There's a lot to consider....

View previous topic View next topic Go down

There's a lot to consider....

Post by DaveLathrop57 on Sun May 12, 2013 2:10 pm

110 is fairly well used up in terms of bearings and pins in holes stuff; the major things like axles look good so far. She's been in at least one wreck, so we'll certainly want to completely disassemble her down to the frame and check tram and work back out from there.

We'll know more about exactly what needs to be completely replaced or what needs to be just repaired or tightened up as we work through it, but we do want to think about things like the best way to tram; modern bearing materials and designs; roller bearing conversion for engine trucks; main box lubrication options; suspension and brake rigging standards and margins; valve and running gear tolerances and bearing options; engine truck overhauling options.

DaveLathrop57

Posts : 242
Join date : 2013-04-14
Location : North Carolina, USA

View user profile

Back to top Go down

Re: There's a lot to consider....

Post by Overmod on Sat May 18, 2013 8:31 pm

IDEAL: Build a 'rotisserie' with external balance counterweights, like the thing for restoring antique car chassis on a larger scale. See if we can get loan of modern laser keyhole-welding equipment... and jig up the frame and weld it forever into the effective equivalent of a cast bed. Add new struts, crossmembers, attach points and so forth with the same full-pen welding.

Is current state-of-the-art for alignment via lasers and mirrors? Cheaper than wires and more accurate? Someone like Hugh -- bring me up to speed on modern best practice for this; I put several in the steam_tech files, but IIRC they're all old relative to cost-effective adaptation of modern tech. (One other approach is to do a 'pointcloud' with surveying-style equipment, but this may not have the accuracy required for many of the desired purposes -- somebody check on this.)

Roller bearings on the lead truck would be comparatively simple, and I suspect the manufacturer would donate some of the engineering and special-fabrication cost in return for PR or deductibility.

I would very strongly look into roller bearings for the drivers if that is at all possible. The alternative would be to provide sectional brasses rather than historical crown brass, to give closer to the full torque and thrust handling that are characteristic of RBs on drivers -- think what UP was doing with sleeves on mains and side rods vs. Timken rollers, in Bruce's book, and apply the principle to driver bearings.

I would consider some sort of chemical superfinish for bearings. And perhaps a test of nanodiamond or similar lubricant additive.

Whatever method is used, use Franklin-style self-adjusting wedges and very hard liners, even if the front liners are only sheet.

The only sophistication required in the suspension might be elastomer sleeves or grommets at the equalizer and spring connection points. Hard coating at the equalizer fulcra, just to reduce lube requirements and lengthen effective life.

The BIG thing I'd like to hit is balance. I'd like to build a portable dynamic-balancing stand and fixture, similar to what the English (and some Americans) used for spin balancing. Apply the sort of sensor technology used in current tire-balancing machines to get exact cross-balancing within a few grams, and then be able to spin up the complete engine, with rodwork attached, to get precise final trim balance to the same general margin. I see no practical reason why this would be particularly difficult. (It would also simplify the design and fabrication of the various rods-off bobweights that would be used when the engine is transported dead-in-train at track speed...)

Overmod

Posts : 110
Join date : 2013-05-17
Location : Memphis, Tennessee

View user profile

Back to top Go down

Re: There's a lot to consider....

Post by DaveLathrop57 on Sun May 19, 2013 10:50 am

NHVRR doesn't even have an enginehouse yet, and the tramming plan hasn't been developed beyond the one described in the Kardes book - running parallel steel strips alongside both sides measured against a wire run down the nominal cenrter line of the locomotive.

There's a dream of a 'real" enginehouse made in a timber frame style since one of our most supportive members (who lives next door) owns a sawmill and can make the timber frame. I don;t know when that might happen - so, we're talking unofficially about options. I think we can raise one section of stub end yard track already located to make a shallow pit, pour some concrete around it and stretch a Tyvek temporary buuilding oover it for a way to startb working - alternatively, we could find a building not at the railroad site in which to do the work. The old Edwards Car Company plany in sanford is pretty close by, and there's no shortage of old industrial structures in the Raleigh area.

So, there's no reason not to work on new tramming technology, especially given the preponderance of universities with engineering departments in proximity. Building partnerships withb these institutions - and with the community colleges with machining programs - has been on my radar for a few years now, I'm just not there to develop it msyelf. Perhaps this project will motivate local members to start to pursue them.

Dave

DaveLathrop57

Posts : 242
Join date : 2013-04-14
Location : North Carolina, USA

View user profile

Back to top Go down

Re: There's a lot to consider....

Post by Overmod on Sun May 19, 2013 12:56 pm

I'd research these programs on line, then write letters to all the appropriate department heads. E-mail, and then personal, follow-ups. In all the early stages, distance is not a problem.

One very useful device I see work on engineering students is to have a contest. Publicize THAT (in the media aswell as at schools) -- provide explanations and drawings that 'spread the gospel' -- and figure out meaningful rewards including actual transcript benefits or certificates of participation with 'teeth'.

IMHO the time to prioritize the partnership building is NOW (so that the tree will be fruit-bearing by the time actual fruit growing is needed...)

Overmod

Posts : 110
Join date : 2013-05-17
Location : Memphis, Tennessee

View user profile

Back to top Go down

Re: There's a lot to consider....

Post by Michael Guy on Fri Aug 09, 2013 11:20 am

Having now seen 110 in the 3D I can only agree that a total strip-down of the chassis is essential. While we were poking around, I think Mike noticed that the front right driver features a ring of weld at the axle seat-wheel hub joint so at least one new axle seems needed.

On the subject of axle bearings, why go to the expense on this loco on this railway? Plain bearings will do the job and any savings from reduced friction on a four-mile run at 15mph would seem purely theoretical and unlikely to pay for the change in anybodys lifetime. Ditto on the tender trucks which have a quite distinctive sideframe design. If history is of interest here as I gather it is, a change to roller bearings would seem inappropriate as well as unnecessary. Just my 2 cents opinion.

On the way home on Tuesday we visited the Cass Scenic railway and toured the workshops. I have no idea whether Cass does any contract work but there is a nice big wheel lathe there and an interesting 400 ton horizontal press intended for wheel & axle work.

Michael.

Michael Guy

Posts : 23
Join date : 2013-05-17

View user profile

Back to top Go down

Re: There's a lot to consider....

Post by DaveLathrop57 on Fri Aug 09, 2013 10:23 pm

I don't think there's ever been thought about not stripping down to the frame and tramming everything out from the center line. She has been pretty well used over the decades. I haven't had the fortune to have gotten out to look her over since the cleaning and painting, so it also isn't surprising to see a couple surprises showing up, like the axle. They aren't really that intimidating, I've done axles before, and we have more than one good source for that and the other heavy wheel and box work we will be needing available.

Dave

DaveLathrop57

Posts : 242
Join date : 2013-04-14
Location : North Carolina, USA

View user profile

Back to top Go down

Re: There's a lot to consider....

Post by Sponsored content


Sponsored content


Back to top Go down

View previous topic View next topic Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum