2 1/2" scale 4-6-0 build

[djjh87]

The temporary rods were made adjustable and installed on both sides.
The set up was fun to figure out. The front and rear rods were pinned at the pivot then a slip fit stub turned to fit the drive bore then the brass over the stub to hold down the temp rod. Indicate with a coaxial. The drill press vise was used to hold in place in the transition for drilling and boring .
Ever time you reset up or transfer readings you lose accuracy. (Old hands know this but we should try to help the new hands. l learn from this site all the time) the accuracy we are talking about is under a ,001 . The first side so far slid on and rolls 360 degrees but has a very little tightness at one point. My guess is about .0005 which will wear in or maybe I will scrape in. Jim

[Odyknuck]

Interesting concept on making the temp rod adjustable. Hopefully the other side will work without readjustment. How tight did you make the bushings on the driver shafts? I noticed the center drivers are flangeless, was that necessary for tight radius curves?

[djjh87]

I have 2 adjustable rods the second is on the other side while rolling. The bushings clearance I was shooting for .003 to .004 for grease. after the press I lost about .0005 to .0008. The combination of lost accuracy on this side makes me pretty happy. Jim

[djjh87]

I guess I should say I have no cnc or dro in my shop. Maybe some day but until I use the skills I was taught and learned on the way. It had been about 20 years since machining any project until starting this loco. Jim

[Odyknuck]

Well then, just a little rusty. Add oil, good as new lol. You're doing a good job with what you have so no need to be concerned about CNC. I am fortunate that my best friend owns a CNC shop otherwise I would be doing it the same way. I do have a DRO on my Mill that comes in handy.

[RThomp]

Looking good! You'll be on air before you know it.

[djjh87]

Steve I think penetrating oil on this noggin.
Hi RThomp yes looking forward to seeing it run.
The fireman side rear rod was finished and holding my breath and a little wiggle wiggle it slid on
With both complete connecting rod in place the loco rolls with a very very little rub at one point.
This accomplishment is one of those moments that my father would say this separates the men from the boys. Jim

[NP317]

Remember the rods require some space in the bushings to allow each axle to independently move vertically on uneven track, without binding.
"Somewhat loose" is good for free operation.
RussN

[djjh87]

Hi Russ
i think that the rub is light enough to wear in but you may be right and I may have to massage them. Maybe today I will look into this a little more by rolling each axle over a rise and see what happens. After Bush Hogging yesterday then into the shop later to finish the boring of the rod end and subsequent fit I could not see to work any more because of the smile on my face. Jim

[djjh87]

Steve my friend Ed pointed out I failed to answer your question about the blind drivers. Yes for tighter curves. Jim

[Odyknuck]

Thanks Jim, that's what thought.

[djjh87]

Once again Russ was right I need more clearance on the bearings. After I got tired patting myself on the back for hitting the 6 pins I realized the pins are .003 to .004 for grease under nominal size. That's when it hit me I had not reamed to nominal size. Jim