Best Of The TP56/TP70 Kitbash thread N scale

[u18b]

Had some time today.
So I started work on the chassis frame.
A lot of work but it had to be done.
I want to have a completed and working mechanism before I start doing any handrails and detail work.

Took the cover off the worm.
Shaved off the guide ridge for pivoting in the Kato chassis (red arrow).  Don't need it here and DO need a flat surface.

Also removed the top plastic.  Also not needed (yellow).




You can see the changes here--- but there is one more thing needed.
I need to get the motor as close as possible and those projections (purple arrow) that support the latches need to go.




Here, you can see they are removed.
You can also see that as the knife progressed, it moved inward where the plastic was thin.
Didn't hurt anything as long as that latch is preserved.




With all obstructions gone, the motor now goes all the way flush with the worm cover.
I then kept everything straight and superglued the motor to the worm cover.
If I ever have to do maintenance, the cover will still come off with the motor.

By the way, this shot shows how perfect this motor is.  It is the exact width of the geartower.



Time for DCC.

I debated and debated where to put that decoder.
To be honest, a TCS Z2 decoder would work well (I think) and is small enough that I could mount it UNDER the motor.   But they cost so very much more that the Digitrax DZ126.

So it seemed the best most secure place for the DZ126  was up on top of the worm cover.
I superglued it in place with the wire pads accessible (insulation and wires were removed).




The wire solder pads are facing the motor.
Once again, for maintenance, I wanted to be able to take this thing apart.
So I installed a 4-pin socket/ microplug from TCS.   I find these things REALLY handy.   I had to spread out the contacts a bit to match the Digitrax pads.  Soldered the plug in place.

I then used TWO 2-pin plugs.
One plug for the motor (orange and gray wires) and one plug for the pick-ups (red and black wires (though I used two black).




To get the loco to run in a traditional fashion, I needed to find which motor pole was the "right" one for the orange wire.
Experimentation showed that the pole that is up when you can read the lettering on the motor will be orange.




As a further check, on the back side, there is a notch which will correspond to orange.
Notch goes up.

BTW- I'm guessing that the tiny hole is for oil since this end is sealed.




Took it for a test spin.
Runs as it should.

Now to the frame.

[peteski]

Time for DCC.

I debated and debated where to put that decoder.
To be honest, a TCS Z2 decoder would work well (I think) and is small enough that I could mount it UNDER the motor.   But they cost so very much more that the Digitrax DZ126.

So it seemed the best most secure place for the DZ126  was up on top of the worm cover.
I superglued it in place with the wire pads accessible (insulation and wires were removed).

Nice write-up Ron.
I also like to let you know that Digitrax came out with a decoder which is very similar in size to TCS Z2: DZ126T ("T" for "tiny").  It is priced similarly to standard DZ126.  It came out probably about 2 years ago. Funny thing is that as far as I know, it came to market without any big announcements from Digitrax. I don't  recall seeing it headlined on their website or advertised in model RR magazines. Not sure why.

From what I recall, I found it by accident while browsing the MBK website.  Since that time I have ordered few of them and they work ok (as expected for Digitrax).  I also think that they chose a rather poor name for it since it is can be easily confused with the standard DZ126.  But then again, Digitrax seems to do many things "differently".

Here is a link to MBK - it will cost you $24 and they currently have 10 in stock.

I try to stay away from the Z2s - they have a firmware bug with speed control which we discussed on this forum. TCS confirmed the problem and stated that newly manufactured decoders will have it fixed, but there is not easy way to identify whether the Z2 you bought is older or newer. 

[JanesCustomTrain]

Perfection !!

Jane

[u18b]

Thanks Jane.

And thanks Pete for the link.

Now for the time consuming part.
Only a few photos.... but a lot of work.

A LOT of thought went into something simple but important--- how does this thing hold together?
Will the shell be loose?
Can I screw it down?
Press-fit?

One thing I was certain..... a frame should be glued directly to that walkway.  This will cause it to flatten out since it is so flexible- especially at the cab.

So thus began a journey of experimentation.
Here is the end result.

I saw that there are a couple of braces in the truck that support the sideframe.  I hoped I could run a screw through there.  The brace toward the back was a tiny bit larger.

Here is a shot with a 00-90 Micro-Trains screw installed.  Did it on both sides.




So I then began to fill in the frame.  I had some sheet brass pretty thick that was same thickness as the tubing.  Tough to work with.
The notches are for the locking tabs on the shell nose.




And after lots of trial and error..... this is what came out at the end.
Of course in hindsight, it would have been better if this was solid brass and I just milled out the inside.




I cleaned up the walkway a bit more-- filing the bottom side flat.
I positioned the frame and superglued it a little at a time to the walkway.
I used a flat surface to press firmly.




The process straightened the walkway at the cab end and straightened the pilot.
Here it is all assembled.  The walkway is screwed to the truck.
The shell will hold on by its locking tabs.



Plenty of room in the nose for weight- though I must leave a path for fiber optics.




The shell sits fairly flat..... but as noted before, turns up at the rear slightly.




You can see that when the walkway is straightened out, the curve at the last 50% of the cab is a bit noticeable.
My plan is to latter add glue blocks in the corners of the cab and run the screws through the frame.  This will pull the cab down.




Time for the fuel tank.
I files the mounting nubs flat.
I then filled the inside with styrene to give it more support.
Plan is to run a screw through it.



This was actually my first mistake in this project.
I should have filled it with lead.
May still do that in the future but I will have to motor tool all that styrene out.



I drilled a hole in the tank as straight as possible.
Marked my hole in the frame.
Then drilled a hole in the frame and tapped it for 00-90 screw.
I then countersunk a pan-head screw.






Now it's starting to look like a locomotive.
Added weight let me take it for a test drive.
More will come later in the weekend.

[keeper]

That looks perfect!
How thick is the brass frame?

Thomas

[u18b]

Thanks Thomas.

I'll have to check when I get home.

The couplers are just a little too low.

So either the frame could be higher or I may try 2004 couplers to get higher.

[peteski]

Ron, you are doing an awesome job.  That thing looks like it is factory-made!  It must e a nice break from your Milwaukee electrics. 

Funny thing: as I was reading your constitution post and I came to the photo of the tank with the piece of styrene next to it (and before even reading the photo's description) I immediately thought "why didn't he use lead or brass to fill it?"  Then I saw your explanation. 

[Ed Kapuscinski]

Whoa.

I seriously cannot believe what I'm seeing here.

This is going to go into RMC, right?

[u18b]

That looks perfect!
How thick is the brass frame?

Thomas

1/16" square brass tubing.
And 1/16" solid brass sheet.

[u18b]

Whoa.

I seriously cannot believe what I'm seeing here.

This is going to go into RMC, right?

Thanks Ed.

I heard they were back in business.
Not sure where I'll send it.
Got a long ways to go.

[JanesCustomTrain]

Is the shell that flexible that you can pull the end of the cab down with two screws (without lifting the nose) or would it be easier if the shell would be two parts ?

Wonderful job !

Jane

[randgust]

Back on the old Atlas forum Verne Niner and I both had Hallmark 4-8-4's that wouldn't negotiate a normal curve of anything less than 19".  We decided to do a joint thread on two drastically different ways to solve the same problem.   I approached the problem by blinding two center drivers the hard way, Verne solved the problem by actually widening the gauge on curved Peco flex.   We had a ball.   

This has turned into just as much fun.    Ron's the one that got me into critters to begin with, with his concept of the Kato 11-105 mechanism into a 44-tonner, wow, maybe 12 years ago???    Now add in David Cutting for coming up with an RP-printed body shell in less time than it takes to debate it.  This is the kind of stuff that really makes a forum worthwhile here.   

Ron, I'm glad to see you take the time for the brass milled frame.   You need that to pull everything flat, and you also need all the weight you can get here.   I think I'm going to make my fuel tank out of a solid lead chunk even at the expense of some detail.

Can you take a shot of the body tipped over in orientation to the frame so it's possible to see how much space is left on either end of the motor and tower in comparison to the body shell?   I went the Roco truck route to have room for the gearhead, but after getting the shell, I'm wondering if there was enough space anyway.

[peteski]

Ron, I'm glad to see you take the time for the brass milled frame.   You need that to pull everything flat, and you also need all the weight you can get here.   I think I'm going to make my fuel tank out of a solid lead chunk even at the expense of some detail.

Milled?  It started as square brass tubing perimeter frame and Ron soldered some pieces of 1/16" brass sheet to fill it in.
Ron, I'm surprised that you just added solid fill to the (hollow) perimeter frame instead of remaking the entire frame as a solid brass piece (to maximize weight).

[metalworkertom]

How about some Tungsten rod inside the tubing ? Great builds By The Way !!

[u18b]

Is the shell that flexible that you can pull the end of the cab down with two screws (without lifting the nose) or would it be easier if the shell would be two parts ?

Wonderful job !

Jane

Yes, the shell will flex.
But I perceive that most of the flex is about at the front edge of the cab.

And yes, the nose stays in place-- I thought of that too.