MRC Tech II 1500 & Z Scale?

GmanJeff Jan 16, 2018

  1. GmanJeff

    GmanJeff TrainBoard Member

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    I have a pair of MRC Tech II 1500 power packs I used some time ago with N gauge before I put my trains away. I'm thinking of trying Z scale, probably with a AZL loco. Would it be imprudent to use one of the Tech II units with a Z scale loco, if I don't turn the throttle up to achieve unrealistic scale speeds? If it would be better to use a more modern DC power pack and to keep the Tech II units for N gauge, what seems to be the brand and model most people recommend for Z scale?
     
  2. tjdreams

    tjdreams TrainBoard Member

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    I Would NOT try it.
    Using a power pack that is not rated for Z scale will void your warranty and may permanently damage your locomotives.
    If you are going to give Z scale a try give it a try. not 1/2 a try Spend the $30 and buy a power pack like the Rokuhan RC-02 that's rated for Z scale.
     
  3. Point353

    Point353 TrainBoard Member

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    You would want to connect a test meter to the output of the MRC pack to determine at what control knob setting the output reaches 10V - and then never exceed that setting. You might even want to attach some sort of mechanical stop to the pack to prevent the control knob from accidentally being turned up too high.

    Another option for a power pack is this modified MRC unit sold by Micro-Trains:
    https://www.micro-trains.com/index.php?_route_=1300-mrc-power-pack-customized-for-z-scale-99513000
     
  4. sumgai

    sumgai TrainBoard Member

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    Use what you have. DC is DC is DC. A $13 general power pack with a piece of plastic to stop the knob becomes a $50 Z scale power pack. Which is sort of the story for anything branded with the letter Z in traingear. Your locs instructions will tell you how many volts they are comfortable with. A $5 multimeter from Harbor Freight will tell you how many volts that is on a MRC Tech II. Use the most sophisticated controller available, your brain, to tell you when to stop turning the knob. Keep the coloring between the lines; but like any starship captain will tell you, it is good to have warp 11 available if needed.
     
  5. GmanJeff

    GmanJeff TrainBoard Member

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    Thanks, all. I appreciate the responses, which help me clarify my thinking and planning how to prudently test out Z without being penny wise and pound foolish.
     
  6. SJ Z-man

    SJ Z-man TrainBoard Member

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    BTW, Everyone, AZL locos (except for the earlier Ajin releases) are rated for 12 volts.

    GmanJeff: as mentioned, just check for ~12 volt setting. The motors won't amazingly blow up at 12.1 volts but . . . if the loco doesn't run as fast as you think it should, it means the motor is being stressed by the drive mechanism. That means more heat an pushing the voltage up makes much worse.

    WELCOME TO Z !!! You will be amazed at all the locos we have and, if sectional track is OK with you, Rokuhan makes multi-radii curves for just about any layout design, along with many styles of turnouts. For roadbed-less track, we use Atlas, Peco and Micro-Trains flex plus hand laid turnouts or the new Atlas turnouts due in March.

    Jeff
     
    Kez likes this.
  7. GmanJeff

    GmanJeff TrainBoard Member

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    Thanks, Jeff, and everyone else on this thread. I'll acquire an inexpensive multimeter so that I can 1) learn to use it, and then 2) use the Tech II in an informed way, hopefully avoiding disaster! I have been thinking about how best to experiment with Z, and am leaning towards attempting a small and simple DC layout for a single loco, possibly with the new Atlas flex track if it doesn't seem too difficult to work with, and a turnout or two, which will allow me to see if I can get the hang of basic track-laying, wiring, landscaping and terrain-making. I'm looking forward to joining and participating in the community, even if only in a modest way to start with, so the encouragement is very welcome!

    Jeff
     
    Kez likes this.
  8. JimJ

    JimJ Staff Member

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    F45A9D72-E3D0-42FA-8632-045935D6BC2E.jpeg Here’s what I bought. It’s just had some screws put in place to limit the throttle knob. An MRC throttle with a MTL modification. I use it for the Nn3 Searails Powermax motor.
     
    Kurt Moose likes this.
  9. Doug Gosha

    Doug Gosha TrainBoard Member

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    Here's how I would do it:

    Set up the track (if it's not already)

    Put the loco on the track

    Hook up the two wires from the 1500 to the track

    Turn the 1500 on.

    Turn up the throttle until the loco moves but no so much that it goes off the track around curves.

    Doug
     
  10. z.scale.hobo

    z.scale.hobo TrainBoard Member

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    An AZL loco is not geared such that it would ever go off the track around a curve. I get the concept, but it is not a good idea.

    @all What happens to this type of power pack MRC 1500 if you hit some sort of short circuit? I have heard that AZL has had some unknown returns (motor burnout) and warranties were voided due to power pack being used - it was proven to be the type of power pack (non z rated). Best to stick to a z rated unit and tjdreams covered it ... I don't think the sub-$50 investment is too much to get the most basic power pack that is z rated.

    Failure mode circuitry in N, HO power packs are set to much higher thresholds. A failure shutoff point in N is likely to fry your AZL locomotive. Those transient spikes can kill the motor.
     
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  11. SJ Z-man

    SJ Z-man TrainBoard Member

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    It is *not* the voltage transients that kill the motor, its the heat. If you place an oscilloscope on the track, you will quite often see ~100 spikes (microsecond type fast), more common with Permanent Magnet motors like marklin and Micro-Trains F7's. The Coreless motors from AZL and Micro-Trains GP9 & 35 have much lessor voltage spikes. These spikes are caused by magnetic principles of the motor and contacts.

    A stalled motor or poor mechanism (binding, lubrication, etc.) will create heat.

    1) No two locomotives will run the same (or sometimes not similar speed)
    2) No two different model locomotives, from the same manufacturer, will run the same (e.g. MTL F7, GP35 an SD-40 or . . AZL GP7, SD70, Mikado or . . . due to gearing and motor and manufacturer changes. marklin is probably the best at keeping all models (steam versions and diesel version) running at near same speed for applied voltage.

    So, you may have one locomotive that runs quite fast and another model/manufacturer that won't do half of that. But that likely will just be the case. however, it may also be lubrication or mechanism friction. Without another model of the same loco, you may not know.

    For all of the AZL locomotives and Micro-Trains GP9 and GP35's you can learn a bit about these using your new volt-ohm-amp meter. Whether a $5 Harbor Freight or $200 Fluke, they will provide useful information. One the dial, there will be an Ampere (Amp or DCA) setting. Use the highest value to start, like 200ma (milliamps). DO NOT CONNECT *across* the track !!! Disconnect ONE wire from the power pack. Connect one meter lead to the track wire and the other meter lead to the power pack that the track wire came off of. Polarity does not matter on a digital meter, we just want the value.

    *Warning / Caution* Do NOT place the loco on the track, with power pack ON. There are protection fuses in the meter that will blow (ONLY in the Amps. For Voltage, there is no issue with the power pack).

    The AZL and MTL GP9-GP35 will likely show 20-50 ma. Lightly place your finger on the loco and watch the current go UP !

    Do NOT do this test with a marklin or MTL F7. The light bulb and permanent magnet motors draw far more (higher) current, typically >>100 ma, with some >250 ma.
     
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