hon30critter
If anyone knows how to do it properly, they will.
Thanks for the link, Dave! It took me a little more "surfing" around their site but I came across this introduction that was very helpful. (last 2 pages)
My replacements came today so I'll make another go at it.
Usually I'll order enough supplies to cover any "oops" and to have plenty of stock on hand for future repairs but in this case by having to increase the shaft size to 2mm I was only left with exactly four of the Horned Balls that I needed, of which I broke two
(Other Ed) Quote: Plastic parts pressed on shafts appear to crack too frequently--I'm think of certain axle gears.
Yep, I've changed out about four-dozen Life-Like axle gears
I think there is so much variability in the molding process and the quality of the raw plastic that getting a plastic part to grip a metal shaft with any reliability is a hit or miss proposition. I noticed that the two horned balls that I split cracked in the same place, on the far side of the mold cavity where the plastic has to force around the shaft hole then meet again on the far side. If the mold is slightly cool or the plastic doesn't form a good bond you have an inherent weakness then the hard steel shafy pushes in and stresses the weak part and — pow!
Close examination of the shafting shows that it is ground to finished OD but, to my feel, it is a fairly rough finish. I may polish the ends with a little crocus cloth before attempting another pressing. I'm using a precision drill press as an arbor press and I'm leaving the ball on the sprue so I can control the position and orientation as I bring the shaft into the bore.
Ed, I'll measure the parts to be sure. Some of the NWSL bores are D shaped so a flat has to be made on the shaft but these are bored round.
Thanks for the suggestions, everyone. I'll report back soon, Ed
