Weaver Diesel Drive Repairs

How about some pictures?  Every one of these that I've seen has used a chain and sprockets to transfer power from the motor to the lower articulated drive shaft.  I've never heard of the gear tower snapping in two.  You can get a replacement gear tower, and probably all of the universals from P&D Hobby.  Northwest Short Line (NWSL) also sells universal joint kits.  For this application, I like the OEM Weaver / P&D universals better, because they're telescoping, and the dogbone shaft won't fall out if the loco enters an abrupt curve or grade.  My $.02.

Get Pat from P&D on the phone, he should have everything you need to repair or even upgrade the drive in your diesel.   Along with most anything else related to 2 rail/3 rail O scale stuff.      Mike. 

sounds like that engine driveline was modified with a NWSL gearbox to replace the chain and sprockets. which is a product they offer. apparently the install did not perform the required clearances for the idler shaft(s). without a photo of existing conditions I cannot be positive.

Pat at P&D should have replacement towers.

I also suggest going to the NWSL website and finding the instructions for that gearbox. or at the very least email them for it.

Ted S posted:

How about some pictures?

Yup, that might help.

When NWSL goes back into operation, they should have the parts to repair the tower drives. As I recall, the Weaver horizontal drive is a single tower with  shaft running from the rear truck to the front under the chassis. P&D Hobbies should also have the parts.

Like Ted I have fiddled with these things for years and that sounds like one of these was fitted incorrectly of course a photo from the thread originator would help. Roo.

Wow Neville!  I forgot that I bought one of those kits back in the day.  Never installed it.  I thought the parts were a little "light duty" for O scale; if it snapped in two it sounds like I was right!  Also, IIRC you had to bugger up your chassis pretty good to make it fit.  I wasn't convinced there would be enough swing for sharp (27" radius) 3-rail curves.  The High Sierra double-reduction gear tower was available at the same time, and IMO that was a MUCH better mod.

Sadly the High Sierra gear tower is no longer available.  But IMO the original poster is better off with an OEM-style gear tower from Pat at P&D.  It's easy enough to change the lower sprocket to a larger one.  8:16 or even 10:16 will approach the 2:1 reduction touted by that monstrosity!

Guys, I talked with Pat at P&D today. According to him, I have a very early drive, which Weaver did manufacture. Apparently it had problems (and now we know what they are...) and Weaver switched to the chain drive tower. I am including a picture of the broken tower. The idler gear shafts are press fit, while the top shaft is held in place with a retaining clip. The tower is identical to the chain drive tower. The difference is, the holes for the idler gears are not used with the chain drive.

Now what is really strange to me, is I bought this engine brand new back in 1994! It's the Magma RS-3 offered by Gadsden Pacific. By this time, all the older gear towers should have been long gone! Does anyone else have a Magma RS-3 and can pop the hood?

Here's the pic.

Chris

LVHR

Chris.

No doubt someone else has seen that geared tower but not me and I have some real early locos from Weaver that only had the one truck drive which I modified by buying the kits from P&D to change to two truck drive so you must have the early, early drive maybe one of the first ever, a collectors item!

Ted,

Remember this ?  You sent it to me years ago. It's just an extract of part of the email, I still have all this info of yours and others. Thanks mate, for providing it your a good bloke. Neville. (Roo)

I would just put the chain drive tower in it if it was my locomotive.  My really heavy All Nation NW2 has twin chain drive towers and is super smooth and quiet.  Quieter than the bevel cut spur gear version I also had for awhile.     Mike

Haha yes!  Thanks Neville!!  It's great that we solve each other's problems!  I wonder what we would be doing if these were all engineered 100% from the factory!?

Time for an update. I had quite a discussion with Pat and decided to replace the gear tower with a chain drive. The fully assembled tower arrived today. The first thing I had to do was disassemble the new parts, as the wheels provided are scale wheels. Also, the drive casting has no provision to attach the 3rd rail pickup. So I disassembled both towers, swapped the necessary pieces, and bolted everything back together. Everything fit, so far... Reassembling the truck though, is “interesting “. I have the spot lower shaft inserted in the brass tube to the other wheel set. But it appears not to seat fully, with about 1/16” of the shaft still showing. This in turn, prevents the wheel set from seating in the holes in the truck. I ‘ve tried twisting, prodding and pushing, but this is as far as it goes. You can see it as the silver band between the brass tube and the white disk of the chain gear. Any ideas?

Chris

LVHR

Hmm, ok.  When you say the point of the axle won't seat in the hole, I presume you mean that you can't shorten the wheelbase enough to make it fit. 

I'm guessing that one or both of the spline shafts (the Ledloy half-shafts with a "D"-profile that protrude from each gearbox) are too long to nestle together fully, and don't allow the axles to get close enough together.

These spline shafts are made of a relatively soft material.  It's easy to take a little length off of the splined portion of one or both, to allow them to nestle within the desired wheelbase.  You can use a Dremel, razor saw, hacksaw, etc.  Measure twice, cut once, and take only as much as you need.  Precision counts!  You don't want it so snug that it's pushing the axles outward as it is now.  But you also don't want it so sloppy that the brass tube binds against the white sprocket while the spline shafts whirl around in an arc like a jump rope, due to too little contact area.

Please let us know if I'm guessing right, and if this solved the problem.  I admit, this drive can be fussy.  But once you get it right, it runs smoothly, offers more possible gear reduction, and potential for scale speeds compared to the toy train vertical motor setup.

I don't get it there are two lengths of brass sleeves how could they be mixed up though? you said the loco was brand new. Then again the tower destroyed itself maybe someone has fiddled with it before you bought it ? Roo.

Success, and I did not have to cut, file, or shape anything! I pulled the tower assembly off the brass tube and laid everything side-by-side. This convinced me I have the right parts and they are the right sizes. I proceeded to try the assembly again, and after a little fuss, everything seated nicely!  I think the brass tube had hung up on an edge, preventing things from going together correctly. Anyway, I'm now finishing the reassembly. Thanks for all your help! This has been a real education.

Now I get to tackle an FA. First thing will be to clean all the rust off the metal parts. I got this one used, and it looks like it had been stored in damp conditions. Joy...

Chris

LVHR

Sure I've read somewhere about replacing one of the gears on the Weaver tower to improve the slow running, but can't recall what the advice is.

Which cog is replaced? Upper or lower, & what with - smaller or larger cog? I appreciate the delrin chain would need adjusting in length to suit.

SundayShunter posted:

Sure I've read somewhere about replacing one of the gears on the Weaver tower to improve the slow running, but can't recall what the advice is.

Which cog is replaced? Upper or lower, & what with - smaller or larger cog? I appreciate the delrin chain would need adjusting in length to suit.

In O Scale Trains No, 38, May/June, 2008

http://oscalemag.com/wordpress/drive-components/

The answer is, "it depends."  The article linked above illustrates replacing the bottom 12-tooth sprocket with an 18-tooth one (which is about the largest that will fit easily.)  However, if the Weaver loco was originally a 3-rail model, it MAY have a 12-tooth upper sprocket.  In which case, IMO, you should replace both.

It also depends on how you want the loco to run.  I find that for a home-sized layout, 45 mph is plenty fast.  So 18:8 x 10:1 = 22.5 to 1.  With a ~10,000 RPM motor and ~40" wheels, this yields a speed range from about 4 to 45 mph.  Good enough for full NMRA points, and fast enough to be convincing on all but the largest layouts.  If you want something faster than that, you might be perfectly happy with the vertical motor "China drive."

Another consideration... I happen to like the Pittman 8000-series, which are high-rpm motors.   If  you're determined to use the wider 9000-series (in a cab unit, for example) you'll need a different ratio.  They are much slower turning!  FWIW.

Ha Ha Ha I'm laughing Ted here we are in a time warp I still use the Weaver locos modified but the majority of locos on my layout now are Atlas SW'S straight out of the box all these endless modifications mate they drive you mad unless you like fiddling with them and do nothing else. I still maintain the locos should have been built like this right from the start the mechanical section should have been built like the Atlas SW's not the other way round.

Anyway it's all in the past I don't care anymore I'm used to modifying almost everything I buy in O scale what with Kadees, Intermountain wheelsets, NWSL scale wheels with good gears, Flywheels, the list goes on forever I am glad Chris sorted his loco out and it's been fun reminiscing about the old days Ted. Thanks Roo.

mwb posted:

SundayShunter posted:

Sure I've read somewhere about replacing one of the gears on the Weaver tower to improve the slow running, but can't recall what the advice is.

Which cog is replaced? Upper or lower, & what with - smaller or larger cog? I appreciate the delrin chain would need adjusting in length to suit.

In O Scale Trains No, 38, May/June, 2008

http://oscalemag.com/wordpress/drive-components/

Ah thanks for that!!

Next question; buying just a few of those sprockets - $1.47 each -  (Sterling acetal resin 18-tooth sprocket (Part #A 6M 7-121806) [www.sdp-si.com] ) is prohibitively expensive to the UK - $10 surcharge on an order below $30, and lowest shipping price about $38-ish.

Soooo.... does anyone happen to have two or three of these exact sprockets that they would sell to  me? I can pay via Paypal. would be very much appreciated!!

PM me if you can help!

I'd like to help you mate but I only have enough for the locos that need putting together I have no spares if it was ten years ago I would order a dozen and send you what you want or bring them over on my next visit, but it's not, it's today. Sorry Roo.

Roo posted:

I'd like to help you mate but I only have enough for the locos that need putting together I have no spares if it was ten years ago I would order a dozen and send you what you want or bring them over on my next visit, but it's not, it's today. Sorry Roo.

No probs Nev mate, it's a long shot anyway I know. To be fair my Weavers run very smoothly with some DCC CV tweaking; this would just be an opportunity to make them crawl even better!!

SundayShunter posted:

Roo posted:

I'd like to help you mate but I only have enough for the locos that need putting together I have no spares if it was ten years ago I would order a dozen and send you what you want or bring them over on my next visit, but it's not, it's today. Sorry Roo.

No probs Nev mate, it's a long shot anyway I know. To be fair my Weavers run very smoothly with some DCC CV tweaking; this would just be an opportunity to make them crawl even better!!

Good news!!! Not a long shot after all..!!  I have found a UK Ebay supplier of all things delrin-chain-drive related, & he does the required sprockets! 

This 18-tooth sprocket (S183 Sprocket 18 tooth 3/16" bore) is £1.85 (about$2.28), but Postage was just £1.00. Much better!!

Here's the link to the Seller; ships more-or-less Worlwide, so might help others outside the Lower 48!!

https://www.ebay.co.uk/usr/gan...rksid=p2047675.l2559

Happy bunny. 

SundayShunter posted:

SundayShunter posted:

Roo posted:

I'd like to help you mate but I only have enough for the locos that need putting together I have no spares if it was ten years ago I would order a dozen and send you what you want or bring them over on my next visit, but it's not, it's today. Sorry Roo.

No probs Nev mate, it's a long shot anyway I know. To be fair my Weavers run very smoothly with some DCC CV tweaking; this would just be an opportunity to make them crawl even better!!

Good news!!! Not a long shot after all..!!  I have found a UK Ebay supplier of all things delrin-chain-drive related, & he does the required sprockets! 

This 18-tooth sprocket (S183 Sprocket 18 tooth 3/16" bore) is £1.85 (about$2.28), but Postage was just £1.00. Much better!!

Here's the link to the Seller; ships more-or-less Worlwide, so might help others outside the Lower 48!!

https://www.ebay.co.uk/usr/gan...rksid=p2047675.l2559

Happy bunny. 

I am not surprised England is full of suppliers of all kinds of items and materials for the modeller. A couple of years ago I wanted some 3mm brass sheet cut to a size to fit the Red Caboose diesels no problem had the material delivered to my sons house in four days! Took it home in my suitcase you have a great country for modellers much better than Australia but we have more blue skies and sunny weather. Ha Ha.  Glad you are sorted out mate. Nev.