Question about switch machines

David Nebenzahl wrote in news:490642f2$0$5792 $ snipped-for-privacy@news.adtechcomputers.com:

Somewhere around 1/16" to 2/16", I think. Some slide switches (electrical) have a similar range movement, so they work as power-routing ground throws. (I did it once as proof of concept, and the throw of the switch was more than the points, so it held the point rails too tight against the stock rails.)

Puckdropper

FWIW, Caboose Industries lists 0.135" for N, 0.190 for HO. Many modellers us the N throws for HO.

Per NMRA RP12.3, heel spread should be 1/8" (0.125"). Heel spread is the distance from the running rail to the point at rail, measured on same edges of rail at the hinge point. Code 100 railhead is about 0.040" wide, so the distance between the rails (flangeway) at this point would be about 0.085". Minimum flangeway per S3 is 0.050".

Hence the throw must be at least 0.050", and should not be more than

0.085". The extra throw in the Caboose Industry turnouts is designed to be taken up some springing arrangement. Their -S series throws have this springing built in.

I've built turnouts with minimum flangeway at the points, this min. flangeway looks very good. However, locos with long wheel bases, and even six wheel trucks (bogies), can brush the open point, which will cause a short if the points (and closure rails) are not insulated from each other.

HTH

Peco uses the *same* switch machines for both N and H0.

[...]

I know. But then their N turnouts are rather coarse. As are all code 80 rail N turnouts.

Wolf, you've got it wrong. All of the dimensions are for a gauge line, not a real rail width. The general rule is that the dimension of the aperture of the guard rail to the running rail (again the gauge lines, not the width of the rail!) is the minimum for the end of the point rail to the running rail (ignoring any cuts that may be made to allow the point rail to snuggle into the stock rail - the flange doesn't care if a bit of rail is missing!). Naturally, this dimension os from the far stock rail.

-- Bob May

rmay at nethere.com http: slash /nav.to slash bobmay http: slash /bobmay dot astr> > David Nebenzahl wrote in news:490642f2$0$5792

The important thing more than absolute throw is that the mechanism to throw the points is flexible enough to take up any differences between the various turnouts you have. Commercial turnouts do tend to be fairly decent for throw between various units on the order of 0.003" or so, not all that important if you are not depending upon the contact of the points to the stock rail for power to the point rails as that small distance won't pick at flanges. However, with homemade/handlaid turnouts or a mixture of turnout makers a compliant mechanism is a lot better as it allows for an automatic adjustment for each side of the throw to be fully thrown to the stock rails. I like a mechanism where a wire goes up under the throwbar and flops back and forth under the throwbar. The bar is retained by a tube at right angles to the section going up through the roadbed. The tube is aligned in the direction of the track and is generally soldered on a backing/mounting plate. The other end of the tube the wire is again bent at a right angle and the switch machine pushes that back and forth to move the throwbar. Use

1/32" wire and there is a lot of flexibility in the wire so that the points are fully pushed against the stock rails without driving the rails out of alignment.

-- Bob May

rmay at nethere.com http: slash /nav.to slash bobmay http: slash /bobmay dot astronomy.net