Been trying to get dark bamboo engraving on my 80W - no dice.
Even if it comes out dark it washes right off… In focus, out of focus, more/less speed/power… anyone got a magic trick ? Do i need to get a diode for dark engravings ?
Yeah, yeah, i know, bamboo is streaky, but i do see very dark engravings on occasion, probably diode lasered…
Yesterdays mess about…
A material can only do what it will do. Your bamboo chopping board is pressed, it isn’t a ply wood, so removing the surface isn’t showing a different grade of material in another layer. Some woods show darker when engraved than some others.
Consider using a stain (though I suppose if you are using this with food then that is out of the question). Other things you could try is changing to a cross hatched fill, slowing down your scanning speed and increasing the scan interval. You could also try putting the material/work table slightly below focus. I’ve even heard of people flipping the lens over so it’s curved side down, to get a different engraving result.
But basically, you can not change the physical properties of the material you have the equipment you’ve got. If you keep doing the same thing you’ll get the same results.
For what its worth, I think the pictures engraving looks ok.
I think what you have here looks good too!
Many people use baking soda/water to enhance the deeper color. I have no idea if it would be usable on your material or not.
Just thought I’d mention it.
You laser may be a little ‘hot’ for this. Seems rather apparent to me that when it ‘washes off’ it’s ‘burnt’…
I have a 50 watt, and I think mine came out darker with no baking soda… It might just be the limit of the material as @Dominic advised.
Good luck
9% and 200 speed. if i go lower and faster it just disappears, higher and slower - burns and washes out… Tried 2 runs at 9%-200 - no change in colour. Might try soda, definitely no borax as its just ashy black mess to clean…
I’m surprised it will lase below 9%. Seems the larger the tube the higher the percentage at the bottom end to get it to lase properly. Mine won’t consistently lase at 9% and it’s a 50 watt.
What is your controllers minimum power set to for laser 1?
What is the dpi you are running?
Can’t say I know what the soda will do on bamboo… might be in the same boat as with borax.
BTW, I meant to say I like the frog graphic, is is sharable?
Oh laser lases below 9%, but bamboo barely changes at all. 0.1 interval.
Controller settings are fine for any other wood materials. Never set anything below lower lasing threshold.
At this point i’m pretty much dismissing bamboo as a material for engraving unless deep engraving is needed. Dark ? nope.
Frog is something i just ran as a test, found on google images, so no idea on copyright. My wife likes frogs, so…she gets the frog. Got the wrong “prince” ? 
That’s the bummer with these… Something sounds great and turn out to be a waste of time and money.
I used to sail and I thought ‘marine’ supplies were a money pit, not I think this has surpassed it… My spouse won’t tell me what I’ve spend on this above the purchase price… says ‘don’t want me to be disappointed’.
I’d be tempted to double everything rather than run 2 passes. Why go at 200mm/s when you can go at 400mm/s and 18% or 600mm/s and 27%… a % range in which your powerful laser will be much happier. Down at this lower end, your laser might not be firing as much as you’d think. Most powerful CO2 laser don’t do anything below about 12% generally speaking.
Dominic, I think you are right. Hitting it will 80 watts is a pretty healthy dose of heat.
My only concern with bumping the speed is exceeding the lps response time. Easy to do on these machines, however nobody seems to be able to tell me what happens when you do exceed the response time.
I guess, I’m saying that there are drawbacks with bumping the speed and staying within the technical/physical limits of the machine.
To compute this you have to know the response time of the lps and the dpi to come up with a proper speed/feed relationship.
I think the power he’s using and the material might just be the issue, as you stated in your first post.
I do lots of slate, some lases light, some dark, along with required speed/feed adjustments. It’s the material… I have had the same batch of slate coaster and two out of 5 had a strange variation in the engraving. Under the microscope you could see material differences over a few mm in a specific area of the coaster … it’s just a rock, so to speak, but even they vary…
You’d think that Somehow, it doesn’t work like that, tried it.
Although it does depend on wood. Bamboo not being wood (it’s technically grass) but being very widely available is super annoying i cant get a good result out of it.
Today did some pieces on beech and some other hardwood, with fairly acceptable results.
Tester Beech board, did at 12% @250mmps and 25% @400mmps - results almost identical colour wise, but 25% is deeper cut.
And whatever this wood is on this bottle opener, ran 25/400mmps it came out just cut but absolutely clean, no colour change, had to slow down and run a second time to get any colour out…
And then there’s this wood i had laying about, i suspect beech ? But soooo much different in colouration. Top run 12/250mmps, bottom run 25/400mmps. Both 1mm out of focus.
If you want to change values, it’s much easier to double them both.
You changed the numeric relationship between speed/feed, making it difficult to really relate the two engravings.
250mm/s@12% → 500mm/s@24% – same relationship - 12/250 = 24/500
250mm/s@12% → 400mm/s@25% – not the same relationship 12/250 not = 25/400
I guess your used to imperial measurements.?
You can cut something at many different speeds/feeds, but only a particular speed/feed is ‘right’ for that material. When you use cnc mills and such, there are calculators to give you the specific speed and feed for that particular bit, bit type/material and the ‘machined’ material. Unfortunately that’s hard to compute with precision on a laser with naturally varying products.
Like the key ring, copied the photo and sent it to a couple of ‘cop’ friends… 
Actually i’m completely metric. Potato measurements do my head in.
But yeah, doubling should be doubling, however power is not linear and my LPS callibration is sideways anyway… 12/25 is how i operate presently. Until i replace this 80w to EFR 100w and then recalibrate my LPS.
Don’t follow you here… 
I don’t think any of these are really linear, people ‘plot’ that out and tack it …
Stands to reason, a 100watt lsp should give you a quicker response time…
What you did with the math conversion, just reminded me of the absurdity of the imperial system.
Good luck
“Calibration sideways” is because my 22mA registers at 42% in LB. So, there… cant be bothered to stick a screwdriver into LPS. I wish i could just dump this machine altogether (long story), but its not in the cards at the moment. So i usually do quick tests on new materials for result i need.
Been doing some oak veneered ply book covers (guestbooks/menus, etc) and it lasers well at very specific range only. 12%/250mmps and 3mm out of focus. In focus or at any other speed/power looks rubbish - either ashy mess (too much power not enough speed, cuts through veneer, burns glue to dust) or not enough power - comes too light. Its the first material so unforgiving i have to work with, very narrow workable range. But i make a lot of these, and quick since settings are already figured out. Been trying to do the same with bamboo with absolutely no luck…
The oak veneered ply example…
This is what it looks like if i bump up power to 15%…
Are these also out of focus? It’s hard for me to tell how this is actually working if it’s not focused. I usually don’t try to get things working with the machine out of focus.
Of course you have so much power, don’t know what that can cause… I think you are more powerful than you think…
The meter is showing 42% of the actual current from the lps.
If your numbers are right, along with my math, you have
22/42 = X/100
42x = 22 * 100
x = 2200/42 = 52mA when it lases.
Sure you don’t want to use that screwdriver?
Plasma is nice and pink 3 years on, but i don’t run 8hr a day (sadly).
I wait for this noname 80w tube (well, CDWG, whatever that is) to go pop so i can install my standby EFR 100W one, do a proper calibration of the lps, etc. This machine was a pain in the derriere since i got it, had to heavily mod it’s mechanical parts for it to run proper’ish, LPS blew 25 hours in, came without any kind of meter on it (now run digital, analog will come with 100w). Bought 100w machine only to get 80w tube with 100w LPS, had to fight seller to give me what i bought (100w sustained EFR tube, 1450mm, got 80w sustained 1200mm). Mechanical parts are a joke - think K40 in 900x600 body - no proper linear motion on Y. Soooo many things wrong. Expensive learning experience (don’t really regret that).
Still many mods to do, but will have to wait till 80w pops off to the co2 gas laser tube heaven.
Given the choice (money, really) i’d put this machine to the angle grinder (replace motion, all welded in) and buy similar sized machine with better mechanical motion.
As i said, long story.
As for out of focus, i do a lot of OOF engraving, as i find it gets me better results for what i do, than in focus. Cutting, yes, engraving i usually run OOF to some degree. Only Slate/marble/glass gets in focus treatment.
Have you put a wattmeter on the output to see what’s it’s actually doing?
I’ve found most of us far exceed what is expected of these… surprised how long some of them endure.
You’ve been running, I’m sure, over the tubes maximum current rating… for how long, 3 years. Most people say these tubes are good for a couple years, you’re doing pretty well…
These are an ‘enlarged’ K40… The K40 is a very(^ 2) low cost machine. It doesn’t even control the lps like the standard design of the lps… That M2Nano is quite the creation…
Simple fact, use higher quality anything → higher costs to produce, higher cost to customers for a purchase.
However you have a Ruida, so there is no comparison about the controller being of good quality. By the time you get all the mods you state, you could have bought the $15k machine … lol
I’ve dumped a lot of money in mine also…
I bought it to learn… I have…
Good luck
Mine came with ruida, wouldnt have accepted any of that k40 control…
I could have added 1k quid on top of what i paid to get proper Y motion, belt reductions, proper belts (mine are 10mm), nema23 motors (mine are 17’s) and drivers, proper mirror holders, etc, etc, etc. I did research before buying but apparently not enough. However now, due to all the experience i got i go round fixing other peoples laser f’ups for money
I burned a bamboo cutting board yesterday. I have a sculpfun s6pro. I used 2400 speed and laser power at 97.5%. It burnt the entire board great. Then I used cutting board oil and the image got even brighter. 2 coats worked to seal it up.
