I haven’t been on in a while, but recently was given a FT-B unit and it looks like the wheels are to big which causes it to to sit slightly higher then the FT-A unit it trails behind. How do you know what size wheels should be on it? what is the best way to measure and is the there a chart of what measurements equal what wheel size?
Prototype FT’s had 40" wheels. 40" in HO is .459 inches. Are both units the same manufacturer?
–Randy
no the units are not the same manufacturers. the A unit is bachmann and the B unit i believe is Athearn. the wheel sets on the B unit measure .475, so clearly they are to big.
Athearn and North West Short Line (NWSL) both offer 40" wheels. The NWSL wheels are nickelsilver (preferable - better pick up/less dirt on the rails) and Athearn’s are sintered iron. If you buy the NWSL wheel sets, you will be getting “half axles”, you will have to remove the old half axles and replace with the new ones, don’t forget to check the wheel spacing with an NMRA check guage.
You will also have to adjust the coupler heights or change the couplers for overset ones (KayDees).
I bought a MicroMark digital caliper, about $24 IIRC, and it’s a handy tool from time to time. If you have a Harbor Freight nearby, watch their Sunday ad as a near twin is often on super sale at a great price. They have several:
http://www.harborfreight.com/catalogsearch/result?q=digital+caliper
Based on the above measurements, the difference between the two wheels is only .016", meaning it will only lower the engine by .008". Eight thousands of an inch will be hardly noticeable !
You would probably have better luck determining how to either raise one shell or lower the other on the chassis itself.
Mark.
I totally agree with you on this, in the long run i think im gonna look for a matching B unit from bachmann, but for noe working on lowering the shell on the frame or frame on the trucks may be my best option.
as a former metal worker for the Army, i have a vast aray of tools at my disposal. one of the first tools i made to sure to buy myself was calipers. have been thru a couple of pairs in my time…but my latest is actually from Harbor freight. a good little 6" digital caliper.
You assuming the A unit is stiiting at the correct height? For reference, I would compare it to a Stewart Hobbies F unit…or Intermountain. …or Rapido…or Athearn Genesis. If you are looking for consistency, by all means…get another Bachmann. Keep in mind that there are much, much better and more accurate offerings out there.