Laser cutter wobbles

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Sam Kelly

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Dec 8, 2011, 2:16:00 PM12/8/11
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Here's the results of today's job - http://www.flickr.com/photos/ravenmagic/6478073579/

All of those horizontals were supposed to be straight lines, and all 12 panels were done from the same code - the teardrops were supposed to be smooth curves.

I think there's something up with one axis!

--
Sam Kelly, http://www.eithin.co.uk/

That's it.  We're not messing around anymore, we're buying a bigger dictionary.  -  Tibor Fischer, The Thought Gang.

Dave Ingram

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Dec 8, 2011, 2:38:51 PM12/8/11
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On 08/12/11 19:16, Sam Kelly wrote:
> Here's the results of today's job -
> http://www.flickr.com/photos/ravenmagic/6478073579/
>
> All of those horizontals were supposed to be straight lines, and all
> 12 panels were done from the same code - the teardrops were supposed
> to be smooth curves.
>
> I think there's something up with one axis!
Grrr :-( I was hoping to be able to cut some things tonight, as I
finally have time before Christmas.


D

M

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Dec 8, 2011, 2:57:36 PM12/8/11
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i noticed a few weeks ago that when someone slowed down the cutter
that it reduced the errors. may be able to slow it down and cut at
less power to compensate?

--
>
++++++++++[>+>+++>++
+++++>++++++++++<<<<
-]>>>+++++++.>++++++
+++++.+++..---------
.++++++++++.<<+++.<.

Tim Storey

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Dec 8, 2011, 3:00:20 PM12/8/11
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which is the x and y axis in relation to the bed of the laser cutter in
your photo Sam would it be correct to assume that x is the long axis ?

\t

Sam Kelly

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Dec 8, 2011, 3:03:17 PM12/8/11
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The top-right-hand corner of my photo is the laser cutter origin.

Tim Storey

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Dec 8, 2011, 3:09:32 PM12/8/11
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thanks Sam, its appears that the y axis is way off and the x is also
playing up, I think it needs stripping down and examining as this is
happening way way to much. I am happy to have a go at this but
assistance would be appreciated...

\t

MSRaynsford

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Dec 8, 2011, 3:59:51 PM12/8/11
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When I was chatting to HPC they were talking about a similar effect
they'd spent ages trying to track down. Check the lense and make sure
it isn't loose.
It's going to be a component like that that produces wibbles in both
axis.

Sam Kelly

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Dec 8, 2011, 4:00:03 PM12/8/11
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I'd be more than happy to help out, if unskilled labour is useful and I can make it in again soon. Certainly free most of next week, but not Tuesday.

Sam

tom

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Dec 8, 2011, 5:13:12 PM12/8/11
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the axis that moves toward the front of the case occasionally causes
case vibrations. I noticed it a whilst it was working before this
breakage and I was leaning on the case.


On Dec 8, 9:00 pm, Sam Kelly <s...@eithin.co.uk> wrote:
> I'd be more than happy to help out, if unskilled labour is useful and I can
> make it in again soon. Certainly free most of next week, but not Tuesday.
>
> Sam
>
>
>
>
>
>
>
>
>
> On Thu, Dec 8, 2011 at 8:09 PM, Tim Storey <tim.sto...@gmail.com> wrote:
> > thanks Sam, its appears that the y axis is way off and the x is also
> > playing up, I think it needs stripping down and examining as this is
> > happening way way to much. I am happy to have a go at this but
> > assistance would be appreciated...
>
> > \t
> > On 08/12/2011 20:03, Sam Kelly wrote:
> > > The top-right-hand corner of my photo is the laser cutter origin.
>

> > > On Thu, Dec 8, 2011 at 8:00 PM, Tim Storey <tim.sto...@gmail.com
> > > <mailto:tim.sto...@gmail.com>> wrote:
>
> > >     which is the x and y axis in relation to the bed of the laser cutter
> > in
> > >     your photo Sam would it be correct to assume that x is the long axis
> > ?
>
> > >     \t
>
> > >     On 08/12/2011 19:16, Sam Kelly wrote:
> > >     > Here's the results of today's job -
> > >     >http://www.flickr.com/photos/ravenmagic/6478073579/
>
> > >     > All of those horizontals were supposed to be straight lines, and
> > >     all 12
> > >     > panels were done from the same code - the teardrops were supposed
> > >     to be
> > >     > smooth curves.
>
> > >     > I think there's something up with one axis!
>
> > >     > --

> > >     > Sam Kelly,http://www.eithin.co.uk/


>
> > >     > That's it.  We're not messing around anymore, we're buying a bigger
> > >     > dictionary.  -  Tibor Fischer, The Thought Gang.
>
> > > --

> > > Sam Kelly,http://www.eithin.co.uk/


>
> > > That's it.  We're not messing around anymore, we're buying a bigger
> > > dictionary.  -  Tibor Fischer, The Thought Gang.
>
> --

> Sam Kelly,http://www.eithin.co.uk/

Sci

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Dec 8, 2011, 6:00:24 PM12/8/11
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Maybe it's a control signal-filtering issue then? Slower operation would
presumably mean slower signals to the motor controllers which would make
motor-step signals more distinctly separate. So may be looking for
something causing noise to the stepper IC inputs?

Sci

Glen

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Dec 9, 2011, 4:46:00 AM12/9/11
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That's not missed steps, if there was a problem with the stepper
motors then the boxes wouldn't be closed rectangles.
Is the bed properly bolted down?

On Dec 8, 11:00 pm, Sci <s...@sci-fi-fox.com> wrote:
> Maybe it's a control signal-filtering issue then? Slower operation would
> presumably mean slower signals to the motor controllers which would make
> motor-step signals more distinctly separate. So may be looking for
> something causing noise to the stepper IC inputs?
>
> Sci
>
> On 08/12/2011 19:57, M wrote:
>
>
>
>
>
>
>
> > i noticed a few weeks ago that when someone slowed down the cutter
> > that it reduced the errors. may be able to slow it down and cut at
> > less power to compensate?
>

tom

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Dec 9, 2011, 5:01:06 AM12/9/11
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didnt Tim re-level it recently?

Tim Storey

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Dec 9, 2011, 5:24:29 AM12/9/11
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I did, and re-calibrated and it was working pretty well other than the
temperature, see note by timS...

http://wiki.london.hackspace.org.uk/view/Equipment/LaserCutter/LogBook

\t

Russ Garrett

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Dec 9, 2011, 5:51:44 AM12/9/11
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On 9 December 2011 10:24, Tim Storey <tim.s...@gmail.com> wrote:
> I did, and re-calibrated and it was working pretty well other than the
> temperature, see note by timS...
>
> http://wiki.london.hackspace.org.uk/view/Equipment/LaserCutter/LogBook

Sounds like the belt tension is coming loose very easily. Might be
worth adding some lock nuts.

--
Russ Garrett
ru...@garrett.co.uk

Sam Kelly

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Dec 9, 2011, 9:14:58 AM12/9/11
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Some of my boxes weren't closed rectangles - there are ca. 1mm gaps where it circled back to its starting point and didn't finish. (Speed 12, power 100, for reference.)

Martin Klang

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Dec 9, 2011, 10:27:12 AM12/9/11
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I've just had a look, couldn't feel any looseness in the bed.

There are a few burn marks around the bed which I think may be new, not sure though.
I'd like to put masking tape down all the way around the cutting area so that we can spot new burns.
Will bring down masking tape later.

/m

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