MTH Operating Platform Issue

I think theres a low voltage option.  mine is in storage right now or else i would look it up for you

walt

@Craftech posted:

30-9107 MTH Operating Platform.  Anyone have one of these?

Bought it second hand NIB.  Passengers do not go all the way up or down.

Measured fixed voltage at my supply distribution terminal.  It is 13.62v  Ac

Requirements are 14-16V.  Tried feeding it track voltage at 16-17v and it went all the way up and down.

Is the voltage that critical or is something internal possibly not working correctly?

John

Yes, the voltage is critical, also critical, knowing if yours has the modifications or adjustments.

KEY from the first PDF A linked in the post below:

This post from @Jon G has 3 PDF files attached you should review

https://ogrforum.ogaugerr.com/...9#144312037651193109

And from a previous topic

@Jon G posted:

It may just need adjustment.  There are arms on each switch that may not be depressed enough to actuate the switch.  You should hear an audible click when the lever is depressed and the switch is actuated.  You can check continuity between terminal 1 (near pivot) and each other terminal (2 & 3).  One side is NO, the other NC.  They will change state when actuated.

Thanks Vernon and Walt

I'll check that out.

John

Again, my take is you have an early unmodified unit with limit switches that are pretty stiff. Because of this having to push over a stiff limit switch to reach fully locked up or down positions is why yours takes additional voltage.

In the bigger picture of things, the problem is this, if you don't have enough voltage and the mechanism binds and doesn't toggle to full locked- you run the risk of cooking the solenoid. The idea is, the mechanism needs to snap sharply and when in the locked position up or down, then the solenoid is no longer powered for that direction. It's that in-between state where things can go bad if it sits there cooking trying to move but cannot.

Sometimes you can get away with running an item undervoltage but not in all cases.  The fact that it runs fine at the recommended voltage tells you nothing is wrong with it.  Does it bind at all when it runs ? Being that close to run and not run I would just try and hit the 16 volts if you can.  You also say you take the feed off of a distribution point.  If something else starts on on that same line it could make your voltage drop enough to stop your unit should you get it to run at the 13.6 volts.  Good luck.

FWIW, I've spent some time with this on the bench because I was working with the idea of using either an oldschool 2 position E-unit or more modern latching state (also called bi-stable) relay module to create an operating station where every other time a train passes the passengers or freight is down waiting, and then disappears up the NEXT time the train passes. With 2 of them spaced around a loop track, and started with one up and one down- the passengers or freight appear to move from one place to another.

Again, one station is cool- 2 working in different locations around the layout takes the effect even further.

Are the spring with lever and Zippy micro switches sold as a modification kit?

If so - where to buy?

Thanks,

John

Well upon closer examination the roof and base are crooked.  I'll start by straightening that out.

There is also a lot of side to side play and wobble in the plastic lever with the passengers attached that swings up and down, but the single screw holding it is tight.

John

Trying to find the kit and coming up short. That said I found key components.

Also, under the older MTH site found the parts breakdown of the platform

https://www.mthtrains.com/site...loded/30as11893e.pdf

Which showed my "guess" was correct- that BB-0000021 was the correct switch.

Spring would be IE0000049A for the modified one?

Sadly, trying all word combinations I could thing of (adjuster, spring, return, platform, operating, kit) I could not find the stamped metal adjuster arm? Maybe use a wire eyelet?

this was "the kit"

https://www.mthpartsandsales.com/shop/search

Thanks for doing all that Vernon.

John

If I search MTH for the word "Zippy" that same switch comes up so it must be right.

To try to help out I don’t got my platform. I guess I was wrong there isn’t a setting for low-voltage. But there are directions in there for how to adjust things for low-voltage versus high voltage.

To try to help out I dug out my platform. I guess I was wrong there isn’t a setting for low-voltage. But there are directions in there for how to adjust things for low voltage versus high voltage.

The directions say though that it is geared to operate at 12 to 14 V AC so that should mean something.

you mentioned in your opening post that you’re directions say 14 to 16 V. I’m looking at my manual right now and it says 12 to 14 V. Even the controller has stamped on it 12 to 14 V. I can’t repeat everything in the manual but there’s actually a segment on how to fix something called a spring tension for the lower voltage and there’s also an adjustment for higher voltage I could’ve sworn there was a setting for low-voltage but obviously I’m thinking of a different device

@walt rapp posted:

To try to help out I don’t got my platform. I guess I was wrong there isn’t a setting for low-voltage. But there are directions in there for how to adjust things for low-voltage versus high voltage.

To try to help out I dug out my platform. I guess I was wrong there isn’t a setting for low-voltage. But there are directions in there for how to adjust things for low voltage versus high voltage.

The directions say though that it is geared to operate at 12 to 14 V AC so that should mean something.

you mentioned in your opening post that you’re directions say 14 to 16 V. I’m looking at my manual right now and it says 12 to 14 V. Even the controller has stamped on it 12 to 14 V. I can’t repeat everything in the manual but there’s actually a segment on how to fix something called a spring tension for the lower voltage and there’s also an adjustment for higher voltage I could’ve sworn there was a setting for low-voltage but obviously I’m thinking of a different device

I bought mine used (NIB) from a forum member.  It could be that it is older and yours is newer with the modification already done on it.  My directions say 14-16v

John

Walt,

I just looked at the controller and you are correct.  It says 12-16V on it, but the directions say 14-16V

I don't understand why 13.65 volts would cause a hangup in both directions.

Again, is there a lot of side play in your plastic lever that has the passengers attached to it?

Internally I can confirm that mine does not have the modification.

John

I had one of these and it would not fully extend at 14 volts, I increased the power to 18 volts, and that did the trick.

@Craftech posted:

Walt,

I just looked at the controller and you are correct.  It says 12-16V on it, but the directions say 14-16V

I don't understand why 13.65 volts would cause a hangup in both directions.

Again, is there a lot of side play in your plastic lever that has the passengers attached to it?

Internally I can confirm that mine does not have the modification.

John

my people go up straigt and true John.  My controller does NOT say 12-16 but rather it says 12-14.  I didn't know, before this thread, that there was a different version.

"my people go up straight and true John."  Mine wobbles and the screw is tight.  Not sure about loosening it to mess with it.

I took it apart to align the roof with the base, but discovered that the entire base is warped so that is impossible.  One of the roof supports is at angle and cannot be straightened (probably due to the warped base)

I shave the inside edges of the guide to 45 degrees as the modification pdf suggested.  Made no difference.  Tested it again at 16V with a separate power supply and it still hung up part way up and part way down.

Got out a separate Z1000 brick and applied a full 18V (as Craig suggested) and this time it went all the way up and all the way down most of the time.

I guess I could mess with the spring and try it again.  Attach an eyelet to it (as Vernon suggested) to loosen some of the tension.  But the solenoid doesn't "sound right" unless 18V is applied.   Two new micro switches (that may or may not work) and a spring (without the extension) delivered will be nearly $30.  Not sure it is worth it.

I have a 16V doorbell transformer I could try.

Thanks,

John

If the modification components are not readily available and/or the modifications are not in your comfort zone (e.g. soldering), has anyone tried a $1 PTC-polyfuse thermal cutoff switch?

The "old" version seems to operate at 16-17V for the OP and 18V for Craig. The issue seems to be the case where the mechanism jams with sustained voltage applied to the solenoid causing meltdown.  The solenoid should do its thing in a fraction of a second and then one of the micro switches cuts power.

The idea is a polyfuse could limit the amount of time power is applied to, say, 2 seconds.

This technique is used in the solenoid in turnouts where micro switches are supposed to cut power. But sometimes the turnout jams midway from an obstruction. Likewise this is used to protect the electromagnet in uncoupling operating tracks to limit the time that the coil is powered.

@stan2004 posted:

If the modification components are not readily available and/or the modifications are not in your comfort zone (e.g. soldering), has anyone tried a $1 PTC-polyfuse thermal cutoff switch?

The "old" version seems to operate at 16-17V for the OP and 18V for Craig. The issue seems to be the case where the mechanism jams with sustained voltage applied to the solenoid causing meltdown.  The solenoid should do its thing in a fraction of a second and then one of the micro switches cuts power.

The idea is a polyfuse could limit the amount of time power is applied to, say, 2 seconds.

This technique is used in the solenoid in turnouts where micro switches are supposed to cut power. But sometimes the turnout jams midway from an obstruction. Likewise this is used to protect the electromagnet in uncoupling operating tracks to limit the time that the coil is powered.

Hi Stan,

Are you saying bypass both switches and put two PTC's in their place?  Something like a Bourns MF-R050?

John

@Craftech posted:

Hi Stan,

Are you saying bypass both switches and put two PTC's in their place?  Something like a Bourns MF-R050?

John

I'm answering for him but no, definitely not that.

The purpose of the switches are to TOTALLY disconnect that coil once it reaches the full position. The purpose of a PTC is to limit the time in theory that a coil cooks if it fails to reach it's full endpoint and get shut off. That said, a PTC keeps cycling off and on until something burns up or the thing finally moves and the switch disconnects the coil from the circuit.

Effectively it's a self resetting thermal circuit breaker. The way to look at it is, it makes an annoying buzz periodically telling you the user "hey turn me off!!!" when the thing gets stuck and hopefully extends that reaction time to prevent total meltdown.

It's not a fix- it's a workaround. Edit, I should rephrase that. The PTC is an added safety device and adding safety is not a bad thing. The problem I was trying to get across is depending on a safety device as a primary fix for a device that we know has a problem and is not working correctly.

Even simpler than that.    You only need 1 PTC in the "hot" connection to the accessory.  You don't need to open up the platform at all.  You still need the internal lever micro-switches (whether the original style or "Zippy") to turn off power when the passengers move back-and-forth between the exposed and hidden positions.

IMO your warped/bent/deformed station is a special case.  That is, even if you ponied up the $30 or whatever to alter the micro-switches for lower voltage operation, it could well be that there would be undue friction or restricted movement that might inhibit complete and definitive passenger movement.  Hence you'd probably still want to use a PTC or whatever.

That you proposed the MF-R050 suggests to me you know what you're talking about and on top of this idea...or maybe you have some of those PTCs lying around from a previous project?  In any case, you choose an appropriate PTC using the "family of curves" as shown above.  In this family, if you run 2 Amps thru the MF-R050 to drive the solenoid, it will trip in about 4 seconds.  Again, when it's working, the solenoid will be done in a fraction of a second.  So the PTC can trip in 1 sec, 2 sec, 3 sec and you'll be good.  I don't think you'd see undue heating/melting or whatever until the solenoid is continuously powered for, say, 10 seconds.  Just a guess.  In other words, there is quite some leeway in choosing a suitable PTC.

It is true that the current flowing thru the PTC as I propose is also carrying a platform lamp but that is surely a fraction of an Amp so not really relevant.

Easy enough Stan.  I'll insert one on the hot side underneath.

But it sounds like unless I swap out the micro switches for the Zippies, I will still need close to 18V for it to operate.

John

Put another way, there is more a problem of control.

If the controller was momentary pushbutton and there was no possible way that a coil could be activated for more than say 2 seconds, and activated only when we wanted to change position, then the limit switches to disconnect the coils are added safety but not required.

But the problem is, the controller is a rocker switch, or most devices you might attach are relay based with normally open and normally closed contacts. They latch and hold that position until a state change (example 153 IR or the MTH version IR relay module) As such, with this type of control system, the switches to disconnect the coils at full throw go from optional safety to suddenly mandatory status.

The problems at hand in this discussion actually apply to nearly any twin coil device for example an Atlas track switch dual coil motor.

Again, while a PTC is a good idea, in the bigger picture, we need a freely working device that work so well there is very limited concern of it getting stuck in the middle of states and the coil cooking.

For example, you could use the same solution for switches- a capacitive discharge circuit that dumps a stored charge across the coil to slam it, but then doesn't allow full power to sit there and cook a coil.

@Vernon Barry posted:

Put another way, there is more a problem of control.

If the controller was momentary pushbutton and there was no possible way that a coil could be activated for more than say 2 seconds, and activated only when we wanted to change position, then the limit switches to disconnect the coils are added safety but not required.

But the problem is, the controller is a rocker switch, or most devices you might attach are relay based with normally open and normally closed contacts. They latch and hold that position until a state change. As such, with this type of control system, the switches to disconnect the coils at full throw go from optional safety to suddenly mandatory status.

The problems at hand in this discussion actually apply to nearly any twin coil device for example an Atlas track switch dual coil motor.

Again, while a PTC is a good idea, in the bigger picture, we need a freely working device that work so well there is very limited concern of it getting stuck in the middle of states and the coil cooking.

For example, you could use the same solution for switches- a capacitive discharge circuit that dumps a stored charge across the coil to slam it, but then doesn't allow full power to sit there and cook a coil.

To be clear, when the passengers stop halfway up or down there is NO solenoid sound.  The switches have cut that off.

John

I just checked my version here on the bench and it definitely has a fair range in the middle where the coil is activated before switching off near the end limit. Mine is also different between up and down but that's just variation in the limit switch lever arm from what I can feel. Mine is a 30-9152

My concern is simple, let's say it doesn't go full lock position up. It's halfway but far enough the switch opened. We have gravity and vibration on the train table and eventually, it could drop back down into the zone where the limit switch connects the coil back. So maybe it rises back up but still not fully locked and then back down again over and over and over.

I was able to replicate this on the bench with mine.

I stand behind what I've said to this point. There are really 2 problems.

#1 you have a used and abused unit from what it sounds like, that works, but not great and requires decent higher voltage to fully go to the locked positions and even that is not 100% reliable.

#2 Combine that fact of an unreliable rough operating example of a unit, with a controller we know that uses a rocker switch and constantly powers either the up or down state- thus depending on  a working unit that will disconnect the coil and go fully locked each time and every time.

So you can add safety like a PTC, you can try to make yours better and more reliable, but the other thing maybe to think about is using a different control method with either momentary push buttons, or maybe even consider a capacitive discharge style designed for twin coil switch motors like Atlas as an example.

https://ogrforum.ogaugerr.com/...s-and-other-switches

A good capacitive discharge example http://www.circuitous.ca/CDPSU.html

@Vernon Barry posted:

I just checked my version here on the bench and it definitely has a fair range in the middle where the coil is activated before switching off near the end limit. Mine is also different between up and down but that's just variation in the limit switch lever arm from what I can feel. Mine is a 30-9152

My concern is simple, let's say it doesn't go full lock position up. It's halfway but far enough the switch opened. We have gravity and vibration on the train table and eventually, it could drop back down into the zone where the limit switch connects the coil back. So maybe it rises back up but still not fully locked and then back down again over and over and over.

I was able to replicate this on the bench with mine.

I think the 30-9107 is a 1999 model and yours 30-9152 is a 2001 model.  Did it come with the modification and Zippy switches?

John

@Craftech posted:

I think the 30-9107 is a 1999 model and yours 30-9152 is a 2001 model.  Did it come with the modification and Zippy switches?

John

I would say yes, it likely has easier switches inside, I haven't opened it up because mine works easily at 12V or even slightly less.

I was using a Zcontroller and 500W brick on the bench to simulate low voltage conditions where it gets stuck halfway.

I suppose one could run the manual lever out the end and use the two finger Presto Chango method.  That's FOOLproof  

John

@Craftech posted:

...

But it sounds like unless I swap out the micro switches for the Zippies, I will still need close to 18V for it to operate.

Correct.  That it needs 18V (when spec is 12-16V) suggests the deformed structure might be in play and other than more fiddling to fix it, this is simply powering-thru the problem with a safety net so-to-speak...like Captain Kirk saying "I need more power Scotty!"

@Vernon Barry posted:

...

The purpose of the switches are to TOTALLY disconnect that coil once it reaches the full position. The purpose of a PTC is to limit the time in theory that a coil cooks if it fails to reach it's full endpoint and get shut off. That said,a PTC keeps cycling off and on until something burns up or the thing finally moves and the switch disconnects the coil from the circuit.

...

I suppose there are some thermal devices that behave this way (cycle on and off when tripped) but the generic PTC resettable fuse stays shut-off as long as the fault condition persists until you remove power.  That is, when it trips, its resistance doesn't go to infinity like a blown traditional fuse.  Instead the resistance goes up to some value that lets a bit of current flow...just enough current to keep it warm and in the tripped condition.  You have to actually remove power to let it cool down and reset.

So you when changing positions, and the solenoid gets stuck in the middle, you would hear the buzzing until the PTC trips, then it will go silent as the current will drop to some trickle level forever until you attend to the situation.  I suppose if you had a stethoscope you might hear a faint buzzing sound.

@Vernon Barry posted:

I would say yes, it likely has easier switches inside, I haven't opened it up because mine works easily at 12V or even slightly less.

I was using a Zcontroller and 500W brick on the bench to simulate low voltage conditions where it gets stuck halfway.

If using a Z-controller or similar "chopped sine" transformer (e.g. CW-80) note that at 12V output as measured by a voltmeter the voltage peaks will nevertheless be those of the 18V pure-sine brick.  Solenoid mechanisms are very fast, in a fraction of a second, as evidenced by the snap-action behavior.  To wit, the buzzing sound is the solenoid "fighting" the spring and slamming the metal plunger rod back and forth 120 times per second.

Reminds me of that Lionel marketing pitch for the CW-80 about how you get better/more smoke than from a traditional pure-sine transformer for the same track voltage.

@Vernon Barry posted:

Trying to find the kit and coming up short. That said I found key components.

Also, under the older MTH site found the parts breakdown of the platform

https://www.mthtrains.com/site...loded/30as11893e.pdf

Which showed my "guess" was correct- that BB-0000021 was the correct switch.

Spring would be IE0000049A for the modified one?

Sadly, trying all word combinations I could thing of (adjuster, spring, return, platform, operating, kit) I could not find the stamped metal adjuster arm? Maybe use a wire eyelet?

this was "the kit"

https://www.mthpartsandsales.com/shop/search

Hi Vernon,

I ended up ordering the parts from MTH and they sent me two different switches.

One is a Zippy SM-G   5A125-250VAC

The other is a DICGU SM-3  3A125-250VAC

Not sure what to do.

Thanks,

John

The question is, when you click the lever on the switch, how much force is required? Does one feel easier than the other? If so, put the lightest one for "up" position limit. Gravity helps on the down one, so it's really the up one that requires improvement.

@Vernon Barry posted:

The question is, when you click the lever on the switch, how much force is required? Does one feel easier than the other? If so, put the lightest one for "up" position limit. Gravity helps on the down one, so it's really the up one that requires improvement.

The Zippy feels lighter.  I haven't opened it up again,  but I think the DICGU is what are in my 1999 station.  Why would they still have those?  And then the 3A rating instead of 5A?

I guess I could only replace one and then Jerry Rig an eyelet to take the place of the unavailable link?

Wondering if this was even worth it, but will give it a shot.

Thanks,

John

Just some quick research https://www.dicgu.com.tw/e-pro01-sm.html

From the markings alone I cannot determine the force rating of that switch, we only know it is 3A rated.

The same thing with the Zippy

http://www.zippy.com/ecproduct...il.aspx?ps_rfnbr=292

So we could order from Digikey or Mouser or someplace else and specify the low force specifically.

Sadly, my searching is showing not much in stock at some suppliers.

@Craftech posted:

The Zippy feels lighter.  I haven't opened it up again,  but I think the DICGU is what are in my 1999 station.

Why would they still have those? because many other operating accessories (car wash, gas station, operating boxcars) used this style of switch but are not sensitive to the force because they use a DC can motor gearbox for actuation, not a solenoid.

And then the 3A rating instead of 5A? Just a common rating from suppliers. For the most part- way more than this switch ever handles as in most cases it's just a logic switch carrying mere microamps. This accessory is one of the few it's carrying the power to the coil but even then the 3A ratings should be adequate.

I guess I could only replace one and then Jerry Rig an eyelet to take the place of the unavailable link?

Wondering if this was even worth it, but will give it a shot.

Thanks,

John

Again, the up position is the more critical one since we are fighting gravity and the switch VS down where gravity helps.

Thanks for all that Vernon.

Regards,

John

@Vernon Barry posted:

Again, the up position is the more critical one since we are fighting gravity and the switch VS down where gravity helps.

What about the lower voltage requirement that the Zippy switches purportedly provided?

John

@Craftech posted:

What about the lower voltage requirement that the Zippy switches purportedly provided?

John

Because the coil now has to fight less force of the drag of the microswitch, it can use less voltage and less force to slam up the platform to it's final resting position.

Basic force VS drag.

Got it,

Thanks Vernon.

John