[radicooldude]

If you go to msc, and you look at their cheapest jaw couplers, I was wondering if they are zero backlash? Has anyone ever gotten them? They are dirt cheap, like 2.30 per jaw, and 1.50 per spider. - zachery

[patveth]

Hi Zachery,

Not sure which jaw couplers you are referring to but I'm using Lovejoy couplers from McMaster Carr, about the same price, and I can't detect any measureable backlash. In addition they solved some really frustrating alignment problems that I have been having.

Pat

[joecnc2006]

I also use the lovejoy, but i make my own spiders, because the one i get are made of rubber and i wanted no play at all.

here is a picture and also the g-code if you want to make your own, takes about 30 seconds each to cut out, more time in setting material than routing.

Joe

[phil burman]

The issue is not only backlash there is also an issue of alignment tolerences and "windup" etc etc. As in most things you get what you pay for. You should really be asking what is appropriate for your application.

Regards
Phil (chair)

If you go to msc, and you look at their cheapest jaw couplers, I was wondering if they are zero backlash? Has anyone ever gotten them? They are dirt cheap, like 2.30 per jaw, and 1.50 per spider. - zachery

[gopackgo]

[B]I used Lovejoy couplers and rubber spiders on my machine and they work great. I was surprised how cheap they were. I've worked at 2 machine manufacturers in my career, Giddings and Lewis being one, and they used Lovejoy couplings with good results 20 years ago which is why I bought them. I've been running them on my machine on all 3 axis for over a year without any problem.

[OwenL]

"Lovejoy" what a curious name for, what I am guessing is, a shaft coupling ..........

Can anyone show me a link to a site for these? I'd like to see one installed to get an idea of what it is I'm looking at in the above picture.

thanks
Owen

[OwenL]

Okay never mind.

I see it now. It sorta just POPed out of the picture ........... at first the white star laying on top threw me off. Now I see it is an example of the peice installed in the motor coupling.

wiredness afoot.

So now I have a question. With out the gear reduction of pullies, what size of motors are these used on? I thought the 2:1 ratio was needed to give servo motors the needed power to drive the axis.
what am I missing?