mike g. posted:RTR Thanks! I know about Micro-Mark and almost bought a set when they were on sale not to long ago. But I didn't know if I was buying the right stuff. You know I am still a rookie at this train stuff, I just fumble along and sooner or later I get it right. But I have to be better at what I buy as some of my mistakes cost $$$! LOL
I think the Micro-Mark rollers work OK on 3 rail O gauge, but as GRJ says, only one center pickup is included. I would try GRJ's suggestion about calling JAK and asking for them. I have never seen any of their rollers, but they seem to be pretty well liked with those that do have them.
I got some from what I think used to be Aristo-Craft (G sized trains)? I believe they may have reformed under a new name? Can't remember the name of the rollers or the company? Anyway, they seem to have come and gone since I got my rollers a few years ago. I'll see if I can find the name of the rollers and do some searching around.
As for the rookie stuff, I am still one of those myself! And I also have a few of those 'mistake' items in my collection! Took me a while to get going...and still happens occasionally. Some of these are train items, but many of them are electronics related, errors on PCBs, wrong parts, wrong designs, oopses, occasional smoke releases (always order extra parts!), etc. Those are all filed under the 'educational and training' expenses category. 
