Can I bore out the center hole of this pulley to fit my ballscrew, or will that screw it up?
as long as it stays centered id imagine it would be fine, otherwise it’ll end up eccentric.
I don’t know, can you? Kenny! If it was me I’d certainly give it a shot.
You will fine as long as you do not bore out the threads for the set screws. Also would be best to bore on a lathe so it will be a true hole.
How much do you have to remove?
Do it
Use a lathe if you can. I do it all the time since finding correct bore pulleys can be difficult and even Stock Drive Products don’t carry every size that is available.
Like everyone else says: do it on a lathe, make sure it’s really well centered. If it isn’t you’ll get position errors. Make sure it’s a very tight sliding fit, for the same reason.
It all depend on the accuracy that you aim for. Do it by hand could lead to huge offset in both direction. When you do it on lathe keep in mind to that boring with standard bore will be somehow enouph but not that great as quolity pulley. Commonly standart bore create a hole that is not true circle and if you use bore of 5mm the hole will be within ± 50 microns.
You either centre it actively (eg on a lathe), or passively- eg on a drill press. I drill will follow the existing hole. Even on a lathe the drill bit will flex to follow the hole. It’s work a try
If you can’t use a lathe set it up with a pretty close fit drill bit in a drill press, then size up as needed. Can you order a new one the right size? If you mess it up thats how much it well cost you lol. If your on good terms with someone at a machine shop or who has a lathe they could chuck it up and do it in a few minutes, for nominal cost. In my area, places that do machining for engines would probably charge about $5 for it (we have a good autovalue here) Btw have you already tried doing it, it’s been a while since you asked? If you do get it off a little, you could use the set screws (maybe) to temporally "true"it up to the shaft. Red neck engineering