Speed and Power Recommendations

[Ross Lowry]

Hi.
I am cutting some 1/8" birch plywood with my 45watt Epilog.
The owners manual says I should be able to cut through it at speed 35, power 100, and freq. 500.
My actual settings though are speed 20, power 100, and freq. 500.
I know that the glue in the plywood may be affecting my speed, but is it usual for it to be this much variance from the manual?
It has a new laser tube and is aligned to the best of my ability.
What is some of your speed settings for cutting this material?
Thanks.

[Joe Pelonio]

You'd be surprised at how much difference there can be between two pieces of the same wood product.

Looking up the last job I did with 1/8" Birch ply, I used speed 60 power 100 freq 5000.

My manual says 25 100 5000.

[Ross Lowry]

Well I wish mine ran it that fast!
The plywood I get is from Michaels, if that makes a difference.

[Rob Bosworth]

Are you sure that you are not looking at the recommended speeds and power for 1/8" thick birch. Plywood will cut much differently than real solid wood. Hard to say what they put in as layers, then they add glue. And for some reason, these machines change pulsing profiles when the movement system goes from a straight line to a curve.

I was cutting some samples yesterday on 3/8" thick 7 layered plywood. I got a great cut in a straight line, but horrible pulsing in the curved areas. I ended up watching the head, and you could see the change is speed as the curve started. I was surprised, the machine seemed to speed up as it was going into the curve. The cut through on the straight was beautiful, and the curved sections were not cut through cleanly. (I haven't figured out why.)

[Tom Buzz Bernard]

The owners manual says I should be able to cut through it at speed 35, power 100, and freq. 500

New tube should cut 1/8" at these settings. Out of alignment, dirty mirrors, or the wood is bad. I once had a customer send me a piece of 1/8" I couldn't cut with 2 passes on a 60 watt.
But you said you cut this at 20 speed - 100 power??? One other issue might be the color of your line cut, RGB or CMYK. I have seen this affect some of the newer machines. If you take a CMYK color such as black, it is not a true 255,0,0 RGB color and the driver sees it as a gradation, therefore reducing your power output. Sort of how rastering works on grayscale.
I have run into this a couple of times, changed the color, and got a faster speed. Let me know if it works on your machine, maybe this is the answer for some newer drivers out there and we can pass it on.
Of course I may have put in a different piece of wood and thought it ran faster because of the color change :confused:

[Nancy Laird]

Ross, we have a ULS 40W machine, and I cut 1/8" birch ply at 90% power and 1.3 speed--and never have a problem cutting through. You might want to reduce your speed and up the DPI a little--I'm at 800.

Also, all of my vector lines are red, but don't know that the color makes a difference--I've also used green and magenta.

[John Noell]

I have two samples of 4mm ply and one cuts at twice the speed of the other. They are supposed to be the same but obviously are not. Even two samples of clear acrylic from the same manufacturer may differ but should be closer to each other.

[Lisa Walter]

I cut a bunch of ply wood back in the winter time.......one thing I noticed was, if I tried to cut through one side, it wouldn't always go all the way through. If I flipped the plywood over and lasered from the opposite side, it went through fine.

Lisa

[Ross Lowry]

Thanks for all your replies!
This is what I have tried so far.
I changed the color of the lines to R255 G0 B0, this still took the same amount of speed to cut, no improvement.
I flipped the board to see if it cut better from the other side, still no better results.
The next thing I will try is another piece of wood.
I wonder if Epilog has a tool they will rent you to check the output of your laser?
If worst comes to worst the I will have to check the mirrors and realign it.

[John Noell]

Have you tried any other materials?

[Ross Lowry]

As far as the vectoring no, that was the only piece I had to vector.
I have done a lot of rastering though and those speeds and powers seem to be fine?
I am leaning more towards the material.
It sure would be nice if Epilog had a meter they would rent so you could check your laser output.
I think I will contact them to see.

[Michael Kowalczyk]

Hey Ross,
Where are you located? If you want I can send you a small leftover piece of our GENUINE B/BB 3mm Russian birch ply that works great for us and many other Creekers that get it from us. PM me if you are interested and we can work out the details. Here is a side view showing the quality of the edge cut. I have a Trotec so I do not know how that would convert to your Speed and power specs.

Let me know if I can help and ...

[Ross Lowry]

Dan from Epilog refered me to this link http://www.laserbits.com/index.php?main_page=product_info&cPath=71_149&products_id=321 for the rental