We may be making too much of the gearing. It started as someone's suggestion for why this unit runs fast, but we have not heard from Ed if the GP-9 was also fast on straight DC or only after conversion to DCC. It may be incorrect programing of the decoder, a bad motor or lack of lubrication for all we know at this point.
Pieter Sent from my iPhone On Sep 20, 2010, at 10:41 AM, Bob Werre <[email protected]> wrote: Bill, I also was unaware of the GP's having different gear ratios, but I did know that he offered his Baldwin that way. I guess most of AM's engines could be made that way since his power truck is seemlingly the same. The motor changes over the years has been interesting to watch. I think I have 14 AM engines from the original FP-7's to SD-60's and there must be a half dozen types and sizes of motors. I've found most of the engines run pretty well together, although I seldom run more than three together. The wheel bearing issue also can be fustrating. I replaced many of my driving axles with NWSL replacements. Sometimes they were returned with the incorrect bearings, so I finally just sent in the bearings my self from the old axles. Of course then I found that I needed to add thin washers to make up for the Code 125 AM wheels compared to the #110 replacements. If some of the wheels hadn't been wobbling, it wouldn't have been worth the cost and effort. I recall back in the 80's there was a lawsuit against GM. Seems that they were swaping motors from there various brands ie. putting Oldsmobile motors in Buicks. This normally wasn't a big deal until you tried to find parts, so you ordered a valve cover for a 85 Pontiac but you really needed one for a Chevy! Bob Werre BobWphoto.com Bill Nielsen wrote: This is the first I have heard of different gear ratios for the AM GP9's. Since I purchased three used DC units with Hi-Rail wheelsets a couple of years ago and simply ordered new scale wheelset replacements which dropped right in (once I got wheelsets with the right style of bearings. I didn't know there were different ones from looking at AM's website), I now have more questions about the gears. Wouldn't changing the worm to get a different ratio also require changing the axle gear as well to match the new worm? Now I'll have to closely inspect all my GP9's to see if any of the gears are different. They all seem to run OK, and any speed difference I had thought was due to different types of motors being used by AM. I seem to recall my first Geep had a motor that was a tiny bit wider than the inside of the body shell, which caused the sides to swell out a bit, so I replaced it with a Sagami flat can motor. My FP7 came from AM with a round Sagami motor, which was not used in later production runs. Regards, Bill __ [Non-text portions of this message have been removed] ------------------------------------ Yahoo! Groups Links ------------------------------------ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/S-Scale/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/S-Scale/join (Yahoo! ID required) <*> To change settings via email: [email protected] [email protected] <*> To unsubscribe from this group, send an email to: [email protected] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
