Bachmann Message Board

Discussion Boards => Large => Topic started by: Kevin Strong on June 30, 2010, 03:02:41 AM



Title: After 7 years of faithful service, the gear failed...
Post by: Kevin Strong on June 30, 2010, 03:02:41 AM
TRR #3, the railroad's venerable Bachmann outside-frame 2-8-0, broke its main gear while pulling a short freight into Shade Gap. EBT #3 was dispatched to pull the train to Blacklog, then pulled #3 to the EBT's Rockhill Furnace shops for repair.

The TRR management considered the options available:
1) Buy the replacement plastic gear from Bachmann ($3 plus shipping) (The individual gears are not the main axle drive gear, but the gears within the gearbox. - K)
2) Buy the replacement wheel, axle and gear from Bachmann ($20 plus shipping)
3) Buy a replacement brass gear from NWSL ($12.95 plus shipping)
4) Buy a BBT motor/drive (Price unknown; well worth it, but not in the budget)

The plastic gear was kicked around, as this one lasted 7 years, and one could buy a handful of replacements for the cost of the NWSL gear. The replacement wheel/axle assembly was deemed unnecessary, as switching out a gear is a fairly mundane task for the shop crews. In the end, they opted for the brass gear from NWSL. The plastic replacement gears may last another 7 years, maybe longer, but maybe shorter, too. The brass gear isn't going to break. Due consideration was placed relative to wear and tear on the other gears in the drive, but failures of those gears have thus far proven rare.

NWSL part # 2226-6

Once the TRR receives the replacement, crews will give #3 a proper overhaul, making sure she's good and ready to return to the road in full form.

Later,

K


Title: Re: After 7 years of faithful service, the gear failed...
Post by: grayfitz on June 30, 2010, 08:35:13 AM
Hi Kevin, I hope my 2/8/0 lasts as long,I understand the references to Bachmann& Barrys, But what is NWSL ,We here in AUSTRALIA we dont have the availability of parts as in USA, GRAYFITZ.


Title: Re: After 7 years of faithful service, the gear failed...
Post by: Craig on June 30, 2010, 09:48:25 AM
Hi Kevin, I hope my 2/8/0 lasts as long,I understand the references to Bachmann& Barrys, But what is NWSL ,We here in AUSTRALIA we dont have the availability of parts as in USA, GRAYFITZ.

NorthWest Short Line
http://www.nwsl.com/ (http://www.nwsl.com/)


Title: Re: After 7 years of faithful service, the gear failed...
Post by: Kevin Strong on June 30, 2010, 10:12:14 AM
Note that Nortwest ShortLine recently got bought out, and the new web site is still something of a work in progress. Finding what you want--even with a part number--can be a bit problematic.

This is NWSL's on-line shopping portal. Enter the part number (2226-6) in the search window and proceed from there.
http://shop.osorail.com/ (http://shop.osorail.com/)

Later,

K


Title: Re: After 7 years of faithful service, the gear failed...
Post by: Barry BBT on July 02, 2010, 07:34:53 PM
Kevin,

I have read about the NWSL replacement gear "in Brass".

I voiced my concern to some of my cohorts and was advised that the NWSL gear was not brass, but Delrin.....a far superior choice.

The rule is that the driving gear must be harder than the driven gear.  I follow this axiom and it works for me.

Info: my repair for the 2-8-0 is a complete new gear box and Pittman motor, plus my warranty.  The Price is $200.00

and the customer can install it.

Barry - BBT


Title: Re: After 7 years of faithful service, the gear failed...
Post by: Kevin Strong on July 02, 2010, 08:00:08 PM
According to the e-mail, it shipped out yesterday. I'll let you know what arrives when it gets here. Brass certainly is less prone to breakage, but if the Delrin lasts, I won't argue there, either.

Thanks also for posting the info about your replacement drive. I wish it were in the budget.

Later,

K


Title: Re: After 7 years of faithful service, the gear failed...
Post by: Barry BBT on July 04, 2010, 06:18:33 PM
Kevin,

I guess I should have made the point why the brass final gear is not a good choice, and that is that it will cause the driving gear (plastic) to wear faster than it would normally.  So you are right the brass would last longer, but would put the driving plastic gear in jeopardy.

Barry - BBT


Title: Re: After 7 years of faithful service, the gear failed...
Post by: StanAmes on July 05, 2010, 12:11:18 AM
Barry

I am confused.
 
On my railroad I use several geared drive boxes with a large reduction and a lot of power that I purchase from Granger.  I use one to turn my turntable. The final gear is metal and the gear on the motor shaft is metal.  All the other reduction gears are some form of plastic.  These gear boxes are in wide spread commercial use (outside model railroading).

By far the greatest force is between the metal gear and the axle it turns.

What confuses me is why would a commercial company who is in the business of making such gear boxes make this selection if it is an inferior design.

I have no expertise in this area so just trying to enhance my knowledge base.

Stan Ames


Title: Re: After 7 years of faithful service, the gear failed...
Post by: Kevin Strong on July 05, 2010, 02:31:52 AM
I'm usually of the "lubricate the daylights out of it" school of thought when it comes to gears, so given that and how little our locomotives are actually run in the grand scheme of things, I'm not sure wear (especially on spur gears as these) is quite as worrisome as it may appear in theory. Given that the stock gear broke with all the teeth looking brand new, I think I'd have to run them a lot more than I do to get any kind of measurable wear.

Speaking of gears, though, my 4-4-0's main gear decided it was going to start spinning on the axle today. It's not broken, it just started slipping on the axle. It's not turning out to be a banner year for gears on the TRR this year. I've got a 2-6-0 gearbox that gets hot to the touch after around 30 minutes of operation. The gears begin to make noise and the loco slows to a crawl on grades. My first 2-6-0 gearbox did the same thing until I lubed the daylights out of it with lithium grease. (I can't find my can of lithium grease at the moment to do this one.)

Later,

K


Title: Re: After 7 years of faithful service, the gear failed...
Post by: Barry BBT on July 06, 2010, 01:39:18 PM
Kevin,

You should know that the axle gear in the Connie, Spectrum 4-4-0 and Spectrum 2-6-0 are identical.  Which means they will have nearly the same fail rate and can be repaired by you.  The repair has a better chance of survival that the stock gear.
I have posted the repair procedure before, if you would like it again, just ask.

Barry - BBT


Title: Re: After 7 years of faithful service, the gear failed...
Post by: Barry BBT on July 06, 2010, 01:44:04 PM
Stanley,

Confused?  Why would a company not follow the engineering rules?  probably because it is cheaper.  Swap out a metal gear in a low risk section of a drive train and it can work.

I follow the rules because I have a different environment, more constant running.  Units with thousands of hours and no gear failures. 

Barry - BBT


Title: Re: After 7 years of faithful service, the gear failed...
Post by: Kevin Strong on July 06, 2010, 03:52:01 PM
Quote
You should know that the axle gear in the Connie, Spectrum 4-4-0 and Spectrum 2-6-0 are identical.
Interesting (good to know, too.) I wonder why they seem to be more stable on the 2-6-0/4-4-0 than the 2-8-0. At least, you rarely hear of people complaining of cracked gears on the smaller two locos. Could it be that there's just enough of a difference in the axle diameter? (I'm in "thinking out loud" mode, not necessarily looking for answers--unless anyone has them.)

Later,

K


Title: Re: After 7 years of faithful service, the gear failed...
Post by: bob kaplan on July 06, 2010, 05:26:15 PM
Interesting and useful info here....thanks. 
 i have a couple of Connies and it seems as if there will be a point where gears will have to replaced on them.   i have instructions for disassembling the boiler from the chassis...but might someone provide info that will help me remove the drive wheel/gear from the chassis....anything would be appreciated.  i've done a couple of searches (perhaps wrong choice of words???) but i have found nothing useful. i have done very little work on large scale engines...i used to assemble Bower, Model Die Casting, and Mantua HO engine kits long time ago....is this replacement probably something i could do...or would i be better off sending them to Bachmann?
   Thanks for the help!!


Title: Re: After 7 years of faithful service, the gear failed...
Post by: Loco Bill on July 06, 2010, 11:01:31 PM
Maybe we can ask Kevin to photograph his repairs to his connie and post it as a how to item!!

Kevin, if no one asks consider that I am asking,  it would be a fantastic contribution to the forum!!!!


Title: Re: After 7 years of faithful service, the gear failed...
Post by: Barry BBT on July 07, 2010, 12:50:49 AM
Dave Goodson has written the dis assembly instructions and I use them (with his permission) in my instruction set for the BBT Motor and gearbox install.  Which includes the 'how-to' for removing the third axle, journal boxes and bearings.  The instructions include photos to help.

Mr. Kaplan send me an email with your address and I will send what you need.

barrysbigtrains@earthlink.net

623-936-6088

Barry - BBT


Title: Re: After 7 years of faithful service, the gear failed...
Post by: Barry BBT on July 07, 2010, 12:56:59 AM
Kevin,

I think the lower weight of the 4-4-0 and 2-6-0 has a great deal to do with they're lasting better.

The axle diameters have to be the same since I have interchanged them from one to the other.

Maybe some of the problem is we perceive the 2-6-0 and 4-4-0 as being smaller locos (true) and the Connie just seems more robust, stronger and in it's image should be able to pull more so we try.

Barry - BBT

P.S. Just to salivate......I am updating the K-27.


Title: Re: After 7 years of faithful service, the gear failed...
Post by: Kevin Strong on July 07, 2010, 06:54:30 PM
I received the gear from NWSL yesterday. It is indeed Delrin (or some other kind of plastic), not brass. No biggie on my part, so long as it fits snugly on the axle and does what it's supposed to do.

I took the 4-4-0 gearbox apart last night to examine the gear. Firstoff, that's not quite the easy task I was hoping it to be. You've got to remove all four drivers off their axles (which was okay since a few of them had worked a touch loose anyway), then tap out the retainer pin that holds the motor end cap in place. Once you do that, you lift out the motor and gearbox, being careful to not lose any of the suspension parts (springs, journal boxes) to the nearest parallel universe. Hint - when pulling off the eccentrics for the valve gear, grab a clamp to keep everything held together once it's off the axle. You'll need two clamps, one for each set of eccentrics.

Once I opened up the gear box, I found the gear had not split entirely, but had minute fractures around the hub that allowed the gear to slide to where it was not engaging the knurling on the axle all that well anymore. The gear itself was still fully intact. I thoroughly cleaned both the gear and the axle, mixed up a small bit of JB-Weld, smeared it around the axle, and slid the gear back in place. I don't know how long that's going to last, but we'll see. Since the gear itself is not split, it may go back to slipping on the axle, at which point I may replace the gear or just have at the axle to increase the grip of the knurling a bit.

I haven't gotten to the 2-8-0 yet. I will take photos of that process for an upcoming GR Basics column on locomotive repair.

Later,

K


Title: Re: After 7 years of faithful service, the gear failed...
Post by: Loco Bill on July 07, 2010, 11:34:49 PM
Kevin,

Great Idea for the Article!!   Please let us know what issue it will be in!!

Thanks


Title: Re: After 7 years of faithful service, the gear failed...
Post by: Kevin Strong on July 08, 2010, 02:53:28 AM
The 2-8-0 gear replacement went very smoothly. I did manage to send one of the bearing block springs into a parallel universe, but I found a suitable replacement. The NWSL gear is a bit tight going on, so you'll have to tap the axle with a hammer to get it on. Do yourself a favor and use a piece of wood on the end of the axle and hit that, lest you slightly deform the end of the axle and can't get it through the bearing in the bearing block. It's nothing a quick once-over with a file didn't fix, but better to be safe.

I'm also happy to report that the JB-Weld fix on the 4-4-0 gear seems to have done the trick also. Both locos are moving under their own power, with no sign of slippage. Ask me again in a year or two how things are holding up, but for now they look promising.

Oh... look for the article in the December or February issue.

Later,

K


Title: Re: After 7 years of faithful service, the gear failed...
Post by: Doneldon on July 09, 2010, 03:01:22 AM
Kevin-

I've used JB materials on a number of fix-it jobs (not trains) and found it to be a good product.  It should work very well on your loco because there isn't really much pressure against your repair.  I wonder if it couldn't be used for slipping or even broken gears which want to rotate around their axis.  I think it would be worth a try if anybody has such a problem.  BUT, I must point out that this stuff needs a really clean surface to bond properly.  Clean it up and then wipe it with naptha or alcohol.
                                                                                                -- D


Title: Re: After 7 years of faithful service, the gear failed...
Post by: guy tyteca on July 09, 2010, 10:32:10 AM
TRR #3, the railroad's venerable Bachmann outside-frame 2-8-0, broke its main gear while pulling a short freight into Shade Gap. EBT #3 was dispatched to pull the train to Blacklog, then pulled #3 to the EBT's Rockhill Furnace shops for repair.

The TRR management considered the options available:
1) Buy the replacement plastic gear from Bachmann ($3 plus shipping)
2) Buy the replacement wheel, axle and gear from Bachmann ($20 plus shipping)
3) Buy a replacement brass gear from NWSL ($12.95 plus shipping)
4) Buy a BBT motor/drive (Price unknown; well worth it, but not in the budget)

The plastic gear was kicked around, as this one lasted 7 years, and one could buy a handful of replacements for the cost of the NWSL gear. The replacement wheel/axle assembly was deemed unnecessary, as switching out a gear is a fairly mundane task for the shop crews. In the end, they opted for the brass gear from NWSL. The plastic replacement gears may last another 7 years, maybe longer, but maybe shorter, too. The brass gear isn't going to break. Due consideration was placed relative to wear and tear on the other gears in the drive, but failures of those gears have thus far proven rare.

NWSL part # 2226-6

Once the TRR receives the replacement, crews will give #3 a proper overhaul, making sure she's good and ready to return to the road in full form.

Later,

K

I just saw this post a couple of days ago. I do have the same problem with a brand new 2-8-0 Consolidation. I want to draw your attention on the following : the first option quoted = Bachmann plastic gears ($ 3.00) is wrong, since the gears they advertised are those inside the gearbox, not the main gear on the axle !
Since mine is new and less than one year old, I will ask for a free replacement !

Bet Regards from hot (well today) Belgium.

Guy Tyteca


Title: Re: After 7 years of faithful service, the gear failed...
Post by: Kevin Strong on July 09, 2010, 10:38:33 AM
My only concern with using the JB-Weld to fix a broken gear (split in one or more places) would be making sure when the gear is put back together that the spacing on the teeth at the break are still even. (That goes for any kind of glue, really.) If you can do that, and the glue holds, then you're good to go. But depending on the difference between the axle diameter and the bore on gear, that may be easier said than done. You may have to do some work to the bore of the gear to ensure a tight fit at the broken joint, then rely solely on the JB-Weld to hold the gear to the axle. Obviously, if a replacement gear is available, that's the preferred method, but 'tis not always the case.

Later,

K


Title: Re: After 7 years of faithful service, the gear failed...
Post by: Kevin Strong on July 09, 2010, 10:44:51 AM
Quote
...the first option quoted = Bachmann plastic gears ($ 3.00) is wrong, since the gears they advertised are those inside the gearbox, not the main gear on the axle !

Ah, so it is! Good catch. I suppose I would have figured that out once I received it, only to have to wallow in my own stupidity for not looking closely at the photo. :-[ Glad I went with the NWSL option. Thanks for pointing that out...

Later,

K


Title: Re: After 7 years of faithful service, the gear failed...
Post by: Loco Bill on July 09, 2010, 01:39:00 PM
Agree with Donaldson on JB weld.  I also like to rough up the surfaces as well whenever possible.  Especially if a metal part is really slick, or if a plastic part is really shiny!!  it doesn't take much, just a hit with 200 grit paper.    Also recommend the regular JB instead of the 5 minute type, on items like gear trains, as opposed to something fixed like a structure joint where the 5 minure type is fine.    I think it would work well on a slipping gear, provided it didn't get out of round in some way.


Title: Re: After 7 years of faithful service, the gear failed...
Post by: Barry BBT on July 09, 2010, 02:09:59 PM
Kevin, et al,

For the record;  I have repaired (?) a few of the axle gears from a 2-6-0 Spectrum and the 2-8-0 Connie.

After removing the gear from the axle, usually with several cracks around the gear hub.  Clean everything up, old grease, etc.  Trial fit brass tubing for a fit on the gear hub.  Slice a couple of rings of the brass tubing about 1/8" thick.  Mix up a small batch of JB Weld (not the quick stuff).  Apply the JB Weld around the hub of the gear, press in the brass tubing slice,
Turn the gear over and repeat on the second side.  Clean up the JB Weld excess.  Let it cure for 24 hrs.  Re-install, Run.

Barry - BBT



Title: Re: After 7 years of faithful service, the gear failed...
Post by: Doneldon on July 11, 2010, 02:52:14 AM
The JB Weld isn't exactly used as a glue in this application.  It's more of a support to either hold the slipping gear in place, be used on both sides of the gear and through holes in the gear to hold the gear itself together (but not as an adhesive), or both.
                                                                                                                -- D


Title: Re: After 7 years of faithful service, the gear failed...
Post by: Barry BBT on July 12, 2010, 12:14:23 AM
D -

No argument.  I liken what I have been doing is like concrete and rebar.  The JB Weld holds everything in place (concrete) and the brass is for strength (rebar).  What I do know.... it is working.  It is not my best suggestion, but not everyone has the budget for it.

Barry - BBT