I have had the problem of the gears between the handles and the pots becoming misaligned several times since I purchased the modern ZW. I have the metal brackets mounting the potentiometers. I have tried two methods of aligning the gears. They are:
Method #1: Set handles at the ‘OFF’ position and turn all four pots until they stop at the full off position.
Method #2: Set handles at the ‘20’ position and turn all four pots until they stop at the full on position.
In all cases, I re-calibrate the ZW using the programming switch.
My problem is that the voltage on all four handles remains essentially off (<0.5 VAC) until I get between 10 and 12 on the ZW scale. That leaves a huge dead-band from ‘OFF’ to 10 VAC and reduces the effective range of the handles and therefore, makes conventional handling a little more difficult.
I have two questions:
Which method of aligning the gears should I use or is there another method?
Is there some way to make the modern ZW use the entire range of throttle movement?
Earl, I have a Back Shop video about realigning handles on modern ZW’s. Maybe someone will know which one or help out. If no one replies soon, I’ll go through my Back Shop library and see which one.
Chief, Thank you for the reply. The Backshop video is #8. I have the video and watched it. The video shows how to tighten the gears, but doesn’t show how to set the pots or how to get rid of the large dead-band between ‘OFF’ and position 10.
This was posted on one of the train forums within the last year/18 months. I’ve tried searching for it but I’m not coming up with much. The service manual was also posted for the new ZW which included wiring diagrams and exploded photo views of the components. I downloaded these and now I can’t find them either (they probably still have their internal names like 6-02791 instead of ZW repair). If I can find them on the Lionel site again I’ll download and rename to something that can easily be found (Like ZW-something_or_another).
Chuck, Thank you for the reply. I would be interested in seeing the ZW service manual. I suspect the issue may be a software issue in an eprom associated with the calibration procedure. I suspect they tried to make a linear throttle response from 0 VAC at ‘OFF’ to 20 VAC at position 20. They should have made the response linear from 5 VAC when the throttle is moved off the ‘OFF’ stop to 20 VAC at position 20. Pure speculation on my part.
I have checked the potentiometers and they are very linear over their range of operation.
You might want to post this to the Lionel tech support web site. You may be correct in that you have a bad/wrong eprom. I thought the fix I saw posted had to do with mechanical adjustment of the arms to force the pot to work within it’s own “sweet spot”.
Thanks for the reply. I did send an email to Lionel Tech Support, but they apparently did not understand the problem. I sent another email further clarifying the issue.
An email from an Lionel Repairs “Expert” [he monitors this site but does not post here].
“The early modern ZWs had a plate under the handle pivot that was the wrong thickness. Lionel replaced them with the correct ones and the gears engaged properly.”
Here is the reply I received from Lionel regarding the large throttle dead-band covering the first 1/3 of throttle movement:
"Hi,
The marks (the ‘10’ and the like) on the ZW are just for decoration,
they are not an accurate rating of the voltage at any particular handle
position. So it sounds like your unit is working normally -at about 1/3
of the way up in handle position you should be getting 4-5 volts, and
then up from there. There isn’t any way to spread out the range or
remove that dead area unfortunately.
I’m a little disappointed (and confused) by the response you got from the Lionel tech support. The rheostat is supposed to go from 0-18 volts? At 1/3 it reads about 5 (this is pretty close) but from that point on it changed to non linear in a short arc and goes from 10 volts 18 volts? That doesn’t sound right.