pad needs to be nice and smooth as the new mounting will sit partially on this.
There two small die ejection pin marks that are in the corners of the carriage at the rear of the buffer beam, these need to be smoothed down to the rest of the surface so that the new coupler mount will sit flush.
Holes should be drilled with a 1/16 inch drill bit to start then finished with a 5/64 inch drill bit or a 2 mm drill bit.
The bogies and the Kadee couplers can be screwed in place with #2 self tapping screws, 1/2 inch (12 mm) long for the bogie and 3/8 inch (10 mm) for the coupler work well. The 3/8 inch (10 mm) screw is just a bit short for the bogie mounting.
The bottom edge of the carriage buffer beam needs to be filed a little to allow the Kadee coupler to sit at the right height. This is achieved by holding the 3D printed coupler mount in place behind the buffer beam and filing the buffer beam down to the level of the coupler mounting pad. A sharp hobby knife could also be used to shave away the 0.5 mm or so of plastic.
Both mountings can be glued in place with ACC Super Glue if you wish but I have found that it isn't really necessary as the screw will hold them in place securely.
 |
| Original Lima 72'6" Carriage |
 |
| Lima Bogie Mount - The small walls on the mount top must go |
 |
| Trimmed and smoothed Lima bogie mount |
 |
| 3D printed bogie and Kadee coupler mounts in place |
 |
| Eureka Models 3AF bogie and Kadee 5 coupler screwed in place |
 |
| Eureka Models 3AF bogie and Kadee 146 long coupler screwed in place |
 |
| Finshed |
Single set of both mounts for one carriage.
Double set of mounts for two carriages.
The mounts come in White Versatile Plastic (previously known as White Strong and Flexible - WSF), Black Versatile Plastic and Smooth Fine Detail Plastic (previously Frosted Ultra Detail - FUD).
Is you use the Smooth Fine Detail Plastic then be very careful when screwing in the bogie mounting screws as the hole in the top of the mount has a very thin wall. This wall can't be any thicker as the hole in the bogie would not fit on it.
I will be at the AMRA Exhibition this coming Sunday 30-9-2018 on Keiran Ryan's Modelling Clinic stand so drop by and say hello.
No comments:
Post a Comment