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SEEP PM1 Point Motor Electrofrog Polarity Problems


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Hello there - I hope this is the right place to post this,

 

I would be very grateful for any help and advice to cure the problem of the unreliability of some of my Seep PM1 points in terms of the polarity of the frogs on my Peco electrofrog points.

 

A quick summary of my new layout would be Peco 100 track and electrofrog points on a DCC system in conjunction with a Guagemaster Prodigy Controller.  For the powering of the points I opted for a separate DC system from my older Guagemaster Controller.  This is fed through a CDU and thereafter I followed Brian Lambert’s superb advice from a 2014 thread regarding how to wire everything up, including connecting the Seep D and E wires to my DCC Bus.  After installing my first points I had some problem with shorting at the frogs but simply followed Brian’s advice and reversed these connecting wires to eliminate the problem and now, by following the same point motor positioning I have no shorts.  Unfortunately after I quickly sorted out one problem I encountered another – the seeming unreliability of the PM1s in terms of switching the polarity of the frog when I switch a change of direction on my control panel switches.  I have taken great care in terms of centering each point motor and have even changed the offending point motor but I still run up against the same problem.

 

Having bought over 20 PM1s in advance of my project to be completed during the current lockdown, I am really committed to the Seep system, but having read several threads on this issue on the Forum I was dispirited to say the least to find that there could be an inherent problem with the switching mechanism of the motors themselves, meaning that locos can proceed smoothly in one direction of the frog but stall in the other.

 

Looking at the past threads on this polarity issue two solutions seem to have been offered:  using “Frog Juicers” for each point at fault, or using ‘micro switches.’  The former being quite an expensive outlay but seemingly quick to install, the latter being cheaper but a little more time taking.  As very much a novice to railway modeling I don’t fully understand either and I cannot find anything on Your Tube about overcoming the polarity issue on some points.

 

Therefore, I would really welcome any detailed advice as to how I can find a solution to this problem by these two (or any other) methods.  If it’s micro switches I’m really asking where I buy them and how I wire them into my existing PM1 point motor/Peco points, as I have to confess I’m clueless on the use of these.

 

If it were a Frog Juicer would that be the Guagemaster one?  And is wiring them into the ‘system’ fairly straightforward.  I know there are many Forum members who seem to have no problem with their Seep PM1s but sadly that is not the situation I’m facing on some of my newly installed point motors.

 

As I said at the start I would be very grateful for any help so I can have the smooth running system I hoped for.

 

Mick

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Alas SEEP PM1 switches can be very temperamental.

 

Fitting micro switches is likely to be the most economical way of solving the problem but probably the simplest way of operating these switches is for them to be operated by the point tiebar which isn't always an acceptable option from an aesthetic point of view.

 

I'm surprised that you're experiencing the problem this early if the PM1s were bought new, in which case I might be tempted to return them to the seller saying that they're not fit for purpose.

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Thank you for your reply Ray.

 

The first thing I'm going to do on the offending points - (just some of them, thankfully some are working well) is check again to see if they are properly centered and aligned.  They are making full contact with the main?/stock rails when I switch them from my control panel but if there is any misalignment mis-centereing, can this still affect polarity switching even though everything seems to be making full contact?

 

If I have no luck after my re-checks confirm everything is aligned and centered could you tell me how/where I purchase the correct micro switches and how I wire them into the system, or where I might find some sort of guide on this?

 

When you say "the simplest way of operating these switches is for them to be operated by the point tiebar which isn't always an acceptable option from an aesthetic point of view", I'm not sure what you mean Ray - please excuse my ignorance as I'm a relative novice who relies mainly on books, the Forum and You Tube to feel my way through new challenges such as creating a full point control panel system and no doubt making many mistakes en route.

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I agree with Ray about the switches on PM1's not being very reliable.

I helped a friend fit 5 to his layout & after taking a look at the switch itself (just a washer on a PCB), I took the precaution of buying some micro-switches like those below:

https://www.rapidonline.com/camdenboss-csm40580a-08a-43mm-lever-solder-switch-78-2408

We fitted the 5 new PM1s & 2 failed to supply current to the frog, so we decided to use microswitches on all 5. It took 35 minutes for us to install & connect all of them. They need to be aligned but they have not moved or caused any issues after 7-8 years of exhibition use.

The switches have a small wiring diagram on them. The common connection goes to the frog & the switches ones go to each rail.

 

The alternative you mentioned is a frog juicer. These are suitable for DCC only (which is fine since you mentioned you will be using that) & they work by detecting a short circuit at the frog & change its polarity so quickly that the control system does not have a chance to react. Tam Valley's juicer is solid state but (unless they have changed it) Gaugemaster's is a relay. TV's is therefore theoretically able to switch more quickly.

 

I can't find my microswitches to photograph right now, but I think what Ray means by operating them from the tiebar is to mount them on the baseboard & have the turnout's tiebar push the actuating lever. They can be operated by the motor's pin but this requires mounting the switch on a block of wood or something similar.

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I have used SEEP solenoids for many years and still use them as my preferred method as they are good value, easy to fit and easy to get replacements at shows if one is to fail and often can be repaired. I pack them out under the board to give the rod more flex when it throws

 

over time after a lot of use the polarity switch does tend to wear out, or sometimes just get dirty. Also some times the coil wires can detach from the PCB. It often depends on the batch. I now wire them to a 9 pin D plug and socket so that they can easily be removed from the layout even at a show, inspected and either repaired or replaced.

 

These days  now that most of my layouts are DCC, I tend to wire to Tam Valley frog juicers but they aren't cheap and as being a USA product not always available. However I tend to isolate the frog from the blades before laying the turnouts to avoid any short on the inside of rolling stock wheels.  If your turnouts are now fixed in place then this isnt so easy to do.

 

The Gaugemaster polarity change circuits are much cheaper if bought in packs of 3 but they dont work so well on 009 short wheelbase locos as they don't appear to hold the set polarity if wheels are all just on the frog but fine on longer wheelbase N scale and OO / HO stock. I have had to swap them out for Tam valley on my new 009 layout. They are now on an HO scale layout and working fine.

 

Before going down buying frog polarity switches it is probably worth spending time adjusting the SEPS on turnouts where you are having issues. If its all of them then it might be a batch issue.

20210312_122016-picsay.jpg

Edited by roundhouse
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Once again thank you for the kind replies.

 

In response to Pete firstly I think even when modellers as experienced as you have fitted PM1s very carefully it seems to be the case that some fail, though fitting can be an issue and I'm going to look at mine again and perhaps use d/s tape to get everything just right and then not screw down fully to allow a bit more play.

 

If I still have no luck with the offending points the micro switch route tempts me most.  Thanks for the reference as to where to get them - in advance of getting the wiring diagram could  I ask do you leave the existing PM1 in it's place (assuming they work in conjunction with the micro switches) when you say the common goes to the frog - at the moment that is the "F" wire (I've used pink dropper wire) from the PM1 to the frog,  and the C connection from the PM1 (I've used blue 24/0 gauge wire is the common (coming from the negative output on my GM CHU) connecting all PM1s as a bus as it were.  The "D" and "E" from the wires connect to my DCC bus (as advised from Brian Lambert) and the "A" and "B" wires connect either side of the switches (DPDT?) on my control panel.  The central tag on these switches comes from the positive output on my GM CDU and daisy chains between each DPDT switch.  So is the "common" you refer to separate to these?  And BTW Peter just to show my ignorance again I don't know what a PCB is in your reference to the weaknesses of the PM1s.

 

I presume all these micro switches are fitted underneath the baseboard and the accompanying literature/wiring diagram will tell me how as I get lost in these details sometimes - indeed I still cannot grasp the last point in your reply relating to Ray's quote but as I will be using the micro switch route perhaps this doesn't matter anyway.  Frog Juicers seem an additional expense when I could have perhaps used Cobalts or Tortoise for the combined price and saved myself a lot of hassle - but hindsight is a wonderful thing and I am where I am and hoping with the kind help on this forum to go forwards.

 

In response to roundhouse I will take heart with you success with PM1s - I do use block terminals to remove them easily.  Once again at the risk at people screaming at my ignorance I don't know what a PCB or 9 pin D plus is I'm afraid.  Cost and the fact that short wheelbase locos can still be fallible with juicers once again directs me down the m/s switch route.

 

Thank you.

 

Mick

 

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The electrics of the microswitch is simple, you just remove the F,D and E wires from the Seep and connect them to the microswitch instead. The problem with the microswitch is the mechanical side. The switch has to be installed such that it operates when the Seep motor operates. It would perhaps help if Pete explained how how he installed the 5 microswitches in 35 minutes.

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PCB is the circuit board that the SEP motor is assembled on ie the blue board.

 

The 9 pin D plugs are as the photo. You can also get 15, 25, 35 and 50 way versions. The 50 way are a pain to wire up!

 

They can be obtained from Squires and also in bulk on Ebay and other model railway electrical traders when shows resume.

20210312_141016-picsay.jpg

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As an alternative to a microswitch, a latching relay wired in parallel with the point motor can be used to switch the frog polarity.  You can buy suitable relays fairly cheaply online, or you could opt for the Gaugemaster product (also available in 'bulk' packs of three at a time).  If you buy DPDT latching relays (as in the Gaugemaster product) then you can get away with using just one relay to switch the frog polarity of points that are switched in pairs e.g. as a crossover - there is a wiring diagram on Gaugemaster's web site that shows how this should be done.  Gaugemaster also do a "DCC Friendly" version of the GM500, however this is intended for use where the points are being operated via a DCC decoder which I gather from your OP is not the case, so the normal version would be the one for you.  (Unlikely as it may seem after blethering on about their products in such detail, I don't have any connection with Gaugemaster whatsoever.)

 

The advantage of using a relay triggered by the point motor operating 'pulse' is that the frog switches when the point does, rather than having to wait until a loco passes over the point to trigger either an electronic or relay-based automatic frog juicer.

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Thank you Grovener and roundhouse, especially for the illustrations rh.  Grovener that wiring you explained makes sense and if Peter can just give me an idiots guide to how he fitted his micro switches (physically and electrically) I would be delighted, I don't care if it takes longer as I would feel if I was making real progress towards smooth and intended operation.

 

At the moment I'm just checking the two faulty points to make sure they have some play and are definitely properly aligned and centred.

 

One other point is that my Peco electrofrogs are made up of new points and old ones I had on my previous layout (which were working fine unmodified by the hand of God and just relying on the switch blades to change polarity).  The newer ones needed very little modification, just bridging the two rails on either side and cutting the two very thin wires.  The older ones needed bridging AND slitting with a cutter disc as explained on several You Tube vids - I'm pretty sure that I have modified them all correctly.  I hadn't  thought about whether the age of the points makes any difference.

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image.png.54b710f1e4a073f3c70790f2d3cf1c6d.pngWe use these micro switches from Rapid Electronics (code  78-0870). The minimum order is 5 at around 46p each plus VAT and P&P on smaller orders. Lay them on their side with the metal "arm" against the end of the tie-bar - that's the bit of plastic that the SEEP pin goes through and to which the two point blades are connected to.

 

It is probably best to fit the switch so that the tiebar has pushed the arm up against the body of the switch and the arm moves away from the switch body when the point direction is changed. The switches are about 12mm wide and 6mm thick and high when laid on the baseboard.

 

You can fix them with panel pins or the like but the pin diameter is often smaller than the two fixing holes which means the switch can move. That isn't necessarily a problem if they're positioned accordingly.

 

We've never used screws but that might be another option as is a Hot Glue Gun, although you have to be careful with adhesives of any sort that you don't apply too much that can spill outside the body of the switch and gum up the arm.

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I've just finished re-centering/aligning the 'faulty' points and on longer wheel base locos they pass over the 'faulty' frogs fine.  Shorter 0-6-0's either stall or struggle.  I will check things with a multi-meter later.

 

Thank you for your reply ejstubbs, when I was researching this problem I saw this "latching relay" mentioned as a solution in older threads.  TBH, at the moment it's double-Dutch to me.  But would there be some online guide as to how to fit them to the system so it would make sense to a novice like me.  I have one crossing on my layout which I haven't got round to thinking about yet, but at the moment if this (latching relay) would be a reasonably straightforward thing to fit (again physically and electrically) I would certainly be interested.

 

Mick

 

 

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8 minutes ago, Ray H said:

image.png.54b710f1e4a073f3c70790f2d3cf1c6d.pngWe use these micro switches from Rapid Electronics (code  78-0870). The minimum order is 5 at around 46p each plus VAT and P&P on smaller orders. Lay them on their side with the metal "arm" against the end of the tie-bar - that's the bit of plastic that the SEEP pin goes through and to which the two point blades are connected to.

 

It is probably best to fit the switch so that the tiebar has pushed the arm up against the body of the switch and the arm moves away from the switch body when the point direction is changed. The switches are about 12mm wide and 6mm thick and high when laid on the baseboard.

 

You can fix them with panel pins or the like but the pin diameter is often smaller than the two fixing holes which means the switch can move. That isn't necessarily a problem if they're positioned accordingly.

 

We've never used screws but that might be another option as is a Hot Glue Gun, although you have to be careful with adhesives of any sort that you don't apply too much that can spill outside the body of the switch and gum up the arm.

Thanks Ray.

 

So, from your description, these micro switches are fixed on the TOP of the layout adjacent to each point at the tie bar position?  Unless I'm interpreting this incorrectly .  But some of my Peco points are in very constrained areas, such as near to station platforms etc.  Others have more space which would allow them to be fitted (i.e. with a 12mm gap for the micro switch length sideways on adjacent to the tie bar) - again if I have got this right.

 

Mick

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We've tended to mount the micro switches at our club effectively at the end of the tiebar travel i.e. as close to the point as you can get but don't forget that the bulk of the switch will lie parallel to the rails.

 

We also have a few that are remote from the tiebar although still in line with it. This can be done by artificially extending the tiebar. For example you could glue something straight to the end of the tiebar and then use the remote end of the extension to operate the microswitch. A stiff piece of wire could also be used as long as you can stop it moving sideways. A lot will depend on each point and where you want to position the micro switch.

 

Don't forget that the microswitches may need attention - perhaps one of the connections has come loose and needs re-soldering - so don't bury them under scenery that you can't easily remove.

 

I use servos to operate the points on my home layout and have them and the microswitches mounted along the edge of the baseboard. Whilst I'm not necessarily suggesting you change to servo operation, you might want to think about mounting the micro switches along the (operator's side) edge of the baseboard for easier access.

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3 hours ago, WILLIAM ADDISON said:

would there be some online guide as to how to fit them to the system so it would make sense to a novice like me.

 

There is a downloadable instruction leaflet for the Gaugemaster GM500 here, and a circuit diagram here.  The principle would be the same if you were instead using cheap DPDT latching relays bought off eBay - you would just need to refer to the relay's spec sheet to work out which pins on the relay corresponded to which solder pads on the GM500.

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1 hour ago, ejstubbs said:

 

There is a downloadable instruction leaflet for the Gaugemaster GM500 here, and a circuit diagram here.  The principle would be the same if you were instead using cheap DPDT latching relays bought off eBay - you would just need to refer to the relay's spec sheet to work out which pins on the relay corresponded to which solder pads on the GM500.

Thank you very much for those references.

 

Mick

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Thank you very much to everyone who responded to my "cry for help" in this thread - so typical of the kindness on the Forum.  I now feel I have enough confidence to pursue a practical solution to any offending Seeps in terms of failed polarity switching on my new layout.

 

Mick

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On 14/03/2021 at 07:48, Ray H said:

Could you swap the apparently defective ones with any spares/currently unused ones?

Swapping as suggested will prove one of two things. If everything works now, the point motor and/or switch was faulty. If still the same problem, then it is almost certainly an alignment issue. A SEEP MUST be properly aligned in both planes. No such thing as 'close enough' with SEEP's, unfortunately.

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