Lobing vs Hexing on Centerless Grinder

[ranparn]

We have an inline feed centerless grinder that's capable of grinding 24 ft. bars and tubes. We are having trouble with lobing and/or hexing on the OD. We've realigned the jack plates to where the work piece is slightly above center. We've also dressed the Reg wheels. Just not sure if lobing and hexing has the same cause or not. We use 3-point v-anvil micrometers to check for lobing. Can we use the same method to check for hexing?

 

[Compositepro]

Perhaps this will help:

http://www.mmsonline.com/articles/centerless-grinding-not-magic

 

[ranparn]

Thanks for the article. This article explains how to setup, which we are already doing this. I need to know if hexing and lobing are the same.

 

[Compositepro]

Well, the way I read the article, lobing is a high spot with a diametrically opposed low spot. This does not describe a hex.

 

[ornerynorsk]

Lobes are usually an odd number on centerless ground work. Are you getting a true hex (6 lobes) deformity? Your best bet is to check a sample for roundness with an indicator.

You could try running the regulating wheel a little faster if that is an option, and setting your workpiece a little higher. Your infeed blade is fairly critical for good work. Also,what runs your regulating wheel, and is there any excessive slack in it (chain in particular)? This can cause roundness problems.

Good luck.



It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.