I suspect the problem is that the bearings are mounted in plastic. I've never checked runout on a Dremel (or anything else) but I have had a few Dremels that vibrated and felt like they had some runout. I took them apart, found the bearings a little loose in the plastic, and retightened by wrapping a few turns of tape around the ball bearings.
Not very elegant, and not very permanent, but they were Dremels at work where they were not going to put out any money on repairs or replacements.
Steve Greenfield AE7HD
--- In Homebrew_PCBs@yahoogroups.com, Mitch Davis <mjd@...> wrote:
>
> On Mon, Jun 10, 2013 at 9:37 PM, Jim <wb8nbs@...> wrote:
> > I also have used a Dremel stand to drill PCBs with mixed results. IMHO, the problem with the Dremel may not be the stand, it may be excessive runout and worn bearings in the tool itself.
>
> Dremel tools have shocking runout from the day they're bought.
>
> We bought a Proxxon tool for the CNC mill we built in our hackerspace.
> It's a beautiful tool, everything the Dremel isn't.
>
> Mitch.
>