Mack 45 ton switcher

[wazzou]

Are you just going to put a floating idler axle in the center?

It looks really, really nice Chris.

[Chris333]

Are you just going to put a floating idler axle in the center?

It looks really, really nice Chris.

No all three will be powered. 4 worms total.

[peteski]

This thing is hot Chris!!

Are you going to also install micro-hydraulics to make it hop like the T-Bird? 

[mmagliaro]

No all three will be powered. 4 worms total.

You just wanted to have more worms in your engine than I have in mine!   

[Chris333]

Adding grab irons was fun. Yeah keep telling yourself that.



There is a missing vertical post that goes in front of the door. Just leaving it off right now while I work on it.

And I will be using 2004 couplers inside a 1015 box. This is not needed, but if I mount the coupler lower it give me more meat to screw into.

Also I gave up on double worm reduction. It would have worked, but when I moved the vertical motor back .040" it made the vertical worm rub right on the center wheel flange. And I wanted to let the center wheel have some side play for sharp curves.  So I'll be able to fit a 40 tooth gear on the lay shaft and a 8 tooth gear on the horizontal motor. That will give me an even 100:1 ratio. I can live with that. 

Still 3 worms though    what do I win?

[Jim Starbuck]

Outstanding work Chris!
I’m impressed how the macro closeup photos just keep revealing how much detail and sophistication has gone into your model so far.  I use closeups to reveal things I need to fix on my stuff.

[Chris333]

Thanks, but it is pretty easy on a computer screen. And yes I can see more in those photos than I could with x10 glasses on in person. I'm happy with it if I can't see it in person 

It was cool finding out that some of those bumps on the hood are little latches that flip over to hold the panels in place. You can see some of those details in this video.

/>
Also something I didn't know until I watched that video. On the end of the cab above the windows there are triangle shaped openings so you can see the whole way through the cab. Must be to get air around the radiators. Mine is open as well.

[u18b]

Wow.    This critter is looking great.

[Ed Kapuscinski]

Chris, you're... Well man, you're on a whole other level.

[mmagliaro]

Well, Chris, since you have 3 worms, but only 100:1 reduction vs 400:1, the judges have ruled this a tie for "engineering insanity"
--
Your model is truly beautiful.  The work on all those grab irons is truly excellent.  Any body who has formed grabs by hand, drilled, and mounted them, knows that making them good enough to fit and look good is one thing.  But getting them precise, with nice even curved elbows, is another thing entirely.  As usual, you are building a terrific model, man, in terms of both engineering and aesthetics.

[Chris333]

The Kato SD40-2 wheels showed up today and I re-did the chassis to fit them. It is in the particle generator right now. And an announcement that may take me out of the running for any prize money    This first chassis is going to be 66.6:1 ratio. 

The reason for the change... With the 8 tooth pinion there isn't enough room between the motor and the worms, they would hit. I can space the motor up higher by using another gear in-between. But first I am going to get this 66.6:1 chassis running and see how it goes. Keep in mind the Bachmann 2-8-0 has a 45:1 ratio and it runs very slow. This should be even slower than that. If not I'll change everything over to 100:1.

To get the 66.6:1 ratio I will be using a 12 tooth pinion to a 40 tooth spur gear. Max says the Kato gears are 20 tooth. All 0.2 mod gears.

[Chris333]

Well all the gear spacing on the first print is correct. Here is what I'm doing.

Yes there is a worm missing     Everything is loose.


The bottom plate is printing now, will have 4 00-90 screws in it.


Snug as a bug in a rug. This motor is from Bachmann and came with the flywheel. The flywheel fits so I'll keep it.

And what you couldn't really see unless I primed the print. There are 2 holes through the frame to insert 1/16" tungsten welding rods. These are just to keep the resin print perfectly straight, and it's 99% tungsten so...

I have to figure out a way to push PB wire down a hole over each wheel to rub the tops, but that is simple compared to everything else so far. The bottom of the frame has a ledge for the side frames to sit against.

[davefoxx]

I can’t even fathom the skill required to design and fabricate a running mechanism.  Heck, you lost me back at the discussion on gear ratios.

Do I understand that you printed that large gear?  Any idea how well it will wear against the metal gear(s)?  Should you have printed the gear in black, or will the sideframes hide it?

DFF

[Chris333]

No I didn't print the gear, ordered it from Poland (I think). The hardest part is trying to accurately measure the tiny gears. After that you just add a .004" gap between them.

You wont see the gear, but I can put some of Max's Maxolube on it.

[Jim Starbuck]

I think you’re going to like that motor. That 7 x 16 is my go-to for all the switcher projects.