Thoughts on a mechanism

[johnb]

Are you sure?

I have a book that has the GE build numbers from 1893 to 1955 and there is no mention of any NS locomotives built or purchased second hand.

Jason

they look GE, look nothing like the Baldwins...

[wcfn100]

they look GE, look nothing like the Baldwins...

I doubt they were built by either.

Jason

[Simon D.]

Chassis: Has this link been posted before: http://www.trainweb.org/tomix/chassis_dim.htm ?


Really helpful.  I have found the Kato 11-05 axle spacing is pretty well exactly the same as a 6 ft between axles archbar truck

[randgust]

Ah, but Peteski, removing a regular gear tower and converting it to a truck-pivot?

I did that approach on my Rokuhan Nn3 Climax A kit design, and instantly found that the difficulty was that the vertical 'slop' could be enough that under full load the worm could start hopping off the worm gear.   You had to have enough weight to hold it down, and design some kind of vertical restraint that allowed the truck to pivot but not move very much at all against the worm, vertically. I got it to work consistently, but not easy by any means.    Pivoting on the truck is one thing, removing the gear tower and pivoting on the truck is different.  Really hard to maintain the worm/worm gear tolerance.   That's the same approach as on the Atlas shay, and if you get that baby just a hair out of alignment on the motor you sure know it.   

The fit of the Kato power truck in the frame is good, but the pickup ears and wipers want to push it down vertically and take a lot of tweaking to get perfect.  On my Climax A kits, I load the bejeesus out of the front with the cast boiler, woodpile weights, and cab weights, to push it down.

Because of all that, I've never tried this approach on this drive, but it's certainly worth a shot.   I've got a couple double-shafted Bachmann 44-tonner motors with the worms on the shaft that would be easy to do.  That's a commercial drive that does this out of the box, and their truck/gear tolerances are very good with a conventional split frame.  Works great.   But the vertical movement of the Kato truck in the frame is a lot looser.

I've done enough Kato custom builds on these chassis I've got a shoebox just full of that tan top clip retainer part.

[narrowminded]

I think, not absolutely sure, but I think you will find that the worm in a pivoting rig looks a little strange because they run the thread very wide and at a closer to vertical angle (how they get the width) than a normal 22 pressure angle gear.  This is another example of technically all wrong, not smooth engagements, therefore poor sharing of the individual tooth loads, but with the light loads they see and acceptance of a little noise that may be induced from the less than smooth tooth loading transitions, it works. 

This is from memory and appearance (and actually just occurred to me as I was pondering this discussion), not from any actual measurements as I never tried to modify anything to run this way, but it might be worth investigating if this was to be a conversion that you wanted to do.  I always wrote that worm profile observation off to just sloppy fits and gave it no more thought than that but maybe it has a distinct purpose, sloppy for a reason.   If it holds true maybe try to use a worm with wide teeth spacing from one designed to operate this way.  That and make sure that it's a narrow profile worm gear mating with the worm.

[Iain]

Some of those things look like easy bashes from a caboose.  You even could leave the end platforms.

Box cars, actually.

[johnb]

Box cars, actually.

I am working on a boxcar caboose myself

[peteski]

Ah, but Peteski, removing a regular gear tower and converting it to a truck-pivot?

While from a purely engineering perspective, it is not optimal. But in N scale there are such small forces involved, and relatively stout gears, so yes, I don't see why not. 

[wazzou]

Could they have been Ingersoll?

[sd45elect2000]

Look like McGuire trucks. GE supplied a lot of electrical equipment to many builders as did Westinghouse.