[Bigbird48]

My 40watt laser never seems to cut all the way thru the material. I'm cutting 1/8 inch baltic birch, with a 2.5 " lens. This machine should have no trouble cutting thru this. The tube has less then 200 hrs on it. The machine is manual focus, so my question is if I focus to the proper height then raise the table a hair more will it cut a little deeper. I'm running at 10 speed right now to see if that makes a difference.

Well I was cutting as I was writing this and I had a fire, can't cut 1/8 at 10 speed to slow will just burn up the wood.Hopefully i did not damage other then melting the wires to the red dot.

But the question still stands can I raise the table to get a deeper cut?

[Bigbird48]

My 40watt laser never seems to cut all the way thru the material. I'm cutting 1/8 inch baltic birch, with a 2.5 " lens. This machine should have no trouble cutting thru this. The tube has less then 200 hrs on it. The machine is manual focus, so my question is if I focus to the proper height then raise the table a hair more will it cut a little deeper. I'm running at 10 speed right now to see if that makes a difference.

Well I was cutting as I was writing this and I had a fire, can't cut 1/8 at 10 speed to slow will just burn up the wood.Hopefully i did not damage other then melting the wires to the red dot.

But the question still stands can I raise the table to get a deeper cut?

This must be a tough one I see 70 people have looked but no one has replied with an answer.

[Exsecratio]

In theory yes Bert, in practice on a 40 watt not really and you will end up with a wider kerf at the bottom. It's done on metal cutting machines as routine but on wood there are no real world gains to be had. If you are getting ignition issues with material them you have too low a pressure on the air assist.

cheers

dave

[cautious32]

When I received my machine recently it had a 25mm focus gauge with it. When I made my first cut it hardly made an impression on the material when it should have cut trough it with no problem. I tried a variety of materials with the same result so I experimented with the focal length and found that the best results were at 21mm. Have you tried experimenting with different heights?

[Bigbird48]

No haven't play with the heights to much. ZIts funy cause it cut most of the design out but always leave a little here and there that doesn't quite make it.

[herby08]

hi there
check the plywood sometimes there are hard parts in it like from glue this brings the problem with some little parts not cut thru.
the next measuring the focal distance is always done from the top of the lens to the top of the material.
I use a strip of the wood put it on a slope and run the power setting what I want, then look where it cuts thru and the line is the thinnest,
then measure the distance that's the focal length.
then I use a square the size of the work area, then set the power to a low setting and run to see if the lines is equal all the way around.
greetings
waltfl

[Bigbird48]

hi there
check the plywood sometimes there are hard parts in it like from glue this brings the problem with some little parts not cut thru.
the next measuring the focal distance is always done from the top of the lens to the top of the material.
I use a strip of the wood put it on a slope and run the power setting what I want, then look where it cuts thru and the line is the thinnest,
then measure the distance that's the focal length.
then I use a square the size of the work area, then set the power to a low setting and run to see if the lines is equal all the way around.
greetings
waltfl

Thanks I'll try that

[TechGraphix]

One other thing: is your focuspoint actualy your focuspoint? Say you have a 2.5" (=50.8mm) lens but your actual focuspoint is not at 50.8 but on 45mm..
You can make a ramp from, lets say Z -0.5cm to Z + 0.5cm with a length of ~10cm. You stick some paper on it, focus it in the middle and let the laser draw a line over the ramp. If the thinnest part of the line is in the middle, your focus is right. But if the thinnest past is on the higher or lower part of the ramp, you need to calculate this error or adjust the thing you use to focus.
Above all: your laserbeam needs to be aligned perfect ofcourse..
Does your laser als have "airassist" and appropriate ventilation? (i only had some ~ 10mm small flames when cutting a kind of plastic once...but never with wood or other materials...)
Kees

[Bigbird48]

Well I checked the focus point and it seems to be ok. Maybe its a combination of the plywood and my tube getting weaker. Altho if its the tube again I'm gonna be a little ticked. my first tube lasted less then 100 hrs and this one doesn't have 200 hrs on it yet. It wouldn't surprise me at all if they put in an old or returned tube.

[herby08]

hi bigbird
if you got so much trouble with tube lasting not long then you should check your current it should never be more then 18mA and your cooling water should never exceed 12 centigrade .
if just one of this parameter exceeds the tube will not last.
this parameter need to be measured with a thermometer and the current with a mA meter.
I drive my 30 W tubes with max 16mA and temperature max 22 centigrade. and my tubes last with heavy cutting 6 mm acryl over 1200 hour.
greetings
waltfl

[Exsecratio]

and your cooling water should never exceed 12 centigrade

there are no fixed figures Walt, if the ambient temp and humidity is high then running a tube that low will cause condensation problems and arcing. 28 is the max before damage and 22 is fine, in theory a laser tube will run better the lower you get the temps but there are practical limits before other problems crop up.

it's all about potential damage / effect

cheers

dave

[Bigbird48]

My water temp stays between 17 and 21 and my tubes never run over 15mA .My laser gets run on avg. an hr or so a day, some days its doesn't get run at all.

[Bigbird48]

Morning Dave or is it good afternoon for you,LOL I found out about humidity back in July and Aug. when we had high humidity of like %55 and I noticed my water lines starting to sweat. I stopped engraving for a while turn ac on till the room cooled down and the lines dried up. Most the time here its not a problem as humidity usually runs around %5, hey ! its the desert ya know .but dam does it get hot here.

[rsilvers]

For material that thin, I would just focus on the surface. You will have less charring on the face. Focusing 1/2 way through would not help you cut faster but it would reduce the taper and make it symmetrical - which is good if you want to make joints with other material. If I were cutting, say, 6mm Acrylic, I would focus 1/2 way down if I wanted to make joints, or on the surface if my goal was the cleanest front face.