The 2-10-0 project

[mmagliaro]

7 mm  is 0.2756".
By saying "7mm", I'm not sure how exactly you are measuring this, but I just want to point out that
"7mm" is a coarse measurement.  Those slots need to be at *least* within .010" tolerance on the spacing,
maybe more like within .005".   In metric-land, about 0.2mm would be .007", so get it within 0.2mm ?
The driver spacing needs to be very accurate to make this work without quartering jams.

By example, I remember moving a driver on a Kato C55 for my SP&S 4-6-2.  I moved that driver by .015", and definitely had to modify the rods to accomodate that. 

[randgust]

I don't know if this will help or not, but it sure helped on my Jamco 4-6-2 rebuild.

Pull the motor and worm out so that the chassis will roll on its own.   That lets you 'feel' a lot more of the binding, see what's moving under slow motion, etc.

I had a hiccup I just couldn't find and tracked it back to the crosshead guides hanging from wear.   You've got a different situation, but on most steam, taking the motor off and working on the running gear that way will sometimes find situations that running under power just won't disclose.

There's a few situations where pulling the worm is more grief than it's worth in split frame chassis, but if you're stuck...you're stuck.

[mike_lawyer]

Max -

I measured with my digital caliper between the slots, 6.98 mm is really tight with calipers, 7mm is perfect fit.  I am going with 7mm here.

[mmagliaro]

Max -

I measured with my digital caliper between the slots, 6.98 mm is really tight with calipers, 7mm is perfect fit.  I am going with 7mm here.

Okay then, your 7mm is within .02mm and is plenty darn good.

[kiwi_al]

Hey Mike,
Have you finished this yet? 

[mike_lawyer]

I actually have the last siderod being epoxied tonight.  Keeping my fingers crossed that everything will work tomorrow morning!  I will post some pictures of my progress.

[mike_lawyer]

Eureka!  I did it!  The mechanism works perfectly now.  I figured out one of the problems was that I was using a driver from the first run of the Mikado as my fifth driver.  I replaced it with a driver from the second run and it came out great!

Now I am going to prepare a second mechanism using the same technique I used for the first one.  I am going to make two PRR I1s.

Pictures to follow soon!

[mmagliaro]

Eureka!  I did it!  The mechanism works perfectly now.  I figured out one of the problems was that I was using a driver from the first run of the Mikado as my fifth driver.  I replaced it with a driver from the second run and it came out great!

Now I am going to prepare a second mechanism using the same technique I used for the first one.  I am going to make two PRR I1s.

Pictures to follow soon!

Well, I don't understand this, because I thought the only driver difference between the first and second runs was the fix to the electrical path to the rim.  But if it works, hooray!

[mike_lawyer]

Finally, I was able to complete two chassis for the PRR I1 project, and they work really smoothly.  I was able to add the brake shoes to the first one, just need to add the brake shoes to the second one:

[randgust]

Possibly the only remaining weak spot in my limited affection for PRR is doing a proper Decapod, and this great work isn't helping me contain it to a rational level....

[71jeep]

I still have three to finish one day.
I used the valve gear from the Gs4 and it really helped our the looks !
I just could not stand the looks of the stock valve gear.
 Your conversion is really looking good!

Allen Eck...

[mike_lawyer]

I still have three to finish one day.
I used the valve gear from the Gs4 and it really helped our the looks !
I just could not stand the looks of the stock valve gear.
 Your conversion is really looking good!

Allen Eck...

Just out of curiosity, does the GS-4 valve gear work on the Mikado without modification?  Or do you have to shorten or lengthen the valve gear?

[mmagliaro]

Using the GS-4 valve gear is a good idea.  That's the only thing about the one I did that I would change if I were going to mess with it again.  The GS-4 came out about 6 months after I finished mine.  Mike, your chassis is looking really fine.  Great going.

[71jeep]

Just out of curiosity, does the GS-4 valve gear work on the Mikado without modification?  Or do you have to shorten or lengthen the valve gear?

Mike it does take a little modifcation the pistons them selves pop right on but there if center pin that needs to be cut off then I drill and repin the new valve gear.
I went as far as to change out the eccentric as well. The one on the mikado is very anemic compared to the Gs4 . But doing this swap is a bit tricky but is really worth it.

Allen....

[mike_lawyer]

Mike it does take a little modifcation the pistons them selves pop right on but there if center pin that needs to be cut off then I drill and repin the new valve gear.
I went as far as to change out the eccentric as well. The one on the mikado is very anemic compared to the Gs4 . But doing this swap is a bit tricky but is really worth it.

Allen....

I would love to see the visual difference with the new valve gear.  Do you have a picture of it.