Re: [SherlineCNC] X table lopsided
- On Monday 09 September 2013 18:31:53 Martin Dobbins wrote:
> For the benefit of anyone else who may want to know:
> I copied your email into a text document, added my comments above that and
> then hit reply on the web interface. I then deleted your message and all
> the attachments on the web mail interface and copied in your email and my
> reply from my text document. Either that is what helped or perhaps Yahoo
> has fixed things? I'll play with that a little and let you know.
> All of those convolutions might be possible on a mobile device but probably
> more trouble than most users want to think about.
thanks for taking the time of explaining what you went thro to send a text
I only hope the rest of the folks on the list can be bothered to fix
yaboo's idiocy,(or at least yell at Yaboo to get their rubbish generator
fixed) especially if they have a query to be answered as that VERY verbose
code is nothing to human eyes.
- Kent -
Assuming that you're measuring at the spindle, and that the standard
sherline table is sort of OK, the issue is variation in the height of
the table above the dovetails to which it is clamped by the gib and its
Consider a table moving under the spindle on the dovetails: if it is the
"same" thickness/height the reading should be the same (within
tolerances, of course).
You've checked the cleanliness of the ways and the saddle per earlier
email. Those are the first things to check.
How are you measuring this difference in Y? The table isn't wide enough
to measure 5" of travel in Y - so you're putting a plate on the table?
I suggest first using a micrometer to measure thickness of the table at
various points, and then a depth micrometer or good digital caliper to
measure the top of the dovetail. Then call A2Z to find out if they're in
spec. You're looking for parallelism and any differences back to font.
If the saddle is out of spec (are you using the standard Sherline saddle
on the X/Y?) it won't show at the spindle as the table moves past. If
the dovetail milling is off, you could get what you described. Or if the
gib isn't properly installed and there's some sag.
You didn't say what kind of mill, and whether you also are using the A2Z
The oddity is the difference between the Sherline and the A2Z X table
measurements. They should be very close to the same. As jowhowho said on
> The base, the saddle, and the table should all be square and parallel from the factory, with no shimming. You should confirm it though.So the only variable left seems to me to be the A2Z extended X table and
On 8/25/13 6:38 PM, kerickson wrote:
> I used a Pro Tram mini and a 7x7x1" precession ground base to get the mill dialed in. On the standard Sherline X table I was able to measure 0.005" of run out across 5" of travel in the Y direction. With the A2Z extended table I measured 0.035". I'm guessing that I'm going to have to do some shimming of the vertical mounting column but why would the A2Z table have more run out (tilt) than the Sherline table. I didn't remove the vertical column for these tests.
> --- In SherlineCNC@yahoogroups.com, "jowhowho" <jowhowho@...> wrote:
>> If you don't have an indicator, get one.
>> For now, you could put a pencil in the spindle, touch it to the near side of the table, and move the Y axis so the spindle is over the far side of the table. Any change in height should be detectible. If there is a difference in height, then maybe you have a messed up gibb.
>> The base, the saddle, and the table should all be square and parallel from the factory, with no shimming. You should confirm it though.
>> Getting the Z axis perpendicular to the X and Y axes, and getting the spindle parallel to the Z axis, is something you have to fiddle with, especially with the 2000.
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