Removing B'mann Driver Centers?

Posted By peter bunce on 09/04/2008 11:14 AM
Hi,
IF the centers are like the 4 4 0 & mogul they just 'flick' out,
Try using the back of a knife (so it is the wide and not the sharp side) and see if the can be lifted by pushing it in between the center and the rest of the wheel; it hides the fixing screw.

Part of my problem is that I don't see any good place to put the blade. I'm not sure how the 4-4-0 and mogul drivers are made, but on thise model, the piece I want to remove is the entire driver center, spokes and all. It seems to be the same construction as the Big Hauler and Annie drivers.

I would not remove the wheels though, they may be difficult to get back: fiddle a piece of paper up the back to stop red paint getting onto the chassis and have another go.

I can remove the wheels without difficulty, though they come out as a unit with both wheels and the axle (and the motor & gearing on the rear set). I don't really need to pull the wheels off the axles, just remove the centers for painting.

The cylinders (again from the 4 4 0 etc) undo with a central screw.

Thanks, Peter, but on this one, all I had to start with was a bare chassis, so the cylinders, boiler, and everything else is scratchbuilt by myself. As such, removing the cylinders hasn't given me any trouble. /DesktopModules/NTForums/themes/mls/emoticons/hehe.gif

Posted By Stan Cedarleaf on 09/04/2008 11:19 AM
Ken, it's been a loooooooooooooooong time since I've been into the B'Mann 0-4-0 but if I recall, those axles are split and you pull them apart from the inside.

Stan, do you know if there is any sort of keying or registration to keep the wheels quartered, or do they just slip into the central insulated portion? I probably won't mess with removing the wheels, but it's crossed my mind. Besides, it's always nice to know how to take something apart if I need to.

Also, if I can remember, the front axle is different from the back and it's not too convenient to take the inserts out.

Are the inserts different, or just the wheels & axles?

Also, do you know if the inserts are glued in, or just press fit?

To try to pry them out with a screwdriver or pull them with a pair of needle nose pliers may scar the spokes.
You solution stated in your signature line is probably the best.... " border=0>" border=0>" border=0>


That may be exactly what I'll have to do, Stan. If the insulators on the axles weren't plastic, I might just take a torch to the wheels, and burn the centers out! Guess I can't play with fire on this one.

Posted By cjwalas on 09/04/2008 11:40 AM
BE very careful! The driver centers do come out, but not as easily as the ten-wheeler ones, in my experience. The rear axle on this model is very delicate in the center, where Stan mentions the half axles meet, and if you grasp the axle too hard prying the wheel centers out, you may break the small metal pin in the axle. If you do that, there's no easy repair for it that I know of. Bachmann is no help at all on this issue and you may wind up having to just dump the loco because of it.
Having said that, the centers can be pried out. I usually use a tiny flathead screwdriver and very gently pry the plastic insert out a little at a time, spoke by spoke. Slowly. Really slowly.
Chris




Thanks, Chris! That's the encouragement I needed - someone who's actually done it. Do you think it would be safer to hold the wheels mounted in the chassis, or take them out and hold them by some other means?

OK, for clarification. I removed one of the centers just now to illustrate.



The entire plastic center is removable. Unlike many spoked wheels, the 0-4-0 has cast wheel and half axles. The axles meet in the axle gear in a plastic insulator. One axle has a smaller square peg to register in the gear. This square peg is the dangerous and delicate part. It snaps very easily, be careful!
I don't know if removing the axle makes it any easier or not. I suspect it would make it easier to break the axle register pin. I was right when I said these don't come out as easily as the ten-wheeler ones. These are a tighter fit. The problem area is the rod arm; it's really tight there. What worked for me was to use a small screwdriver from behind the wheel, i.e., from between the wheels underneath the chassis. Position the wheel so that the rod arm section is accessible through the small open area at the back of the wheel. Mine's moved a little here, but you can see what I mean, I think;



GENTLY push the plastic center from behind, working from one side and the other until it moves out a bit. Then, from the outside of the wheel, use the screwdriver to GENTLY pry the counterweight section of plastic loose. Be forewarned that the counterweight section comes loose MUCH easier than the rod arm section.
You should be able to work the whole center loose this way. I'm not sure I would do it just to paint the wheel center myself, as you really should be painting the metal spokes as well as the plastic center spokes, no?
The important thing is that it can be done, if you feel the need to do so. But again, I advise great care as I think I must have snapped three or more of these axles doing bashes...and I was careful!
Good luck and I look forward to seeing the finished loco!
Chris

Posted By cjwalas on 09/04/2008 3:00 PM
OK, for clarification. I removed one of the centers just now to illustrate.
...
You should be able to work the whole center loose this way. I'm not sure I would do it just to paint the wheel center myself, as you really should be painting the metal spokes as well as the plastic center spokes, no?

I plan on painting the entire metal portion of the wheel (except the rim and tread) flat black, to make it hide in the shadows. By painting only the plastic portion, hopefully the spokes will look nice and thin, fitting the dainty lady they're going on.

The important thing is that it can be done, if you feel the need to do so. But again, I advise great care as I think I must have snapped three or more of these axles doing bashes...and I was careful!
Good luck and I look forward to seeing the finished loco!
Chris


I ended up breaking the plastic centers, but thankfully not the axles. I tried not to, but as you mention, they're fragile. And having painted them, the paint had glued them in place. I'm not too upset about that, since I really wanted to slim that huge counterweight down anyway. I may ever cut out a little of the metal behind it's location, and open the spokes up close to the hub. Depends on how much grinding I feel like doing.

Thanks for your help, Chris. It's great to have folks out here with the useful knowledge and willingness to help a new modeller.