Post by NickelPlate on May 19, 2016 17:36:55 GMT -5
I mentioned that I'd improved the electrical pickup for my B&O President Fillmore in a recent LOTW thread, so I wanted to detail them here. The trailing truck fix is a simple improvement that can be done for any Rivarossi Pacific, but the work on the lead truck addresses a problem that applies only to the later red box runs with a Japanese can motor.
There are two problems with the redesigned lead truck. While it's nice that it's now cast of Zamac and provides it's own tracking weight, there is only pickup from ONE wheel. See the little piece of phosphor bronze wire that rubs the back of the rear RH wheel? That's it. The old design picked up power through metal disks on the back of both RH wheels that connected the metal tire and the axle electrically. This newer design reduced current collection on the loco itself to one unpowered wheel and the two RH drivers.
The other problem -- and this is almost worse -- is that there is no spring tension on the truck mounting pivot, so continual contact between the truck, pivot arm, and loco frame isn't ensured. (In fact the whole thing flops around to either side like the tongue of some dead animal when you pick it up, which is extremely annoying.
Some ribs should have been molded into the bottom cover to restrict the arm's lateral movement.)
Ultimately I want to install a wiper for the front RH wheel, but first I just wanted to address the lack of reliable contact. I used a small piece of NWSL flex wire -- which I highly recommend for any situation like this where there's a lot of movement -- from the top of the truck rivet to a NWSL 2mm washer on the other end, which goes under the pivot screw on the loco, bypassing the arm entirely. I didn't have a small electrical lug on hand, so a washer does nicely. You could also make something out of scrap brass.
On to the trailing truck...
There are two problems with the redesigned lead truck. While it's nice that it's now cast of Zamac and provides it's own tracking weight, there is only pickup from ONE wheel. See the little piece of phosphor bronze wire that rubs the back of the rear RH wheel? That's it. The old design picked up power through metal disks on the back of both RH wheels that connected the metal tire and the axle electrically. This newer design reduced current collection on the loco itself to one unpowered wheel and the two RH drivers.
The other problem -- and this is almost worse -- is that there is no spring tension on the truck mounting pivot, so continual contact between the truck, pivot arm, and loco frame isn't ensured. (In fact the whole thing flops around to either side like the tongue of some dead animal when you pick it up, which is extremely annoying.
Some ribs should have been molded into the bottom cover to restrict the arm's lateral movement.) Ultimately I want to install a wiper for the front RH wheel, but first I just wanted to address the lack of reliable contact. I used a small piece of NWSL flex wire -- which I highly recommend for any situation like this where there's a lot of movement -- from the top of the truck rivet to a NWSL 2mm washer on the other end, which goes under the pivot screw on the loco, bypassing the arm entirely. I didn't have a small electrical lug on hand, so a washer does nicely. You could also make something out of scrap brass.
On to the trailing truck...
), and had to reassemble it with Zap. I should have started with a smaller bit, or better still, used a diamond burr to gradually open it up.
On the front truck all I did was hardwire it, the way many do with blue box Athearn.
