Scratchbuilt frog polarity switcher..

[Katier]

Hi All,

 

 

 

 

I decided a while back that for the layout I'm building at the moment I would use wire in the tube for the points. As all the points would be hand made this of course presented a problem as the frog polarity would need switching. I quickly figured a change-over micro-switch would do the job but the problem was developing the interface.

 

Today I had the idea of how to do it.. and an hour later had the first switch/prototype done.

 

Starting point - few bits of brass

 

 

The end support for the mechanism is a piece of L angle brass.

 

 

End support in place. I used a single sheet of brass as the 'base' of the mechanism and this will be bonded to a piece of wood which will then be bolted to the baseboard.

 

 

I then soldered a small piece of square section brass to form a channel and assembled the 'slider' which would incorporate a small piece of brass which activates the switch. I also soldered a small piece of L shape waste etch brass to the slider with a hole in it to take the Omega wire from the lever. In practice I may have to replace the Omega wire with solid brass wire and put the Omega on the other side of the switch as the omega may stop the switch switching if their isn't enough movement in the points. Here the slider is in position connected to the lever frame.

 

 

I then clamped a switch in place and did a test. Seemed to work so next step would be to bolt the switch in place.

 

 

For now two 10BA nuts and bolts hold the switch in place. In the final assembly two 2mm threaded bars will be used. The holes in the switches are exactly 2mm so should work - if not I'll gently open the holes a smidgeon.

 

Unfortunatly when I tested it I hadn't left enough length on the slider and the micro-switches operating arm was covering the section needed to connect the point wire. The solution proved to be to move the operating block on the slider back a few millimeters.

 

 

 

 

Quite test and she works fine. Now waiting for some more brass from Eileens before I can complete the project but the rest will consist on six more channels using the small square section then a final channel using another piece of 'L'. Threaded bar will hold all the switches in alignment and I will either bolt the lever frame to wood or solder it to the brass ( it's white metal so I know I can do that).