PRR D16sb research for a build

[mmagliaro]

Looking really nice, Randy.  I am enjoying this project.
One thing that continues to stand out, and really does even more now that you have the driver flanges turned down, is
how darn good those old Rivarossi wheels were.  Made in the 1960s, they are still really beautiful see-thru drivers with nice delicate spokes. 

[narrowminded]

I take it from the pictures that you were able to get the assembly, gauging, and quartering dialed in.  Did that go smoothly or was it a chore?

[randgust]

The fixture I made to mount the wheels on the axles took me about a week to figure out and make.  It held the driver by the tread and flange while my press pushed the axle in, then a top part held the top driver in quarter and pressed it on square.  It had stops to keep it in gauge.  I used the old Rivarossi driver on the original axle as a test case and to set the gauge tolerances.   Once I got the fixture figured out I had both wheels mounted in about 10 minutes.   I had to adjust the quarter slightly on the rear axle after the dual Bachmann worms engaged, but your tolerances were dead on for a tight fit that still allowed minor tweaking.

It really runs well.   I wouldn't invest this much time in this now if I weren't completely satisfied on performance.   Getting the crosshead, pistons and siderods in with no binding at all was another big step and that went well.   Lots and lots of puzzles remain but the mechanism is pretty darn solid.   One of the biggest surprises to me is wondering how I was going to get the electrical pickup back on the drivers.  Well, the 8x8 Kato caboose trucks under the tender work so well I think I'm not going to bother.   The only wires going to the locomotive will be for the headlight.  I can really load the boiler up with weight and some more on the tender, too.

[narrowminded]

It's always nice to hear that the best laid plans actually worked.  

And per @mmagliaro, those ARE some good looking wheels.

[randgust]

Hey, it's still alive.  And I've got to get more pictures done.

I got the entire back end of the locomotive fabricated out of brass and secured to the frame.  And got an annoying growl out of the mechanism

Have been working on the cab, and concluded that the more weight I could stuff in the cab, the more I could use it as a counterweight to add more weight to the boiler.   It appears intuitive to me that you still have to make an attempt to balance the weight on the drivers, and if you filled up the entire boiler with lead, it would be really nose heavy and be too heavy on the lead driver.

So I cut down the cab, shortened the front wall, modified the roofline, widened out the windows, and started concealing weight in it.   By the time I was done I got the cab itself up to a whopping 7.6 grams.   And, just because I can complicate almost anything, I figured how to drill and tap from under the running boards to make the cab removable with hidden screws.   Not sure why but seemed like a good idea.

I'd shoved a round fishing sinker in the boiler to test with, it wasn't secured and was a temporary.   For a permanent weight, I also wanted to be able to get it out as anything that can go wrong will, and I do want to have an operating headlight on a locomotive where there is no electrical pickup now in the locomotive itself, so I'm running headlight power back to the tender.  So I need to be able to get that out to do that step later.

Couldn't figure that out until I realized that I could use the next size smaller of K&S brass tubing and make an insert out of it by soldering a cap over one end and then pouring Type 160 metal in it in layers until I got the balance I wanted.    Surprisingly, that worked, it' fits snugly but I can still get it right back out.

And now, this thing is HEAVY.   I scaled it out last night at 56.8 grams without the tender, that's a little heavier than a Kato NW2.    If I add more weight it's going to be nose-heavy, so we'll see if this works as well as I think it will.  I only need to pull 2-3 cars with it anyway, the  PRR Oil City-Olean local appears to have usually run with a baggage/RPO and a coach, or an RPO, baggage, and coach.

I'm back at the tender again, and there's a weight challenge there to get reliable electrical pickup, so I'm trying to add as much there as humanly possible to improve electrical pickup.   Got the Dolphin truck sideframes on.  I may live to regret this, but I'm not putting any electrical pickup on the locomotive as during testing, the tender 8x8 is that good and pickup wipers are one more thing to go wrong when I can only get 3 points anyway (one Rivarossi driver has a traction tire, remember).   I can drag around a heavy tender when I have a boiler weighted up as much as I do now.

The D16sb drawings I have show a water scoop and I got one, but did ALL those PRR tenders have one as a standard class feature?    No water pans up this way for sure.

[randgust]

OK, some progress shots.

Now that the locomotive is weighted up, I need to load up the tender as well for the final electrical contact tests.

And that starts a chain reaction that I need to get the tender body made to figure out how much space I have and where it is.

When I did HVRR #5, I used etched brass tender sheets from RLW, which wouldn't seem to work as they are Nn3 parts, but I discovered they work for small steam, were wonderfully done, and were fairly easy to work with.   I'd ordered doubles because I didn't know what I'd have to splice, and now years later those stashed sheets are coming out.   What worked was the dimension of the sides - this is a small tender, and I had to splice in more material to get a 10' wide tender and slightly longer.   That's all soldered up here:



I really like working in all brass when I can.   It's taken me years to get my soldering skills up to par to splice sheets.  And yes, I know I need to add those diagonal rivet lines that show so well, I'll add Archer rivet lines much later. 

Here's how it looks from the top, fitting around the motor and gearhead:



As you can see, there's room in there for lead, on the sides, and I'll hammer it out and add it probably today

And here's what this all looks like from the side.  I was really pleased that 'in the end' the edge of the tender lines up with the bottom edge of the cab window (when you add weight and depress the pickup springs) and the trucks are 'tucked up inside' the frame edges as they should be:



Now, I used black styrene .020 sheet to make the sill edges and drop it over the frame edges there.   Those truck sideframes are Shapeways, filed the Kato truck sideframes off and added them.   

So far, so good.  And you can see how I modified the cab roofline, shortened it in height and length, and filed the windows out.

Hey, you guys got me the drawing source, without that this was just a someday dream.  But this is about a 9 on the 10 scale for difficulty against my skills and tools.

[Lemosteam]

Loving me some PRR “Dolphin” trucks. Are those the ones I have that use Bachman needlepoint contacts?

[randgust]

Nope, those are Kato caboose trucks in a shortened Kato caboose frame, filed off and replaced with the Shapeways printed sideframes.

I also got a PRR slotted pilot and the water scoop for the tender from Shapeways, although I'm not exactly sure that was standard equipment by 1927 on the survivors.

This is the third small tender I've built this way, all of them are just wonderful performers, and the fifth use of the RLW etched tender brass sides.  And, of course, putting a gearhead in the tender goes back to Chris333's first effort on the Atlas 2-6-0.

[Ed Kapuscinski]

Beautiful. I'm loving this!

[mmagliaro]

Excellent proportions and ride height!  This is going to look fantastic, man.

[narrowminded]

... and I'm not seeing the pics.

[peteski]

... and I'm not seeing the pics.

Mark, you are likely running into a known problem about mixed (secure/insecure) Web contents.  Go to the Admin section ( https://www.therailwire.net/forum/index.php?board=11.0 ) and there, towards the top there are 3 threads about not seeing photos while using Chrome (still valid info even if you arent using Chrome).

[narrowminded]

Mark, you are likely running into a known problem about mixed (secure/insecure) Web contents.  Go to the Admin section ( https://www.therailwire.net/forum/index.php?board=11.0 ) and there, towards the top there are 3 threads about not seeing photos while using Chrome (still valid info even if you arent using Chrome).

    It works.  Now, do I need to worry about being "Not secure"?

[peteski]

   It works.  Now, do I need to worry about being "Not secure"?

No, the not-secure contents is just photos. I don't think those could be hacked.

[randgust]

Remember your settings here are only your settings here for this site - not a universal browser setting.    You'd have to have a hacked image posted to Railwire.   

What baffles me is that unlike other websites, if you have a non-secure image posting link, at least you get the empty image box showing so you know there is an image there you can't see.   My signature shows that way here but my other posted images don't, and that's a Railwire-exclusive mystery.

Meanwhile, back at the project, after loading up the tender with lead and reassembling the driveshaft again, I ran it around the layout some more.  The lead dampened a lot of the tender/motor vibration and you can hear it clicking over rail joints.  Mark's (Narrowminded) precision work on the drivers and axles was a real turning point, as the fixed wheelbase on this thing is so short than any irregularity on the drivers is magnified, and it's running flat and smooth.   I've done so many special builds that didn't really perform the way I expected (remember the TP56 critter build on the Roco truck?) that it's just a complete relief that this is running the way I'd hoped it might.

The other 'fun thing' I want to do is pose this beside a borrowed Model Power 4-4-0 for comparison to see just how different it really looks.   I certainly have my suspicions, but it still would be nice to see if this has really been worth the battle.
http://www.spookshow.net/loco/mp440.html

OK, here's nose to nose.   Now, I did a little research, and that MP 4-4-0 is apparently a 2-6-0 boiler on a 4-4-0 chassis and really has no prototype.  There were some pretty big 1920's 4-4-0's (SP had a couple classes) but when you look at the data, the D16 was still heavier than those classes, had more tractive effort, and from a performance standpoint, had no apologies. And the MP is...just...big.    And while the MP 4-4-0 isn't bad, there's no passing it off as a D16 either.