Friday, October 18, 2013

Handlaid Points

The latest project on my workbench is a No.6 left hand point.  This one uses Code 83 rail (equivalent to 82 lb/yd rail in S scale).

Construction follows the same techniques I have been using for well over 30 years, with real wood sleepers and gluing the rail down with Pliobond adhesive.

Although I usually use Northeastern 12" x 6" HO scale lumber for the sleepers, this time I used precut On3/On2½ "switch ties" by Mt Albert Scale Models in Canada (available from The Railcar near Newcastle, NSW).  The thickness of the Mt Albert sleepers closely matches the On2½ flexible track and points available from Micro Engineering.  Prior to construction, I stained the sleepers with potassium permanganate solution.

The sleeper size and spacing of the Micro Engineering On2½ flexible track and points are just about spot on for Sn3½ track, except that the sleepers are 4-5 mm too long, but that is fairly easily fixed by trimming the ends of the sleepers.  Micro Engineering only makes #5 points in the On2½ range, so handlaying is the only option for other types other than converting HO points "sleeper by sleeper".  They do make a "kit" for No. 6 points consisting of a cast metal frog and machined blades, which could reduce the time and skills needed for handlaying.

Thursday, October 10, 2013

American Models Bettendorf Bogies

Bettendorf bogie on a VG van
Another source of bogies for relatively modern WAGR wagons is from American Models.  This company, based in Michigan, USA, make a wide range of S scale standard gauge locos, rolling stock and track.

In the parts section of their web site, they list a number of styles of bogies (or trucks as they call them).  The most useful for WAGR modellers are the Bettendorf freight car trucks and, for some modern Westrail era wagons, the 50-ton roller bearing trucks.

Bettendorf with "scale" wheels
50-ton roller bearing, with "scale" wheels
I first came across the Bettendoorf style when I visited Caboose Hobbies in Denver, during a holiday in the US in 1984.  I bought one pair just to try them.  That was a long time ago and, since then, I have bought two batches of 10 pairs, and asked for the bogies without wheelsets, which cuts the price almost in half.

Of course, the bogies are standard gauge so they have to be narrowed to suit Sn3½.  The Bettendorf bogies are sprung so they can be easily be dismantled - but don't lose the springs.  Kadee make an inexpensive manual uncoupling tool (#241), one end of which doubles as a "spring pic", which I have found useful for removing and inserting the springs.

The basic principle to narrow the bogies is to cut the centre from the original plastic bolster, and rejoin the two halves of the bolster.  For a while, I was using K&S 6.35 mm brass channel to splice the two halves of the bolster back together.  Recently, I went to the local hobby shop to get some more channel and they didn't have any, so I bought some K&S 6.35 mm x 3.2 mm rectangular brass tube instead and that actually worked better.
Original bolster (bottom) and shortened bolster.

The bolster is deeper towards the centre with a slope on both the top and bottom surfaces.  I found that by grinding away the sloping parts with a Dremel motor tool and "plastic" cutting disk, the end pieces of the bolster are a snug fit in the rectangular brass tube.  I found it easier to do the grinding with the original bolster in one piece, before cutting it into three pieces.  Take care not to damage the "bumps" which locate the springs.

A length of between 18 and 18.5 mm seems to work well for the brass tube.  This is based on fitting replacement wheelsets with 26 mm axles.  The bearing holes in the sideframes are quite deep and I don't think 25 mm axles would work as the wheels would rub against the inside of the sideframes.

Cut sections of original bolster with rectangular brass tube.

I drill the centre pivot hole 2.2 mm as this will take a 2-56 screw with minimal slop.  I drill the matching hole in the bottom of the brass tube a bit larger, say 2.5 mm, so that the bogie can rock a little bit from side to side or end to end.  Obviously, it is important to get the pivot holes in the exact centre of the brass tube.

I have also drilled 2 small holes in the underside of the brass tube so that I can use small screws to secure the two halves of the bolster in place although, if they are a tight fit, this may not be necessary.

The bogies I have bought have been "rust brown" in colour so I have have airbrushed them (Revell 9 "Anthracite") before reassembling them.  The current production are available in black, judging by the website photo, which would be better.

The 50-ton roller bearing bogies are not sprung, and are cast in one piece.  I haven't actually used this type, but I have seen some that have been converted to Sn3½ (and there are no springs to lose).

Update - 23 January 2014

To simplify regauging of the Bettendorf bogies, I have designed a new bolster for 3D printing.  The first test prints arrived today and they seem to have worked very well.

Bettendorf bogies with 3D-printed bolsters (grey)