100% Speed is not universally the same

[George M. Perzel]

Hi gang;l
I have noted recently a lot of discussions in the threads comparing speeds and power settings on various machines, particularly in comparing some Chinese units to USA or Euro units. In general 100% power on a 30 watt unit is approx to 50% power on a 60watt unit-most people mention the power of their unit when talking settings but seldom the max speed of the unit. Some Chinese units run at about 25% of the speed of my Laserpro unit (42 ips).
This has caused a bit of confusion for some who have expressed concern that their unit cannot cut similar material as fast as others who have posted settings- 100% speed in my Ford truck is not the same as 100% speed in my Porsche.
Best Regards;
George
Laserarts

[Robert Walters]

Most folks have what their machine is (including wattage) in the signature line.

Then it would be:

(Their_wattage * their_percentage) / Your_wattage = your_percentage

OR

Their_wattage / Your_wattage * their_percentage = your_percentage

Example:
Their_wattage: 60W
Their_percentage = 50%
Your_wattage = 40W

(60 * .50) / 40 = .75 or 75%

OR

60W / 40W * .50 = .75 or 75%


Speed I can't address as the IPM (Inches per minute) isn't that universally known or available.

[George M. Perzel]

Robert;
Thanks for the math lesson but think that you have missed my point completely
Best Regards;
George
Laserarts

[Rodne Gold]

in terms of cutting , most lasers will cut at the same real vector speed as cutting is normally a LOT less than advertised max speed/max vector speed and vector speed is normally a LOT less than linear scanning head speed after ramping (which is generally the advertised maximum speed)
If you cut thru a material with a certain power (ignoring power density) the next laser will also be able to cut at that same real speed if it has the same power or it's speed will be relative to a proportion of its power. The 0-100% speed scale manufacturers allow in their software may or may not be linear and may refer different actual speeds dependent on whether the laser is scanning or vector cutting. Same can also apply to power ratings in terms of mentioning a percentage , as it's really power density that matters. For eg 25w on a spot of 1mm diameter is NOT the same power density as 50w on a 2mm spot size as the area of a 2mm spot is not merely double a 1mm.
That and material differences and the fact that a 50w tube can be under or over 50w is the reason speed/power settings don't translate well between different models and even within the same models.

[Gary Hair]

Hi gang;l
I have noted recently a lot of discussions in the threads comparing speeds and power settings on various machines, particularly in comparing some Chinese units to USA or Euro units. In general 100% power on a 30 watt unit is approx to 50% power on a 60watt unit-most people mention the power of their unit when talking settings but seldom the max speed of the unit. Some Chinese units run at about 25% of the speed of my Laserpro unit (42 ips).
This has caused a bit of confusion for some who have expressed concern that their unit cannot cut similar material as fast as others who have posted settings- 100% speed in my Ford truck is not the same as 100% speed in my Porsche.
Best Regards;
George
Laserarts

And that's why I try to make it a habit to express my settings as either watts and speed or my % settings along with the max of each so they can calculate it themselves. My posts are likely to read something like "100%power and 80% speed with my 30 watt 80ips machine, adjust these settings to match your machine." It's not really rocket science but too many people either don't understand it or don't know the speed/power of their machine. How many know that the vector speed and raster speed are different on most machines? Mine is 80ips raster and 40 vector, for example.

Gary

[Bill Cunningham]

I find that my current 100% speed is nowhere near the 100% speed I had when I was 20

[Dan Hintz]

George,

The two most common machines on here (at least at the moment), Epilog and ULS, are in the 75 ips range. The lower Trotecs are, as well, with the higher-end Trotecs in the 150 ips range (if memory serves), so about double. Most likely why the majority of settings posted are listed at "100S", meaning 75ips.

The Chinese machines are usually quite a bit less, often clocking in around 35-55 ips.

In academic parlance, "We leave it up to the reader" to make the conversion...

[George M. Perzel]

Hi Guys;
Gary got it- that's the way to describe settings so anyone can do the math.
Bill- Amen, brother, Amen
Rodne-am really confused-are you saying all lasers cut at the same speed??? I agree that two lasers with the same power can cut at the same actual speed (forget the damn % stuff) and get the same results-approximately.
Best Regards;
George (soon turning 70)

Laserarts

[Larry Bratton]

The faster I go the behinder I get
Larry
(soon to be 66)

[Robert Walters]

Thanks for the math lesson but think that you have missed my point completely

I thought I did when I said "Speed I can't address as the IPM (Inches per minute) isn't that universally known or available."
or at least in part

[Michael Hunter]

George is right, but it is not very helpful.
Most people only know their own machine and even then, don't have all the details. (The non-linear speed scale of the Epilog makes anything other than 100% speed completely meaningless to anyone except those with an identical machine).
Nonetheless, power setting tips ARE useful across the different machines, even if all you can get out of it is fast, slow, high or low power etc..
So don't give up - just give the best info you can and let others make their own judgements and adjustments.

[Richard Rumancik]

Gary's way to express it is the best you can do. I think that what Rodne is saying is that in actual practice it is an exercise in futility to compare different lasers. If Rodne isn't saying that, then I am. To restate some of his reasons and elaborate on why it is futile:

1. the percentage scales used by the manufacturers are not necessarily linear eg 50% speed does not necessarily mean .50 x max speed and 50% power does not necessarily mean .50 x laser output
2. use of ramping can alter relationships
3. curves and straight lines will cut differently
4. the effect of ppi (pulses per inch) or use of continuous mode is not taken into account
5. a laser tube that is nominally 50 watts could be 60 watts or 40 watts (or even less) and the user usually does not know which because only a few people have a test instrument.
6. spot size has a factor - using a 2.5" or 2" lens is quite a bit different than 1.5" FL lens.
7. many manufacturers don't spec the maximum cutting speed of their lasers - just max raster speed.
8. different manufacturers have different interpretations of what the % speed means. ULS and GCC specify vector cutting speed as a % of max raster speed. (Which does not make much sense). Epilog specs vector speed as a % of maximum vector speed. I can't comment on Trotec or others.
9. I have seen claims that an 80 watt Chinese tube is equal to a 40 watt Synrad. I can't confirm, as I don't have a Chinese tube. I'm sure some will disagree based on a sample of one. Perhaps there is more variability in the Chinese glass tubes. Synrad tubes (for example) are usually toleranced about plus 20% minus zero% (meaning a new tube will not output less than nominal.)
10. Cleanliness and condition of optics can make a 10 or 20% difference in results.

There's probably more reasons but these should be adequate to make the point. Until the laser manufacturers offer built-in sensors where the machine can self-monitor the laser output and display actual delivered watts, along with a display of actual/average speed, comparisions are very tenuous at best.

[Rodne Gold]

Yeh, I was saying what Richard expanded on.
In terms of power output , it's pretty likely the higher quality glass tubes do put out rated power and in fact more if you raise the firing milliamps but overdriving em will fry em real quick in fact it seems to actually get the rated hours lifespan you need to drive them at below max current. Have a look at some of the documents ar www.recilaser.com
Even if they do give rated output , from what I have seen of the output, the spot sizes are not equal to my RF CO2 lasers , so their power density is lower due to larger spot sizes. Ive seen output of an 80w "cheap" glass tube thru a 40mm lens and it wasnt nearly as detailed as my 30w tubes thru a 50mm lens , however the cost of the cheapy is $190 vs $4000....
The reci tubes are 3x the price and evidently a lot better re spot size etc..
ive ordered my new larger format machine with a Reci ..I hope I havent wasted my money compared to a cheapy tube..
Albeit It's not part of the original thread , heres some info on the Reci which is supposedly the best glass tube

The working current: test current is 29mA. Maximum working current is 29mA. The running current must be kept below 27mA. The life span can reach 10,000 hours if the current is kept below 25mA.

Output Power: Itsoutput power can reach 85w. The production process of the tube is standardized,so the output power and output model are guaranteed. Its cutting effect and cuttingspeed is the same as 90w laser tube of other brands. (The other laser tubes arehandmade and its quality is different from one tube to another)

Long life span: We have catalyst plating in the innerwall of the laser tube. Designing lifespan is 10,000 hours and the warranty is10 months. (No catalyst technique is used by other laser tubes manufacturers.Their lifespan is 3000 hours and the warranty is only 3 months)

Appearance: The tube is sealed by metal material. It is industrialproduct.

(Nometal material is used by other manufacturers. Their tubes are handmade andneed extra water cooling for front and rare mirrors)

Tube frame: Thisis exclusive design for Reci laser tube. You can use it to install our lasertubes into the machine to spare the freight cost. This frame is shockproof andmakes sure the tube will not move during the transport. (No frame is providedby other manufacturers.)

Length: Thelength is only 1.2m. It reduces the volume of the machine and minimizes freightcost.

(The length of other 80w tubes is 1.64m. 300mm must be projecting in themachine. That costs more for machine panel, package and transport)

High photoelectric conversion rate: No compression typewater chiller should be equipped. The output power will decrease for less than1w when the cooling water’s temperature is 42℃. Its heat productivity is lower than 60w tubes of other brands. (Otherbrands: The output power decreases rapidly when the cooling water’s temperatureis 42℃)

Very good engraving function: It can compare with 50wlaser tubes of other manufacturer. The tube can engrave with 5mA workingcurrent when there is still no laser beam in the laser tube. (Other brands: Noengraving function)

Warranty: 10months, international warranty service, Reci charges the freight for exchangingthe defect tube.(For others laser tube brands: warranty for3 months, no international warranty service）