CBN wheel possibility

[Alan S]

I have a grinder with a friable coarse wheel and a wire wheel that work well for most of my purposes.  I am considering adding a relatively finer CBN wheel for lathe tools, which might necessitate another grinder without a good place to put it.  My lathe is a small older spindle lathe with a 3/4"-16 threaded arbor. 

I am considering adding a CBN wheel to outboard end of the lathe itself, by a left handed nut.

I know I am expected to upgrade my lathe at some point, but don't plan on it soon.  If I do the CBN wheel will be ready for another upgrade there too, as it would need to be the 3/4" arbor wheel that fits a Baldor grinder.

Am I nuts?  What problems might I encounter with such a wheel on the lathe?

[AHill]

You may overspeed the lathe to the point where the CBN wheel will eat away too much metal from anything you're sharpening. Also. that much weight on the end of the lathe will cause the arbor bearing to prematurely fail, since it's a lot of weight always pushing the spindle down.

[Arlin Eastman]

You may overspeed the lathe to the point where the CBN wheel will eat away too much metal from anything you're sharpening.  Also. that much weight on the end of the lathe will cause the arbor bearing to prematurely fail, since it's a lot of weight always pushing the spindle down.

Allan

I am not following what you said. 
    Did you say it was bad for the CBN wheel or the lathe??  If the lathe has VS then it can be slowed down or????   I know most lathes go slower then 4000 rpm and that is about what a slow speed grinder does.

[iclark]

Allan

I am not following what you said. 
    Did you say it was bad for the CBN wheel or the lathe??  If the lathe has VS then it can be slowed down or????   I know most lathes go slower then 4000 rpm and that is about what a slow speed grinder does.

Arlin,

A small older spindle lathe is not going to have VS other than (probably) a 2 or 3 step pulley.

A regular speed grinder runs ~3600 rpm. A slow speed grinder is ~1800 rpm.
I would guess that the older spindle lathe is probably in the 600-1000 rpm range.

Allan's comments were about the extra wear on the spindle bearing(s) if you use a 4+ lb CBN wheel as a hand wheel on the lathe.

Another issue would be the tool rest for the grinder side. Teknatool has advertised a grinder attachment for one of their mini-lathes but I think that it would be hard to attach it to any other lathe.

[Arlin Eastman]

Arlin,

A small older spindle lathe is not going to have VS other than (probably) a 2 or 3 step pulley.

A regular speed grinder runs ~3600 rpm. A slow speed grinder is ~1800 rpm.
I would guess that the older spindle lathe is probably in the 600-1000 rpm range.

Allan's comments were about the extra wear on the spindle bearing(s) if you use a 4+ lb CBN wheel as a hand wheel on the lathe.

Another issue would be the tool rest for the grinder side. Teknatool has advertised a grinder attachment for one of their mini-lathes but I think that it would be hard to attach it to any other lathe.

Thank you.  I know I was not thinking of something and did not understand what.

[SceneryMaker]

I run my 180 grit CBN wheel at 900 rpm on my $50 Shopsmith, right beside my real lathe. What ever you choose, put your grinder close to your lathe so that you won't put off touching up your gouge often. As has been said many times by many people, "If you think it could stand sharpening, it has needed it for quite a while."

[Robin Dobbie]

...might necessitate another grinder without a good place to put it.

[Alan S]

Thank you all.
I had considered that I'd want to use the wheel only at certain speeds, but not that I might not want to switch speeds back and forth while using the lathe.
The mass of the wheel is a question.  The woodturner's wonders CBN wheels are mostly aluminum.  The only one where the weight is mentioned is the mega square at 4 lbs 10 oz.  It might be a bit much to leave on all the time.
I had not considered the New York City approach to grinder placement: build up!

[Arlin Eastman]

Crafty idea.  For me it would not work having to bend down but side by side with 10" to 12" apart would be nice like that.

[iclark]

Doing a flip-top cabinet with a grinder on both sides is something that I have been considering.