Acceleration & max/min power basic questions- Chinese area

This may be really simple to answer - I don't know - and I'm almost embarrassed to ask it, as I can usually figure stuff out.

The Universal simply rasters and cuts at X speed - whatever it is set at. The weight in the head is next to nothing, so it's always at high speed if the software was set for that.

This Goldenlaser has settings like Ruida's, I suppose, where there's acceleration as well as speed, and a maximum power and a minimum power to set for each colour's path.
I've watched it raster-engraving, and see how you need a landing area and a take-off area each side of the substrate for acceleration and deceleration,
and I've watched it a little cutting cardboard, where it accelerates up to a faster speed along the straights, and slows down for shorter straights.

I generally set it for acceleration of 10 to 20 for cutting, and the speed in mm/sec depending oni the thickness & substrate.
I've had terribly wobbly letter corners etc when acceleration was set much higher. (I can set acceleration as high as 3 or 5000 in the Goldenlaser software, for what it's worth- only feasible in rastering)

Power, I've generally set Max at a figure, and minimum at 2% less than Max, eg 72 & 70% or 100 & 98% etc

My first question is what is the point or reason for a max & min power setting when I'm not interested in the minimum - I want to to run at what I set it at?

Secondly, when accelerating on a straight, cutting, is it capable of increa At what stage is the maximum power going to happen, on a long straight, or a rounded curve. I see it slowing down for a corner - does that mean it lessens the power as it slows? It does not seem like it with my 2% range, but then some corners on thicker substrates have rather average-looking back edges to the cuts on 15 & 20mm acrylic.

I have not bothered to waste any acrylic testing various ends of the failure scale to figure extremes of speed & power out - just too busy getting important things done! i did notice that if I set a 10-15% difference between max & min, it fails to cut much at all, as if it prefers the mininimum.

Sorry if these seem basic, but my head is in Universal mode, and I'm trying to comprehend the variations available in chinese mode, and why they'd be needed!

Thanks!

I don't know if this would help or not but Russ does and excellent job explaining how the min max works in a series of videos
https://www.youtube.com/user/SarbarM...arch?query=min

Working your Universal is akin to driving a Luxury car (your pick ;) )-- you get in, fire up the engine, put in gear, and get to your destination, easy peasy...

Your Goldenlaser is akin to a driving a 1965 Mack truck with a 5-speed main and 4-speed auxiliary transmissions, and a 2-speed Eaton differential for good measure... ;)

In short--almost everything about the Universal is fully automatic, and almost everything about a Chinese laser- isn't!

As for your minimum power settings- you mentioned how Chinese machine speeds up in the long straights, and slows down for short straights (and corners)-- So what do you suppose happens power-wise when the machine does slow down? If you watch your Universal as it does this, you can visually see the power reduction at the beam spot--and it's all automatic. Since nothing is automatic with a Chinese laser, you get to choose how much the power reduces when it slows down! And that's what your "min" power settings are for.

My software also has a separate option that allows me (or MAKES me is more like it) choose how fast circles and arcs will cut; I can enter any diameter and give the machine a speed and that's what it will do. But since these speeds are typically less than the main set speed, then the min power comes into play.

How much to reduce the minimum? I cut about 5 watts from 60 is all...

Thanks Ernest, and Bill.
I understand the analogy, Bill- yes I'm spoiled, but I still need to know how to get the best of the 1965 Bedford truck (couldn't afford a Mack)...

To my naiive mind, I want the max power all the time, you see, and I'm afraid that if I give it a minimum figure that's too different, it'll want to run itself on the minimum all the time, cheating me out of precious seconds/minutes/hours...

I put 7 hours yesterday into cutting heaps and heaps of letters from 15mm acrylic, and I have to put the 20mm sheet back in to finish that job- it's been about 20 hours on the go over a couple of days & evenings.

(I have just added in air-compressor air into the air assist line, to help blow out any underneath fires that like to start themselves on those thicker sheets.)

Thanks.

Quote:

---

Originally Posted by Kev Williams

Working your Universal is akin to driving a Luxury car (your pick ;) )-- you get in, fire up the engine, put in gear, and get to your destination, easy peasy...

Your Goldenlaser is akin to a driving a 1965 Mack truck with a 5-speed main and 4-speed auxiliary transmissions, and a 2-speed Eaton differential for good measure... ;)

In short--almost everything about the Universal is fully automatic, and almost everything about a Chinese laser- isn't!

---

I have only used a Universal Laser for one evening. We needed to cut a bunch of 8" gears out of plywood. We loaded up the same dxf as was used on my Chinese laser, set the power and speed and it choked on the gear teeth. Something about each tooth being comprised of dozens of small line segments slowed it down to a crawl, like 2 mm/sec when it should have been 20. My Chinese laser on the other hand was not bothered by all those segments. We thought that the expensive mainstream laser would get them done faster - or at least more accurately, but that wasn't the case.

That's odd, Rich... but I'd blame the software rather than the machine...!

The Youtube videos were good- but it still leaves me a lot in the dark- having to do my own trial & error to suss out our own best variables between max & min...
and I don;t have the time right now!

I've also figured a bit of a problem, or an answer to it- an past fire melted a tiny hole in the air assist line, so not all air was coming out of the nozzle.

it is now! Much better!

This was the one of the first jobs I ever did on my Triumph.
All was well, EXCEPT, check out the corners of the large rectangle...
Attachment 374318
lots of overburn, and I did not want to sand down 150 of these...

This is when I found out what the min power was for :)
--after a lowering the min power a few watts--
Attachment 374319
-- perfect corners :D

Quote:

---

Originally Posted by Ian Stewart-Koster

That's odd, Rich... but I'd blame the software rather than the machine...!

---

Not sure what you are getting at. Both the machine and the software are by Universal. Surely it was the software at fault, I don't think there was a problem with the mechanics of the machine.

I'm really not a fan of Russ's videos, he makes too many assumptions and guesses based on assumptions

After watching the 3 videos on Max/Min settings, I didn't really find his 'conclusion' very much help, so I did some tests tonight in 20mm clear acrylic.

I have in the past been cutting 20mm acrylic, Max at 99 to 100% power in the software, min at 97%, speed 1.2mm/sec, and acceleration of 10.

I decided to set this on speed of 5mm/s so I could see how deep and what shape the corners were etc.
After trying 2 runs, one with power 99%/97% (max/min) and speed 5mm/s, and the second with a minimum of 50%, actually the 99/50% path looked better than the 99/97% path.

I changed accelerations to 20 tries again, and then to 50 - no real difference.
I altered speeds, and found it all inconclusive.. some variations had a better cut at 99/50%, and some were better at Power 99/97%.
There was no gradual improvement as I changed one thing at a time and compared ity with before. NONE.
Generally the 99/50% gave a better path, but only GENERALLY.
A few of the other paths were better at times.

I tried it shallower and also deeper. Inconclusive. Faster & slower...
I occasionally stumbled on a good combination option, but it often failed to replicate itself... Weird.

I found this thread I posted up awhile back about some speed changes I made, with noticeably better results I got, maybe it will be of some help--

http://www.sawmillcreek.org/showthre...B+acceleration

My tests have been fairly inconclusive so far...but yesterday I lasered some 20mm acryluc with Max 100%, min 98% as usual, & speed 1.2mm/s, acceleration 10 (units are ?), and it performed as usual.
I tried a 2nd time, with the minimum at 67%, max 100, no other changes - minor improvement in bottom edge quality.
Tried 3rd time, with 35% as minimum - just slightly better again. Tried 30% - worse.
It also was better slowing it to 1 mm/sec, which is the speed I can cut 25mm acrylic at...

Sorry, but I can;t explain the whys & wherefores. I have acceleration set at 10 - that's the lowest figure the software will allow.
I set it low so that it gives the bottom edge of the cut time to catch up to the top edge before turning a corner.

Maybe I should increase the acceleration a bit, and see if that helps?

(But last time I did increase the acceletarion on a perimeter/vector engrave, it was terrible.)

This afternoon, I did a heap of 20mm acrylic letters - max power 100% in the software, (running at 18 mA, actually, which is really about 65% tube max P)
Minimum power 45%, speed 1.2mm/s, acceleration 10.

The cuts were lovely, and the bottom corners were not a bit abstract, but very neat and clean.
I'd formerly used minimum 98%, but the low minimum was miles better in cut quality.

For the record, I spend a lot of today cutting 25mm letters: set power max 100%, minimum 50%, speed 1.0 mm/sec, , acceleration 10, overlap 3.2mm.
Absolutely beautiful!
P.S. Cleaned the lens with my wife's Norwex non-scratch spectacles cleaner- way, way better than IPA and a Q-tip.