Momentum Guard's Van Build

Yet another Farcebook album transfer - The poor man's version of the SSP Slomo..

This one's not written as well as my more recent work, but as it's merely a transfer of earlier writing, I'll leave it as-is.


23/06/16
A while back, I came across an ingenious piece of rollingstock called a 'momentum van'.

It's a wagon, built around a friction-drive tinplate toy called a "Zecar".
The Zecar has a flywheel and gears which, when built into a wagon, helps stop a train from running away on the straights and downhill, and helps stop the train from stalling on curves or gradients.

As I'm a fan of realistic operations, this thing could be the answer to all my operating troubles..

Here's how a momentum wagon works. The one in this video uses two Zecar mechanisms instead of one but it's the same principle.
https://www.youtube.com/watch?v=UbYEPjcr3NA


The Zecar as delivered.
By the time you get them to Oz, this was the cheapest I could find one, $35 posted.


19/07/16
The unit required very little modification. The wheels were supported in the vice, and the axles lightly tapped out of the wheels with a punch.

IP Engineering 24mm wheels were a nice fit on the 3mm axles. Some wheels were slightly loose on the axles however, so they were fixed to gauge with shockproof superglue.
 

 The bodywork will be kitbashed from an IP Engineering Vale of Rheidol Railway matchboard guard's van. This kit also provided the 24mm wheels.
Unlike the open passenger carriage, this kit is laser-cut MDF, rather then lasered ply. As MDF has no grain to it, it's been much quicker to prepare the parts prior to assembly.


The body has been cut down and the shorter sections will be used. The excess will go in the parts stores.
 
This guard's van from the Innnisfail Tramway is what I'm loosely basing mine on - except mine will have duckets on the sides and no windows in the ends.
This drawing is one of many loco and rollingstock drawings by the late Jim Fainges.
Go to this Link and enter "Fainges" in the search box, to access the rest of the drawings.
They're not perfect, (they are known to have inaccuracies) but they are nevertheless a useful resource for the narrow-gauge modeller.

21/07/16


The chassis is being made to fit inside the body, and will be held in by the coupling mounting studs, which will pass through holes, yet to be drilled in the middle of the end beams of the MDF frame in this picture.


 A box was made from the lasered-out offcuts to prevent the sound of the mechanism from bouncing around inside the body and being noisy.

For the same reason, the mech also does not touch any part of the chassis, aside from the axles, to reduce the amount of vibration being transmitted to the body, further reducing noise. The mech has also been thoroughly lubricated and that alone makes a huge difference to the gear noise.

 
Wagon's coming together. Bit of a contrast between my brother's and my own things - we shared a bedroom at the time.

25/07/16
All of my lead offcuts have finally been put to use on this wagon, as it needs to be quite heavy to work.
Turns out the axleboxes aren't 100% perfectly aligned, so I oiled the mechanism thoroughly and ran it in by pushing it round with the Stainz.

 26/07/16
Some cheap scrap screwdriver shafts were hacked up with a grinder and glued on, bringing the chassis to around 750 grams.


27/07/16
The frame around the bottom has been painted black, plus the window frames and all handles were fitted.

11/09/16
I figured the top of the steel and lead inside the van could stand a coat of black paint to make it less conspicuous through the windows.

The roof was made about a month ago, but the glue I used to attach it caused the styrene roof to 'melt' and sag a bit.
So a new one was made and I finally got round to fitting it.

 
A tidy up of the paintwork, replacing a wonky step bracket and final assembly completes the momentum guard's van, pending a proper test run outdoors..

As can be seen in this and other videos, (search "zecar momentum steam" on YouTube) the Zecar makes a night-and-day difference to live steam running. The momentum van kept my little Ruby running at a nice steady pace on the 2ft radius curves. The extra load on the loco makes for a nice boost to the sound, too.


The van looks right at home anywhere on passenger, goods or mixed trains. Photo taken on a visit to my friend Glenn's track

I've seen the SSP Slowmo and the Zecar conversion in use. Both work equally well, both sound the same, though I suspect the Slowmo might be better-wearing in the long run. If like me, you can't afford a Slomo unit, a Zecar is definitely a viable substitute.