You think I'd know better - Trix 2-10-0 rebuild

[Bill H]

Apologies for responding on Randy's behalf.

@Bill H, this a RLW/GHQ headlight from the PRR L1s kit. Don't think it is available anymore.

I offer a design that is based off that headlight, only it is hollow and a pre-wired 0402 LED can be fed into pre-printed passages.  A mating PRR stle support bracket can be used to support it:



http://www.keystonedetails.com/products/n-scale-details/2016/9/3/n-scale-prr-head-and-backup-lights-8pk?rq=headlight

http://www.keystonedetails.com/products/n-scale-details/2016/9/3/4-pk-prr-steam-engine-headlight-braket-for-trix-boiler-shell?rq=headlight

Thanks John for the heads up on this, I am sure Randy did not mind your input to my question. That's one of the great things about RW, the collective knowledge and the willingness to share.

[randgust]

Oh, this one is super collaberative via RW.   I've sent John my feedwater heater to examine, and am taking measurements for him as well on the chassis.   I've got his sand dome on mine, and going back one project, my D16 is peppered with his parts.

I've always griped about Shapeways designers that make wonderful parts that don't fit anything, John is one of the few that designs backwards out of the fit to see what works, or if not, what's darn close.

With Marshall gone, and Bruce apparently not willing to sort loose parts with tweezers and identify them, this is our best hope here.

[Zack L-J]

Well, with a coupler on, testing is starting.

Using my home-brew dynamometer car, I'm getting 15g of drawbar pull off an 'original' chassis and 18g off of the new one, I think mostly because of the new lead weight in the front end of the boiler and a little more off the cast cab.

For comparison, im my measurements, that's equal to an Intermountain F-unit for pull, but way below the Kato L1 with the pewter boiler (my recordholder at 34g for a single locomotive)

But that's good, I have no issues with that, might find a little more room for weight but I'll probably only get 1g more of pull at best.  That 5 pole will never overheat, so it's a matter of finding room for cast metal.  I did change the plug wires to the softest Miniatronix stranded wire I have.  I can get another pair of wires in for the headlight, so putting a decoder in this one still looks possible.

I'm a long way from final detail, painting, etc.  Yes, the flanges are turned, and yes, the entire frame will be grimy and neolubed just like my L1. The tender body is just sitting there.  I haven't seen enough difference on the truck sideframes to swap them, I did that on my D16. 

 This is shakedown week for engineering changes, the Altoona test plant.   The dynamics of all these changes can result in some interesting tracking issues under load.  But no more detail, or decoders, or anything else until this design passes train pulling 101.

Sorry if this is too off topic but could you give some more information on this dynamometer car? I’ve always wanted to know which of my locomotives actually pulls the best so I can use it for my caboose train.

[randgust]

I literally took an inexpensive spring scale that's normally used for classrooms, flipped it horizontally, and mounted trucks on it.   It measures in grams.   Then I weigh the equipment in grams with a digital scale.     pull/weight gives you coefficient of traction, and I was astounded how different that came out, based on wheel material, etc.   The pull is not incredibly precise, but good enough; I test it on clean track up to full slip.  I can also put it on the front of a train to measure drag, that's useful because you can actually SEE the results of wheel cleaning, wheel replacement, etc., and also gain an understanding of just how much power you need to drag at train around - I've got a 2.5% grade with a 15" radius horseshoe curve at the top, compensated.  That is where everthing goes wrong on my layout, stalls and stringlines, dragging 30 car trains around it.    I never had much trouble until DCC came out and locomotives suddenly got a lot lighter, now you really had to work at it to get tractive effort.    It shouldn't be that a 1982 Kato GP38 outpulls an Atlas new GP38 by 3:1, but it is.   

It also gets rid of all the speculative BS about powered axles per truck, gear ratios, five pole vs three pole, etc.   Hey pull/weight, can't be much simpler than that.   What was surprising was how much of a penalty is paid for lighter frames, DCC and sound cutouts, and harder wheels that are 'slippery'.  Everybody else has opinion, I have data.

[randgust]

OK, weekend update.

Testing pulling an actual train has done what I thought it would do, proove what I need to work on.   First, at full slip, there's all kinds of gear noise from that drive train.  Between the traction tires, etc, she really cuts loose when it gets to that point.

Second, I made the loco to tender connection just a hair too tight, and it's wedged the leading driver off on a couple diverging turnouts.  That's fixable. 

You can certainly see that it needs all that lateral in the drivers.  Wow, watching that thing slide around the drivers hitting an 11" curve is rather interesting, but it still works.  When it's under load the lateral behaviour is completely different from running light, it tends to crab but deal with it.  I may have to expiriment with putting washers in the rear driver because it's really twisting the entire frame around.

The unspring and narrower wheels on the pilot truck appear to do just fine, so far, only time it's derailed is when the cab has jammed into the tender pusing the whole front end off.

Looking for John's pilot assembly with anticipation here.     I'll continue to beat on this thing, the basic drive is quite solid.

Night 2, got the clearance thing solved, but yeah, she's really crabbing to the right so I've got to play with the lateral on the rear driver set and maybe the front.  Really noticeable.

[Lemosteam]

Received my test prints of the Worthington heater kits today. Before and after cleaning, here they are. I printed them in the new materials, gray, and ultra clear. WAAAAY less wax, and less striation that primer won’t fill.

Don’t worry Randy, cylinder covers and pilot will be done soon.






Both types off the sprue and assembled:



Lying in near position on my long-dormant I1sa conversion:

[mike_lawyer]

John -

How did you built the single cross head valve gear to use on the Kato Mike?  Looks really cool.  Someday I want to build one with the proper cross head guide.

[peteski]

John -

How did you built the single cross head valve gear to use on the Kato Mike?  Looks really cool.  Someday I want to build one with the proper cross head guide.

Maybe John adapted one of the Kato's crossheads.  GS-4?  FEF3?

[Lemosteam]

John -

How did you built the single cross head valve gear to use on the Kato Mike?  Looks really cool.  Someday I want to build one with the proper cross head guide.

This is the ONLY reason I decided to build one.  The parts are from an old Rowa Berkshire that I purchased form Max.

https://www.therailwire.net/forum/index.php?topic=35505.0

https://photos.app.goo.gl/XXsCt3DAzR5vwgCj6

[peteski]

I revisited that thread - it was a fun read.  Can't believe it  was 8 years ago!  Where did the time go?!

[Lemosteam]

@peteski more importantly, why is it still unfinished???  Was I waiting for this feedwater heater?  LOL.

[peteski]

@peteski more importantly, why is it still unfinished???  Was I waiting for this feedwater heater?  LOL.

LOL!  As a master of unfinished projects, I'm not the one to talk.  I have some that are over 20 years!!

[randgust]

OK, well, I found the solution to the crabbing from the excess lateral motion.

I cut two of the MT truck washers (nylon) to slipover "C" shape - exactly the right size for the Trix axles, and slipped them over the lead and trailing axles on the sides that for some unknown reason, it wanted to push against.

It straightened the entire locomotive out, and even after running, proved that it didn't compromise tracking.   And oddly enough, it made it slightly quieter.

OK, full speed ahead.  I think I'm good with this thing operationally.

[randgust]

Here you go, mostly to prove I can actually creep it with that motor.

[mike_lawyer]

Looks really nice!