Re-detailing The Bachmann On30 Climax
Re-Gauging & Replacing the Bell
Bachmann Climax Conversion to Date (September 17, 2010).
Re-Gauging to 3′ Gauge:
The prototype Bachmann chose for this locomotive is Construction No. 952, which was built as a 3′ (not 30″) gauge locomotive. Why Bachmann only offers this locomotive in 30″ gauge is something of a mystery; as the truck side frames and brake shoes are already spaced for 3′ gauge. Luckily for On3 fans of this locomotive, the conversion to 3′ gauge couldn’t be easier (and should take all of 10 minutes). You probably even have all the tools you’ll need already: A small Phillips screwdriver, a pair of tweezers, any decent wheel puller (any of NWSL’s “The Puller”s will do), an On3 wheel gauge, and a good foam cradle to safely hold the locomotive in place, upside-down. The process is fairly obvious, but I’ll run through it here anyway:
- Remove the correct screws. The gearbox/wheel assembly can be removed from the truck side frames, as a unit, independently from the individual axles and gears. You only need to remove the three screws from the cover plate to re-gauge the truck.
- Remove only one axle at a time (yes, you can put the gearbox back together backwards) and re-gauge it using your wheel puller. Move wheel by the insulator at the center of the wheel, not by outside of the wheel (you can easily pull the wheel off of the insulator if you’re not careful). You will end up moving each wheel out 0.050″. Check with your wheel gauge. The NMRA lists On3 back-to-back as 0.666″, P48n3 as 0.673″. The axle should come out roughly flush with the wheel face when you’re done. Note: My wheel castings were very rough and collected dirt VERY quickly. So, I polished the treads and wheel backs and haven’t had a problem (or even had to clean them, for that matter) since. Be sure to wash off any polishing compound thoroughly and re-lube before re-installing the axle.
- Use your pair of tweezers to bend (at the base) the electrical pick-up contacts out to the side frames. This will put the correct tension back onto the wheel backs.
- Replace the re-gauged axle, matching the orientation of the other axle. You’ll have to use your tweezers to flex the contacts out of the way to let the axle drop in.
- Repeat the re-gauging procedure to the other axle.
- Replace the cover plate and screws.
- Repeat the entire procedure for the other truck. Done.
Remove the Cover Plate Screws, not the Gearbox/Wheel Assembly Screws.
Where to Push (and Not).
Bend Pick-Up Wipers Here.
Completed On3 Conversion with axle gears in the correct orientation.
Replacing the Bell:
Original Bachmann Bell.
One of the things I was quick to notice after getting this model is the bell. While the bell is a funky shape and appears to be too big, the real problem is that the steam dome to too far forward on the boiler. With the end result being that it is physically impossible to ring the bell (aka swing the bell without hitting the sand and steam domes or the pop valve). There are, of course, several solutions to this problem:
- Move the steam dome back where it belongs - Not likely. The steam dome is mounted in a cup-like depression cast into the boiler. Filling the hole, moving the lagging band, and fitting a new steam dome in place is way more work than I’m willing to do here.
- Use a sand dome mounted bell - Not really to my taste, and not very common on the prototype.
- Use an air ringer - Easy enough, but couldn’t really find any factory prototype Climaxes that used them.
- Use a smaller bell - That’ll work!
The original bell is about 0.262″ (6.7mm) or about 12 5/8″ (in O scale) in diameter at the lip. The bells in PSC’s catalog start at 7.0mm in diameter at the lip and go up from there, so no help there. Luckily, Grandt Line Products has a beautiful 11 1/2″ diameter bell Cliff Grandt did for their Porter kits. Their part No. 105 - 11 1/2″ DIAMETER LOCO BELL. The bell itself can be found in brass and the yoke and mount are even in black Delrin™, so you don’t have to paint it if you don’t want to.
Grandt Line No. 105 Bell with rough Back Shop casting and available Grandt Line brass turning.
The procedure for replacing the bell is easy and fairly straightforward:
- Cut the bell cord. There’s nothing to save here. The knots at the ends are glued together anyway with cyanoacrylate glue and hole in the cab front in on the wrong side too.
- Remove the old bell. If you’re really lucky, the bell will come off in one piece. If not, don’t worry, just snap off what you can and file what remains off flush with the top of the boiler. Don’t use your best plastic nippers or an X-acto
®knife for this. The bell casting is white metal.
- Drill straight through the center of the old bell mount with a #53 drill. If you got your old bell off in one piece, you’re in luck. Both bells mount in the same size hole, no drilling required. This is best done using a small drill press. I lowered the table on our Cameron drill press down all the way and set the fully assembled locomotive on a short section of display track mounted to a small board. That way any hole I drilled would necessarily end up being perfectly plumb to the rest of the locomotive. I had some trouble getting my #53 drill start straight in the old bell casting, but perseverance and an Opti-VISOR eventually won out.
- Assembling the bell is straightforward, if a little fiddly. Cleaning the flash off of the parts is easier done before de-spruing them. One of the pivot baring bosses will have to be split open with sharp razor blade in order to span the yoke onto the stand or cradle. The mounting flange then just slips onto the mounting shaft of the cradle. However, if you want to do a true Climax bell, you’ll have to modify the yoke. On a true Climax bell, the crank is mounted way out on a long pivot shaft so the bell cord doesn’t rub on the steam dome. I trimmed out the existing pivot pin and then drilled the crank and the yoke for a length of 0.020″ wire, which I then glued in place using cyanoacrylate glue.
- On to the bell itself. You can certainly use the Delrin™ bell, painted brass, if you like. We use bells cast in brass. While you can find Grandt Line No. 105 bells with a brass turning for the bell, we had our Delrin™ bells burned into brass by The Back Shop. We then polish our bells by mounting them on a wooden dowel and using a Q-tip (or any of the many Dremel polishing bits), soaked in a fine polishing compound, mounted in a Dremel Tool. Polish to suit and remember to clear coat it when you’re done to keep it from tarnishing over time.
- Mount your new bell in the #53 hole. For some reason, the Chinese think the Engineer rings the bell on an American locomotive. Obviously this is wrong, the Fireman does. So, make sure the ringer handle on the left side of the locomotive. You may be able to just press-fit the bell casting in place or you may need to use cyanoacrylate adhesive to hold in place. In either case, you may want to wait until you finish painting your locomotive to do so (IF you’re going to paint it).
- Obviously, now that your bell is turned around the right way, you’ll need a new bell cord hole in the cab front. Drill an appropriately sized hole for your bell cord material through the cab front at a location that is the mirror image of the Bachmann hole. You can fill the old hole if you like, but it’s pretty unobtrusive. This is best done with the cab removed and, as such, should probably be done when you have the cab off for other work as the handrails can be a pain.
- Adding the new bell cord should probably wait until you’re completely through modifying and painting your Climax, as nothing good is likely to happen to it while you’re working on it. Especially, if, like me, you’re going to use a fine brass wire for a bell cord. And, yes, if you didn’t modify your bell crank as above, it’s perfectly OK for the bell cord to rub on the steam dome.
Blow-up of prototype bell crank and cradle on Pacific Lumber Climax at Roots of Motive power, circa 2000.
Rough -> Light Filing -> Polish. You can’t get closer to the look of polished brass than with, well, polished brass!
No small difference!
New bell in place!
Bell with temporary bell cord.
OK, we still have some work to do to the steam dome’s pop valve, but this is still a vast improvement over the stock bell!
Continues on Next Page!
©2010, 2011, Scott Kitts. All rights reserved.