04 – Fixing The RF Laser Source Wiring

Transcript for Fixing the RF Laser Source Wiring

0:01welcome to another session with my little tangerine tiger um

0:07today i say today but over the next few days

0:14because i’m going to be dipping in and out of this because i’ve got quite a few projects on beside this

0:19um so you might see me get handsome ugly fat thin change of clothes

0:28um you’ll see me messing around with the electrics now i thought i’d start off by

0:36doing the easy stuff at the top here but it turns out it’s not quite as easy as i thought it was going to be

0:42it is pretty simple um but i’m not an electrician by profession but

0:48i understand quite a bit about electrics and the one thing that is key to this

0:54is making sure that we choose the right sort of power cable that we’re going to connect these things up with

1:00we want some coax cable to connect between here and the ruida controller

1:07and then we need some powerful wire to connect between here and here now this is only a short

1:13distance and then we’re also going to require heavy duty mains input cable to here

1:19because when we look on the rating plate here it tells us that the output is 12 amps roughly but it also tells us

1:28that at 240 volts we’re still going to require 7.5 amps now

1:337.5 amps is not too bad um but it’s going to consume quite a bit of

1:39the power that runs through the emergency stop switch as we’ve talked about before

1:45this is not much different to what would normally happen with the high voltage power supply

1:50we’re not going to be putting too much extra load through that emergency stop switch you may remember that i’ve got a

1:56separate power inlet here to take the load from the extract fan

2:02and the air assist the air compressor that load does not pass through the emergency stop switch

Transcript for Fixing the RF Laser Source Wiring (Cont…)

2:07these are running through a separate relay controlled by the emergency stop switch as i was

2:12digging around trying to find out what power this device actually consumes

2:18this is the cloud ray unit which you can go and see on their website you can see it costs i mean i’ve got a cr30 which is what

2:24this one is and it’s about two and a half thousand us dollars okay and here’s the rating

2:32for it and it says 48 volts dc 12.5 amps well

2:40that just happens to miraculously coincide with the output of this power supply so i’m not entirely

2:46sure whether or not that number is correct i thought well i’ll go and have a check elsewhere just see what the

2:52the original manufacturer specifies and this is the original manufacturer looks

2:58i know galvo and i will post a link to this page

3:04on the description below this video so you can go and look at it for yourself it says 48 volt dc with a maximum

3:10current of 12 amps it looks as though it does require 12 amps which is quite heavy duty wiring the

3:17other interesting thing here is it says maximum heat load 575 watts so that this thing is going to

3:23pump out quite a lot of heat and i think i’m going to have to put some additional fans in here to blow air

3:29through this control cabinet as i was looking for the link i came across the same product supplied

3:36by edmunds optics and it appears to be half the price that cloud ray are charging but then

3:43when you look into it a little bit deeper you find that don’t know what that number actually means because

3:50here we’ve got a 20 watt output unit which cost 2 700 pounds so that’s probably what

3:56three and a half thousand dollars and the 40 watt unit is what

Transcript for Fixing the RF Laser Source Wiring (Cont…)

4:02probably five probably close to six thousand dollars you remember how i mounted this unit on four

4:08cheap aluminium pillars that i just turned up into tubes i could buy a mounting bracket here

4:15for 212 pounds i just thought there was some interesting numbers there for you to

4:21digest so that means we should be able to get away with standard

4:26iec 10 amp computer cable into the machine the link between here

4:32and here is going to be a bit more demanding because we’ve got to carry

4:37at least the capability of 12 amps there now i’ve got some fairly heavy duty

4:44mains cable here well it’s a bit more than mains cable it’s industrial cable which is rated at 300 volts which is no

4:50problem but it’s three cores at 15 awg

4:56capable of taking up to 28 amps when it’s what they call chassis wiring so i’m going to have to take the cores out of here

5:02and we’re just going to put a link between here as open cable but i just point that out because

5:07you can’t use theme cable like this to link these two pieces together it’s got to be heavy duty

5:12mains cable i’ve played with these little spacers a few times

5:18trying to get the screws in and lined up with the spacers four of them and it’s tricky so what i’ve done now

5:25i’ve just put a pin a three millimeter pin down the middle of them to hold them in place but what i should be able to do this time

5:31is to locate the pins in the holes like that remove a pin and replace it

5:38with a screw on the back of this power supply very conveniently we’ve got a couple of

5:43m3 holes so there you go that’s nice and stable on there so i might have to be a little bit um

5:50non-conventional with my connections here because if i put them out this way

5:56it’s going to construct the back face that i want to use to reference with

6:01now although i don’t think there’s a problem here with this against the back face because this is only 48 volts i feel slightly

Transcript for Fixing the RF Laser Source Wiring (Cont…)

6:08uncomfortable about leaving these terminals very slightly exposed here on the edge

6:15they’re not close to the metal work that’s at the back here but but i’m going to be sliding this backwards and forwards along this back plane here

6:22so what i’ve done i’ve just knocked up a little teeny weeny petg shield just to slide over there

6:29it doesn’t fix on it just slides over and gives us some sort of protection between the metal work and those

6:36potentially well they’re bare terminals but then they’re not going to spark because they’re only 48 volts okay so

6:44basically that’s that wiring done i’ve done further checks and the only connection that we need on here

6:50it says in the manual i’ve checked with cloud ray i lack an understanding of some sort of how this

6:55system is going to work i’m wiring it up correctly and then we’ll have to find out by

7:02hooking the oscilloscope in what’s actually happening to this pwm that i’m going to connect it to

7:08is it truly pwm or is the pwm somehow reconfigured when i change

7:16the vendor settings away from a glass tube to an rf tube that’s the sort of thing that reader

7:22will do and they don’t tell you anything about it in the manual it’s another day change a plan again

7:29look what we’ve got here we’ve got a piece of three millimeter cold rolled

7:35mild steel with a bend this is the new table without any

7:41further ado rather than having it laying around i’m going to fit it

7:47every one of those nuts is loose but i can’t take the table off because the table is fixed down with

7:54these bolts so i’d have to remove a hell of a lot of stuff to get the table off or i could lift the

8:02bot lift these fixings up and then i could um cut this away but

Transcript for Fixing the RF Laser Source Wiring (Cont…)

8:10this is not doing any harm as it sits here if i’ve got my dimensions right

8:21i don’t believe it that’s how much i need to take off i think well let’s

8:27just have a look see whether we can actually squeeze this in and in any way [Music]

8:35so we’ll just give it a gentle kiss

8:50now i’ve put a fold across the back edge for a couple of reasons as you’ll see in a minute but of course the great advantage of

8:56putting a bend is it automatically straightens the material whereas this unbent edge lots of light

9:01under it it’s bent this way but it’s not going to worry me because we’re going to flatten it out by

9:07pulling it down to the table frame so i’ve been around and i’ve countersunk all these holes suitable for an m4 screw

9:14[Music] it’s now a nice snug fit in there it’s very rare that i’m going to have the

9:20table much lower than this and there’s my vent across the back there to suck

9:25air out i’ve got very little gap down the side here some but very little and when you look

9:32over at the front of the table there you’ll see why i’ve got this flange on here it’s so that i can cover up the big

9:40gap that’s likely to be across the front here so our air will come in here at this level

9:46and go out across there now the other thing that i’ve done is made sure that when i put these holes in

9:52it didn’t coincide with any of the existing holes so it’s just a matter of drilling a whole load of

9:58four millimetre holes through here now I’ll do I’ll put one there to lock it but i mean this thing is not

Transcript for Fixing the RF Laser Source Wiring (Cont…)

10:03going to move because i’ve locked it up at the corners

10:30[Music] that’s the table fitted here i’ve got a replacement for the stepper drive

10:36bracket so it’s had its position moved that way relative to the fixing points and i’ve

10:42added a tongue here for fixing the cable chain on with i’ve also put a stiffener along the back edge

10:49this is going to be mightily stiff this bracket i’m most uncomfortable with the fact that

10:54i’ve only got two fixing screws holding this bearing and this gantry

11:00together that’s a lesser problem than this

11:05i’ve only got two fixing screws that are stopping that plate from wobbling so what i’m going to do

11:12now as i’ve just made myself a little plastic template there with the

11:18additional holes in it so there’s four holes on a 26 mil centers and i’ve put two holes in there and made

11:25a template which hopefully will enable me to allow me to spot through and it does look as though there are

11:32some holes in there which maybe should have been spotted through so what i’ve done i’ve taken the tapped

11:38holes at the top here and opened that to six mil because when i fix my

11:44bracket on here i should be using some additional additional fixing holes

11:58[Music]

Transcript for Fixing the RF Laser Source Wiring (Cont…)

12:07got them nicely scented now so i’ll take my template off so i’ll

12:12just put a piece of three millimeter acrylic under there

12:18just so that i can drill into the acrylic

12:31now i’m fixing this in with button head screws because i don’t want the heads to stick up too much and damage the edge of the belt

12:38but i do feel comfortable now when all four of these screws are locked up then yes that bearing that plate is now

12:46absolutely rock solid now somewhere in there the belt was turned over is it that way

12:54yes it is there we go it’s nice and that’s fixed the belt is the right way around i’ve got four longer screws to fix the

13:00motor on just makes it easier to get the nuts on

13:07it doesn’t matter that they stick down quite a lot there we go just one screw fixes that on

13:14and just put the chain back together because i purposely broke the chain to pull some cable through

13:20i’m going to try and use the bearing itself there’s the mechanism

13:26for switching there should be enough metal on there that allows me to do that but that means i can’t do that until

13:33i’ve got the head on and i know roughly where i want it to stop so that i can position this switch okay

13:39now it looks as though i’m going to have to position this switch on a plate of some sort or a bracket

13:45[Music] because i haven’t got enough material at the back here [Music]

13:51now the last thing i want to do is add weight to the head here with another bracket to trip this sensor

13:57so i’d like to use something that’s already here that’s metal i think it’s reasonably safe to switch the machine on if i haven’t got any

Transcript for Fixing the RF Laser Source Wiring (Cont…)

14:03loose wires anywhere i’ll just go and check that now we can’t connect anything up because we’ve got all these wires that are mains

14:09wires so we’ll have to fix the wiring before we can do anything else i’m spending a

14:16few hours tracing all the wires around this machine seeing where they go

14:21and uh trying to make sense i’ll make a drawing of it because there’s lots of wires that i don’t need and i just don’t want to

14:28rip them out willy-nilly i want to take them out and make them safe properly i mean here’s a classic example

14:35here are the two wires that i cut out for the mains supply

14:40for the fan on the back of the unit i don’t need the fan so i literally just snipped it off but now i’ve got to

14:47trace it back and find out where it’s connected how it’s connected and take it out properly here’s how they’ve

14:53pinched the 240 volts here’s the mains and here’s the return

15:00i’ve taken the insulation tape off of the mains cable so that they’ve snicked a piece of wire

15:06a piece of insulation out of the cable and then they’ve just wrapped a piece of thinner wire around it and that’s how

15:12they borrowed the electricity for the fan and yet look just here

15:17we’ve got the mains input cable about four inches further on for what was the power supply they could

15:23easily have just integrated those thin cables into this boot lace here okay now this borrowing of mains

15:30off of one cable is rather alarming because

15:36i’m following these white wires back which come off of this led strip light

15:43in the back of the machine and i was expecting to find them back to

15:49something like a 24 volt supply or maybe a 12 volt supply to run the leds

15:57but when i start pulling the cables out i find they’re borrowing red and blue

Transcript for Fixing the RF Laser Source Wiring (Cont…)

16:05mains cables so these two wires that go to feed the leds are actually 240 volts now when i look a

16:13little bit closer at this led and start taking it apart click the end off and the bad thing about this end is

16:20although there’s a plug which is not earth i might add although it’s got a three pin plug on

16:26that end on the other end there’s an extension plug

16:31which has got live mains on it so you could put your finger in there and get a nasty shock so if you’ve got

16:37one of these led strip lights in your machine the first thing i would ask you to do is put a bit of insulation tape over the

16:42end there so that you actually make it safe but let’s just have a quick look i’ll cut the cables off this end because i’m not

16:49going to be using it anymore and let’s take this one out completely

16:54and here we go here’s our voltage converter for driving the leds it’s not what it seems it’s not a safe

17:01led 12 volt system so this machine is full of surprises i’ve just traced the red led pointer

17:09that was on the head back to here and that’s coming off the power supply

17:15at 5 volts dc so that’s completely safe to run the led strip

17:21or any other led strip that we want to put onto the underneath of the gantry so i’m

17:26going to produce a diagram of how these what these switches are doing because i wanted to work out

17:32what these switches were operating and at the moment they’re not operating much at all now

17:37something else that’s very confusing these sockets here so once a usb

17:44connection between the pc and the machine the ruida controller and the other one

17:49is a usb socket well they’re both usb sockets but this

17:57one is actually udisk

Transcript for Fixing the RF Laser Source Wiring (Cont…)

18:03i mean there’s basically only one thing in front of that control switch and that’s the emergency stop switch

18:08so in essence this is on off it turns the machine

18:15completely on and off everything else it becomes disabled when you turn this off so it’s like a master switch

18:22this one is going to remain laser switch on off and this one air pump

18:29well it’s not going to be air pump it’s going to be air assist disable now

18:35what that’s going to do that’s going to disable the air assist manually so

18:41if you happen to have air assist on during a cycle and you want to turn it off you can

18:47switch it off here but it won’t turn it off completely what it will do it’ll just

18:52disable the valve into bypass mode so you’ll still get air out of your

18:58nozzle to protect the lens and that one well that one is unused now but

19:06i might decide to put the led lights from under the gantry on this switch so that we can have the

19:12lights on or off now here’s the basic circuit for connecting up the air assist switch

19:18now in addition to what cloud ray what you’ll see on the cloud ray website

19:24um we’re using the other half of the cloud ray relay that’s been supplied to

19:31control a fan with a delay on it so

19:39that part there is basically what you’ll see on the cloud ray website and this other part here is something

19:46that i’ve added to this machine just because i think it’s a useful feature for those that you’re not particularly experienced with

19:52reading circuit diagrams this is very very simple trust me i’m no electrician myself

19:59but i’ve made this is a very simple point-to-point wiring picture that you should be able to follow easily

Transcript for Fixing the RF Laser Source Wiring (Cont…)

20:04before we go any further we need to put some tails on this put some wires on it because they’re soldered on and we need

20:10them in before we really start doing any wiring inside the machine we don’t know how long we want them but

20:16they’re about a meter and we don’t need anything special by way of wire

20:21i mean you could strip the wire out of some ordinary thin cable if you wish um i just happen to

20:28have some very thin cable here which is capable of doing the job we’re only taking a few milliamps so

20:34we only need very thin cable now i’ve got about a meter just over a meter of red cable there

20:42and i’m going to have two of those we need to strip back no more than about three millimeters now we’ve got our

20:48solder and our soldering iron the first thing we’re going to do is just uh clean our soldering iron

20:55and then we’re going to tin the end just melt some solder on the end like

21:02that okay and then once you’ve got a little pool of solder on there you can just touch it on the end of your

21:07wire like that and that will put a little puddle of solder right on the end of the

21:13wire the tricky bit are these little

21:19terminals here so you don’t certainly don’t need a big soldering iron you want a fairly small tip

21:26and what we’re going to do is tin the two center ones and two end ones it doesn’t matter which end you do because

21:32this can work either way round just we just tin our soldering iron

21:38and then we’ll just try and get a little puddle like that

21:46onto the terminal

21:51okay now it’s probably best if you do turn it over and do the center one from

21:57the other side

Transcript for Fixing the RF Laser Source Wiring (Cont…)

22:07and there we go so we’ve got little puddles of solder on each one of those terminals now okay

22:13now that we’ve got our blob of solder on there

22:18i’m going to stand my solder on the switch to act as a an extra hand almost

22:26we might just trim these pieces of wire so they’re around about three millimeters two to three millimeters long

22:34and then what we’re trying to do is just remelt the solder and let the wire fuse into

22:43the puddle that’s two red wires on if you look at the way in which this

22:49second set is connected it looks as though we’ve got one two three wires

22:54in fact we only need one wire one black wire so again we’ll have the same sort

22:59of length that meter we’ve got to strip a piece enough to cover two terminals just twist

23:06the end of the wire to make it neat and just check you’ve got enough wire to cover both terminals

23:13a little bit of solder on it and then just run it along your wire and there we go we’ve tinned the wire

23:18and this time we’ll orientate it so that it’s the right way for you to work with your hands

23:25so you need to feel comfortable about this just a little teeny mini blob of solder on the end there

23:30and then we’re going to lay the wire across the terminals this time and fuse the wires

23:41like that across the terminals now i’ve got some little rubber sleeves here we thread the rubber onto the end of the

23:48wire and pull it right the way back to the switch and just to keep them nice and neat i’ve

23:53just got a small tie wrap here which i’ll use to bundle up the cables with

24:00now we’ve got manual on at the top and automatic at the bottom and

Transcript for Fixing the RF Laser Source Wiring (Cont…)

24:06basically what that means is when you switch it down you’re disabling this bypass

24:15so what we need to do is make sure when we fit this inside here we put the wires at the bottom

24:23not at the top and then the label will be the correct way round

24:29now i would put the uh the crinkly washer on first

24:36clamp it up fairly tight and then you’ve got a second lock nut

24:44or a second nut which you can put on the front to act as a lock nut

24:51and that’s our switch mechanically fitted now we’re going to have to do the wiring now that we’ve got our air assist switching those people that know how to

24:59wire up a machine and read a circuit diagram you might as well jump on a little bit

25:05because what i’m going to do now is tediously work my way through the way in which we should wire these

25:11components up in here particularly the relays and the timers for the benefit of those people that are

25:17a little bit uncertain about electric electrics i think before we start any of this we

25:23ought to clear these two switches down here we have to rip some wires off so that we can take these unused

25:30mains wires away now if you like to just come inside the cabinet with me you’ll see that it’s a bit of a a bit of

25:37a rat’s nest up there look all sorts of wires and what we’re going to have to do we’re going to have to take these wires off the bottom here

25:45but we’ve still got to maintain there are links between these wires which we mustn’t disturb so we’ve got to

25:52take for instance a link from this power here this 240 volts here there’s a link down to here and there’s

25:59another link down to here well we’ve got to break that 240 volt link rather than climbing around inside the

Transcript for Fixing the RF Laser Source Wiring (Cont…)

26:04cabinet look we could just inside here we can just these are pressing fittings so we can just

26:10unclip push a little bit on the back of the switch and the front of the switch and we

26:15should be able to pull all these switches out so we’ve got much easier access to the wiring first

26:21thing we can do is to take the take the wiring off these bottom switches

26:28because they’re the switches that we want to reuse in a different way we should find that this air pump pair

26:33and let me just disconnect them separately so that they don’t get in each other’s way

26:40i should find that that one is that one so magic i used to cut this little

26:48ferrule off first and then all of a sudden it should pull out easily yeah it can

26:53look very intimidating all these wires but hey we’re making life simpler because we’re

26:58removing some of them now we’ll take this pair out here

27:05which is the bottom switch and again we’ll just cut the boot laces

27:12off so that all the bootleg ferrules off so that the wires pull out easily that should be that one

27:20blue one sp connect will be connected to somewhere else it’s that one there

27:25[Music] this is the end link in the chain where the blue wire carries on and connects to

27:31many other things and technically what i’ve got to do i’ve

27:37got to make that connection there back into there that’s the blue ongoing

27:44link established now we’ve got to do the same for the red so we’ve got to get rid of those two

27:50links and make a new connection on here so there we go

27:56we’ve removed the extra links and we’ve now just got two switches in

28:01there and as you can see it’s a lot tidier now now to those guys that are not

Transcript for Fixing the RF Laser Source Wiring (Cont…)

28:07particularly familiar with circuit diagrams let me just very basically explain quickly how

28:13this ruida controller now this is the air assist solenoid which is driven by 24

28:18volts and this is the um the main control solenoid for switching the system on and off

28:25which is the solenoid supplied by cloud ray in the kit and then further over here we’ve got a timer which

28:31we’ll talk about later but let’s just stay with the basic connections to the air assist solenoid and the control relay now this 24 volts

28:39goes two ways at this point okay it goes this way to the air assist

28:44solenoid valve and it goes this way to the control relay let’s just work our way through and show

28:50you what happens 24 volts goes to the air assist solenoid

28:56and while the system is not working i.e the ruida controller is saying i don’t want

29:03any air assist there will be no current flow down this

29:09line there will be voltage here 24 volts and the 24 volts will appear through

29:15here and it will still be 24 volts all the way down here through here and this switch here would

29:21normally be closed and that’s this switch here which we’re going to use okay so that will be closed so that’s 24

29:27volts all the way down here 24 volts right down to this point here at number five so if i measure the voltage

29:33difference between six and five when the solenoid valve is off it’ll be zero

29:38now when the ruida controller says ah i want some air assist now turn it on blowing

29:43on internally what that does there’s a switch internally which connects wind to ground

29:53and as soon as wind and ground are connected all the voltage drains away from this

29:59side of the circuit here and we now get 24 volts difference across the solenoid valve itself so

Transcript for Fixing the RF Laser Source Wiring (Cont…)

30:07you’ll have 24 volts to here and then it will be zero almost down to there and down to ground

30:15and that will make the current flow through this coil here which will energize the relay

30:22and as soon as this switch is off this line will go back to 24 volts again

30:29what we’re going to do first of all is to wire these two lines in the wind and the 24 volt and i think we’ll start

30:36off with the wind we work our way back to here to this particular switch because this is a

30:43very convenient point to start here we’ve got one wire that comes back

30:48from our solenoid valve this is the white wire remember that we installed now this is the white wire here and

30:54you’ll see what i’ve done i’ve stripped it back so that we’ve got lots and lots of cable here left over so we didn’t know how much

31:02cable we wanted and we still don’t know how much cable we want so what we do we’ll just work with these one cable at a time we don’t

31:08need the earth wire so we can cut the earth wire off because that’s just a nuisance

31:15and now we’ve just got two pieces of cable the blue and the brown and the blue is going to be the negative side to

31:22ground so we take a look at our diagram here and we say well look this is the positive side which is the brown side

31:28which is going to be connected to 24 volts that’s not what we want to start with what we want to do is we want to work

31:34with the blue wire which is going to be this one and we’re going to connect it to

31:40here that and that are connected when you switch and that and that are connected when you

31:45switch but they’re two completely separate switches so we only want one of those switches

31:50we’ll leave yourself enough blue cable in there to just tie it all into that loop there

31:59now i’ve purposely done that wrong by just thinking one step ahead i.e of connecting this

Transcript for Fixing the RF Laser Source Wiring (Cont…)

32:05cable to k the switch i need this red cable

32:11that’s coming from the air assist switch to go in there as well but i’ve done it wrong purposely

32:17to demonstrate that you need to think ahead when you’re doing this so what we’re going to have to do is remake this and at the same time that

32:24we’re doing this we need to pull one of these wires through it doesn’t matter which one

32:29again we just leave some slack in there and just so you don’t get confused

32:34it’s probably a good idea to do something like that look there’s the red wire and there’s our blue wire

32:43okay so that’s what we’ve done so far

32:48now this is nice and simple look coming out the end the other side of that switch all we’ve

32:54got to do is make a connection into the number five terminal on the ruida controller to do that i’m going to use a

32:59slightly different sort of connector i think coming out of there we’ll probably use black cable

33:05because that’s that’s going to ground and it’s dc so we’ve got a nice firm connection on

33:10there so we’ve now got to get to terminal number five which is that one there which is wind that’s running through that piece of

33:17trunking there and just drop down there somewhere like that

33:22now you could wire these directly in with bits of bare wire but i like to put terminations on i mean

33:29they’ve done they’ve done a half decent job of tailing all these ends off with little boot lace um crimps

33:34and then just to get access to that we can disconnect the plug okay so now we can put that one in there

33:41and for the time being we’ll just pop that back in there okay so we now pencil that line in blank so this 24 volt line here coming back

33:48from the solenoid was our white cable so it’s going to have a piece of brown wire there this one is going to be 24 volt so

33:56it’s going to be red wire so i think the convenient point to make a joint is at terminal 6. so here is our brown

Transcript for Fixing the RF Laser Source Wiring (Cont…)

34:04wire and again i think we’ll bring it in at

34:12the bottom there run it up that cable run it up that network of cables there

34:18and across the top and down into it would normally be

34:25terminal 6 24 volt we’ve got 24 volts in there already something is already using that but

34:30if we look below here we shall find we’ve got another 24 volt there’s no reason why we can’t use that

34:3624 volt from this terminal so that’s what we’re going to do so we’ll just cut that off there so

34:44we’ve picked up our 24 volt supply and sent it to the air assist solenoid what we’ve now got to do is to pick up

34:50the other side of the 24 volt which is the red cable and we’ve got to send it to this relay

34:56here now it’s going to go to connection number 14 which would also be internationally

35:03known as a2 now that’s the plus side there isn’t a plus and a minus side but

35:09in fact we are going to nominate the plus side as being 14.

35:15so where is terminal 14 on here well that’s why when we had the whole

35:21thing out we decided to draw a picture okay so terminal 14 is actually that one

35:27there which is right at this top right hand corner we’ve got a fit a diode across a1 and a2 and that’s going to

35:35make it quite difficult so what i’m going to have to do is integrate the diode into the two wires that go

35:41into there so here’s the little diode that they supply and on one end you’ll see there’s a sort of a silver or white bar

35:48now that’s the plus end and what we’ve got to do we’ve got to put the plus end to the red wire and what we’ll do we’ll

35:55wind this onto the end here then we’ll crimp

36:01them together so let’s just mark what we’ve done so far we’ve got the brown wire into there

Transcript for Fixing the RF Laser Source Wiring (Cont…)

36:07then we’ve got the red wire out of there into a2 so just to keep our drawing up

36:14to date here’s what we’ve done we’ve done that one now i didn’t take

36:21that cable into that ground just there i took it into this ground here it doesn’t matter

36:26where you find a ground any one of the places where it says ground will be the same now we’re going to make

36:33a connection between our switch which has got a red wire coming out of it remember into four which is status and then we’ve

36:40got a black wire coming out the let’s call it the negative side of that relay

36:46a1 which has got to go back to status as [Music]

36:52well and we make a connection into the status

36:58line and this is where we’re going to have to make the negative side of the diode

37:05connect up to this line here and there we are we’ve got our little diode now connected between the

37:11plus and the minus [Music] and we’ve done that line there now

37:21diode as well there so that’s basically the low voltage control side of the system

37:27so now we’ll take a look in here at the solenoid valve and we take the cap off

37:32and they put that little slot in there for a reason obviously so you can take the cap off

37:41i’ve cut the diode wires down to about half an inch long on each end and i’ve tucked it into the

37:48brown wire there i’m now going to remove the blue wire but before you put the blue wire back

37:55bend the diode and get that into the hole as well so we’ve got the diode across

38:01there tucked in the hole and then we’ll pop that blue wire back in there

Transcript for Fixing the RF Laser Source Wiring (Cont…)

38:07and that’s a very neat invisible way of losing the diode so we can now complete that part of the

38:15picture as well so now we’ve done this bit we’re going to look at the bigger picture and start connecting mains into these

38:22connections here and into these relays and timers and we’re going to do that with 10 amp

38:28cable the cheapest way to buy cable as in the form of an iec cable or a computer cable

38:34you can get three meters of this for probably less than two dollars and you get three 10 amp cables in there

38:40each of the right color now although it’s not essential for current carrying capacity to have heavy-duty cable into this relay

38:47here this delay timer here we’re going to use all the same cables because that then keeps it clear that this is

38:52all mains cable 240 volt although this looks like a fairly complicated path here

38:59in reality what we’re going to do is to link these two together here with the tail and then we’ll link these two together

39:06here and we’ll pull this tail in as well here we’ll have a double connection on one of these a double

39:11connection on there a single on there and a single into there so it’s not going to be difficult

39:16at all now we’ve just done that on there

39:22into 11 we’ve already linked like this

39:29and we’ve got a tail on it and that tail has got to go into a2

39:40and then we’re going to bring this one down

39:47and we’re going to connect that together in here

39:54so we’re going to try and probably put two connections into that a2 on the timer

40:01delay relay or we can bring them in as two separate cables like this and join them there with one

Transcript for Fixing the RF Laser Source Wiring (Cont…)

40:06connection that’s what we’ll do well we’ve done all our wiring by numbers now and we’ve hopefully got all

40:12the cables in i’m not going to tidy them up until i’ve proved that it all works i’m moderately confident but

40:19not going to waste too much time doing it to start with we’ve got to make this a properly and to do that i’ve i’ve got

40:27the original earth connection but i’ve drilled a hole down here and

40:32the key thing that was missing before was a metal to metal connection so i’m just going to remove the paint

40:39around this hole and now we’ve got bare metal exposed onto which at least this piece will

40:45connect but we can go a little bit better than that and do it the proper way

40:51which is to put an m5

40:56external crinkle washer on there which guarantees when you tighten it up

41:01that even if you’ve got something like a metal coating on here it should spike its way through and make

41:07a contact well it’s a bank holiday today and everybody’s out in their garden

41:12uh doing things cutting the grass as you can hear the guy next door is doing

41:18my dad was a bit of a philosopher and he warned me when i got married he said son he said never have any more grass than your wife

41:25will mow and i haven’t got any grass i probably can test this electrical system before i

41:32finish off the mechanicals okay well i think we’re just about ready to start

41:39firing this thing up again for real now obviously nothing is going to move because i’ve

41:44got the x belt disconnected so the stepper motor will drive but the y stepper motor won’t drive

41:51because that’s disconnected as well over the back there we’ve got the y sensor

41:56but i can’t get to that to remove it and reposition it until i take this out so this is not

Transcript for Fixing the RF Laser Source Wiring (Cont…)

42:03permanently fixed at the moment it’s got to come out and have fixings in so there are lots of mechanical things to be sorted out if we

42:11find the electrics is working okay right let’s turn the power on and see

42:17what happens nothing

42:24well that’s because i’ve done a very stupid thing

42:32i haven’t released the emergency stop button let’s see what happens now we have power

42:49so yeah we’ve got number 14 is flashing so the machine has reset itself

42:54perfectly okay well here’s the new head completely assembled with its mirror

43:00and i’m pretty pleased with the way that that design has come out actually i’ve made one or

43:06two small changes from the mark one

43:13now i’m not going to die it’s been a little bit tricky getting that on

43:32get that through there

43:40yep done it that’s difficult as well but we’re there

43:47[Applause] there we go right so we have to check

43:52first of all whether the belt is touching on the frame

43:58which it is because of all the adjustment i’ve got on the motor bracket i can move the bracket

Transcript for Fixing the RF Laser Source Wiring (Cont…)

44:06forward and make sure the belt clears

44:13the back of the gantry

44:21it’s a bit tricky getting to these screws but once they’re done

44:26it’s a once-off job and nicely clamped and that bracket is

44:32now really solid in all sorts of planes before i even attempt to bolt this down

44:41so we’ve got plenty of adjustment on the screws here to push it forward which is what we want to do

44:46we’ve got to push it forward to get it tight pushed onto the pulley

44:54so go push it forward

45:00and then i’ve got to lock the stepper motor up in that position

45:06[Music] drill through onto a piece of wood 4.2

45:18i know there’s nothing behind there because i checked

45:30well now i’ve got a small problem i could take the head off and get access to that or i could drill another hole in there

45:37um i think another hole is the only really alternative

45:44so we need to get to the second screw so i need a hole that’s probably at

45:50least there i can put a little plug in that one it will then look as though i

45:55intended it only you will know that i made a mistake but promise me you won’t tell anyone

46:02there we go you can get a square peg in a round hole and here is why you have to put the

Transcript for Fixing the RF Laser Source Wiring (Cont…)

46:07mirror plate on second because the mirror plate just probably can interfere with the flange

46:16on this wheel just but once the flange once the motor is put in you can

46:21you can put that plate on with impunity it all sits nice and clear

46:30there we go that’s on now we’ve got to tighten up the tensioners and see what we get

46:44[Music] so that’s interesting it’s sounds smooth

46:50one way and not the other so what’s the problem take the mirror off again because it’s masking the holes

46:57it’s taking a little bit of tension off of it

47:04what i’m trying to do i’m trying to push the belt into engagement with the teeth let me

47:10just tighten up those screws and now we’ve got a bit more tension on

47:16the belt

47:22so now sounds good now i’ve put these holes in here

47:30especially these along the back here in case we want to put a tapped hole in there and lock that

47:36tension i don’t think it’s going to need it to be honest i think the tension that i’ve put on the

47:42um on the belt via the stepper motor fixings is going to be adequate but you

47:49know if you need to you could always put a tapped hole in there then adjust

47:55the tension and then tighten up the stepper motor but you saw how i managed to achieve it

48:01without it so maybe we don’t need this clamp bracket on here especially i mean the main reason why this was on

Transcript for Fixing the RF Laser Source Wiring (Cont…)

48:07here was to stop the twist of the mirror but i mean this bracket is so stiff now

48:13the mirror is not going to twist well now i want to try and fix this sensor on somewhere here

48:21but at the moment as soon as i turn it on this head is not going to go that way

48:28towards this sensor because i’ve now reversed the direction in which the motor

48:34is operating on the belt i’m going to have to go and change the direction of the motor in the vendor settings soon

48:40but for the time being when we turn this on the y will go nowhere because we still

48:45haven’t got it connected up and the x will go that way looking for a zero

48:53so we can fold the system with our screwdriver when we turn it on

49:05[Music] so the good news is that i can detect

49:13off of the back of that bearing as you can see

49:20all i’ve got to do is find a suitable position and make a little plate to mount this on from the back here now

49:27i’ve made myself a very simple bracket out of a piece of uh eight or ten millimeter thick acrylic

49:33it’s got a couple of m3 tapped holes in it there and i’ve put a slot across the back there i’ve also drilled and tapped an m3

49:39hole in the back of the gantry there just one here’s what i’m trying to achieve

49:45this does not interfere with this bracket here look i’ve got plenty of room underneath so there’s no chance of this hitting that i just need to make sure

49:53that that is clear of that i’ve got that set up about

49:59a millimetre clear of this metal part of the bearing at the back here so now all i’ve

Transcript for Fixing the RF Laser Source Wiring (Cont…)

50:06got to do is find the on off position by sliding this

50:13along like that now i can slide it back

50:18until it just comes on like that and that’s my zero position we’ll just begin to tidy

50:24up these cables at this end and pull all the slack back through the cable chain

50:29now to do that what i’ve done i’ve prized apart the cable chain just here

50:35so that we’ve got two half chains now and the beauty of that is that this is a

50:41straight line and we can pull the cable we can pull the air pipe back

50:47so it’s nice and neat can do the same with the sensor cable but what we’ve now got to do is to pull this back into the machine

50:55so that’s all fairly neat at the end now

51:01the only thing that we’ve got left floating around here at the moment

51:06is this thing which we’re not going to make a decision on at the moment i’ve got to go and find some leds and

51:12probably as i said we’re going to mount them underneath the gantry here

51:18just have a bit of a tidy up now if you look carefully at this y-axis you’ll see i can’t even get to the

51:24screws under there to take it off because it’s going to be masked by this tray here which was holding the

51:31tube how did they do it if you can’t get it let’s make a bloody

51:39great big hole now i’m just checking the stroke of why

51:46because we can come forward to about there without hitting this 315 318 so

51:53we should be able to make this machine bigger by at least 10 mil just means i can then

51:59comfortably do 300 by 500 pieces of material on here or engravings

Transcript for Fixing the RF Laser Source Wiring (Cont…)

52:04on here with some overrun here we’ve got a particularly poor piece of design which i think i’m going to

52:10have to fix the way in which the belt is fixed on the front here

52:15means that when it passes around this idler pulley here look you can see how it’s not parallel

52:21with the rail it’s actually running in an angle which means as it gets to this end there’s got a tendency to put a load

52:28backwards on the bearing the belt length doesn’t change but it wants to change by a small amount

52:33by doing this so what i’m going to have to do is i’m going to mount that belt behind its fixing in some way but we’re not

52:41going to do that at the moment but eventually i want that to run parallel with this bearing okay well i’ve now

52:47mounted the y sensor what i’m going to do is sense underneath the gantry

52:52so it really doesn’t matter where along here i choose because the gantry is the same all the way along so i don’t have

52:57to be tucked right up in that corner three one five there we go and that’s where i’m going to set the

53:02sensor [Applause]

53:08[Music] just check again

53:16but there somewhere there we go about there just clean all the junk out

53:22from here as we go as with more or less finish

53:27that side well here’s the here’s the uh the tube mount tray at the back of the machine

53:33which i’ve just laid in here at the moment and i’ve marked the center line because on this center line i’m going to

53:40be supporting it with this bracket remember the middle of it was a little bit flexible can’t afford to

53:48have it flexible so we’re going to support it with a bracket we’ve fixed that shelf in

53:54nice and solid now um next time we should be reaching the

54:00point where we’ve got to reinstall the rf unit back into here and fix it in so that it’s adjustable

Transcript for Fixing the RF Laser Source Wiring (Cont…)

54:06and we’ve got to sort the control unit out the vendor settings because at the moment

54:11the x-axis is working backwards and we’ve got to set the table

54:16parameters up what size at the moment it says 500 by 300 but i suspect we should be able to get 510

54:22or 5 15 by 3 15. so until then thanks for your time and patience and

54:29we look forward to the next session