Water pump eccentric fastenening

[Dale Grice]

Hi all,

Looking for other's experience here. I am working on a RR Supply/Warehouse Heavy Mikado. Prints say to silver solder the water pump eccentrics to the axle.

Well - before I finished the axle, I should have seen this. Heating up all that metal concerns me that I may warp the axle. Since it is finished, when the drivers are pressed on the axle, the drivers may would be parallel if the axle warped. In retrospect, the finish cuts on the axle should be taken once the eccentrics are silver soldered on.

Now I have prints for the Little Engines Northern, (new or old - I don't remember). In those prints they use a set screw to fasten the single eccentric to the axle.

What are your experiences/thoughts. I am leaning toward two grub screws 90 degrees apart and making the eccentrics with a collar for the grub screws.

Thanks much,

Dale Grice

[jscarmozza]

Dale, when I purchased this 1" LE Atlantic project the chassis and axles were assembled with no pump eccentric and I didn't want to take it apart to install one so I made the eccentric in 2 pieces and clamped it to the axle. The eccentric hole is slightly undersized with a drop of lock tight for good measure. I haven't put it into service but it appears to be solid, it also took me three tries to get it right. John

[Bill Shields]

why not try it like this?



two eccentrics on a sleeve. double set screw the sleeve to the axle

[10KPete]

why not try it like this?



two eccentrics on a sleeve. double set screw the sleeve to the axle

That gets my vote!!

Pete

[shayloco]

On my Climax I used a woodruff key and a set screw. I don't trust dual set screws.

[NP317]

I also did the same as jscarmozza: Split eccentric clamped to the axle.
It seems to work as intended.
~RN

[PeterCraymer]

On my Allen 10-wheeler, the eccentric is a slip fit on the axle. It has 2 setscrews 90 degrees apart on a collar - loctite of course. That is all. No twisting, rotating etc. I figure if the pump ever offers enough resistance to try to spin that, I have bigger issues!

If I ever get to building my next loco, I will use a twin ram style pump to hopefully counter some of the cogging that comes as a result of the single ram.

Peter