Home Made Switch Machine

Your design looks somewhat complicated to build in quantity. Have you priced out the parts and figured construction time?

Manual linkages under the table can be easy, inexpensive and convenient if the switches aren't spread all over a large area.

Pneumatic controls have had some use on model railroads; they are relatively simple but need an air supply and rely on spring return IIRC.

If it works, then why not.  Looks like you have it documented fairly well, keep it in a safe place.

I manufactured and sold several type of circuit boards back in the 80's and 90's to do various railroad functions.  I didn't write anything down cause it was on the design system at work and fairly clear in my head.  Got out of trains for twenty years; the design center moved to China in 2004; and I never thought about the CAD designs and the physical design information which left also.  Came across the box with all the units packaged with user instructions on how to use them, but I have very little remembrance of the designs and chips I used to make them with.  The chips were house numbered chips I could get pretty cheap back then.  Back engineering the boards is possible until you get to the pinouts of the chips.  Argh.

Hi ACE:

Yes, I have put some time in studying the alternatives.  Mechanical linkages are easiest if the entire railroad is on a single plain.  Mine is not.  Also, with mechanical linkages you need to run all around the layout throwing turnouts.  Also, mechanical linkages has you building mostly under the layout during the entire construction.

Pneumatic controls are mostly purchased and can add up quickly even if you have an air compressor.

I was going to go with Tortoise switch machines until I found out that many who have them, end up burning out the traces on the circuit board that feed there insulated frogs and that a relay is recommended for higher current carrying issues, like derailments.

With my setup, I can power my insulated frogs by going to Double Pole SW-1's and SW-2's.

Also, I have saved up a pile of DC Motors over the years and have most of the components required.

I will build one up and re-post with pictures and my results.  If nothing else, this is a neat Model Railroad Engineering project.

Good comments though....

Thanks...

Tom, there is no point reinventing the wheel. How many of these would you like? I have over 100.

If you are interested, email me and I'll explain the whole system.

I found that one of the easiest  and lowest cost ways to operate track switches was with small servomechanisms. I wrote a series of articles on this subject in several club magazines in 2008.

Bob:

I just took a look on e-bay and small servo's are available for less than $2 each in quantity.  Anyway I can get a copy of your articles?  

Thank you...  Tom

Do you have a diagram/photo showing dimensions and range of motion you are trying to achieve? 

One feature of the traditional snap-action solenoid switches is the ability to manually rotate the lantern to change switch position via the rack-and-pinion rotary-to-linear design.  With most threaded-rod or geared motor/servomotor designs you cannot manually "back-drive" the mechanism.  Is this an issue?

What makes servomechanisms useful for operating track switches is the smooth controlled linear motion of the servo arm when activated.  Since there are so many brands of track switches, each one requires a different mechanical approach to link the servo arm to the switch and this is where good design instincts are needed. As a bonus, I was always able to get an electrical direction signal from the servo control system. I also developed an IR detector based non-derail system. Can't post the articles here because of copyright issues, but could email.