Bushing runout

[jd99]

I was doing some work on my metal lathe, and I decided to make the bushings I have work for turning between centers, I thought the runout I have been getting was because I was using the mandrel.

Well I chucked up one of the bushings and noticed the runout on the hole, pulled it out and checked it and sure enough the hole is not in the center of the bushing, I checked the other bushings I have and for the most part they are all that way.
I have maybe one or two that are close.

Have you noticed this with your bushings?

I guess the only way to get them on center is to start making my own.

Thanks
Danny.

 

[leehljp]

I was doing some work on my metal lathe, and I decided to make the bushings I have work for turning between centers, I thought the runout I have been getting was because I was using the mandrel.

Well I chucked up one of the bushings and noticed the runout on the hole, pulled it out and checked it and sure enough the hole is not in the center of the bushing, I checked the other bushings I have and for the most part they are all that way.
I have maybe one or two that are close.

Have you noticed this with your bushings?

I guess the only way to get them on center is to start making my own.

Thanks
Danny.

Yes, this has been a problem for years. It is a wise idea to check the bushings when you buy them and notify the vendor immediately. Most will replace them. And then check the replacements! I think it was the Sierras bushings that had a large number of bad off center hold 5 or 6 years ago. Even since then, I have received a few bushings of other pens that had the hole off center.

I either make my own from aluminum, plastic resin or order them from Johnny CNC. I haven't been checking for a couple of years due to a move and workload change - but there may be other vendors offering custom Quality bushings - at a higher price than most large commercial vendors, and they are worth the extra price, IMHO. Every bushing from the large commercial vendors need to be checked for the hole being drilled on or off center - when they arrive! Don't hesitate to notify the vendor if the bushings or out of tolerance range!

Making your own is not that hard to do. If you are good enough to notice a problem like this and find there reason on your own, you most certainly will be able to make a better bushing than large commercial vendors make. One thing to watch for is the outside diameter that fits INSIDE the tube. Most commercial vendor bushings are too loose in the tubes. And most pen turners don't give a second thought to this. Closer tolerances in fitting into the tube so that it slides in, rather than "drops in" (like most large commercial vendor's bushings do without any resistance - the tighter fitting closer tolerance bushings make for a better turned blank! When you make your bushings, take note of that aspect.