Best Of The TP56/TP70 Kitbash thread N scale

[u18b]

Heads up for anyone who wanted to build one of these.

Acquiring the truck is the hard part.

A guy on ebay is parting out his loco.

Selling two trucks.

https://www.ebay.com/itm/SD40-2-Mid-Trucks-Silver-ASSEMBLY-PAIR-KATO-929343-N-SCALE/372141202689?hash=item56a5581d01:g:36UAAOSwBkRaEaia

[u18b]

There were several people building these .... and we haven't heard anything in a while.

Any updates?

Randy?

Thomas?

Others?


I have an update-- just got word that MR accepted my article.
Have no idea when or if they will actually publish.
But I'm thankful.


 

[randgust]

I did a lot of tweaking with mine mechanically and its running well.   I made custom cast weights, painted the body, put on the grabs.

I'm still designing a way to get the shell on and off the brass frame with only one screw, haven't finished that yet.

And, thanks to you, I'm trying to get directional LED headlights in there.   Perfect being the enemy of good though.

For a while there I thought that Gizmoszone had dropped the GH514V3 gearheads, but it was only their web page that was all balled up, and I just got a fresh shipment today from China.

I'm equally astounded that you can still find the Roco E-unit truck on Ebay, although I still think this has got to be harder to do that using the Kato truck, although mine pulls about as much as a regular locomotive.   That Roco truck takes a lot of tuning between the pickups, lateral clearances, and gauge adjustments.   But man, with the gearhead and the cast weights, and the old-style non-slick wheels, holy smokes can it pull, and it has excellent slow speed and pickup.   Almost worth the grief.

When I primed mine I was also astounded just how good the surface is on that Shapeways black acetal plastic.   I'll never take FUD again if I can get this stuff.

Not that I'm skeptical.... but I've seen 'acceptance' and 'publish' vary by several calendar years by Kalmbach.

[u18b]

So @randgust
How many cars does yours pull.   Since I opted for an open cab on mine, I assume yours can pull a lot more than my 8 or 9.

Can you post any pics?

[keeper]

Well, there wasn't any modeling at all lately...

At the end of November my brother suddenly passed away. He went to bed and never woke up again.
As you can imagine, that was a shock to all of us and still is.
He has no family of his own so organising everything is quite a huge task for us as he was not living nearby.

So I'm afraid this little critter has to wait a little more for the maiden run...

Thomas

PS: My offer still stands. If someone of you would like to have one of the printed brass frames, I could order them in one batch and ship them to you.

[Jbub]

Well, there wasn't any modeling at all lately...

At the end of November my brother suddenly passed away. He went to bed and never woke up again.
As you can imagine, that was a shock to all of us and still is.
He has no family of his own so organising everything is quite a huge task for us as he was not living nearby.

So I'm afraid this little critter has to wait a little more for the maiden run...

Thomas

PS: My offer still stands. If someone of you would like to have one of the printed brass frames, I could order them in one batch and ship them to you.

So sorry to hear of your loss

[u18b]

Thomas.  So sorry to hear about your loss.

[randgust]

With cultural references back to Monty Python.... this particular project has just about been cancelled several times. 

'But I'm not dead yet!'.....

This worked its way back to the front of the workbench.  Darn you Ron, I was doing great until I saw those headlights of yours.   Then I just had to have them.   That's made a difficult model much more difficult, but I finally got them in and working and can still get it apart.

So this shows the big honking metal casting I made for the cab, with adaptation for the LED lights, and the modified nose weight that now has a chunk milled out for the dropping resistor.   It all still fits, runs rather well.  I didn't want to finish it until I was satisfied it actually ran right.







I'm doing the jade green one, so the body is primed white.    Painted white you can see just how good that acetal Shapeways surface is.   Head and shoulders beyond FUD.

This is more than a little beat up from the hours and hours that I've spent fiddling with the mechanism.    One of the good breaks though was getting the handrail holes successfully drilled in the brass frame, I anticipated that would be at the cost of several .015 bits and it went rather easily.

Finding a way to secure the body onto the brass frame was another matter.  The piece of square brass on the cab back is drilled and tapped to take a 00-90 screw from under the frame, and the nose has a piece of brass in it that's also drilled and tapped from underneath.

This project has pretty much made the 'never again' threshold, but it's at least worth finishing from the way it runs.    One of the ongoing problems was the gearhead noise, I finally decided there was only so much I could do about that, and that if it ran really smoothly to just live with it.

The other 'heck with it' was trying to build in enough slack to get the weights and headlights off the drive, it turned out to be easier to put two solder joints safely beside the plastic gearhead body and make them 'quick release' with no wire twists so that I could just touch an iron to it and have it off in seconds.  Not exactly recommended, but it works well here.

While I've got the gearhead and universal concept working just fine, the overriding 'glitch' in this approach is the marginal quality of the Roco truck.  Had to take up all the lateral slack on the powered axles (center and cab rear one) so that it didn't 'crab' sideways.  Then hours of tinkering with the lead unpowered wheel to get the pickups and equalization 'just right' so that it rolled, centered, and sprung right, because when it doesn't it stalls rather quickly on an insulated frog switch.   Bottom line is that this would work a heck of a lot better either with the original Roco truck that I can't find (all three axles powered and picking up) or anybody elses truck frame with an offset gear tower to the end and all powered axles.   Doing it with this truck is kinda nuts, but I've made it work. 

[u18b]

I appreciate all the hard work you have put into this.  Thank you for your diligence.

And can't wait to see the painted green version.

Your experience with the mechanism makes me think that the Kato truck is probably the best way to go- even if it lacks the gearhead.

[peteski]

I appreciate all the hard work you have put into this.  Thank you for your diligence.

And can't wait to see the painted green version.

Your experience with the mechanism makes me think that the Kato truck is probably the best way to go- even if it lacks the gearhead.

From what I  saw in this thread, I agree.  Also remember to cover the gear openings in the bottom plate with a strip of making tape. Even small pieces of debris (or packed dust of fuzz) can jam the gears. Piece of tape is a super-easy mod which seals the gear case minimizing the chances of contamination.

[randgust]

I don't know if this ever got posted.... but after looking at it two things immediately come to mind.

1)  No sense with a sound chip, you can't hear it run!  Truck engine charging batteries at what sounds like constant RPM.
2)  All the work for a gearhead seems appropriate when it's not moving much over 5mph.

/>
And I'm sorry, this is just evil on this forum, but I'll say it anyway.

Notice how much the air hoses look just like MT trip pins?

[mmagliaro]

From what I  saw in this thread, I agree.  Also remember to cover the gear openings in the bottom plate with a strip of making tape. Even small pieces of debris (or packed dust of fuzz) can jam the gears. Piece of tape is a super-easy mod which seals the gear case minimizing the chances of contamination.

I'm curious about this.  Don't all diesels, in fact, all of our engines, have open gears under the bottom that could pick up fuzz or junk from the track?  Is this truck somehow more sensitive or susceptible to this problem?  Or is this just something you do to all your engines as a precaution?

[peteski]

I'm curious about this.  Don't all diesels, in fact, all of our engines, have open gears under the bottom that could pick up fuzz or junk from the track?  Is this truck somehow more sensitive or susceptible to this problem?  Or is this just something you do to all your engines as a precaution?

Yes, most diesels have open slots for gears and yes, this one is much more sensitive to foreign matter in the gears.

This "advanced" design truck uses gears with a finer pitch than the "regular" N scale models. They run extremely smooth, but are much more sensitive to any debris in the gears.  Just a week ago I dealt with a loco which was not running well at low speed (but didn't exhibit the familiar click when a fine piece of ballast is stuck between teeth).  The gears were definitely binding slightly when I was tuning the wheels by hand (after removing the worm), but I didn't see any debris in the gears.  Only after putting on my Optivisor and running pointy tweezers between the fine teeth of the tiny idler gears I realized that there was fuzz tightly compacted between few teeth. It was black so it visually blended with the gear.  Picking it out made the truck run smoothly again.

While I'm a huge Kato fanboy, and I marvel at their engineering feats, I think they have "jumped the shark" with this design.  It is incredibly smooth if kept impeccably clean, but to me it is too delicate for its purpose. The standard truck design still results in smooth running models, while it is much less susceptible to be affected by the typical debris found on layouts.

These trucks also are designed in a way tha the gears do not protrude below the surface of the bottom cover, so this simple fix of using tape to cover the slots works well. The other design has the gears protruding slightly, so the slots cannot be covered.

[mmagliaro]

Yes, I know the truck you are talking about because that's where I got the axle gear for my 0-6-0.
Finding a module 0.2 axle tube gear that is centered on the axle is not easy.   

And yes, mod 0.2 gears are FUSSY.  They use the same ones in their GG1.

Yes, most diesels have open slots for gears and yes, this one is much more sensitive to foreign matter in the gears.

This "advanced" design truck uses gears with a finer pitch than the "regular" N scale models. They run extremely smooth, but are much more sensitive to any debris in the gears.  Just a week ago I dealt with a loco which was not running well at low speed (but didn't exhibit the familiar click when a fine piece of ballast is stuck between teeth).  The gears were definitely binding slightly when I was tuning the wheels by hand (after removing the worm), but I didn't see any debris in the gears.  Only after putting on my Optivisor and running pointy tweezers between the fine teeth of the tiny idler gears I realized that there was fuzz tightly compacted between few teeth. It was black so it visually blended with the gear.  Picking it out made the truck run smoothly again.

While I'm a huge Kato fanboy, and I marvel at their engineering feats, I think they have "jumped the shark" with this design.  It is incredibly smooth if kept impeccably clean, but to me it is too delicate for its purpose. The standard truck design still results in smooth running models, while it is much less susceptible to be affected by the typical debris found on layouts.

These trucks also are designed in a way tha the gears do not protrude below the surface of the bottom cover, so this simple fix of using tape to cover the slots works well. The other design has the gears protruding slightly, so the slots cannot be covered.

[randgust]

Spent another evening tuning the mechanism and pickups.

The ultimate test on my main layout is an old Atlas C80 #6 crossover with insulated frogs.   BIG dead spot, alternates both sides.   Any locomotive that run that entire crossover in all directions effectively tests all the wheel pickups at once, and isolates one side of one truck for testing.   A short four-wheel can't make it.  I used it to test my 11-105 Climax builds prior to shipping, too.   This TP56 truck is just long enough to bridge it, which is one of the reasons I gave it a go to build.

It makes it without a hiccup maybe 7 of 8 attempts, and dead stops the other.   In pursuit of perfection....hours go by.   But it really runs well, particularly at low speed.  It's so heavy on that one truck that it's audibly loud over the rail joints.  I haven't tested it yet for tractive effort and adhesion.

But I have got it rough-painted, some of the brass handrails on, etc.   It's beginning to look like something.   

I tried Tru-color TCP053 Jade Green on a test and it was just too..green.   Found an old and unopened bottle of Floquil Jade Green and it's dead on, lighter for sure.  Man, I've had that for years....

Ordered the rest of the detail parts off of the list posted here.