# switch-cutting



## CliffyJ (Apr 29, 2009)

I've have 2 reversing loops (DCC rail power), and am ok with them being uni-directional. I need the switches to be automatic, one way or another. 

I'm up for simple springing of the points, but haven't done that yet. Strings of short ore cars might be involved, and I understand that cutting the switches (with lighter cars) is asking for trouble.
BTW, in Train Li's switch machine instructions, they suggest getting an LGB machine for such "cutting" operations...

Here's the prior thread on all this:
http://www.mylargescale.com/Communi...fault.aspx



Based on that discussion, I've got 2 PSXAR reverse-loop controllers, and 2 Train-Li DCC machines, thinking there might be a way to automatically throw the switches from the PSXAR. 

Unfortunately, I'm still a little unclear as to whether the (DCC-powered) PSXAR can issue a controlling DC signal to the Proline DCC machine (in DC mode). 

Now that the track is finally getting laid, I'm coming back to that decision. Unlike the other thread, I'll be in a position soon to try things out.


Thanks,
===Cliffy


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## Greg Elmassian (Jan 3, 2008)

It seems that the "tortoise" outputs should do the trick for your switch machines. 

I'd contact DCC specialties, I have never used these outputs. 

Greg


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## toddalin (Jan 4, 2008)

One of the guys in our club runs DCC and was asking me how to fire his LGB turnout motors using the "MRD2" module. The module is configured to use the Tortoise Switch machines. He presented me with this diagram from the mfg.



I determined that is was just a matter of replacing the two dc sources with an ac source, "Teeing" two diodes in opposite directions off one leg of the ac source that are then run into the module and selected by the MRD2, where they then run to the turnout motor, and run to the other leg of the ac source directly to the turnout motor. The MRD2 is configured to pulse the turnout of 1/2 second after activation.

The club member reported that the system works perfectly.


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## CliffyJ (Apr 29, 2009)

Thanks Todd, good to hear from you. I'd not noticed that MRD2 system before, looks really cool: 
http://www.azatrax.com/dual-train-detector.html 

However, I'll try to get away with the PSXAR only, at least until I run into a dead end. 

Greg, the DCCS gentleman had said the PSXAR would not work w/ the Prodrive, but from what Axel said it seemed like it might. Over July 4th weekend, I'll be attempting the setup, so we'll see!


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## toddalin (Jan 4, 2008)

Cliffy, 

The idea here is that if the MRD2 is configured to run the _Tortoise Turnout_ (gottaloveit) motors and can drive the LGB motors, if yours is too (or can be), maybe you can also do this in a similar fashion using your unit?


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## CliffyJ (Apr 29, 2009)

Sorry Todd for my being dense, thanks for clarifying. 
Now I get it! If the PSXAR is outputting DCC to a theoretical Tortoise, then rectify that output with a couple of diodes. Yes?


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## toddalin (Jan 4, 2008)

I can't imagine that the PSXAR is outputting DCC to Tortoise machine. I don't think the Tortoise units are designed to work that way. Can you provide documentation/user manual as to your unit? An ac source and a couple diodes _may_ well be all that are necessary.


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## CliffyJ (Apr 29, 2009)

Todd, here's the manual: 

http://www.dccspecialties.com/products/pdf/man_psxar.pdf 

Thanks for your help!


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## toddalin (Jan 4, 2008)

I don't see any reason that we can't use a pair of diodes to properly route the current to the turnout motor. This assumes that the module puts out enough voltage to drive the LGB turnout motors. I didn't see the voltage/current ratings listed for this.

The system uses a common + and switches between two - sources. We need a way to ensure that when one of the - sources is selected, the - goes to one of the turnout contact and the common + goes to the other. Then then the other - source throws, we need to reverse the polarity to the turnout contacts.

Rather than draw out how this needs to go down, I'll bottow a picture from George Schreyer's web site and show how we can apply this logic to accomplish our goal.



Take away the part that says twin coil switching machine and connect the common + up to the center circle. Connect a - to each of the outter circles. The turnout motor will replace the "To 5474 A or B Output."

Now assuming that I have the diodes facing in the proper direction, when the top - and common + trigger the current flows to the turnout motor with the - at the top of the turnout motor and with the + controled by the diode from the bottom of hte motor. The same situation occurs when the bottom - and common + trigger except that the current flows in the opposite direction and the - goes to the bottom of the turnout motor and the + goes to the top.


These manufacturer's should document this stuff.


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## chuck n (Jan 2, 2008)

Cliffy:


If your are OK with your train going left on the first pass in to the return loop and right on the next, let me make a suggestion. John, aka totalwrecker, has an very nice spring switch control. No diodes or circuit boards. The engine pops the switch over and the spring holds it. Simple and no electrons are necessary. For me outside that is a plus. Go through the posts in his thread.

John's magic switch control 


Chuck


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## Greg Elmassian (Jan 3, 2008)

You guys may be missing the original question, and perhaps it would be best to read the manual proffered. 

He already has electronics that is capable of sensing the train and sending an output to a tortise type (stall type) or a snap action type turnout motor. 

Why don't we try to work an answer to his question? 

So the key is can the prodrive take constant power and it will move and stop, or can it take a short pulse and move and stop? 

If you get me that info, I can figure out what the PSX-AR will do for you. 

Greg


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## toddalin (Jan 4, 2008)

I'm not familiar with the ProDrive, but if it requires a pulse and the module puts out a continuous voltage, we can easily change that voltage to a pulse using a couple... wait for it... relays.


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## Dan Pierce (Jan 2, 2008)

The ProDrive in DC operation will need a 555 timer as it needs more than a quick pulse like the LGB EPL drive, it needs approx. 3-5 second long pulse. 
This is due to the use of a servo in the prodrive whereas the LGB is a snap action motor doing a half rotation. 
And the ProDrive control has a programmable timer/direction/add-on light.


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## Greg Elmassian (Jan 3, 2008)

Dan, will the 555 handle the current of the prodrive? 

greg


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## Totalwrecker (Feb 26, 2009)

Whoa Greg, don't get all bent out of shape over a non electrical solution..... The OP opened that door with his second paragraph. 

"I'm up for simple springing of the points, but haven't done that yet. Strings of short ore cars might be involved, and I understand that cutting the switches (with lighter cars) is asking for trouble." 

Just one note to clarify the above, if the Spring is a 'flop over' type, only the lead wheels move it or are affected. Light cars are not affected. Only concern eliminated. 

Now back to your other automations..... carry on electrons! 

John


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## Greg Elmassian (Jan 3, 2008)

I was commenting on the electrical solutions of using a different electrical controller when he already has an electrical controller. 

It seems that the Prodrive is "different" in that it is neither a "snap action" (quick pulse) nor "stall"... 

There might be something simple that can be set in the PSX-AR controller now that I know what the ProDrive "needs", it is a microprocessor driven DCC unit, so lots of things can be set. 

If not, all you need is that 555 to "stretch" the pulse, or maybe something as simple as a big cap.

Dan, since I cannot find any manual on the Train-Li site, how many wires does the switch motor have (trying to find out how it works and is wired)

Greg


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## Totalwrecker (Feb 26, 2009)

That's cool. 

(had tried to post this a second ago, post was dropped and I ended up in forums) 

John


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## Totalwrecker (Feb 26, 2009)

Another unique MLS duplication post...









edited


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## chuck n (Jan 2, 2008)

After about 30 years of garden railroading, I am a firm believer of the KISS method (keep it simple...). I will use manual over automatic every time, if it is at all possible. If I were to use an automatic switch throw, I would use the ones that are powered by compressed air. Doc Watson used them here in Virginia without any problems. They are pretty well sealed, unlike the LGB ones I was using. Several times a year I would have to clean out the mud and ants. That is why I'm using a brass rod as a spring to hold my switches where I want them. John's spring is great if you want to flip the direction and have it stay. The method I use, courtesy of Dr. Rivet, permits the train, if it is heavy enough, to pass through and return to the previous setting. I'm on my iPad and I can't easily post the link to the thread on what I am using. 


Chuck

back on the computer here are some pictures of the rod spring.


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## toddalin (Jan 4, 2008)

Posted By Greg Elmassian on 24 Jun 2013 07:15 AM 
Dan, will the 555 handle the current of the prodrive? 

greg 

Wouldn't matter. You wouldn't connect the output of a 555 directly to the Prodrive without asking for all kinds of trouble. The 555 would drive a relay or transistor to drive the prodrive. 
Using 555 chips to set the length of time that a turnout motor toggles is no big deal and that's what we do on our "leap frog." I don't trust the reed switches to completely throw the turnouts every time, or at higher speeds, and a reeds can't really handle two turnouts simultaneously..., for long.


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## Greg Elmassian (Jan 3, 2008)

so with proper "anti-kickback" diodes and possibly inrush protection, still would not work? 

Greg


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## toddalin (Jan 4, 2008)

Posted By Greg Elmassian on 24 Jun 2013 11:58 AM 
so with proper "anti-kickback" diodes and possibly inrush protection, still would not work? 

Greg 

Possibly, especially if you also also add ferrite beads, but "iffy" until proven. Also recognize that there is a voltage drop through the 555 so the supply voltage needs to be ~1.5 volts higher than the requirement if you take the output off the chip as opposed to using a relay or transistor. 
It is actually very easy to generate the pulse using a couple relays and if we need that pulse to last a few seconds, a regulator and couple supercaps (in series with a parallel resistor/pot to adjust the bleed-off/duration) across the relay should be more than adequate to get several seconds duration.


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## CliffyJ (Apr 29, 2009)

Posted By chuck n on 23 Jun 2013 05:43 PM 
Cliffy:


If your are OK with your train going left on the first pass in to the return loop and right on the next, let me make a suggestion. John, aka totalwrecker, has an very nice spring switch control. No diodes or circuit boards. The engine pops the switch over and the spring holds it. Simple and no electrons are necessary. For me outside that is a plus. Go through the posts in his thread.

John's magic switch control 


Chuck


Chuck,

Thanks for that link, great thread & ideas, I'll have to look into that more. It sure looks like a good backup plan, if the automated route doesn't work. Maybe the best plan, but I've not absorbed it all yet. 

===>Cliffy


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## CliffyJ (Apr 29, 2009)

Thanks guys for digging into this, I really appreciate it.

Main thing for me is simple reliability, without manual intervention, with sometimes long strings of smaller ore cars. 

I'll sacrifice choice (loop direction) to achieve that, but having choice is a nice-to-have. So if a sprung solution is best (for uni-directional op's), cool. BUT, I have this gear, and it seems we're so close... 

I tried to find the manual on line, but couldn't. I have it in my hand though, so here's the relevant quote:

DC Operation with ProDrive DC/DCC

ProDrive DC/DCC work in default as a DC drive. CV1 (the address of the drive) is set to 0. Any other value for the address and the drive operates as a DC drive. 

Connect the DC wires to the switch and solder them to the two terminal points. The two points are polarized, so that the reversal of the polarity will change the switch position. *Use a momentary toggle switch (hold down for 2-3 seconds) or a regular toggle switch to control the switch drive (switch drive automatically stops at end point).*

The first time the drive is the switch servo motor is running at a faster speed and you will hear a high pitch noise. This initialization procedure, which is normal, allows the servo to "memorize" the end positions. After the initialization the servo will operate at slower speeds. The operational voltage should be between 12V and 28V.

(quote ends here).

Then it goes on to describe DCC op's.

Sounds like it handles a sustained (DC) input. Which would suggest... wait for it... no, I can't say it yet Todd...









It also sounds like the 2-wire switch-controller output from the PSX-AR. 2-wire means polarized / DC, right? 

===>Cliffy


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## chuck n (Jan 2, 2008)

Cliffy:

My question is where do your live? In dry climates electronic switch machines may be OK. I didn't have any problems with my LGB switch machines in Denver (dry). When we moved to Virginia (wet) I had problems. In addition to mud and insects in the mechanism the iron in the motor (magnet) rusted.

What engines are your going to run on your layout? I have never had any problems with any LGB engine crossing a switch (mogul, mallet, electric, or diesel). I do have problems with some of my Accucraft and Bachmann steamers (K-27, C-19,). The pilot truck doesn't have enough weight to pop the switch before it derails. I could add weight, but I haven't. I have never had any problems with any diesels (LGB, USAt). 

With John's spring, it is only the engine that matters. If it throws the switch the light ore cars will be fine. I would think that if your pilot truck has problems, it wouldn't take too much tweaking to adjust the tension on the spring to solve the problem.

Chuck

If you want the run the train in the same direction through the return loop, you can use the straight rod spring i showed in the picture. It may take some adjusting to keep the lighter cars on the track. Or add weight to the cars (ore is heavy).


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## Totalwrecker (Feb 26, 2009)

For your record of ideas ... or for the record of note; My spring can be used either way. On my reverse loops they flop over, on sidings a train can exit, but must be manually thrown to enter. The hole in the throwbar is drilled towrds the preferred side from center. The mainline is protected and trains are not trapped. like Chucks. 
John


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## CliffyJ (Apr 29, 2009)

Hey Chuck,

I'm in way-northern Virginia (Maryland).









Part of me says, Naah, it can't be that simple... But I'll definitely read that thread and ask more after. 

I've been trying to think of the operational consequences, and came up with one more thing. Like I said, I'm ok with the train entering the loop always from one side. But, it also needs to be able to back out from that same side. I guess that works with John's spring approach. Sorry, just thinking out loud.

====>Cliffy


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## Greg Elmassian (Jan 3, 2008)

Yes Cliffy, according to the documentation, you connect the Pro-Drive to J5-1 and J5-2. That's all. 

The DCCS people must have been confused when you told them it was a DCC turnout motor... now I hope the ProDrive you received is configured right.... have you tested it on DC?

Greg


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## CliffyJ (Apr 29, 2009)

Posted By Totalwrecker on 24 Jun 2013 06:35 PM 
For your record of ideas ... or for the record of note; My spring can be used either way. On my reverse loops they flop over, on sidings a train can exit, but must be manually thrown to enter. The hole in the throwbar is drilled towrds the preferred side from center. The mainline is protected and trains are not trapped. like Chucks. 
John 
See, that's really interesting. I have several switches along the mainline that will be used only infrequently. 

===>Cliffy


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## chuck n (Jan 2, 2008)

Cliffy, since John's only flips when the engine throws it you should be able to backup the way you came in. With the bar spring you may go on the other track. It all depends on how the switch was oriented when you came out.

Chuck 

PS It is a little far out, but next Christmas Dr. and Mrs. Rivet, along with some elves, including me, will be running trains at the Colvin Run Mill Park, in Great Falls, Va. I think that we are scheduled for the weekend before Christmas and the weekend between Christmas and New Years. Come down and visit.

PSS I just tried to send you a PM and got a message that you aren't accepting them.


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## CliffyJ (Apr 29, 2009)

Posted By Greg Elmassian on 24 Jun 2013 06:48 PM 
Yes Cliffy, according to the documentation, you connect the Pro-Drive to J5-1 and J5-2. That's all. 

The DCCS people must have been confused when you told them it was a DCC turnout motor... now I hope the ProDrive you received is configured right.... have you tested it on DC?

Greg That's great, thanks Greg. I agree with your assessment.

No, I've not tested anything yet. And it will probably be July 4 weekend until I can. So maybe here's a mini procedure:
- Hook the PSX-AR up to the loop, per instructions
- Confirm J5-1 / 2 for sustained DC output, with alternating polarity 
- Hook up the Proline...

And it should work fine... So we'll see! 

====>Cliffy


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## CliffyJ (Apr 29, 2009)

If your are OK with your train going left on the first pass in to the return loop and right on the next... 
Chuck

OK Chuck, I just read John's thread and now get what you meant about the alternating nature of this solution. I'll have to think about that, because only one side of each loop represents the "prototype" side, with the other being the practical necessity for continuous model running. Great point, and thanks again.

====>Cliffy


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## chuck n (Jan 2, 2008)

Cliffy:


Last April I ran my Mallet around John's layout. He has reversing loops at each end. What is described is exactly what happened. The engine went left the first time and right the next, alternating every other trip. Never a problem.

You might scroll through this thread when you have a chance. I was running on battery in a trailing box car.

Totalwreckers layout 

Chuck


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## Greg Elmassian (Jan 3, 2008)

Cliffy, please test the proline on DC also, BEFORE trying it on the PSX-AR.... the more individual testing you can do the better. 

Greg


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## CliffyJ (Apr 29, 2009)

Another great tip Greg, thanks! 

Great pics John & Chuck, beautiful layout! I believe you Chuck, and I think I'll be using John's method elsewhere. So simple. Since I have to use the PSX-AR though, and have those and the Prolines, I'll start with that for the loops. 

BTW, maybe I just missed it, but how is John changing polairrriiitt.... wait, you're using battery power! Is John as well? 

Thanks guys, 
===>Cliffy


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## chuck n (Jan 2, 2008)

Cliffy, my Mallet was powered by battery. John can say how he is planning to power his trains. I have three battery powered engines. The main reason is that I can take trains anywhere and run them. Most of my engines are track powered. I have never counted them and I really don't want to know. I do not know anything about DCC. My understanding after being corrected by Greg (several times) is that DCC is polarity indendant. There must be some gaps but I'm at a loss where or when. All I can help with is the switches into the reversing loop and manual is easier than automatic. Chuck PS, I'd like to communicate a few things though PM, but you have blocked it.


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## Totalwrecker (Feb 26, 2009)

We don't need no stinkin' polarity! 
Battery here. 
I'm electron challenged, if I can keep them contained in a loco and transmitter, then I have a chance. When they get spread around, I'm at a loss.... 

I did pick up the 3 smallest sizes of spring wire today so I can lessen the tension for cut through operation. I'll run some experiments and see what we can do. I have the same pilot truck concerns, mine are light. 

Happy Rails, 

John


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## CliffyJ (Apr 29, 2009)

Roger that, John. 

I don't know what the DCC equivalent for 'polarity' is, but what ever it is, it needs to be managed by that "auto-reverse" unit for the return loops. 

Happy Spikes! 

===>Cliffy


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## Greg Elmassian (Jan 3, 2008)

In AC circuits, you use "phase" normally, but most people can accept polarity... 

Since DCC is a modulated frequency square wave, it's not something that is exactly thought of in the same way as a constant frequency AC sinusoidal wave like house current. 

Greg


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## CliffyJ (Apr 29, 2009)

Thanks Greg. I'm guessing the PSX-AR is aligning the phase of the return loop with whatever leg the train enters on, and at the other side (once the first metal wheels cross the exit gap) aligns / inverts / reverses the phase of the main line...? I still can't quite get my head wrapped around it all, but thanks for the further input. 

I just hope I'm not asking you the same questions ten years from now... if I do, just send me an e-dope-slap and call it a day...  

===>Cliffy


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## Greg Elmassian (Jan 3, 2008)

This is the key: it NEVER reverses the main line, ALWAYS the reversing loop. 

This is the mistake others made in saying that the autoreversers interacted with each other. 

The key to understanding is reversing the power "phase" or "polarity" can be done to a RUNNING loco with no effect on speed or direction. 

Suppose you enter a loop and your entry is ALREADY in phase... crossing into the reversing loop requires no changes, no short is detected on either gap on either rail, and the train runs into the loop. Now exiting the loop, as the short occurs, the LOOP is reversed to match the main line. 

Suppose you enter a loop and your entry is OUT of phase. As soon as you enter the loop and a short is detected, the loop is reversed... now when you exit, your polarity is ALREADY right so nothing happens. 

What is extremely hard for some people to "get" is that the direction of the loco is INDEPENDENT of the "polarity". The loco receives a COMMAND for direction, it does not run in a certain direction because of polarity. The AC from the rails is rectified and turned into DC to operate the decoder... the decoder connects to the motor, so the motor is not a "Slave" to the track polarity. 

Hope this helps. 

Greg


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## CliffyJ (Apr 29, 2009)

That's such a relief! I was vaguely concerned about the following from the PSX-AR lit:

What is Double Reverse Mode?
We have developed and added a great new feature to the PSX-AR Series.
These features were requested by several users!
There are layouts that have back-to-back reverse loops so that the current PSX-AR's tend to flip/flop
each other and the transition from one loop to the next, as would be expected, is jerky or sporadic.

I'd had the impression from the above that the mainline phase was being reversed. And I have three reverse loops. So I was mind-blocking until I had to deal with the issue. 
My loops are separated quite a lot, in a long Y-shape. So if I'm understanding you correctly, it should be no big deal, and the above quote might be referring to loops that are REALLY close together.

The epoxy packs are coming today, got the spool of outdoor #10-2, so I think I'm set for wiring next week.

So cool! And thanks once again, Greg!

====>Cliffy


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## Greg Elmassian (Jan 3, 2008)

First, a "reversing loop" is never referred to as the "mainline". Don't get yourself confused please. (you could put an autoreverser on a main line, but does not make good sense in 99% of the cases) 

The quote is not referring to REALLY close, but TOUCHING....Two adjacent (touching each other) reversing loops or a loop within a loop. 

You do NOT have this situation. 

Everyone seems to be making this more complex than it is. 

Don't worry, it will work fine. You apprehension surely was not helped by other statements by people who were guessing on how things work, but presented their guesses as "facts"... a key "gripe" of mine. 

IMPORTANT NOTE: THE ABOVE STATEMENT DOES NOT REFERENCE ANYONE ON THIS THREAD.... 

Greg


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## CliffyJ (Apr 29, 2009)

Very good, thanks again Greg.


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## CliffyJ (Apr 29, 2009)

Since things have become sort of intertwined with another thread at this point, I've aggregated my delirium there. Here's a link: 
http://www.mylargescale.com/Communi...f/9/aft/128433/afv/topic/afpgj/5/Default.aspx


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