Two locos with the same issue...
I recently installed a Digitrax DH142 on a newer BB GP38-2. She runs ok once she gets moving (and ran fine prior to conversion to DCC), but before she gets underway she buzzes until reaching speed step 7, and then takes off. I have done the basic Athearn Tune-up, and hardwired the motor, "erased" the commutator, cleaned the flash, and lubricated the gears.
I know the DH142 isn't a "silent running" decoder ( i have a DH163 i could use, but i don't need all of the FX's) so adjusting CVs isn't an option...the second loco is a newer SD-9 with a DZ123. This decoder is Supersonic (silent running) equipped, but I'm not sure how to go about tweaking the CV's (kick start, etc) to achieve quiet(er) running. I would think that I need to resolve the issue of getting them underway before I can begin to tweak the CVs (on the SD-9 anyway).
So... What has proved successful for you in loosening up the Athearn drive to facilitate smooth operation and/or overcome the buzzing? I've read of people shortening the brush springs, "Goo"ing the magnets to reduce vibration, polishing the commutator (which frightens me), using Pearl Drops to "wear in" the gears, rubber bands or aquarium tubing to take the slop out of the universals, "Conducta lubing" parts...I am plan to upgrade the wheels to NWSL or JB Nickel-Silver and may see if I can locate some Conducta Lube at the Syracuse show. Re-motoring is outside of my meager budget, so it is off the table right now. What has worked for you?
David- Thanks for the suggestions. These will obviously help with getting the locos underway, but will they also reduce the buzzing? Can you recommend any steps I might take with the DZ123 Supersonic equipped decoder? I gather from the Digitrax site that the Supersonic is enabled from the factory, so it puzzles me why the motor buzzes. Is there a way to adjust the pulse rate or otherwise stiffle the bees nest?
Can anyone explain how to go about adjusting the kick start and other pertinent CVs that will allow for smooth start-up? The Digitrax instructions are less than helpful
Thanks
That's it?
After attempting to read the Digitrax instructions I was thinking I would need to call NASA for help...
I am no rocket scientist (probably why i can't decipher the instructions)
Thanks for the info.
IMHO Digitrax instructions are either non-existant or fairly poorly written and confusing. I'd suggest trying TCS decoders in the future, they can do everything a Digitrax decoder does, and their worksheet that comes with the decoders works you through the CVs step by step, explaining what to enter to get a particular result.
BTW I'm not sure re the Digitrax supersonic decoder and the buzzing issue, but I beleive some decoders have features like that that only kick in if CV 2,5 or 6 is a value other than zero (the default value)...so sometimes just changing one of those CV's will 'turn on' the feature.
wjstix...I'd suggest trying TCS decoders in the future, they can do everything a Digitrax decoder does...