A Sussex countryside model railway

Very Inventive.....

What would be your estimated cost per complete point, using only one micro switch ( for us non-computer controlled layout builders)?

 

As an option, could you adapt the servo base to also incorporate the micro switches as well? I know this complicates the one unit, but if the servo itself is removable it should still fall in your remit of 'simple to fix'. The advantage is the under-point unit can be dispensed with and replaced by a simple rod with a pin.

Edited October 10, 2020 by Stubby47

Clever, and the option for multiple m/switches is useful, when I fitted a 3-way point,

I needed the extra m/switches for interlocking (saves bending switch blades!)

21 hours ago, Stubby47 said:

What would be your estimated cost per complete point, using only one micro switch ( for us non-computer controlled layout builders)?

 

As an option, could you adapt the servo base to also incorporate the micro switches as well? I know this complicates the one unit, but if the servo itself is removable it should still fall in your remit of 'simple to fix'. The advantage is the under-point unit can be dispensed with and replaced by a simple rod with a pin.

 

Estimated cost per switch is a little tricky.  The servos are really cheap at about £1.15 each off ebay, and a really cheap arduino to run it is about £3.50 but can control a number of servos. 3D printing is cheap but the printer isn't, unless you've a friend with one. How you make it all hang together and operate is really the question, to which there are many approaches, mine being just one (and technically far from the simplest).

 

Could the switches be incorporated into the servo unit?  Yes. The mount  for the servo has been deliberately centrally located meaning the switches could  be positioned either side as part of the same component. Then,  yes,  it could be used to drive a simple rod and pin to the point. 

Thanks Jeff.

I've experimented with the MERG 3D servo bases,, the horn has a pin which fits into a staple/goalpost on a dowel rod.

As I've left the Peco point springs in place, the pin/ staple connection allows the point to be changed as the pin pushes the side of the staple far enough over.

The dowel itself is just supported by a drilled out cheap plastic corner bracket, and has another pin through the board into the tiebar. The MERG Esypoint board is run from half a DPDT switch , the other half changing the frog.

 

I like your method of replacing the horn with a rotary movement , and the built-in replacement Omega loops.

 

Hope the trials go well.

Stu

Hi Stu,

 

I have looked at the MERG servo mounts, and thought they were a bit fiddly, especially the "pin" moving between the goal posts.  The wheel I've modelled screws in-place of the arm normally found on a servo so it feels more rigid and secure.  It's also put the loads closer to the motor so the twisting forces are reduced.  To be honest I couldn't quite see how I was going to fit the pin to the arm reliably.

 

On the subject of the built-in point springs, I would remove them.  They're essential for the electro-magnet point motors, otherwise the blades would not remain in one position or the other.  For a more driven solution like servo motors or stall motor based systems (e.g. tortoise point motors) then the spring is working against you IMHO.  I'd also electrically tie the point blades to their accompanying rail and let the mirco-switch power up the frog.  Of course this last statement is probably only really pertinent to electro frog points.

 

Jeff