Micro Engineering C55 switches

[central.vermont]

Not sure if this is the right place for this or not but am sure it will be moved if needed. 

Was talking with fellow  about these switches and we are wondering what is the difference between the newer "DCC Friendly" and older "Non DCC friendly ME C55 switches? Is there something one can pick out at first glance so you know in advance and also if it is deemed "Non DCC friendly" what can be done to correct it?

Thanks, Jon

[Ron McF]

Is there something one can pick out at first glance so you know in advance?

Jon,

the DCC friendly ME turnouts have two jumpers connecting the stock rail to the closure rails:


To convert an older turnout you can cut the closure rails leading to the frog, and add jumpers as shown in the photo. (Edit - you also need to modify or replace the throw bar, as Ed points out below.) That subject has been covered many times here and elsewhere, but this link will get you started:
http://www.wiringfordcc.com/switches.htm

Regards,
Ron

[ednadolski]

IIRC the non-DCC ones also had a conductive throwbar that would have to be replaced for use with DCC.

Ed

[Ron McF]

IIRC the non-DCC ones also had a conductive throwbar that would have to be replaced for use with DCC.

Ed

Good pick-up, Ed. Thanks. I'll amend my comment.
Ron

[Santa Fe Guy]

Good pick-up, Ed. Thanks. I'll amend my comment.
Ron

Lads, not sure that is correct. I purchased my ME Code 55 N Scale turnouts direct from the manufacturer as soon as they were announced in 1994/5. They were installed on my SFRSD Running DC for many years, long before I converted to DCC. I did not have to do anything to the throw bars until they started coming adrift then they were modified. That was in 2003 when still on DC.
Rod.

[Ron McF]

Rod,

I still have a few old ME turnouts in original condition. They don't have a full-length throwbar like the DCC friendly version - it's just a metal (brass?) strip connecting the point rails, and extending slightly past them to touch the stock rails on one side only. As it's never in contact with both stock rails at the same time there's no short circuit.

Here's a photo of one that I found on the 'net:


We found that the easiest way to isolate the point rails from each other was to replace the throwbar with a new one made from circuit board material, as Ed mentions.

Regards,
Ron

[robert3985]

Here's what I did to make an old ME C55 turnout "DCC-friendly"....

First, I cut & soldered a PCB tie to the bottom of the brass "throw rod", making sure it didn't impede the over-center spring keeper mechanism. 

Then....

Photo (1) - I removed a couple of ties and soldered in PCB tie replacements which jumpered the adjacent stock rails to the point rails, gapping the PCB ties so there's not a short between the two stock rails, then gapped both point rails near the frog:


Photo (2) - Then, I cut the brass "tie bar" off center between the closure point toes to gap it and isolate each closure point from each other, making sure I cut through the copper cladding on the PCB part soldered underneath.  Make sure to cut JUST the copper cladding and not clear through the PCB part as this is what keeps the closure point toes at the correct gauge:


Voila!!  DCC friendly old ME #6 turnout....

Cheerio!
Bob Gilmore

[central.vermont]

Thanks for all this info gang, guess I will be doing some retrofitting of these.

Jon

[HattyDamp]

Hi everyone...i am a new user here. In my case i purchased ME Code 55 N Scale turnouts direct from the manufacturer as soon as they were announced in 1994/5. They were installed on my SFRSD Running DC for many years, long before I converted to DCC. I did not have to do anything to the throw bars until they started coming adrift then they were modified. That was in 2003 when still on DC.

[ednadolski]

I did not have to do anything to the throw bars until they started coming adrift then they were modified.

DCC may work with a conductive throwbar, but that leaves the open point rail at the opposite polarity of its adjacent stock rail. If a metal wheel bridges the gap then it creates a (usually) momentary short.  Momentary shorts are typically not a concern with DC (and may go unnoticed), but with DCC it can trip the short detection circuitry in the booster and shut down the system, requiring a reset.

Ed

[wcfn100]

but with DCC it can trip the short detection circuitry in the booster and shut down the system...

And melt stuff if it doesn't trip.


Jason

[peteski]

If track-work works reliably in DC, it will also work in DCC.  Obviously HattyDamp has his track and wheel gauge adjusted well enough that it works even with both switch points having the same polarity.   The changed made to turnouts like the one we are discussing to make them more DCC-friendly are an extra insurance that nothing nasty (like a short) can happen. As others have already mentioned, DCC booster can supply much higher than a DC throttle. If there is a short and the breaker does not trip (for whatever reason), the current passing through the circuit can be high enough to heat up or melt some part of the model or trackwork.

If HattyDamp's layout works reliably as-is then I don't see a reason for him to change anything.

[Ron McF]

If track-work works reliably in DC, it will also work in DCC.

Most of the dozen or so ME C55 turnouts that I have on my layout still have the original throwbar where both points have the same polarity, and they've never given me any trouble at all on either DC or DCC.  There was a time when I was going to convert them all, but their reliable operation convinced me otherwise.

Regards,
Ron

[Ron McF]

Lads, not sure that is correct. I purchased my ME Code 55 N Scale turnouts direct from the manufacturer as soon as they were announced in 1994/5. They were installed on my SFRSD Running DC for many years, long before I converted to DCC. I did not have to do anything to the throw bars until they started coming adrift then they were modified. That was in 2003 when still on DC.
Rod.

Hi everyone...i am a new user here. In my case i purchased ME Code 55 N Scale turnouts direct from the manufacturer as soon as they were announced in 1994/5. They were installed on my SFRSD Running DC for many years, long before I converted to DCC. I did not have to do anything to the throw bars until they started coming adrift then they were modified. That was in 2003 when still on DC.

Isn't it a bit odd that HattyDamp posted an almost identical message to an earlier one from Santa Fe Guy? They apparently even have the same name for their railroads ("SFRSD")

Regards,
Ron