PRR I1sa build thread

[Lemosteam]

Definitely no prisoners Max!

After I added the rear driver block support, I heat welded two cover plates to create a single 5 axle cover. The rear pin that would have gone in the split drawbar pin now goes into a hole in the block.









I wanted to make sure the block would not move so I added a winged spacer between the block and the chassis.  Then I added screws on each wing.  Phosphor bronze washers under the heads will allow me to connect the tender wires to the chassis.



The block now became the drawbar mount by using a 2-56 nylon screw right up through the block and into the gap in the chassis.  The hole is threaded all the way, and then a groove was cut into the block to mate to the thickness of the drawbar after I cut the end off (up to the angle).  I eyeballed the drawbar length, cut out the center and heat welded it back together.





Here is the loco chassis with the shortened drawbar in place, the screw is nylon to avoid shorting the chassis.



Below is the loco chassis and the tender chassis on the test track.

[mmagliaro]

All coming along nicely, John.   I like the use of the wing blocks and screws.  I must say, as the years have trickled by, I have tried more and more to use screws and solder and not so much glue, and it really ends up making
a difference for sturdiness and serviceability.

I would suggest threading a 00-90 into the rear of your extended gear cover plate, just to keep that
thing from being too flippy back there.   Right now, it's only held on by that plastic heat weld and those
are not particularly super-strong.

The drawbar hookup looks good, very clever and neat.   I'm not sure that heat-welded loop will hold up
to the stress of pulling trains, but you'll find out soon enough!  And you can always cobble together a new drawbar from a strip of brass if you really have to.

It's going good, man.   I'm enjoying it.

[Cajonpassfan]

John, very clever, nice going! Yet another way to stretch the Mike. Following with great interest here.
Otto K.

[Iain]

I always cringe a bit when people say they glue any part of the mechanicals of a locomotive.  It makes it hard to work on things later.

[mmagliaro]

I always cringe a bit when people say they glue any part of the mechanicals of a locomotive.  It makes it hard to work on things later.

It depends on what mechanicals.  People cringe at glueing in motors, but I have done it plenty of times.
And honestly?  The amount of times I have ever had a motor fail in an engine is about zero (other than ones that
were doomed to fail upon arrival like the Bachmann 2-6-6-2 motors).  And glue , JB Weld, or otherwise,
comes out surprisingly easy with you slice it with a sharp knife or touch it with a soldering iron.

But yes, I hear what you are saying.  For a lot of parts, screws and solder are better.  It comes down to
the fact that we are often pushing the limits
of what will fit in these engines more than a commercial procuct ever would.  For example,
if I were building my own, and could fit a 12mm diameter motor in there if I glued it, vs a 10mm if I made some sort
of bracket, you better believe I would glue in the 12mm.  I would have a much stronger running engine.  And the glue?
Meh.   It can always be undone if it really has to be.   I'd rather live with that and have a bigger motor.

[peteski]

Like Iain I prefer to have the mechanism which can easily be fully disassembled.  When I do tune-ups I like to fully take the model apart. If things like the motor are glued, that makes this difficult.  Just like I prefer not having wires between the chassis and the shell.  I usually use contacts between bodies and shells. If not feasible I use wires but use a mini-connector in-line to facilitate full disassembly without need for desoldering anything.

[Lemosteam]

Yep, there will be no gluing on this loco.  All my stuff is serviceable unless absolutely necessary.

Max, your concern is duly noted. I am more worried about the drill wander leaving little material at the business end of the drawbar. I am heat welding with a medium touch on these parts, on all four sides.  I can't pull them apart. There is no real load on the driver plate, and it is very rigid under there.  If I do anything it may be to reuse the current pin location for a new drawbar pivot and drawbar.  That will add a third screw. I'm not sure how much im going to like all of that material likely visible under the chassis. Still chewing in it...

Thanks for looking fellas!

[Lemosteam]

So who can ignore the advice of Max Magliaro?  Not I!  So I took to the drawbar again by fashioning a little longer one from brass strip, bent and shaped. I folded, hammered and soldered the ends before drilling for a double thickness and additional strength.



I cut off the cover plate pin, drilled and countersunk for a 2-56 flat head screw and used the former hole for a threaded hole into the block.  I extended the slot in the block under the new hole to allow for the front of the drawbar hole and trimmed off the excess Clovis from the block.



Here is the new drawbar installed in the new clevis location:



And with the tender frame installed:



And a silhouette of the chassis in track: 



I think this will be much better than my last solution...

[chicken45]

You should do one of those LD tenders!

[mmagliaro]

That drawbar is smashing, John!   What a nice job!
Heck, I was just thinking of a plain strip of brass with 2 holes in it and bend.

[Lemosteam]

And so I have success, with one inherent failure.  More on that later.  Installed the siderods, main rod and Laird type slides on the revised mech:


A very short video of the running loco:
https://photos.app.goo.gl/3bdgt8kVfkXAjPZy7

Now for the Epic Fail:
Having been planning these two Hippos for several years, I had forgotten one very important part- crankpins.  I need four more!  Dang, now Kato is out...

Stay tuned...

[Chris333]

I should have some Kato pins if you can't find any.

[Lemosteam]

Thanks Chris!  I may not need them, but if folks can convince me that what I have done below won't work, I may take you up on this, Max has offered a couple too but I really don't want to scavenge anyone's stash!

...Continued from my last post...

I decided there may be a way to make my own crankpins.

Starting with the K & S product below, cut a 3/4" - 1" piece and insert it into a threaded collet pin vise, with 1/8" to 1/4" protruding. 





I own a straight dental pick, ground to a sharp point and flame hardened.  I used the pick to roll flare the tubing slightly by wobbling the pick around and around, to get a start on the head forming.





Next, using a small brass hammer, I lightly hammered the end until I could feel a fine shoulder around the edge of the tube at the top.







The next two steps are to fill the end of the tube with solder and check the tube in the side rod hole to make sure the shoulder is large enough and cut the pin to length.  Make sure there are no burrs on the unflared end.







Here is a comparison between the Kato original and one of mine.



Here is one pin installed in a driver: 



I wanted to make these out of stainless steel or steel, but I can't find any materials locally in this diameter.

Comments?

[mmagliaro]

I think that will work.  As far as the looks go, you should be able to fill it in with some epoxy and just paint it silver (although, you could have just completely filled in the end with solder and filed it smooth and that would probably do it).  And remember,
these will probably end up blackened anyway.

I am still looking around for  plain old steel straight pin with the right size head, that I would chuck in a Dremel or the mill,
and then just turn down the pin shaft to 1mm.   

For those following along:
The shaft diameter needs to be 1.0mm.  The head diameter is 1.4mm

I doubt these really need to be made of stainless.  They just keep the rods from popping off.  There should not be much rubbing friction against them to actually wear them down.  The front driver is propelled by the rods alone, so if you feel antsy, use whatever genuine Kato ones you have on that driver.

I'd love to see how Kato makes these.

[peteski]

I think those pins are forged from a stainless steel rod.  They don't look to be machined.

My thought is that the stainless steel photoetched siderods will eventually wear out the soft brass pin. I woud prefer to use the original steel pins.

As far as them being stainless, I think it is a good practice. regular steel can rust. If that happens inside the hole in the plastic spoke insert the rust will expand and possibly crack the wall surrounding the hole.  I'm probably paranoid, but there is a reason why those are stainless.