EOB - Train America Studios jerking in Atlas F unit

Make sure there is grease on the worm gear.  Atlas's factory has been known to skip adding the grease.  If it's got low run time it will need break in and should smooth out over time.  With EOB yes, the tach tape if not perfect will cause this also.  Also check the spacing between the tape and sensor.  Others can tell you what the distance should be.  I can't remember it's been so long.

Check the manual for how to adjust the EOB “pre-pulse” and “background pulse” settings. Supposedly one of those can be adjusted to smooth out low speed running. Adjustments involve a set of TMCC commands and are worth trying before opening up anything on the engine. 

RM

Besides the obvious things to look for like lack of lubrication and some mechanical binding, the EOB boards have tuning parameter called a background pulse. Changing the value can smooth out the low speed performance. Look in your manual to see how to change the value.

Ken

superwarp1 posted:

With EOB yes, the tach tape if not perfect will cause this also.  Also check the spacing between the tape and sensor.  Others can tell you what the distance should be.  I can't remember it's been so long.

EOB tach sensor to flywheel distance is specified to be 0.030 inches.  I used to use a piece of 0.030 styrene to check it.  All of my EOB's have been converted to ERR now.

Bob posted:

superwarp1 posted:

With EOB yes, the tach tape if not perfect will cause this also.  Also check the spacing between the tape and sensor.  Others can tell you what the distance should be.  I can't remember it's been so long.

EOB tach sensor to flywheel distance is specified to be 0.030 inches.  I used to use a piece of 0.030 styrene to check it.  All of my EOB's have been converted to ERR now.

I still have three, I won't convert until they fail.  Thanks for the info

As Rich noted:  "Check the manual for how to adjust the EOB “pre-pulse” and “background pulse” settings."

Mike CT posted:

As Rich noted:  "Check the manual for how to adjust the EOB “pre-pulse” and “background pulse” settings."

Check the TMCC section of this forum.  The manuals for EOB are posted in a thread over there.

kanawha posted:

Besides the obvious things to look for like lack of lubrication and some mechanical binding, the EOB boards have tuning parameter called a background pulse. Changing the value can smooth out the low speed performance. Look in your manual to see how to change the value.

Ken

Bob posted:

superwarp1 posted:

With EOB yes, the tach tape if not perfect will cause this also.  Also check the spacing between the tape and sensor.  Others can tell you what the distance should be.  I can't remember it's been so long.

EOB tach sensor to flywheel distance is specified to be 0.030 inches.  I used to use a piece of 0.030 styrene to check it.  All of my EOB's have been converted to ERR now.

Thanks guys, printed the manual John has graciously posted and we will work on them this weekend.

Another failure point I've experienced with two EOB installations is burn-through of wire traces, especially on the bottom side of the motherboard. ERR replacements have been my solution for this issue.

D&H 65 posted:

Another failure point I've experienced with two EOB installations is burn-through of wire traces, especially on the bottom side of the motherboard. ERR replacements have been my solution for this issue.

Those burn traces between the connector and the full wave bridge rectifier is easily repaired and can be prevented my soldering the wires from the ground and the pickup roller directly to that same rectifier.

I think the easiest thing to check first is the reading of the tach tape. You’ll need to remove the shell. With power on, turn the flywheel by hand and watch to see it the red LED blinks at every black stripe. If not then that’s mostly the problem. Either adjust the .030 gap or replace the tach tape.