[kev82]

Hi

Last week I received a laser cutter from g weike with a 130w reci tube. I've been experimenting with it for the past few days and been pretty happy so far.

There's one issue I seem to be having though:

I made a test pattern consisting of just a few lines at varying power/speed settings in lasercut 5.3:
power%/speed
20/400
25/400
30/400
35/400
40/400
45/400

All layers are set at cut.

I can push that to the laser just fine, but when I start the job it looks like 20-30 is all at the same power and isn't even visible in the 3mm masonite. 35-45 all cut almost completely through the material.
With this particular test pattern my intention wasn't really to cut the material, but to just mark it, so that's why I have such a high speed and low power.

I've noticed similar inconsistencies before, so I am wondering if there's something wrong, stopping me from fine tuning the laser power or is this as expected?
I've also noticed that with engravings I can set the speed as high as 600 but 400 is max on cut layers.


Any thoughts or input appreciated.

[ELaser]

Only way to tell for sure is use a power meter and measure the actual output at each setting, this is the only way to *know*

Having said that, I wouldn't *entirely* discount your gut feeling, what does the mAmeter show if you look at it for each setting? Still not an accurate *instrument* calibrated and all, but easier than guessing from results left by beam passage.

The 400/600 mm/sec thing is pretty normal, in theory the stepper drivers and steppers and so on can peak out much faster, but this is for rapids, not actual feeds and speeds, and IMHO it's got **** all to do with servos or steppers, I won't run past either 500 mm/sec or 4G acceleration on my machine, because the limiting factor for precision is stretch / bounce in the belts, no matter how good they are, IMHO they aren't good enough for more than this, if you want faster, upgrade to full ball-screw rails.

If you are a newb, one thing to watch for when you start doing the faster speeds is that everything in the head can work loose, including the focus lens, so you can suddenly lose focus half way through a job.... the effect looks like one axis is missing steps

Check the tube, Recli label it, if it's 130 watt nominal it *should* have a peak power much higher, if it's only a little higher than the nominal rating, limit it to 75% of peak power, if its got a *lot* of headroom, say 175 watt peak, you can push it to 95% peak.

Do not use anything less than a 5200 series chiller either, IMHO.

HTH etc

[kev82]

Hi

Thanks for your reply.

The mA meter doesn't move in the first steps, but starts to move at 35 and seems to move a little more in every increment, so that seems to be working fine. But the smaller power settings seemto be just "off" until somewhere between 30 and 35. Engraving at 20/600 works great however.

I checked the reci tube and it's rated at 156w, and I have a CW-5000 chiller attached to it. So far I haven't been running any long jobs on the laser so I've yet to see the temperature raised even a little bit on the water.

[ELaser]

This is why you need a pukka power meter, *could* be the milliammeter is just not reading right, of course that is an easy thing to test, or replace.

If it is reading right, then your machine has an issue, as in at the very least it wasn't set up correctly and tested prior to shipping

130/156 = 17% overhead which isn't bad, mine has a 24% overhead and allegedly that is 1% under as high as it goes, and have seen Reci tubes with only 1% overhead fitted to cheaper machines, "allegedly" it all depends what "grade" of X watts tube you buy from Reci, and of course the ones with higher peak overhead are worth more than those with less.

If it was me I'd swap the mA meter out with a tested / calibrated one, and if still unexpected answers then chase the vendor.