Formula for Engraving..Help!!

[Phil Garcia]

I was wondering if anyone has come up with a formula to know how much time it would take to laser engrave a job knowing the settings, i.e. if the size of the engraving is(let's say) 2" x 2" and it's going to be engraved at 50 speed, 50 Power(if power matters in this or not?) at 400dpi...How much time would it take to engrave it????
The reason I am asking this is to figure a cost to charge a customer without running a test of the engraving. Some recommended charges have been a $1.00 a minute. But if the customer ask, is there a cost difference if I want it to be 3"x3" instead of 2"x2", I would like to plug in the figures to get a estimate of run time at a certain speed, power and dpi.
Ok, any answers or is this just stupid to ask.:eek:

[Garrett Nors]

I am working on an excel file and should have it done tomorrow some time... I'm building it for the exact reason you have.

[Dan Hintz]

For accurate times, you need to determine how long it takes your carriage to speed up and slow down from zero to max speed and back and over what distance (the distance will decrease with decreasing speed settings). You'll need these distances, plus the distance traveled at your requested speed (after removing the ramp up/down distance)... once you have that, you can get quite accurate results. The tedious part will be determining these values. It's not hard, but you will have to run a large number of controlled tests... figure the better part of a day, at least several hours at a minimum.

[Phil Garcia]

Thanks Garrett, I glad that I am not the only with the idea. For a minute there I was getting concern that maybe I was spending to much time at the bench.:D

[Darren Null]

It's area you're dealing with, so 2x2= 4. Say that's a minute: $1/4 = 0.25. 3x3 is 9, so it's 0.25x9, so your multiplication factor is
Original price x (0.25x9=2.25) = New price.

So you can reckon on time + materials being about 2.25x the original job, but you've got the same design time to make the 2.25 not quite so scary to the customer.

[Phil Garcia]

Right, however, if the same 2"x2" logo let's say, was to be put on glass, wood, coated metal, granite and plastic, then there would be different run times, power settings and dpi's. If the customer ask, does it cost the same to engrave it on glass as it does wood or plastic, I would like to know the run time to figure cost quickly based on speed and dpi. I think that would be great to figure out on the fly, specially for 1000 piece's or more. I don't know if I am making sense or not about this....I hope I am.:confused: Maybe I should have another Scotch!!:)

[Darren Null]

That'd depend on your particular machine. You'd have to do a test burn of the same thing at the same size on a bunch of different materials. And time them. Pick your fastest material to be 1, slower materials would be 1.25x, 2.7x etc. Glass would probably be quickest, as it's a light burn and 150 dpi (also cheap and fast to calibrate on), so you end up with a table like:

Material embuggerance factor:
Glass = 1
Marble = 3.2
Acrylic = 4
Acrylic (cutting) = 7.2
...etc.

So then it'd be:

Glass burn time x Material embuggerance factor x Number of pieces.

...if a range of sizes are needed, you work out an area factor as above; use the smallest piece as 1, and multiply that in too. Job done. Test burn your image on a piece of glass and you have the whole thing priced and timed.

[Dave Lock]

Out of interest the LaserCut software that we use on the Chinese lasers has this feature built in.

This is from the manual.

http://lincs-hft-club.co.uk/forum/uploads/IMG2-1251285050.jpg

It is only an estimate of coarse but it's not a million miles out. From memory, on a raster job that takes about 40 minutes I found it estimates at around 36 minutes.

[Dan Hintz]

I can't say about the Epilogs, but it's standard on ULS machines (and darn accurate... within a few seconds). The machine manufacturer has the advantage as they know to the millisecond how long it takes their motors to wind up/down and over what distance. Once you have those few bits of info, making a (highly accurate) timing estimator is as easy as pie...

[Dave Johnson29]

I was wondering if anyone has come up with a formula to know how much time it would take to laser engrave a job knowing the settings,

Phil,
I am including that in some software I am developing. See this thread and notice the third pic.

http://www.sawmillcreek.org/showpost.php?p=1191345&postcount=9

The software is calibrated using some Corel layouts that you run and time with a stop watch. So far it is working within seconds of the real burn time. That last page will be cleaned up a lot as it is displaying a lot of stuff that is not needed by the operator but I need to see the data and calculations during development.

The software also allows recording of settings for future use for an unlimited array of materials. Still working on it though. :):)

[Phil Garcia]

Thanks Dave that sounds and looks really great. And thanks everyone else for your inputs, I think this is real important to have. It would really help on the buz side.:D

[Garrett Nors]

Well it looks like I'm not going to be able to do it like I thought. I ran some real world tests and I just can't get the information I need. The laser's overlap on the x axis completely throws me off. I was thinking of just trying a vector line test but I don't think it would do me any good.

Here are my results in case anyone is interested.

100s/150dpi - 2"x2" - 0m36s
100s/300dpi - 2"x2" - 1m12s
100s/600dpi - 2"x2" - 2m24s
050s/150dpi - 2"x2" - 0m41s
050s/300dpi - 2"x2" - 1m24s
050s/600dpi - 2"x2" - 2m48s
025s/150dpi - 2"x2" - 1m03s
025s/300dpi - 2"x2" - 2m06s
025s/600dpi - 2"x2" - 4m12s

100s/300dpi - 2"x6" - 1m53s
100s/300dpi - 6"x2" - 3m34s

I will definitely be purchasing that program if it works as advertised! I am fed up with math for one millennium :)

[Martin Boekers]

I guess this would all change per piece if you did one up or quantities as well if the quantities were layed out horizontal or vertical.

You should be able to give him a ballpark figure from data on previous jobs and let him know that this is an est and he will be charged by actual laser time, if thats how you bill.


Marty

[Phil Garcia]

You gave me a great idea however, by getting a base line on the speed and dpi, a formula could be done. I.E. if at 50 speed 600 dpi it takes 2 min., then at 25 speed at 600 dpi it would take 1 min.(right, that's simple enough and we all know that, right). So, I will work on a base line per dpi and per material and when it's ready, I will let you know. Of course it would only be for my Epilog which is 35 watts. Thanks guys.

[Dan Hintz]

if at 50 speed 600 dpi it takes 2 min., then at 25 speed at 600 dpi it would take 1 min.(right, that's simple enough and we all know that, right)
No, and that's the problem, it's not that simple. That does not take into account ramp up/down speed and time. Time a 1"x2" block at 100S, then time a 12"x2" block... the second one will not take 12 times as long.

[Phil Garcia]

Got it, I guess I will just have to spend the time to time engraving speed's at different dpi's. Sometimes, you just have to do it like Nike.

[Rodne Gold]

Pricing on a time based model is not ideal , there is a price the market, customer and item will bear and its thru experience and a bit of market research that you determine this.
On a time based model you will often be way too pricey or way too cheap.
Apart from that , if your laser is slow, or you using high DPI to engrave deep cos your laser is less potent , you are charging your customer for its slowness compared to another faster more powerful laser.

[Bob Davis]

Rodne, I couldn't agree with you more.
Just for another complication of it, the GCC lasers have a setting in the driver for "cluster" where time can be saved by not having the head traverse large blank areas. And if the job has lines of text you would need to measure each line and then add them up...
Why the focus on time? Lasers are quick, and the vast majority (of our jobs anyway) take longer to setup than to actually engrave. The customer is purchasing a result, not your time, and you should charge what the market will bear.
I really hate it if a customer says "Is that all it costs?" That means I have left money on the table. I also don't like it much if I don't pickup a job because the customer thinks it is too expensive, but if that doesn't happen every now and again I know I'm too cheap... and as I said, I really hate that.

[Stephen Beckham]

Got to go with Rodne here as well. IF you estimate $10 on a job and it actually takes 13.253642 minutes - are you loosing $3 and change? No - you gained $10 because you made the sell. If you estimate $10 on a job and it takes 26 minutes - you don't know your laser very well. That comes with time. I've been in it for almost four years now and I've got a pretty good sense of how much it's going to take for different sizes - not to the minute.second breakdown, but by looking at the item and asking myself "how much would I pay to have that etched?" and a guestimate of how long similar items have taken - I give pretty accurate quotes.

Have I been grossly off before? Yea - that's when I tell the customer they got a bargin and that future items if repeated would incur the additional costs by how far off I was. It let's them concur that sell (business 101 - let your customer feel a win without breaking your bank) and gives them an honest assessment if they come back with additional similar items. It also builds good customer relation because you show that when you make the mistake, the customer will prevail - earning the respect of that customer.

Keep in mind - I'm not telling you to give it away - just keep pluggin away and things will become second nature. I believe that most of us (I too) who start some excel spreadsheet or some macro or anything similar to help with this issue - reach a point where it becomes unnecessary.

[Scott Shepherd]

I'm with Rodney and Stephen on this one as well. If I ever get to a point where I have to fight over pennies and seconds, I've transitioned into the wrong market for me.

I would imagine Trophy's are that competitive, where .05 cents matters, but for 100% of my work, it's not that critical. You have to be somewhat aware of what the cost would be at your competitor is they selected them.

You can do a name tag in 5 minutes, start to finish. So it's worth $5 plus material, plus the catch, or maybe $6 total? Now go find someone that will sell 1 name tag for $6. For 1, you can get $15, if not a little more. So your pricing model would have lost you money on that deal. However, they can't go anywhere in town and have one name tag made for $6.

You have to learn your market to some degree and that just comes with time.

[Martin Boekers]

Rodne is a wise man!

If it helps in early stages of learning your laser keep an informal log as to substrates, powers, time etc. There can be many variables but as you get better you will be able to figure a fairly acurate time.

If your doing many single pieces focus on the first then turn focus off for the rest. Focusing takes a fair amount of "reletive" time.

When I do alot of metal plates, it's nice to have an outline to trim square to. Instead of rastering the outline around the live area (as previous manager recommended) I vector the outline, by doing this I cut engraving time typically by 2/3s as the raster only does the type and skips the space inbetween. A quick vector outline and I'm set.

If the order is quite large say 1000 name tags it's usually to my benefit to run a test at different resolutions to see how much I can cut laser time while still keeping quality high.

I tend to run most every thing at a higher resolution if possible as it seems most local competition tends to run lower and there is a visible difference in the quality of the product.


Marty