I am just starting to draw up a plan to use Bachman's 0-4-0 Porter, 4-4-0 American, & a Railbus + trailer. I have a Minimum radius Guide for everything, but I was hoping to get my radius down to a 17 or 16-1/2 radius. According to the guide, the Railbus can only use an Absolute Minimum Radius of 18 inches. Has anyone tried to see if this will go down to a 17 inch or lower radius for the Railbus + Trailer? I can work with the 18 inch radius, but I would like to tighten it up just a little bit. I will be testing it out as the track goes down temporarily, but before I get that far, I was wondering if anyone has tried & had any success with the tighter radius. Thank you, Dennis
2-14-'20 Results (Minimum Radius - on Center)
I set up a partial test loop using the Peco On30 (and some Atlas HO) track for the Bachman Rail Bus. Starting at 16 inches on center, then 17 inches, then 18 inches. The units attached together can take a tighter curve than 16 inches, but that is not even considered here.
At 16 inches the bus would not move. I found out that since the diameter of the wheels (not talking about flanges) are large and spaced far apart, the outside wheel flanges would climb the rail. (16-1/2 inch radius, same issue)
With a 17 inch radius, the bus & trailer worked, but it seemed like it was not loose enough on the curve, so I think it was still binding just a bit between rails & flanges.
Of course, the 18 inch on center was just great.
I did find that the bus & trailer together worked well at 17-1/2 inch on a center radius. I'm going to go with the 18-inch radius unless I need to squeeze it down to 17-1/2 inch where I know it will still work.
I was hoping for better results, but it is what it is. My next test is can it climb ANY slight grade to eventually get over itself. This unit does not have a lot of power but can move quickly.
One additional point to mention. This Bus likes, no, MUST have a perfectly level track. An incline seems to be OK at the moment, but it must be level side to side.
I was glad I was able to do these tests as my back required many time-outs over several days. Thanks for following along.
3-13-2020 Update (Climbing Grades)
I finally got around to testing the ability of the 0-4-0, 4-4-0, and the Bus & trailer to climb grades. What a surprise! I did not get any cars out, but I used my hand as drag & all three can really climb a 4% grade with ease. I even started them out in the middle of the grade & hit the power at low, medium, or high and each time they took right off. I suppose if someone wanted too they could go steeper. Even though I hoped to go with a 3% grade, I need a 4% because of the small size of my On30 layout.
So there you go. I'm done with my track planning exercises, so I'm off to start laying track bed & track. Thanks for following along.