RailPro User Group

General => General Discussion => Topic started by: atsfguy on December 03, 2018, 09:32:25 AM

Title: Twin coil switch machines
Post by: atsfguy on December 03, 2018, 09:32:25 AM

 Alright, Ihave one for our electronics guys.
I have 15 switch machines from the 1970s that I would like to use on the road I am building. These were made in Watford, England, by Hammant and Morgan. When new, these machines worked very well and I really like them but now I can’t get them to function.
I have cleaned and oiled them as the instructions specify but they will not throw. They are AC/DC and I have tried both a trainpack and a 15volt 2 amp power supply off Ebay.
I have wired them per the instructions to no avail. I will greatly appreciate any any and all suggestions, even if it is to discard them. I have worked on them several times, thinking I will eventually find the solutions but finally decided to poll this group for help. BTW, I have an old, new in box Kemtron machine that refuses to operate also.
Thanks for your help.
Cecil

Title: Re: Twin coil switch machines
Post by: Alan on December 07, 2018, 01:33:05 PM

I am not familiar whatsoever with the machines you are describing however, that doesn't mean we can't figure it out together.

Can you post several good photos of them so I at least can see them. We can take it from there.

Title: Re: Twin coil switch machines
Post by: Alan on December 08, 2018, 06:54:58 PM

Cecil, thanks for sending the images. I posted them here so all can see and help you.









These are old twin coil switch machines. Off the top of my head I would suggest:

• Verify the plunger and over-center mechanism move freely
• Place an ohm meter on each coil wire pair. If resistance is less than 3 - 4 ohms the coil is shorted and not repairable. If the resistance is infinite the coil is open and not repairable.
• Lightly abrade and clean the contact points on the blade switch
• Apply power directly to the coil leads bypassing switching components

Let us know how you make out.

Title: Re: Twin coil switch machines
Post by: atsfguy on December 10, 2018, 07:24:35 AM

 Thanks, Alan. I tried all your suggestions last week with no success, so into the trash they go. I appreciate your looking into the problem.
Cecil

Title: Re: Twin coil switch machines
Post by: Alan on December 10, 2018, 07:32:14 AM

Probably best anyhow. Solenoid machines are rough on point rails. Much gentler to use geared stall or servo.