gears, ballscrews, and setscrews

[BarryB]

Hi folks, I've been a modeling madman getting all my parts in the modeling app so I can get some precise connecting plates fabricated.  IN the process, I was assembling lots of parts together, like ballscrews, end supports, gearing...

This is where I noticed that the gears lock in place using a set screw, only the ballscrews are machined smooth.  There's no flat side for the set screw to lock onto.  Is this customary, we just screw directly onto the round shaft?  Do we drill a detent for the screw?  Do we file down a side?

Forgive my ignorance n this matter, it's not something I do everyday;)

Barry

[SteinarN]

If you don't do anything then it will be hard to get the gear off because of the burrs made by the set screw when you tighten it. I would have drilled a shallow recession in the shaft with a drill bit somewhat larger than the diameter of the set screw. Don't drill it deep! Only so deep that the diameter of the recession becomes slightly larger than the set screw. Then it should not be any problem removing the gear later. If the gear doesn't fit tight on the shaft I would have used locktite on the shaft also.

[Tweakie.CNC]

My ballscrews were a lot harder than my drills so I ground a small flat on the machined portion of the ballscrews.

Hope this helps.

Tweakie.

[Dan13]

On my machines the timing pulleys are screwed onto the ballscrew end, and are locked with a counter nut (or counter bolt in my case), and Loctite is applied to the whole assembly.

Daniel

[BarryB]

Thanks for the tips.  I think the first thing to do is machine some flats as some have suggested.  I'll see if I can do that this weekend.

Barry