Aristocraft Dash-9 (also SD-45, E-8) Gear-box noise:
As noted on my Garden Railroad page, my new Dash-9 suffered from an apparently 'defective' front motor block as it ran choppy and was noisy.
UPDATE: (7/6/08) - Problem corrected
The U shaped power transfer strips that
route power from the top circuit board to the + and - motor power leads on the
motors can create downward pressure on the power lead side of the motors. This
causes a binding when the motor block is screwed up secure against the truck
frame and above circuit board. I had one motor block that was running choppy and
finally after hours and hours of experimenting I found that if I installed the
motor block in the engine (and took the bottom cover plate off) and used a flat
blade solder tip and melted the solder on the motor lead ends while pushing down
one the motor lead with the soldering iron I found the motors actually moved
down into proper position. (showing they were pushed out of alignment) I
repeated this on all four motor power leads.
Afterwards, the motor block ran perfectly smooth and silent.
What I think is happening at the factory is that the motor blocks are assembled and the motor leads are soldered in place with the block OUTSIDE of the engine (not installed). When they finally go to install the block, if U shaped power transfer strip isn't already perfectly pressed against the top of the block, it will get pushed down as it is pressed against the power transfer circuit board on the above truck frame. When the U transfer strip pushes down, it pushes the motor ends out of alignment and causes them to bind inside the gear boxes.
INSTRUCTIONS ON HOW TO FIX:
First, flip the engine upside down and
only remove the bottom shell casing of the motor block. DO NOT remove the motor
block from the engine. (note, mine in the photos below is out of the engine, but
is still installed in the truck frame and is solid against the circuit board
above which is the key to all this.)
Simply use the soldering iron with this type of tip till you soften the solder on each terminal. Be sure to apply some pressure down on the tab of motor block power lead to push it back into place.
Here is a video to illustrate the before and after results. It shows how
the stress on the end of the motor from the U power strips is negatively
impacting the motor driveline alignment.
Notice the center gear box movement before and after the solder is loosened.
http://www.rayman4449.com/Motorblock_2100kbs.wmv - 27mb
http://www.rayman4449.com/Motorblock_1000kbs.wmv - 13mb
http://www.rayman4449.com/Motorblock_150kbs.wmv - 2mb
Thanks to Bob who originally started the discussion thread and posted several videos to illustrate a severe form of the problem with the blocks installed in and removed from the engine.
(Note the last two show a comparison between a noisy and quiet gear-box.)
The original location for these files is gone so please use these below to access Bob's videos.
Note: For these videos you will likely need to right click on the link and "Save As" the file to your
computer and then play them
Dash 9 gear-box problem video #1 (679 KB)
Dash 9 gear-box problem video #2 (586 KB)
Dash 9 gear-box problem video #3 (340 KB)
Dash 9 gear-box problem video #4 (187 KB)
Dash 9 gear-box problem video #5 (512 KB)
Dash 9 gear-box problem video #6 (278 KB)
Dash 9 gear-box problem video #7 Slow-speed pass-lurching (5 MB)
Dash 9 gear-box problem video #8 Startup and Rev (5 MB)
Dash 9 gear-box problem video #9 Motor Throttle up and down (5 MB)
Dash 9 gear-box problem video #10 Repaired gear-box (553 KB)
Dash 9 gear-box problem video #11 Loud/defective gear-box (5 MB)
Dash 9 gear-box problem video #12 Quiet gear-box (4 MB)
Return to Garden Railroad Modification page.