Point decoders and frog switching

[AndrueC]

4 hours ago, KingEdwardII said:

Switches built into point motors like the MTB MP1s don't have this problem. They are constructed to work in tandem with the motion of the motor and enable the frog polarity to match the position of the turnout tie bar. I have no problems with my 30+ MP1s.

 

Yours, Mike.

I never have had either. You'd have to install the motor either badly aligned or configured with far too much throw.

Edited February 20 by AndrueC

[WIMorrison]

the 3, 6 and 9mm throw isn't deadly accurate and doesn't work perfectly for all turnout makes which means that centering of the throw needs to be carefully done when the throw is greater than the tie-bar movement (and omega loops used if surface mount) 😉

[Pete the Elaner]

3 hours ago, KingEdwardII said:

Switches built into point motors like the MTB MP1s don't have this problem. They are constructed to work in tandem with the motion of the motor and enable the frog polarity to match the position of the turnout tie bar. I have no problems with my 30+ MP1s.

 

Yours, Mike.

 

Included switches have a different problem. I don't know if they had a QC issue at some time, but 3 of the 5 Seep PM1s installed on a layout provided no electrical connection when installed for the first time. Having previously looked at the contact itself (a small washer pressed by a spring against 2 PCB tracks) I decided they looked like a failure waiting to happen & that it would be prudent to buy some micro-switches as a backup plan. With 2 of 5 not working from new, I was glad to have the switches & installed them on all points immediately.

 

As for switches v frog juicers, the above mentioned layout was exhibited on Saturday. One of the other operators told me that he wanted to use juicers on a future layout, pointing out that there were several occasions when the yard operator had failed to throw a point & this had cut off the main line.

 

The other argument in favour of frog juicers is that for complex pointwork like 3-ways, switching requires some electrical understanding which many modellers do not want to learn. A frog juicer will just sort it.

I was not a fan of the principal of frog juicers, but having seen how seamlessly they work, I have been converted.

[peterm1]

15 hours ago, AndrueC said:

How do you do that when trains can pass through the diamond from either direction without any turnout motors changing? My crossing has only two modes - both lines straight through or both lines crossing. The latter requires that the frog polarities be changed by something unconnected to the turnouts.

Yes, that's about the only exception I can think of.