Re: [CAD_CAM_EDM_DRO] Lovejoy Couplings

Jack,

My CNC knee mill uses Lovejoy couplers in a direct drive setup.
I'm replacing the spiders as I can see free play in them, probably a
thou or two. Mine have the SW type spiders, these connect externally and
use a split ring to make sure everything stays in place. This allows
room at the center for the nut that secures one side to the leadscrews.
(the same nut that would retain a manual handle)

I ordered these this morning, and while on the phone with the sales rep
(for Motion Ind., not Lovejoy) I asked about a more solid coupling that
would still allow use of the nut, he said he couldn't think of one off
hand.

From comments I've read here regarding coupling encoders to screws or
motors, I suspect there's going to be too much free play. The flexible
beam (helical) couplers would work better IMHO.
MSC lists one that uses an acetal part to couple the hubs and claim zero
backlash. I was tempted to try them, but at $48 ea in the size I'd need,
I wasn't willing to gamble.

Jon