[RandomStyuff]

Hi,
I mentor a team here in Israel and we have recently come across how expensive it is for us to order many common parts from the states (shipping and import taxes can double the price on anything we buy.)

A few days ago my team was planning an order for parts to build our first in-house designed drive train (simple WCD), and I came across the thunderhex line of products.

Now, the cost of bearings really add up with the taxes, and seeing as the thunderhex bearings are metric sized, I thought I would be able to find them locally, but I didn't. Instead I came across 14mm ID bearings. Now, the thunderhex ones are supposed to be 13.75mm. When put to CAD, the difference between them looks very small. I was thinking of taking a regular hex and using a lathe to round the corners to a 14mm radius and using 14mm bearings in the same way.

Would that work properly in the same way that Thunderhex works? My basic math makes it seem like I still keep 80% of the contact surface with the bearing. I'm not sure if that is enough, or even what the adverse effects that too little contact surface would cause.

Thanks