12 – Laser Beam Alignment Setting – Dream or Nightmare (42:34)

00:22

well welcome to my warm and comfy easy

00:25

suite I’ve just completed the Edit of my

00:32

benches in laser beam alignment and now as a

00:36

thinklaser customer what I’m just about

00:38

to show you in the following video is

00:42

not something that you need to do the

00:46

machine that you have bought is a very

00:49

good machine I know because I’ve had a

00:52

go at pulling it to pieces

00:53

I love the machine but if I see

00:57

something that isn’t quite to my liking

01:00

I’m not in the least bit worried about

01:02

pulling it to pieces and doing something

01:04

about it now I came across a small

01:06

problem with laser beam alignment which piqued

01:10

my interest the system of

01:14

beam alignment on this machine is no

01:17

different than that of thousands of

01:19

other machines that come out of China I

01:21

had to have a different machine with a

01:25

different beam alignment system that

01:27

I’ve been used to so I found ourselves

01:30

in a certain amount of deep water when I

01:34

started fiddling with the beam alignment

01:37

system on this machine

01:38

now the beam alignment system is not

01:40

something that you will have to fiddle

01:42

with and then every day user if there’s

01:46

a problem you will call in your service

01:48

tech I have a responsibility to you as I

01:51

think later customer to make sure that

01:54

you don’t invalidate the warranty on

01:56

this machine what you see me do is not

Transcript For Laser Beam Alignment Setting – Dream or Nightmare (Cont…)

02:00

something that you necessarily need to

02:02

do want to do or have to do I’m afraid

02:06

of old school engineer and warranty plan

02:08

warranties don’t mean much to me if I

02:11

see a problem and I see a solution

02:13

I’ll go about fixing it sometimes it

02:19

gets me into trouble sometimes it leads

02:22

me into new and green pastures now what

02:28

are you going to see today is a

02:30

completely different approach to

02:32

aligning and setting up the Machine the

02:35

flexible standard kit that mounts the

02:38

mirrors on these machines is a piece of

02:40

kit that’s used on all sorts of machine

02:43

design and as such it has to be flexible

02:47

now that flexibility comes at a cost and

02:52

that’s complexity of set up now

02:56

complexity of setup is not something

02:58

that you will ever encounter because the

03:01

mirrors are already factory preset the

03:05

most you will have to do is probably

03:07

just tweak the mirrors a little bit but

03:10

even then I would suggest you probably

03:12

don’t because there is no reason why the

03:15

beam will guide an alignment

03:17

unless you start thrashing the machine

03:18

around so you’re going to join me in a

03:20

session where I will explain what

03:23

beam alignments all about now it’s your

03:26

interest rather than for your doing what

03:29

it has done for me as made me realize

03:33

that I think there’s an even better way

03:37

that maybe another adventure that you

03:39

watch me and it take or maybe it’s

03:42

something I should do behind closed

03:44

doors and you’ll never know it really

03:47

things on how to glaze a view my

03:50

reengineering approach so sit back relax

03:56

and enjoy but don’t do thanks very much

Transcript For Laser Beam Alignment Setting – Dream or Nightmare (Cont…)

04:02

let’s get on with the video well welcome

04:08

to another lightblade learning lab I

04:11

think you get the impression this might

04:13

be a quite a relaxed session I think

04:17

you’ve got that wrong

04:19

it’s going to start off in a very casual

04:22

way it’s all about beam alignment today

04:26

now beam alignment is actually a very

04:30

simple subject but it’s a bit like

04:35

entering a jungle without a map you can

04:40

very quickly get lost and not understand

04:43

which way to turn

04:45

you need a compass you need a map and

04:47

you can find your way through the jungle

04:49

what I’m going to do to start with is

04:51

give you an outline basically provides

04:54

you with the map before we enter into

04:57

this jungle I’m not going to touch this

04:59

machine myself again because already I

05:02

wouldn’t say burned my fingers but I

05:05

learned the hard way that this machine

05:07

is not the same as my other Chinese

05:11

machine over there and that it requires

05:13

a completely different strategy to set

05:16

this one up although I shall be focusing

05:19

on this machine anybody with a red sail

05:22

clone will have similar problems because

05:26

this is the style of machine that you

05:28

will have but anybody with the China

05:30

blue machine like I have over there well

05:33

I’ve already got well documented

05:34

procedures for calibrating and setting

05:37

the beam on that but these procedures

05:41

the basic principles this road map will

05:45

help you as well to understand how you

05:47

should go about and why you go about

05:50

things in a certain way in a certain

05:52

order I just want to lay down a few

05:54

ground rules before we start this piece

05:58

here all around the outside it is what I

Transcript For Laser Beam Alignment Setting – Dream or Nightmare (Cont…)

06:02

would classes on this on this drawing

06:06

I’ve got here it’s called the light

06:07

blade floor and that is this flat

06:11

surface here upon which everything is

06:13

mounted then we got the top surface of

06:17

the gantry which is this piece here now

06:20

on this top surface we’ve got a bearing

06:22

rail and the head runs backwards and

06:25

forwards on this bearing rail and then

06:27

we’ve got the Y bearing rails down the

06:31

side here now the other key

06:33

here is that this bearing rail is 90

06:37

degrees to these two wine bearing rails

06:41

where we’re going to start off with a

06:43

plan view of the machine this is typical

06:45

of any of these small laces we’ve got a

06:47

later two we’ve got our two 45-degree

06:50

bending mirrors another 45-degree mirror

06:53

to bend the beam down towards the head

06:56

and the other key thing here whenever we

07:00

bend the corner we’ve got to finish up

07:03

with the beam running parallel to the X

07:06

or the Y bearing row that’s a that’s an

07:10

absolute fact we cannot deviate from

07:13

that what’s the problem well the problem

07:17

is on this machine with all sorts of

07:21

degrees of adjustment and non adjustment

07:26

for example the head mirror itself it

07:30

totally non adjustable it is what it is

07:33

it’s fixed and all it does it moves

07:36

backwards and forwards along this x axis

07:39

it’s angle can be adjusted very slightly

07:43

but it can’t be adjusted that way and it

07:46

can’t be adjusted in and out we’ve got

07:49

one mirror which is absolutely fixed in

07:52

space we’ve got this second mirror here

07:56

which is at the end of the beam you can

Transcript For Laser Beam Alignment Setting – Dream or Nightmare (Cont…)

08:00

move it in X you can move it in Y you

08:02

can rotate it a little bit and you

08:05

certainly got adjustment on the mirror

08:07

to just tweak the mirror in addition to

08:10

that there’s a further plane of

08:12

adjustment which is up and down which I

08:15

haven’t shown on that picture and then

08:18

we’ve got mirror number one which is the

08:21

one that turns the laser as it comes out

08:23

of the tube now that’s only got

08:25

basically two degrees of freedom on it

08:28

it can move this way across the plane of

08:31

the beam it’s got a lot of twist

08:32

adjustment on it and it’s also got some

08:35

minor adjustment on it for just tweaking

08:38

the mirror the lace of itself had got

08:40

horrendous amounts of adjustment on it

08:42

you can swing it around you can lift it

08:44

up and down

08:45

you can twist it from end to end you can

08:48

twist it from side to side you can

08:49

basically swing the hold of that beam

08:51

around in space like that this is what

08:53

we’ve got to finish up with but how do

08:56

we get there that’s the problem ideally

08:59

we’d like to finish up with this beam

09:00

here running parallel to that bearing

09:04

rail there is it absolutely essential as

09:07

I kick the two round by five degrees you

09:09

can see what happens it misses the

09:11

mirror it’s got to hit the central point

09:13

of the mirror otherwise it won’t reflect

09:15

okay let’s look at the next picture

09:17

we’ve corrected that problem now we’ve

09:19

moved the mirror in that direction there

09:21

and we caught the beam on the center of

09:26

the mirror but because the laser is

09:28

tipped over at five degrees and this is

09:31

45 degrees we get a reflection off of

09:34

that surface which is there you could

09:37

say that we just move this mirror over

09:39

this way and catch the beam well and

09:43

then we can steer it back towards this

09:46

one that is true we could if there was

09:48

enough adjustment on there but the

09:51

problem is we’ve broken golden rule

09:54

number one we are no longer parallel to

09:57

the bearing row so we can’t do that what

Transcript For Laser Beam Alignment Setting – Dream or Nightmare (Cont…)

10:00

we’ve got to do is adjust this mirror

10:03

here let’s see what happens when we

10:05

adjust this mirror fine but we can we

10:08

can put two and a half degrees of

10:10

rotation on this mirror and we can make

10:13

that beam round parallel here again

10:15

brilliant so we’ve got a degree of

10:19

freedom here and we have got some

10:21

ability to fix the problem that’s caused

10:25

by misaligning a plain view of the laser

10:28

tube and we’re back in back on plan

10:32

again so now this is running parallel

10:35

what can we do here so I leave my

10:38

biscuit to come into play now this makes

10:42

a great mirror doesn’t it until I eat it

10:44

we’ve already agreed that we can’t move

10:46

the mirror out of position because if we

10:49

do the beam will be non parallel to the

10:52

Royal so that technically means there’s

10:54

only one position in if you like the x

10:58

axis

10:59

direction for this mirror to be sitting

11:02

and that is absolutely in line with this

11:06

mirror so that it can pick up a parallel

11:09

beam on its center that’s parallel to

11:12

the bearing row we already said this

11:16

mirror has got zero degrees of freedom

11:19

on it

11:19

we need a beam to hit the center of that

11:22

mirror and it’s got to run parallel to

11:24

this bearing row

11:27

therefore we cannot have although that

11:32

was moving this mirror this way would

11:35

satisfy the parallelism in this plane if

11:38

it bounced off the mirror here it would

11:41

not be parallel in this plane so by

11:45

default there is literally only one

11:48

position for that mirror to be in so you

11:52

cannot mess around with these mirrors

11:53

very much and I’m very surprised that

11:55

this mirror on this machine has got so

11:59

many degrees of freedom it doesn’t need

Transcript For Laser Beam Alignment Setting – Dream or Nightmare (Cont…)

12:03

them and it doesn’t need them because

12:05

the head is fixed okay so this is the

12:09

fixed head and underneath this

12:12

adjustable plate at the top here we’ve

12:14

got a gap this head here and this piece

12:19

are completely solid and fixed they’re

12:22

fixed to the bearing and the bearing

12:23

rail underneath so there’s zero

12:26

adjustment on there except for a small

12:28

amount of Swing on this plate just to

12:31

guide the beam okay so you see what it

12:33

looks like in reality here’s what it

12:35

looks like in detail now I’ve done a

12:37

fairly careful drawing and analysis of

12:40

this machine I’ve looked at it in great

12:43

detail and I’ve done all sorts of

12:44

measurements on it and I’ve done a good

12:46

detailed analysis of the actual head

12:49

assembly itself and what’s inside here

12:51

the rate is obviously the path the ideal

12:54

path of the laser beam now when I say

12:57

the ideal path of the laser beam I’m

13:01

going to explain that a little bit more

13:03

detail in a few seconds what I want you

13:06

to do is look at this drawing to start

13:08

with now here

13:11

is the mirror so allow a 25 millimeter

13:17

mirror it’s set inside a recess and the

13:22

exposed part of the mirror is only 20

13:25

3.1 millimeters diameter well I say 23.1

13:32

millimeters diameter if you were a laser

13:34

beam coming at this here’s what you

13:38

would see you’ve got a hole in the front

13:41

which is there and I’ll just put those

13:42

two dots there to show you how they

13:44

tally up and that’s the first thing I’ve

13:49

got to see I will see the entry to the

13:51

hate but then hiding behind that I’ve

13:54

got a mirror but because the mirror is

13:57

slanted back at 45 degrees it’s no

14:00

longer 23.1 diameter in fact it becomes

Transcript For Laser Beam Alignment Setting – Dream or Nightmare (Cont…)

14:04

an ellipse but of course I can’t if I

14:10

was the laser beam I can’t see the four

14:12

mirror so that’s what the laser beam

14:14

will actually see by way of a mirror

14:17

it’s a very strange shape and I’ve drawn

14:21

this laser beam at 10 millimetres

14:23

diameter now most people are going to

14:26

say well the beam is only five or four

14:28

or five millimeters diameter well I

14:31

think we demonstrated the last time we

14:34

looked at mirrors that that beam is

14:36

something other than what most people

14:38

think it’s influenced its power its heat

14:43

extends way out beyond maybe the point

14:46

where it can do any damage but that heat

14:50

is still part of the power output of the

14:53

beam itself so we’re going to

14:57

investigate that a little bit further

14:58

later on but for the moment just assume

Transcript For Laser Beam Alignment Setting – Dream or Nightmare (Cont…)

15:01

that we’ve got a 10 millimeter beam here

15:03

let’s be a little bit cautious and you

15:06

can see that we really don’t have much

15:08

room for error on either side to get our

15:13

beam onto the center point of that

15:15

mirror now if we aim at the center point

15:20

of the mirror which is this

15:22

point just here and look there’s the

15:25

centerline of the mirror through here

15:27

and there’s the mirror face just there

15:30

and we’re aiming specifically for that

15:34

point the bad news is the design of this

15:39

head is such that the center point of

15:43

the the center point of the beam does

15:47

not run down the center point of the

15:49

bore this is one of the lens tubes that

15:54

goes into the bottom of the machine what

15:56

we’ve got down the inside there is a 17

15:59

millimeter ball and what we’re hoping to

16:02

do is to aim that we’re trying to aim

16:07

this beam at the lens which is in the

16:10

bottom there we really want to be on the

16:13

centerline or the axis of the actual

16:16

lens itself but at the moment we’re not

16:19

and we cannot be even if I remove this

16:23

one millimeter gap here which will still

16:26

be slightly off-center so there’s a

16:29

fundamental design issue with this head

16:33

the other fundamental design issue with

16:36

this head is exactly the same issue that

16:38

I found with my China blue machine and

16:41

that is that if we take a look here

16:44

you’ll see that the center line of the

16:47

true mirror center point is not the same

16:51

as the port entry ie

16:55

the hole in the front here does not

16:58

represent the true center line of the

17:00

mirror so I think that my little targets

17:03

that I made are probably inaccurate and

17:07

need remaking a mistake I made I didn’t

17:11

check the position of the mirror it

17:12

looked nearly right so I I designed my

17:14

target to sit on the front there and

17:16

assume that the design was right but now

17:19

that I look at it in detail I think you

17:21

can clearly say look we’re 1.3

17:23

millimeters high so there’s several

17:29

sorts of design issues with this head

17:33

small details

17:36

but annoyingly important especially when

17:41

we’ve got a very small amount of error

17:45

here I mean that’s what 1.3 millimeters

17:48

looks like hey that’s nearly what we’ve

17:52

got here look so I’ve only got to be a

17:54

little bit out with my settings and I

17:57

can easily clip the bottom of the beam

17:59

or the top of the beam as I found out in

Transcript For Laser Beam Alignment Setting – Dream or Nightmare (Cont…)

18:02

the previous session the beam was

18:04

somehow clipping the bottom here and

18:05

some of the power was being lost because

18:08

it was never getting through okay that’s

18:11

a detailed look at the head itself and

18:13

it’s quite important that you understand

18:14

that but what we’re going to do is let’s

18:16

assume for a minute that the head is

18:18

good enough which it probably is to

18:22

allow me to set to its center point

18:25

which is here the main reason I’m just

18:30

showing you this drawing here is the

18:32

fact that the the bore is 17.2 and the

18:36

difference between the beam centreline

18:39

and the true center line of that bore is

18:42

1.1 millimeters okay now this is this is

18:48

probably the most important drawing with

18:51

the least amount of information on it

18:53

okay

18:54

so now we’re on a completely different

18:56

plane instead of looking from above we

19:00

are now looking in from the side of the

19:03

machine and the same rules apply when we

19:08

look in this way as they do when we

19:10

looked in from above and that is this

19:13

beam must run parallel to the bearing

19:17

rails now the bearing rail for Y is more

19:21

or less fixed to the floor of the light

19:23

blade and the X bearing rail runs across

19:26

the gantry that runs across the machine

19:29

so the gantry is set parallel to the

19:32

floor the bearing rail is set parallel

19:35

to the floor this bearing rail is

19:37

parallel to the floor and therefore the

19:40

actual laser beam must be parallel to

19:43

the floor as well if it isn’t it ain’t

19:47

going to work

19:48

so how do we achieve that well we have

19:53

got a fixed head the head might be very

19:57

slightly out but if it is very slightly

Transcript For Laser Beam Alignment Setting – Dream or Nightmare (Cont…)

20:00

out position wise there’s this little

20:03

plate on the top here which allows us to

20:05

direct the beam downwards and correct

20:08

for slight very slight manufacturing

20:12

errors on the head itself but in essence

20:16

what we’ve got to do is make sure that

20:19

the laser is outputting its beam

20:24

parallel to these rails and this as

20:29

simple as that so we cannot have this

20:32

tube sitting like this or can we well

20:39

let’s have a look at that because this

20:43

is the most critical part of

20:46

understanding about a laser beams path

20:50

people ignore this axis they concentrate

20:54

on the plan view which is actually easy

20:56

this is the bit that’s going to screw

20:59

you trust me okay so very crudely we’ve

21:07

got our straight laser beam that’s

21:10

coming out of the laser and into the

21:14

hate the laser tube itself is a very

21:17

long tube and the fact that it relies on

21:22

this surface here there is a part

21:26

reflecting mirror and right at the other

21:28

end of the tube

21:29

there is another reflecting mirror now

21:33

those surfaces are absolutely parallel

21:37

and normal to each other so that the

21:40

light can pass backwards and forwards

21:42

between them now that’s that’s a

21:45

mechanical fact so that beam has to come

21:49

out of there in a straight line that

21:51

beam can’t come out of here an angle

21:54

it’s coaxial with the basic construction

21:57

of the laser itself now even if this

Transcript For Laser Beam Alignment Setting – Dream or Nightmare (Cont…)

22:00

tube is very slightly

22:02

eccentric because the tube is so long

22:04

you can still probably assume that the

22:08

external glass work will still give you

22:11

a very good representation of the axis

22:14

of the beam itself so let’s assume that

22:18

we set the laser tube itself parallel to

22:24

the floor that’s a good starting point

22:27

because everything on this machine is

22:29

fixed to this ground point this floor

22:32

okay so we’ve now got our laser beam

22:36

traveling in a horizontal direction but

22:40

just in case we didn’t do that let’s

22:44

just do this for a minute let’s make it

22:47

slightly wrong how do we do with that

22:49

well we could raise this mirror here

22:55

because this mirror is adjustable so we

22:57

can raise that mirror up so that it

23:01

catches the beam but then we got to make

23:04

sure that it still runs parallel beyond

23:07

there which we can do because we can

23:10

swing the beam so that it sits parallel

23:15

with this bearing row but then it means

23:18

we’ve got to move this mirror up to

23:20

catch that beam so we can move that

23:25

mirror up to catch that beam but the

23:29

head is not adjustable

23:31

so therefore the beam has got to run

23:34

downhill to get to the to get to the

23:38

head and we can’t allow that because

23:40

that means this part of the beam is now

23:43

totally unable to sit parallel with the

23:46

X rail so we may well have satisfied

23:48

this condition here but we can’t satisfy

23:50

it here now on my blue machine I don’t

23:53

have to worry about that because I have

23:55

made a bracket which allows me to move

23:59

my head into line and catch the beam

Transcript For Laser Beam Alignment Setting – Dream or Nightmare (Cont…)

24:03

this machine has got a fixed head and I

24:06

don’t have that option so we’ve got to

24:08

deal with it in a completely different

24:10

way that’s why I’m saying this through

24:12

me because I don’t have the flexibility

24:14

this machine to play with so everything

24:17

has got to work from the centerline of

24:18

the head which brings us back to this

24:21

first picture here that’s what we’re

24:24

trying to achieve parallel to the

24:27

bearings and straight into the

24:29

centerline of the heap as I said it’s

24:31

very very simple to see on a piece of

24:33

paper how do we do it in practice my

24:37

background in design and production

24:38

engineering says spend the time and make

24:43

it simple don’t struggle so what I’ve

24:46

done having spent the time and measured

24:48

the machine up very carefully to

24:50

establish what the problems are I’ve

24:53

also checked and found out why my beam

24:57

is not correct by using a very laborious

24:59

iteration method my axis did not pass

25:03

through completely flat and at this

25:06

point I was only one point three

25:08

millimeters high so yeah I got there but

25:16

it was a bit of a struggle and I

25:18

wouldn’t want anybody else to go through

25:20

that same pain so I’m looking to try and

25:22

make it a lot simpler and a lot easier

25:25

by design it would be a lot easier by

25:30

design if the head was adjustable into

25:33

planes it’s not at the moment and I say

25:36

at the moment because if my first

25:39

attempt at setting this machine doesn’t

25:42

come out too good and you’re going to

25:45

witness that you’re going to see me go

25:48

down in a blaze of glory or be a hero

25:52

yet to be decided but I always know that

25:56

there’s a back-up plan

25:57

as I mentioned turning yesterday I’m a

Transcript For Laser Beam Alignment Setting – Dream or Nightmare (Cont…)

26:00

bit of a wrecker I’m very happy to take

26:02

this head apart here and I’ll make this

26:04

adjustable that way I can catch the beam

26:07

just as I can on my other machine and

26:09

all of a sudden beam setting becomes a

26:11

doddle but I’m going to persevere with

26:14

this machine because not everybody has

26:16

the ability to go in and modify this

26:18

head so I’ll stay with as it is and see

26:22

if we can generate a jig that people can

26:26

emulate

26:28

maybe they can’t copy it directly

26:30

because it depends on the layout of the

26:32

various bits of the machine but the

26:34

principle you probably can copy or you

26:36

can modify the jig that I’m going to

26:38

manufacture let me despite the despite

26:47

the approximate setup that I use for

26:49

FEMA linemen it’s cutting reasonably

26:52

well

26:58

here we’ve got various pieces to our 3d

27:00

jigsaw puzzle hopefully this will make

27:04

the setting up of the beam and mirrors

27:08

on this new light blade machine an

27:11

absolute dream when as I dream I mean

27:15

maybe as little as 10 or 15 minutes who

27:18

knows but let’s make a start we’ve got a

27:25

base plate and on the base plate we’re

27:30

going to put this piece which sadly is

27:32

not quite a match for the other pieces

27:35

but hey the material was free so and we

27:38

had to use the material that would fit

27:40

the job so I think the first thing that

27:42

we’ll do and we just run some glue I

27:47

would like to work on kitchen roll

27:49

because if this stuff that goes through

27:50

then it just hold it upright and solid

Transcript For Laser Beam Alignment Setting – Dream or Nightmare (Cont…)

28:01

okay what’s the basic frame the base

28:04

frame done well that’s just hardening

28:08

off a little bit let’s just do this one

28:11

now I could really do with how you keep

28:13

making sure that this stays although

28:16

this there’s nothing that kids do

28:17

anything I don’t think no so but I will

28:20

try and take it up right I’ll use that

28:23

one cell phone put my glue

28:38

we’ll pop this on next

28:50

turn it upside down there so that we can

28:52

just know the glue along the edges there

29:01

we put the brackets on first then this

29:06

piece just glue down these edges here

29:13

and we do the same thing on this end

29:19

we’ll put our brackets on there is our

29:25

finished cute now I’m going to take the

29:31

machine to pieces I thought I might as

29:33

well and put a case extension on because

29:36

I could do with a bit more space between

29:39

the later head and the first mirror so

29:42

I’ve got three pieces of ten millimeter

29:44

thick acrylic nail which I didn’t really

29:47

have the right size pieces so what I’ve

29:49

done I’ve just made myself a little

29:51

jigsaw piece to make the frames up so

29:53

I’ve put three frames on there ten

29:54

millimeters and that will give me a 13

29:57

millimeter extension which will be

29:58

plenty enough and there we go there’s

30:02

our little 30 millimeter extents have

30:03

already started to do some destruction

30:05

but let’s just explain what we’re trying

30:07

to do what we’ve got here we’ve got two

30:10

mirror reference points now these

30:13

mirrors are set the correct height from

30:16

the base to match the centerline of this

30:20

mirror here not the centre line the hole

30:21

that the calculated centre line of the

30:23

mirror itself and these two holes

30:29

represent the front edge of these two

30:31

holes have to be roughly where the

30:33

mirror faces are and they will tell us

30:35

the correct position in space

30:38

45 degrees each and the correct height

30:41

so which I’ll hopefully have three

30:43

mirrors which are one two three mirrors

30:45

all fixed and they will be fixed at 45

30:49

degrees so that we know that they’re in

30:51

the right positions to start with and

30:55

then all we’ve got to do is hopefully

30:56

tweak the mirrors mainly in the XY

30:59

direction because

Transcript For Laser Beam Alignment Setting – Dream or Nightmare (Cont…)

31:00

can’t play with the Z so we’ll offer

31:05

this up and you’ll see what we’re trying

31:06

to achieve well okay we’ve now arrived

31:09

at the moment of truth the gate start

31:11

wrecking the machine and undoing all the

31:14

good work I did one new are removed the

31:18

thing is when I look at this there’s a

31:21

lot of adjustment on there but there is

31:24

no adjustment it’s right at the top of

31:26

the stroke already well we’ve removed

31:28

the mirror and I don’t think we could

31:31

have made it any more sloppy than happy

31:34

so we need to remove the y-axis cable we

31:39

slide our jig in to start with and then

31:41

we hook it over the end of the gantry

31:44

here and just move it forward so that

31:48

slips over the socket that’s in there

31:51

the Y drive socket now we’ve got a

31:54

certain amount of movement in Y not much

31:59

of a little bit hopefully that’s going

Transcript For Laser Beam Alignment Setting – Dream or Nightmare (Cont…)

32:01

to be enough to allow us to make sure we

32:03

line all the mirrors up okay now it’s

32:06

very important that the first thing that

32:07

we do to both these mirrors this one and

32:10

this one is to set the gap behind the

32:13

mirror plate so that it’s exactly one

32:17

millimeter when we doing that with a hex

32:21

or blade and that’s a millimeter it just

32:24

happens to be a millimeter so we undo

32:26

the screw until it grips the hacksaw

32:28

blade you can fail because the screw

32:30

goes loose and then just take the

32:32

slightest amount of tension back on the

32:34

screw and the axle blade comes out okay

32:38

so we do that for all six positions on

32:41

these mirrors I’ve already loosened the

32:45

screws on the base plate here so that I

32:47

can slide this slide it around a bit

32:52

like this okay because what I want to do

32:54

is to slide it around in a minute but

32:58

before we do any movement of things now

33:00

we’ve got everything loose everything’s

33:02

upset we’ve got to set the beam to a

33:04

known position and the beam itself

33:07

should push against it and stop

33:11

that’s the known position where I

33:13

measured everything from when I designed

33:16

the jig so we push that against the end

33:18

stock the beam no longer moves and

33:21

because that’s our reference that we’re

33:23

going to work from now and the first

33:24

thing we’re going to try and do is to

33:25

get this set nicely so that it sits

33:27

snugly against that plate as you can see

33:30

at the moment this mirror plate does not

33:33

line up with this perspective plate so

33:36

it’s set approximately to the right

33:37

height now and it’s not too bad for

33:42

position so I just tighten up the screws

33:46

on the bottom there I think you can see

33:48

there that’s pretty good match those

33:52

holes and they will repeat the same

33:55

exercise on the back end look we’ve got

33:57

this thing all nice and floppy let me

Transcript For Laser Beam Alignment Setting – Dream or Nightmare (Cont…)

34:00

just put my key I need to do two things

34:04

first of all I need to put then

34:06

approximately the right position and

34:08

just put a little bit of tension on

34:10

these screws just a little bit because

34:14

you can see the brackets in the

34:15

background are all floppy so what I’ve

34:17

got to do I’ve got to push this against

34:19

the plate now in approximately the right

34:22

position let’s just see if we can get it

34:23

into approximately the right position

34:25

and tighten up the screws I’ve already

34:29

got one screw that I can tighten up on

34:31

both of the brackets so there’s two

34:34

brackets and four screws and I can only

34:36

tighten up two of the four screws one on

34:38

each bracket now we’ve tightened it up

34:41

this way and see how much it moves now

34:44

you’re slightly out of line so you’re

34:46

seeing a little bit of perspective there

34:48

but from dead-on it looks pretty well

34:52

aligned up

34:55

so I can take that jig out now we’ve

34:59

removed the jig and I’ll just now

35:01

tighten up all the screws to make sure

35:04

that nothing is going to move and

35:06

technically what we’ve now done we set

35:09

this mirror and that mirror at 45

35:11

degrees to each other they’re the same

35:13

height and they’re also the same height

35:16

as the mirror down at the other end

35:19

there so we should have technically a

35:21

nice straight line beam that runs

35:23

through all the center line of these

35:25

we’re gonna push the beam forward again

35:28

we’re going to lug it up just now we’ve

35:31

got one more thing to do okay now here

35:34

we are at the back of the machine I’ve

35:36

got two pieces of kit but I’m going to

35:38

be using now this piece here what it’s

35:41

designed to do is to take the later tube

35:44

so it’s designed to set the laser beam

35:47

which sits in here the correct height

35:49

from the base from the floor and also

35:52

the correct position from the beam the

35:55

correct Center from the beam and as you

35:57

could see they’re loose they’re not in

Transcript For Laser Beam Alignment Setting – Dream or Nightmare (Cont…)

36:01

the right position for moment so I just

36:03

laid it in there this one you’ll see the

36:07

reason why we’ve got this big notch in

36:08

here now and that’s because we’ve got

36:11

this water tube underneath here I’m also

36:13

loosening the fixings for the later

36:15

tubes itself okay I think you’ll see

36:21

that that’s rather loose right so that

36:24

one’s loose as well we will loosen this

36:26

one off and there are some screw

36:31

adjusters on the top here we’re going to

36:33

let those down or we’re going to wind

36:35

them up so that the beam can sag and

36:39

drop down onto the Vblock we do the same

36:46

with this one

36:46

whine the adjusting screw up the collar

36:51

and then we’ll put this

36:56

on – it’s very block and we’ll push it

36:59

back against make sure that is sitting

37:03

back yet we’re pushing it back there we

37:09

go

37:09

push it down bend it back and now I’ll

37:15

tighten up these screws on this one

37:22

again if I just lift that up and let it

37:26

fall down into the bracket there we go

37:31

now I’ll just lock that up there like

37:34

that I’m gonna tighten up – diagonally

37:40

up screws now we need our target and

37:48

this is the moment of truth before I

37:51

start I must remember to put the y-axis

37:55

plug on set my beam power to 15% we’ll

Transcript For Laser Beam Alignment Setting – Dream or Nightmare (Cont…)

38:05

try a false

38:08

and what didn’t get surprise surprise

38:11

Wow look at that we’re just a smidge

38:16

off-center and how do we get it back

38:20

onto center to be honest I think it

38:23

would be very easy to just set that back

38:27

another milliliter and how I’m going to

38:32

do that I’m going to cheat I’m going to

38:35

stick a piece of masking tape across the

38:38

back of that bracket like that

38:46

the piece of masking tape across the

38:48

other fractal and we’re about just a

38:51

millimetre off-centre so what I’m now

38:54

going to do is to just gently slacken

38:58

off these screws and tap it a Military

39:01

Cross I just slipped the laser being

39:03

across after their leader or a

39:06

millimeter

39:14

that’s looking pretty damn good I just

39:18

put a couple of pieces of masking tape

39:20

on the back of the bracket here and I

39:23

slipped the bracket forward to give

39:25

myself a 1 millimeter gap on here so

39:28

it’s quite important that we put the

39:30

mirrors back in before we have a an

39:32

interesting accident

39:51

well there’s our target at the far end

39:53

of the stroke

Transcript For Laser Beam Alignment Setting – Dream or Nightmare (Cont…)

40:00

is largely off-centre

40:06

and now we’ll check it close in

40:12

I think it might be good because there’s

40:14

a really strange characteristic coming

40:16

into the beam if we look the beam is not

40:19

even it’s just do that test first so

40:26

that’s pretty central height wise and

40:29

slightly to the right so we just check

40:33

it at the other end of the stroke

40:34

[Music]

40:39

you see and that looks absolutely

40:41

spot-on maybe it’s not spot on Center

40:47

perfect in that way which is what we

40:49

need that’s the most crucial direction

40:51

the up-and-down direction we’ve got a

40:53

little bit more latitude left and right

40:56

so I’m pretty damn smug about that now

41:03

suppose there’s one final check that we

41:04

ought to carry out well the good news is

41:08

we’ve got a perfect set of incorrect

41:10

marks and by that I mean I think you can

41:12

see that they’re all sitting down around

41:15

about six o’clock and there’s our final

41:17

set of results not bad they’re all

41:22

comfortably inside the target they’re

41:24

nice round holes there’s nothing clipped

41:26

there at all so we’ve got a full beam

41:28

that’s passing through the nozzle well

41:31

there’s the end result of our endeavors

41:33

I hope that you’ve learned something

41:36

from this exercise

41:37

I ain’t it with actually a great deal of

41:41

confidence because once I understood the

41:44

principles behind setting this machine I

41:47

felt very confident that it would all

41:50

work out well in the end and to be

41:52

honest it has it took about half an hour

41:56

maybe two mechanically set the Machine

41:58

and then it took about another half an

Transcript For Laser Beam Alignment Setting – Dream or Nightmare (Cont…)

42:00

hour to physically tweak the machine

42:02

just through the mirrors to get it into

42:05

a very good shape

42:08

and I hope that you won’t have any fear

42:10

in the future if you need to do the same

42:12

thing yourself obviously if this is the

42:16

think placer machine that you’re worried

42:18

about and you can see that you’ve got a

42:19

problem I suspect that you’re calling

42:21

the servers engineer but maybe you would

42:25

be brave enough to have a go on your own

42:27

good luck to you and wish you see it in

42:31

the next session