Original subtitles

hey it's Rich the Louisiana hobby guy. you know my last video I talked about kerf offset and it

just stimulated a whole rash of messages that I got uh asking about why my circles are in circles

my squares aren't squares my boxes don't fit in to get fit together my box joints and today we're

going to talk about that just by running a simple calibration in light burn and I'm going to show

you how to do these how to calibrate your laser so that your circles are circles your squares are

squares so uh let's get started okay so I've got my wood set up I checked it on the camera

this is in the right spot it's going to cut out of the top left corner the only thing that I've

got left to do now is I need to just set my cut real quick and this is Basswood two millimeter cut

go ahead and assign that to the layer and we're ready to run this job so I'm gonna run this job

and cut out this 150 by 150 and then we're gonna go and measure it and make our adjustments so I'm

just going to come over here and hit start I've got everything turned on the air assist is on

the machine is on we're ready to go lasers on air assist on Focus set everything's good so I

can just say yes and go ahead and run the job and there you can see it's cutting it out just fine

I'm Gonna Leave This in real time and if you're interested the cut settings are 600 speed 50 power

that is the recommended settings for two millimeter Basswood as you can see it's

hotter on the sides than it is going across the X so the Y is a perfect cut through

as compared to the X which does a little more flashing

and it's almost finished and we can go and take a look at our cut out

and see what we got now there you can see the x is a little more flashing in the background

and we're finished so let's go ahead and go over and measure it now and see what we get

all right here's our final product all right

take it out and what I'm going to do now is let me close this door I can't turn off the uh laser

because then we won't be able to get to the actual settings so what I'm going to do is

move this camera up just a little bit like that and this is our final cut piece right here

so I'm going to take my digital caliper I'm going to make sure that it zeros properly and you really

do need to have a good digital caliper to do this I have my Harbor Freight one which isn't

very accurate uh so that's I like this one I'll put a link down below if you're interested in

seeing this one but so I'm going to come out to the one 150 and this is what I do so now

I take six different measurements so as you can see I've got 149.73 there I've got 149 .64 here

149.69 here so I just take 149.40 there just take six different measurements on the Y and

then I flip it over and do the X and I really shouldn't do that uh that was the x that I did

okay so now I have to do the Y this way you have to keep the orientation proper as well

so I've got 149.36 you can see they're pretty close 149.62

149.55 so I'm going to write down all of these measurements now and I'm going to

do an average of all of those measurements I'm going to actually redo this off camera

write down all the measurements and then use the averages to go ahead and set the curve or

excuse me to set the calibration okay so here we go uh here are the final results

on the Y I came up with 149.71 as the average and on the X I came up with 149.55

so that's actually very close this is a you know factory default on this 8

or 20 watt but let's go ahead and make this even better and fix this so now in

your case you know your numbers may be off you may wind up with a 149 you might be a

whole full millimeter off in One Direction or the other so let's come up here to the

top menu over here and let's click on edit and go to machine settings down here on the bottom

when we bring up the machine settings you're going to see a function here called calibrate access

why do I keep saying access calibrate axis we're going to click on that now it's going to say

calibration of axis x what were you asking for so requested distance my requested distance was 150.

and what did it produce so now we're on the X so I have to put in 149.55

and now you'll see the correction is being done down here this is

a queued change so we're going to write this to the controller

so we're going to click right and that is now done and I always click right again

even though it says uh it was done I click right control the settings written successfully now

I'm going to click calibrate axis one more time this time I'm going to pull down and do the y

axis on it my requested distance again is going to be the same at 150 and on the Y I got 149.71

so I'll put that in here 149.71 and there is our change I'm going to hit right and then I'm going

to hit right one more time so it says controller settings written successfully what I can do now is

save these controller settings just so that I have a backup of the file I would hit save and go to my

drive that has I'm not going to do that right now I'll do that offline but just go ahead and save

your controller settings so that you have them for the future in case you switch computers or

something like that so now we can say OK and we're going to run this job one more time so

let me go load some new material into the laser and run this job again and look at the results

all right so here are the results of the second cut test as you can see I've got 150.09 150.10

150.11 on the Y which works out to 150.01 I just did it three times this time because I knew it

would be more accurate than the first test and then on the X I also came very close 150.03 so

that was the average of all three of those and now I know that I am close enough uh to run accurate

jobs so this makes me feel very comfortable that I'm close enough I could go back into the machine

settings and put these numbers in and calibrate it one more time and I probably will um but you know

this this is close enough for government work as far as I'm concerned here and I think we've

got uh probably as close to Accurate as we're going to get and keep in mind that your focus

has a lot to do with this as well uh those little uh tents and hundredths that it's off so uh if

your focus is not perfect then your measurements are not going to be perfect so you don't want to

refocus the machine while you're doing this test or change any of the variables that are involved

all right so a lot of people are probably thinking well why do I need to do this mine is pretty close

what's the difference between you know 149.5 6 and 150. well there's no difference if you're cutting

a square that's this big but if you're cutting something that might be the size of your work bed

that little uh you know Point whatever that it's off gets exponentially larger the bigger that you

go so if you have like for instance a 400 by 400 work area and let's say you want to cut something

that's 17 inches across well by the time you reached at 17 inches you know that that half of a

millimeter that it's off turns into a much bigger number and if you're putting Parts together if

you're doing modeling or anything like that you're going to notice that difference and you're going

to have to compensate for it maybe by shaving down some pieces of the wood to get it to fit together

and you really don't want to do any of that the a CNC control board is capable of following your

commands combining this with my last video with the kerf well you know you're right out the gate

you're not going to be able to do a 150 by 150 square or 100 by 100 square because of the kerf

so it is a good idea on every machine to run this calibration test I mean you saw

it doesn't take long very very simple to do you know uh just cutting a square marking it

down so this is the first one that I did and I got 149.71 on the Y and I got 149.55 on the X

now and that's the average of all these numbers and the taking the average is important as well

um because it does it does change as it moves with the grain and things like that so the average is

going to give you a more accurate number but um now on this one here it seems if you put them side

by side they seem to be exactly the same size on top of each other but they're really not because

this one here was adjusted and this one is exactly I say exactly 150.01 by 150.03 so that in you know

as far as I'm concerned that's 150 millimeters I could go back again and readjust these numbers

and recalibrate one more time and cut another square and probably get that both of them down

to 150.01 just by redoing the X so you know you can you can get really Precision Cuts using any

laser as long as you have your axises your axes I just have such a hard time with that word as long

as you have your axes calibrated properly you can get 100 accurate cuts and we're not talking about

doing a four foot by eight foot you know bed laser here we're talking about a regular hobby

laser CO2 laser you know something that's not uh a sheet laser so the sheet lasers you absolutely

have to be have to have 100 calibration and of course you know there are other things too on

your CO2 your backlash some manufacturers set up a backlash number on it that you know throws these

numbers off so check in your controller and see what your backlash is it should be set to zero

um now mine came set to 0.02 and which kind of puzzled me and I don't know why it was set that

way but that's the way it was set 0.02 on the Ruida so I actually wound up resetting that to

.00 and running my calibration test and making the adjustments in light burn which I think

is the best way to do it we're designing in light burn you know it should be calibrated

for light burns now let's talk about for a minute about the other factors that are involved here

such as on your diode laser your eccentric nuts as an example I know a lot of people don't understand

what an eccentric nut is so let's cover that real quickly Centric nut is basically when you turn the

nut on the other side of that nut there's a circle a piece of metal and it's thicker on one side and

thinner on the other side so as you turn it puts pressure up against the plate that holds that

wheel gusset in place and the as you turn it it'll get tighter and because that thicker part will

come up and it'll tighten it up so that it doesn't wobble and then if you keep turning it it'll get

you'll get to the thinner part and it'll get loose again so you can turn it forever and it'll get

tighter looser tighter looser as you go around so um you know that a lot of people don't understand

stand that so you have when you adjust that eccentric nut you've got to turn it and try and

Wobble the uh housing as you go and when as soon as the wobble stops that's where you stop turning

that nut because if you keep turning it it's going to start wobbling again so that's one thing are

The Eccentric nuts so before you do these tests you want to make sure that your eccentric nuts

are adjusted properly and then on all lasers make sure that your belts are adjusted properly and

make sure that especially on diodes that your frame is square you know run a square test get

a regular framing square put it in the corners make so you got to have a square frame you got

to have adjusted belts you have to have adjusted eccentric nuts before you can even start this test

real easy calibration to do on your laser very simple nothing complicated about this anyone

can do it if you just follow the Steps step by step and I you know I guarantee you that

if you want your boxes to come out boxes and to be perfectly lined up on the joints

then you're going to need to calibrate your laser that's all there is to it do this calibration test

on all of your lasers when you first get it and you want to also do the calibration test on a

regular basis so if you do like a semi-annual adjusting and cleaning and all that kind of

stuff do your calibration test at the same time because with lasers all lasers whether it's CO2

or diode you're going to have some variations over time and use and the reason why you get

those variations is because you have your timing gear teeth and you have your especially if you're

using bi-directional scan and you have your timing belts and what happens is when it scans to the

right and then turns Direction you get a little bit of belt climb on those teeth which wears the

belt and then of course the belt stretches and anytime you adjust your belts you're going to

need to recalibrate create your laser you have to compensate for on a regular basis you have

to check this for belt wear for a belt climb you know where the teeth take away some of the

material on the actual uh timing belts themselves on co2 lasers for the backlash there are several

reasons why you have to do this and it's something that should be done on a regular basis incorporate

this as part of your regular maintenance and on some users if you're doing this as a business and

you're running a lot of projects I would suggest that running this test on a monthly basis to make

sure that all of your projects are going to be a hundred percent accurate so remember a CNC

machine is capable of 100 percent accuracy so why not make sure that your projects are 100 to

scale so anyway I hope you learned something from this video today I hope you enjoyed it as much as

I enjoyed making it for you and as always I thank you for watching and I'll see you in the next one