I have had a Hobby Holidays Chassis Jig for a good number of years and I am really pleased with it.
It came with additional components to make it into a rolling road. I do use this but I have never really been happy with it. The rollers are set at 32mm apart to suit Peco track but as with the inherent slop in Peco track I find that the loco being tested tends to hunt from side to side never really giving a true reflection of how it’s actually running. I tried once a few years ago to reduce the distance by adding washers behind the roller bearings but my washers were too wide and all it did was seize up the rollers so I took them back out. When I bought my mill I had the bright idea to mill of 0.5mm from each spacer to reduce the slop but never got around to it until yesterday. I was about to dismantle the roller sets to mill them when I remembered that a former guild member had given me a collection of various nuts, screws and washers so I had a look through them and found some 0.5mm thick washers that were also very thin in terms of the washer area which while acting as a spacer to take off 0.5mm didn’t inhibit the movement of the bearings.
Hopefully this photo will show what I am struggling to describe.
This cured the hunting immediately, so I can’t recommend it enough to anyone else experiencing the same issue.
If you are connecting power directly the the motor the HH rolling road units are fine but if you actually want to test pickups then that’s a bit more interesting because the unit really isn’t designed for it. For years I have used a bit of a lash up of some lengths of copper wire and some crocodile clips to transfer power to each of the wheel cradles.
After doing a recent repair job for a fellow member which required testing pickups I thought it about time I did something a bit better. I found in my stash of “it will come in useful some day” materials a strip of aluminium which when cut into two pieces was perfect to create two bus bars. I milled some slots in them to allow adjustment to cover all my rolling road cradles (mine is a 5 axle jig).
As luck would have it in the front of the rolling road units is a hole to allow you to fit a hex key to get at some cap screws on the rear. These were just the right size to tap M4 while still allowing the hex key passage. There are also a set of holes already tapped M4 on top of the adjusters which will pass the current to the other side.
This is the bus bars in place. All that’s left for me to do is shorten a few cap screws to make them fit better. The end tabs allow me to connect via crocodile clip either DC or DCC
To prove it all works I took a shot video but instead of there being a boring video of a loco on the Rolling Road I played with the video editor to to turn it into a cartoon.