I discussed this problem in the General Discussion forum here at the Model Railroad Forums and thought maybe that was the wrong place to ask about the topic, so I'm asking about this again here in the electronics and DCC forum:
When I started my layout in 1988, I used atlas under table and side by mounted switch machines. I have a Snapper capacitor discharge system powering these switch machines. Where I have passing sidings, both turnouts at the ends of the siding are powered by a single toggle switch and momentary push button to activate, plus, I have also used Atlas relays to power the frogs and cut power to the by-passed siding and activate power to the active siding. So, the reality is I'm more or less powering three switch machines when I change routes through a siding.
Where I am only powering one switch machine and relay to power a single turn out and frog, the Snapper capacitor discharge system snaps both with authority. However, the siding system described above seems to lack power. Am I over taxing the Snapper by powering the two turn outs and one relay?
I understand there are more expensive systems available and maybe in the end I will have to bite the bullet and go to a Tortoise type of slow motion switch machine; but, I would prefer to use what I have as changing out some of my switch machines will be a real chore!
My layout sat for 6 years while I was involved in another hobby. Previous to this 6 years of inactivity, the system worked well. Upon return this problem developed. So, my opinion is that wire size and track conditions are not the cause as previously everything worked o.k.
If you can help me out, it will be greatly appreciated. I will try any suggestions excepting if you feel I should remove the switch machines to do maintenece to them, because if it comes to this, my opinion is I should change to a different more reliabvle system.
Thanks in advance for any advise!
NP 2626 "Northern Pacific, really terrific"
Northern Pacific Railway Historical Association: http://www.nprha.org/
Two turnouts plus a snap realy may indeed be too much for the Snapper to handle at once. The solution is usually a larger capacitor, but without a circuit diagram and some knowledge of the rest of the components it might not be so simple as sodlering on another capacitor in prallel. The increased capacitance will cause a greater inrush current to recharge it - the diode on the input might not be able to handle this current, of there is one, or if it uses a transistor for fast recharge, it may not be able to handle it - even the relatively small unit I built for N scale had the transistor on a heat sink, and with repeated use it would get slightly warm. I don;t see a heat sink on the Snapper so either they don't use the quick recharge circuit or they didn;t feel the transistor needed a heat sink and it's just there.
I saw over there someone suggested a second Snapper - that won;t work in this case, since even if you put all other turnouts on a second Snapper, you're still trying to run essentially 3 at the same time. Unless you mechanically gang the control buttons, or use a DPDT momentary toggle, you can;t hook up say the two turnouts to one Snapper and the snap relay to a second Snapper.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Thank you Randy. Naturally the one siding I'm having the most trouble with is, the one that is least accessible. Must be a Murphy's Law that applies for this type of problem!
Just to be clear, is this something that has always occurred or did it just show up.
In other words, did the snapper ever drive the 3 machines properly?
Jim
Soo Line fan Just to be clear, is this something that has always occurred or did it just show up. In other words, did the snapper ever drive the 3 machines properly?
"My layout sat for 6 years while I was involved in another hobby. Previous to this 6 years of inactivity, the system worked well. Upon return this problem developed. So, my opinion is that wire size and track conditions are not the cause as previously everything worked o.k."
So we know the Snapper was capable of driving the three machines back then. Atlas switch machines draw 2.9- 3.1 amps each. That's 6 amps for the 2 switches plus the relay.
On the Circuittron site it states: "With a 24 volt AC input, the SNAPPER™ should be able to activate between 5 and 10 coils if they are all connected to the same control"
Do you know what the original input voltage was to the snapper back when it worked?
Can you now verify it with a DMM?
The Snapper does need about 20-24 volts input for more than 2-4 turnouts. My Snapper will throw a 7-9 combination of Atlas and Pecos (Route Control) with no hesitation.
If you do have adequate power for your Snapper, then the following would be my next go-toos:
If the layout was inactive for 6 years, I would suspect one electrical issue if you are using Atlas switches to control your turnouts, corroded contacts, spray all your control switches with contact cleaner like CRC 2-26 (avail at HD or Lowes and other stores).
Otherwise, I would expect mechanical problems. Check and manually operate all the turnouts and feel and see how each one opereates. Some of them may have become tight with 6 years of inactivity. What kind of room has the layout been stored in? The iron bar that is thrown by the 2 coils can and will rust, depending on the amount of moisture in the room and can get severe enough to restrict the movement of said bar. Working the turnout back and forth manually may loosen things up again. Some Kadee Grease'Um (graphite powder) squirted in one end can help
Jay
C-415 Build: https://imageshack.com/a/tShC/1
Other builds: https://imageshack.com/my/albums
modelmaker51 The Snapper does need about 20-24 volts input for more than 2-4 turnouts. My Snapper will throw a 7-9 combination of Atlas and Pecos (Route Control) with no hesitation. If you do have adequate power for your Snapper, then the following would be my next go-toos: If the layout was inactive for 6 years, I would suspect one electrical issue if you are using Atlas switches to control your turnouts, corroded contacts, spray all your control switches with contact cleaner like CRC 2-26 (avail at HD or Lowes and other stores). Otherwise, I would expect mechanical problems. Check and manually operate all the turnouts and feel and see how each one opereates. Some of them may have become tight with 6 years of inactivity. What kind of room has the layout been stored in? The iron bar that is thrown by the 2 coils can and will rust, depending on the amount of moisture in the room and can get severe enough to restrict the movement of said bar. Working the turnout back and forth manually may loosen things up again. Some Kadee Grease'Um (graphite powder) squirted in one end can help
My next endeavor will be to determine the voltage I'm supplying to the Snapper. I think this may be the problem as it seems to me the power source was less than 20-24 volts; but, I will check this out. Thanks for the suggestions!
Well, you already have your heart set on keeping those Atlas Snappers, but the truth is the LION got rid of all of his. By now everybody knows that the LION is cheap, and him will not put a penny where it is not needed, but the Tortoise machines are so good, so versatile, so easy and so simple to wire that even the LION broke down and asked the Abbot for money to buy these switch machines for his railroad.
You know it is important when you have to go and ask somebody else for permission to spend the money.
And actually, the Tortoise are far cheaper if you have to string lots of wire: One wire beats two wires any day of the week. LION has 50 turnouts and so a 25 pair cat-3 cable can handle the job.
Mounting could not be simpler. You already have a hole under your turn out for the Atlas machine. Just carefully enlarge it (I like 3/8" of an inch but have used 1/2" if that was the bit that was in my drill). Set the actuator by hand in the center position, place a glob of silicone caulk on the top but away from the actuator, and push it up through the hole and into the throwbar. Adjust the position of the machine until the switch points are also centered. Prop it in place if needed, it usually does not. It is done.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
Have you tried manually flipping the Atlas machines? How easily do they move, and are they OK in both directions? From the top of the layout, how easily can you shove the points over, even though they'll move back with the spring pressure from the machines? Do they move back quickly under spring pressure?
Another thing to try, if you can get to the machines and activate them manually, is to try various combinations of "initial conditions" to see if you can identify one particular machine that's causing problems. Mismatch the turnout positions, or set the relay opposite to where it should be. If you have a sticking problem, most likely it's only one of the machines.
It takes an iron man to play with a toy iron horse.
What is happing is this: When I throw the turn out, one of the switch machines will snap to the other side, the other will maybe go 1/2 way and stop and maybe the relay will only move a small amount. Generally, I can get the sequence to complete if I hit the actuator button several times allowing the Snapper some time to build up a charge.
Disconnect each of machines electrically one at a time. Try different combinations and see if a pattern develops.
NP2626 What is happing is this: When I throw the turn out, one of the switch machines will snap to the other side, the other will maybe go 1/2 way and stop and maybe the relay will only move a small amount. Generally, I can get the sequence to complete if I hit the actuator button several times allowing the Snapper some time to build up a charge.
Am I right in assuming that the one that snaps to the other side is the same one every time? And the other turnout doesn't move well no matter which side it starts on? Try putting a tiny drop of oil (Labelle if you have it, and make a trip to your LHS if you don't) into the slot where you can manually flip the machines, and work it back and forth. (Yes, it's trickier with inverted machines, but it can be done.)
I'm still convinced there is nothing wrong with the Snapper. But, if there's any sticking at all, by the time the machine builds up enough force to overcome the sticking, the fast pulse of the Snapper has faded and there's not enough power left to get the rest of the way over.
MisterBeasleyI'm still convinced there is nothing wrong with the Snapper. But, if there's any sticking at all, by the time the machine builds up enough force to overcome the sticking, the fast pulse of the Snapper has faded and there's not enough power left to get the rest of the way over.
I agree, all my Atlas motors are activated with a CDS and work quite well. That being said, the Atlas motors do not have any extra power.The turnout must be free moving. Dry graphite will help if worked under the turnout throw bar.
Good luck.
Lee
Since the layout sat unused for six years, the contacts on the switch motor, snapper, or push buttons could have corroded, causing a loss of power. Try loosening and re-tightening the screws that hold the wire to the Atlas switch motor that isn't working properly, and to the push buttons if you're using the Atlas switch controllers..
As a further description of the problem: I have three sidings set up in the way first described in previous post on this topic. Let's label them Closest, Middle and Farthest (Distance from the Snapper). Really only one is giving me trouble. As far as distance from the Snapper is concerned, the solenoid closest to Snapper (6 inches) and the switch machine in this siding that is closest to the snapper (3 feet) are balky. The siding farthest from the Snapper works perfectly. The closest one has one balky switch machine which finishes it's travel the second time the button is pushed.
The suggestions I've tried are: 1). I've worked the lazy switch machine and solenoid many many times hoping to free them up. 2). Checked the voltage supplied to the Snapper, which is 18.5 volts as measured with my digital Multimeter. 3). I've loosened and tightened all connection screws many times, for both input and output. This should burnish the metal surface that make contact, improving continuity. 4). I can see using graphite to lubricate the mechinisms in the switch machines and solenoids; but, won't be squirting any light oil into them, as I think this will eventually gum up the works!
As a said earlier the switch machine that is giving me the most trouble would be very difficult to remove, disconnect; or, replace.
Thanks to everyone for scratching your head over this one! Much appreciated!
NP 2626
As I stated in my last post. Try putting graphite under the throw bar itself. Take some on small 1/4" paint brush and work the graphite under the bar that holds the movable rails in gauge as they go back an forth. Works for me.
You have one of two problems with that turnout. 1. The throw bar (the tie that moves the points) has tightened up some how, probably due to expansiom and contraction of the rail and/or movement of the roadbed. 2. Rusting of the iron rod inside the solenoid. In either case the best solution is to disconect the switch machine from the switch, if you have enough wiggle room to pull the actuating pin from the throw bar so both are free to move, If the throw bar is not moving freely, you could try a .005 or .010 piece of styrene as a shim under each tie on either side of the throwbar. Some graphite under and around the throwbar may also help. While you have the actuating pin disconnected from the throw bar,throw the switchmachine bach and forth check for free movement. If it's not moving freely, I would exchange the switch machine out for a new one or take it to the work bench and tke it apart and clean the iron rod with some 400/600 grit emory cloth and add sme graphite to the moving parts. I agree with you, do not use any oil in a switch it can and will end up gumming up the works. Jay.
O.K., thank you to everyone for their suggestions. After testing this thing everyway you and I have come up with, it appears I'm faced with replacement of the switch machine. This will not be an easy task as the thing is under the scenery and above my staging yard, so access to this particular switch machine is poor.
Again, thanks!
I got to thinking that maybe the solinoid is what is causing the slow reaction of the switch machine. So, I replaced this solinoid with a new one and tested the system and to my delight the slow switch machine now slaps the points over to the other side with authority!
So the mystery is solved and I've learned a thing or two about diagnosing these types of problems. Again thanks to everyone for their suggestions.