Best Of The TP56/TP70 Kitbash thread N scale

[u18b]

There is no Fuel tank on that drawing... perhaps it was an early concept before they built any...

The truck also looks like a Flexcoil not a HTC like on the production units...

I noticed that too.

And here's what I believe is the case.

As you suggest.... that drawing has no fuel tank.

And lo and behold, there is one that they made that has no fuel tank.
That one was the prototype-  the test bed.

Here it is.

The photo caption is from when they were just starting it up.




And then made this...
This is the prototype.




And this is the production unit.



Are they the same length?
I don't know.

But the one with the fuel tank is the one I want.

By the way... I discovered from their website that this is a different model number.
This is a TP70.
I'm guessing it is identical to the TP56, but it just has a bigger CAT engine in it.



http://www.pacificwestsystems.com/wp-content/uploads/2016/06/Locomotive-Sales-California.png

[up1950s]

Has anybody thought of using the slowest running steam loco drive line and adapting sideframes , idler gears , axle locations , and diesel wheels to it .
Maybe the 0-8-0 , Max would be brain trust go to guy on that one .
Even a single axle railbus mech that runs slow can have slave driven wheels added .
Or a long a$$ worm that hits all 3 axles , and then no idlers needed between the wheels .

[narrowminded]

Or a long a$$ worm that hits all 3 axles , and then no idlers needed between the wheels .

That's a doable with the design I've been developing for a while now and is even on the list of configurations that would actually be made when the need presents itself.  That end is close.  It can also be measurably smaller, over 100:1 gearing, and for its size, quite heavy.  A LOT of effort, time, and development testing went into getting the project to this point.

[Chris333]

Is there room in the cab for a vertical offset motor?



It would be around 100:1 and with the Kato pick-ups should run like a dream at very low speeds.
old video of mine running:

[u18b]

To me, it doesn't look like it would work that far off-set.   But it would be interesting to try.

When my life settles down in a couple of weeks, I hope I'll have all the parts I need to start tinkering.

With all of the ideas here, a good solution is bound to emerge.

It will be fun to see several solutions actually worked out -- and then we as a group can decide which way might work best.

[up1950s]

The Price Is Right ...........so is the RPMs , size , and volts . The fit and mesh is up to inventive , adaptive , ingenious , clever minds .

https://www.aliexpress.com/item/2PCS-GA12YN20-M3-Great-Screw-Gear-Motor-Micro-Thread-Motor-DIY-Miniature-DC-Motor-With-55mm/32645741369.html?spm=2114.40010208.4.100.M7GC74

[C855B]

... inventive , adaptive , ingenious , clever minds . ...

Apparently the seller is very creative.

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[randgust]

Well, the arrival of the vintage Roco E7 truck confirmed my suspicions.  It may be vintage, but parking that worm over top of the rear axle produces enough room to jam a universal in there and it looks like everything will fit.  Those old Roco universals are a POS, but they can be trimmed and polished to work.  I've put just the horn on one end of the shaft and the cup on the other.  Given the torque of the gearhead, wheel wipers don't bother me a bit. 



Interestingly enough, there's a slight downward force on the wheels due to the wipers, it actually equalizes.

I'm going to design this with the worm under the cab and the motor in the nose, and pack all the lead in the cab end.

The wheelbase is right on and different sideframes will be easy.   If the deep flanges bug you the wheels could be turned, I'm using Peco C55 so not an issue.

[Chris333]

That worm over the end looks ideal.

[dcutting]

I think I have a new solution for y'all. Instead of using a cannibalized Kato truck, we can use brand-new gears from existing tooling. I talked to Jason at Rapido and he said the he can supply the delrin gears from any of his models in bulk. In addition, he's also able to get the worms and wheels for me. This is really great! I'm thinking that the flexicoil truck from the FP9 will be a fine starting point, and then I can rearrange the gears to a flexicoil arrangement by changing the gear case dimensions. I can also move the worm down to the very end of the truck and give us some more room for the motor.

Motor-wise, I'm not so happy about throwing a gizmoszone motor in here because the worms that I am planning for won't fit those shafts. Making them fit will require an adapter. In addition, the 3V rating of the motor is a problem in my mind. I know you can get around it, but I would rather do it right. I really like the NWSL lineup of motors, and now with the ability to move the worm to any place inside the hood I think there's enough space for a motor that is 10mm on the flats, 12mm diameter, and 20mm long. That's without a gearhead, but the NWSL motors are purpose-made custom motors and from my testing they have a very good speed curve.  They use these things on the stanton drives in HO with only a worm. The FP9 also has a compound worm gear, so that should slow things down a bit as well. I can work on making a decoder that will fit in the limited space that we have.

I should add one more thing... the minimum quantities for turned stuff (the worm and wheels) is 1000 parts. I don't think this is an issue though... the wheel figure can be divided by six and the parts are probably cheap enough that having stock of worms wouldn't be a huge deal. Could always use them for other projects, and now that I have a source for gears I can make just about anything. This solution will make it so that the Kato stock of SD40-2 trucks doesn't die every time that they are released.

David

Not sure if anyone saw this post... looks like everyone took the route of taking apart old stuff for parts. I can continue to develop this if anyone thinks that there would be interest, but if you guys don't see any worth in it I will abandon it.

[u18b]

I saw your post.

But I'm in a kind of holding pattern.
I have a Kato HT-C truck and I have two on the B unit chassis coming in the mail.

So in about another week or two, I'll be able to try my hand in what I have in mind.

So I'm not sure which result will work out the best.

I'm going to test what I'm going to do regardless of what anyone else does--- just to do it.

But there are obviously problems- even if it works.

The biggest problem is the lack of truck parts.  Kato will eventually get more-- but how long will that be?

If we could use another readily available truck, that would be great.

Is there any way to test your development without committing to 1,000 parts?

Oh... and by the way.... I think Randy was recommending buying the 3 volt Gizmozone motor with gearhead and then tossing the motor and keeping the gearhead.   I think he says he likes to place these on 12 volt motors.   He just buys the 3 volt package because the price is reasonable.  He views the motor as something of a freebie.

[JanesCustomTrain]

Not sure if anyone saw this post... looks like everyone took the route of taking apart old stuff for parts. I can continue to develop this if anyone thinks that there would be interest, but if you guys don't see any worth in it I will abandon it.

Not sure if you saw it but the picture in your first post still doesn't show.

And yes, I like taking apart old stuff for parts, at least these parts I have in my hands and they are not vapor ware.

Jane 

[Chris333]

Lots of proto info here:
http://www.altoonaworks.info/curry.html

[dcutting]

Understood. I think I will pursue this one with the idea that the extra parts can be re-used later for other critters that don't use the HT-C truck.

David

[randgust]

There really are two different models here with distinct difference in the body.   The TP70 has a longer body, different doors, etc.   

I'm leaning toward the TP70 because there's more room to work with inside the shell, and also that really nice dead-on side shot for scaling.

And I'm still not sure how close the real TP56 is to their drawing.   You do have to remember that there's only two of these things, it's not like they are all over the place, and if/when they build more it probably will have additional changes as well.

Between the capabilities of most trackmobiles, and the lower price of older buy/lease conventional locomotives I the current market, I'm not sure there's much of a market for this new locomotive despite the coolness factor.  So for modelers, it's pretty nifty as a critter concept but I'm not sure you'll ever see much happen on the prototype.