Prevent Racking (X cuts faster then Y travel)

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atrueresistance
Posts: 13
Joined: Wed Nov 04, 2015 10:22 pm

Prevent Racking (X cuts faster then Y travel)

Postby atrueresistance » Fri Nov 13, 2015 12:06 am

I'm attempting something that probably shouldn't be attempted using a 3W diode.

Trying to cut through .25" baltic birch plywood. This is a photo of it in action, somewhere around 20 pass mark.
Image



Now Objectworks (beginning to be less and less of a fan), as you can see doesn't alter z which when going though this much material would cause the beam to be out of focus.

Image

So this first run is going to be ran without varying the height, until the piece is fully cut out. I'll update with the final number of passes.
------------------------------------------------------------------------------------------------------------------------------------------------------
Giving up, 33 passes in and it cut ~2-3mm of the 5.27mm needed.
Image

The second run will be hand written gcode to lower z every pass a small amount. You can find it attached.

First time writing something by hand :crazy)

Code: Select all

G00X0Y25.4F1400
S12000
M3
G01X25.4Y25.4F60
G01X25.4Y0F60
G01X0Y0F60
G01X0Y25.4F60

G01X25.4Y25.4Z-.1F60
G01X25.4Y0Z-.1F60
G01X0Y0Z-.1F60
G01X0Y25.4Z-.1F60

G01X25.4Y25.4Z-.2F60
G01X25.4Y0Z-.2F60
G01X0Y0Z-.2F60
G01X0Y25.4Z-.2F60

G01X25.4Y25.4Z-.3F60
G01X25.4Y0Z-.3F60
G01X0Y0Z-.3F60
G01X0Y25.4Z-.3F60

G01X25.4Y25.4Z-.4F60
G01X25.4Y0Z-.4F60
G01X0Y0Z-.4F60
G01X0Y25.4Z-.4F60

G01X25.4Y25.4Z-.5F60
G01X25.4Y0Z-.5F60
G01X0Y0Z-.5F60
G01X0Y25.4Z-.5F60

G01X25.4Y25.4Z-.6F60
G01X25.4Y0Z-.6F60
G01X0Y0Z-.6F60
G01X0Y25.4Z-.6F60

G01X25.4Y25.4Z-.7F60
G01X25.4Y0Z-.7F60
G01X0Y0Z-.7F60
G01X0Y25.4Z-.7F60

G01X25.4Y25.4Z-.8F60
G01X25.4Y0Z-.8F60
G01X0Y0Z-.8F60
G01X0Y25.4Z-.8F60

G01X25.4Y25.4Z-.9F60
G01X25.4Y0Z-.9F60
G01X0Y0Z-.9F60
G01X0Y25.4Z-.9F60
M5


10 passes in lowering .1 each pass and I can start to see the laser all the way through.
Image
---------------------------------------------------------------------------------------------------------------------------------
I shut the laser off at the 12 pass mark.

Everything in the X direction was completely cut, really X direction was cut in the 10th pass. The Y direction was not cut after the 12th pass. I'm guessing this is due to the laser module not being properly housed inside the LaserInk case. This could also be my machine racking slightly. When the machine was cutting in the X direction travel was nice and smooth. During Y direction travel you could see some variation where the diode slightly vibrated in the Y direction.


I can freely move the diode when focusing, without much force. Notice the amount of travel when focusing the laser when on. Is this just mine or does this happen to all LaserInk? I haven't popped the case to look and see if any bolts are loose. .
Image



The next photo shows from the bottom the clean cut.
Image



I ran the board through the table saw to get a closer look at the Y direction that didn't quite cut through all the way.
Image



Roughly 10 passes on a smooth machine with .1 step down @ 60mm/m will get you a nicely cut piece of baltic birch ply.

Image


Is that the speed you PicEngrave folks run at for cutting? What is the easiest way to prevent the vibration when SO3 is travelling in the Y direction?

I've never dealt with anything this precise before.

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Picengravertoo
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Re: Prevent Racking (X cuts faster then Y travel)

Postby Picengravertoo » Fri Nov 13, 2015 9:56 am

I can tell you need to secure the lens from moving after it's focused with some hot melt glue between the lens thread and laser module. We have no S03 here, only S02, so we can't suggest anything to stop vibration other then try readjusting the V wheels and belts.

Also in your wave engraving post the Pixel Resolution you used was .254mm and that tells me you are getting a rectangular focal point and that is why it cuts better in one direction then the other. The beam is more intense on the narrower side of the focal spot and is not trying to cut a wider kerf as the wider side of the focal point is. You should try using a 3" focal length and focus the lens better to get a smaller size focal point. We get half the focal spot size you are at .005" (.127mm) and is almost completely round with a 3EG lens.

We use a piece of black anodized aluminum to focus on and the amber laser safety glasses works best to see when the focal point is the smallest compared to using the red safety glasses.

atrueresistance
Posts: 13
Joined: Wed Nov 04, 2015 10:22 pm

Re: Prevent Racking (X cuts faster then Y travel)

Postby atrueresistance » Sun Nov 15, 2015 2:07 pm

Hot glue and the 3" focus worked amazingly!!!!!!!!!!!!!! It doesn't take 10 passes anymore to cut through

Your awesome, thank you :-)

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Picengravertoo
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Re: Prevent Racking (X cuts faster then Y travel)

Postby Picengravertoo » Sun Nov 15, 2015 3:22 pm

Glad I could help. It should improve your raster engraving also.


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