12-08-2010, 07:37 PM
Hello.
Introducing a grade seems to have highlighted a slight problem. Slow speed operation seems to create a jerky motion when going down hill. I've noticed that at speed step 1 the jerky motion does not seem to be too bad. However when increased to speed step 2, 3, 4 and 5 it only seems to exaggerate the problem ever so slightly. Especially at 2. I have a theory and I suspect it has something to do with slop or play in the truck gears which causes a load-no-load on the motor. A curious annoyance to say the least and something I honestly did not anticipate. At speed step 1 the loco goes slow enough to help hide the play by allowing gears to catch up or stay meshed together but there is still some excess movement there.
Going uphill it climbs like a champ. No problem there.
Please bear in mind that this is meant to be a slow speed down grade to a transfer slip, so putting the pedal into the fire wall is not an option in terms of operation. All that said, I haven't completely laid the full run of approx. 54 inches of track on the grade so perhaps as the loco gets a bit further into the slope the slop will "disappear". Or perhaps when I start pushing a ten car train on to the float the added weight pulling the loco down the grade will help disguise the problem.
As a refresher the loco is P2K GP 7 with a Tsunami decoder. It also does this with my P2K SW900 as well so its not just the one engine.
Thoughts? Any ideas for improvement other then getting some custom made precision gears for the locomotive's trucks? Has anyone else encountered this before?
Introducing a grade seems to have highlighted a slight problem. Slow speed operation seems to create a jerky motion when going down hill. I've noticed that at speed step 1 the jerky motion does not seem to be too bad. However when increased to speed step 2, 3, 4 and 5 it only seems to exaggerate the problem ever so slightly. Especially at 2. I have a theory and I suspect it has something to do with slop or play in the truck gears which causes a load-no-load on the motor. A curious annoyance to say the least and something I honestly did not anticipate. At speed step 1 the loco goes slow enough to help hide the play by allowing gears to catch up or stay meshed together but there is still some excess movement there.
Going uphill it climbs like a champ. No problem there.
Please bear in mind that this is meant to be a slow speed down grade to a transfer slip, so putting the pedal into the fire wall is not an option in terms of operation. All that said, I haven't completely laid the full run of approx. 54 inches of track on the grade so perhaps as the loco gets a bit further into the slope the slop will "disappear". Or perhaps when I start pushing a ten car train on to the float the added weight pulling the loco down the grade will help disguise the problem.
As a refresher the loco is P2K GP 7 with a Tsunami decoder. It also does this with my P2K SW900 as well so its not just the one engine.
Thoughts? Any ideas for improvement other then getting some custom made precision gears for the locomotive's trucks? Has anyone else encountered this before?