[Joeee83]

Thx hububalli

More progress here. The axis are moving!
I have uncommented

#define DISABLE_MAX_ENDSTOPS

in the configuration.h
recompiled and programmed. After resoldering every trough hole component.
Homing the axis seems to work. Both motors drive into them and then kind of back out.

Actually I'm trying to start my first program from the sd card. Generated by the Inscape plugin which is by the way really super work!

G21 ; All units in mm

; Cut Feedrate 1400
; Move Feedrate 1400
; Laser Intensity 10
G28 ; home all

M5

;(************************************************ ************)
;(***** LAYER: 10 *****)
;(************************************************ ************)
;(MSG,Starting layer '10')

G00 X3.299782 Y118.552030
T01 (select tool)
M6 (tool change)

M5

G00 X3.299782 Y118.552030 F1400

Executing this it homes ok, but then does nothing for quiet a long time. I thought it was not working but while typing here it started to move the mirror in the expected way.
Is this normal? Does it wait for the tube to heat up?
Finishing 10 minutes later and letting the mirror stay on the working area. But that seems ok because G Code ends with.

G01 S10.00 X82.755565 Y95.318838 F1400
M5

EDIT:

Another thing that crossed my mind. My Laser has a dedicated PSU for +24V which also supplys GND for the Marlin PCB. In order to not get static voltage in the way isn't it mandoratory to wire GND along with the signals to the Laser PSU?
Mine is connected to Earth & 230V. Perhaps this it the reason for some of you destroying their controllers?!

[hububalli]

How To: Swapping out your old K40 electronics for an Arduino/RAMPS 1.4 setup 06/08/15 V0.1f

**Some of the pictures didn't work for some reason. I will replace those soon**

This is my first draft so expect a few errors, will update soon with the rest. I would suggest trying to flash your Arduino before doing anything else so you are comfortable doing that first.

AS requested here is an in depth look at what's involved in swapping out your old K40 electronics for an Arduno/RAMPS 1.4 setup. This is what was involved in converting my K40, chances are it is a bit/very different on yours as there are a lot of different versions out there so you may need to do more research. This is especially true for the power supply! Make sure you fully understand what each connector does on your power supply before you start. As I am sure you have read everywhere, these laser power supplies can be FATAL, they are very high voltage so don't go messing around with it unless you understand what your doing. For the purpose of this project we are only working on low voltage end of the power supply so it is quite safe to do overall. I suggest you read the whole post first to make sure you are happy with continuing.

This project also relies on your power supply using an "Active low" laser trigger. This means that when the laser is fired, a signal goes to 0V from a higher voltage, hence active low. you can test this out by measuring the voltage at the following points: (remember you supply might be different!):

While your multimeter is connected you should see about 4v, Now fire the laser with the power turned right down (just for safety reasons) with the test button, the multimeter should now say 0v. If it is the other way round, or active HIGH, then the firmware will not work correctly and also be quite dangerous, the laser will be on the whole time! It is still possible to do the conversion with an active high power supply but that involves modifying the firmware, which goes beyond the scope of this tutorial.


Removing the old electronics

I would recommend removing the redundant wiring at the start rather than at the end like I did, this way you have a nice selection of different coloured wires to use in your new install, unlike me having to use what I had in my collection and have a lot of repeating colours.

Removing the old board is pretty straight forward. Remove all the connectors on the board, they just pull out, being a bit more careful with the ribbon cable. There are 3 bolts holding the board mount, undo those then you can take the mounting plate out and remove the old board easier.

Next you can remove the redundant wring. If you have it, undo all the spiral cable wrapping. On the power supply you can remove the wiring in the yellow box:



On the front panel, you can remove the following:



Preparing the RAMPS board:

We need to remove a few components so we can get 24v through the RAMPS board. Without doing this the 24v will get regulated down the 5v. Obviously the board isn't designed for this so it may cause issues, or it may not, we shall see. First remove the two large yellow poly fuses, and replace them with some wire to short the connection. Next remove the diode D1, no need to short this one.





You want all 3 jumpers to be in place, which is is how ramps boards usually come in my experience. This configuration give you the most precise stepper control. (1/16 micro stepping). Don't forget to put your heat sinks on the stepper drivers.




The new wiring on the power supply

Here is the diagram provided by TurnkeyTyranny, I have added some coloured dots to the diagram to illustrate what each wire is in reality. I added jumper type connectors to the ends of the wires. I did it with a pair of pliers and then put a tiny bit of solder on so don't worry if you don't have the proper crimping tool. I also soldered a pin header to the ramps board for the 5v connection.












24v, ground and 5v from the power supply (Red, Black, Yellow):

Laser PWM (Green)

Pulse width modulation, this is why I wanted to do this conversion (that and getting away from that awful software!) This was originally connected to a potentiometer that was called "Current Regulation" on my front panel. This allows us to regulate the laser intensity via software, meaning we can have multiple power settings in one print job. This means we can engrave and cut in one go and also do proper raster work. This is where some of you will be disappointed as older generation K40's do not have a power supply that supports this, sorry!

Laser fire (Blue)

Next is "Laser fire" This is an Active low, meaning when the laser is fired the voltage drops to 0V:

P1 and P2 on the diagram (Pink)

This is loop that must be closed for the laser to fire. It currently goes to the button on the front panel, mine is called "Laser Switch". This can be used to accommodate other safety features such as lid switch or water flow switch. You can connected as many as you like as long as when they are all in the "safe" position they are closed, so the loop is completed.



Ribbon cable from X axis and end stops

This is the most fiddly bit. I was going to create some kind of interface for the ribbon cable but was actually quite satisfied with solder directly to the ribbon cable and using heat shrink tubing.On the other end of the wires are jumper connector type fittings so the board remains removable.


Find the orientation of the ribbon cable

Annoyingly I cant remember my findings as to which way round the ribbon is orientated. So I will explain what I did to find out. If you look at the TurnkeyTyranny Diagram, we can see that on the ribbon cable, pin 1 is not connected to anything but pin 12 is. What you need to do is use a multimeter to see which end of the cable is pin 12. I did this by testing between the ribbon cable and the following pin at the other end of the ribbon on the carriage.



This is the stepper motor connector. If you remove this you expose the pins for testing. We know from the diagram that pin 12 is connected to the stepper. If you test from the top pin and either end of the ribbon cable you can work out which end is which. Pin 12 will complete the circuit. Pin 1 wont as it isn't connected to anything. I hope that makes sense, its much easier to do than explain!



Connecting up the ribbon cable and Y Stepper.

For the Y stepper connector again I was unsure as to the orientation of the cable so I just plugged it in and test. The way I have it in this picture works for me. You wont do any harm getting your stepper the wrong way round so just try it. If it behaves strangely swap it round.



This is my ribbon cable after it was soldered and heat shrinked. It is very secure so will leave it like this and scrap my interface board idea. Just make sure you remember which wire goes to which pin. I suggest using different coloured wire for each pin, unlike me







1A = XA+
1B = XA-
2A = XB+
2B = XB-


What it looks like all done








Modification because of LCD screen

Here I ran in to my first problem. My LCD screen required the use of AUX-3 on the ramps board (bottom right of board). This is where we are getting 5v and GND from for the end stops so we need to move them. This was easily done by using AUX-1 for the 5v and GND. All you need to do is use the following pins. White dots are the old ones the coloured dots have moved to their new locations. You might not need to do this as it depends on the interface you have with the LCD screen.



Now you can see that the screen can slot on no problem.




Mounting of the Arduino

At this point everything was going great and it will all working perfectly. The PC and screen could control the laser and I had made a few test cuts. I mounted the new controller board in the chassis using the screws and plastic spacers that where under the original board. All the wiring was 100% correct. I then turned it on and it blew the power supply! I am still not sure as to what happened, from what I have been told/read these machines have questionable wiring and can have all sorts of grounding /Neutral issues. It was suggested to me that I should replace all the existing mains stage wiring the proper rated, insulated wiring and check which way round it was originally, for example has the in-line fuse been put on the live or neutral side.

I got the power supply going again after replacing a blow cap so its not too bad.

I have changed my mounting solution to self adhesive PCB mounts. This way I know the board is completely isolated. With this configuration everything is now working properly and the board is securely mounted.






Firmware

The firmware you want is TurnkeyTyranny's modified Marlin 3D printer firmware:

https://github.com/TurnkeyTyranny/bu...rcutter-marlin - Various useful informations available here.
https://github.com/TurnkeyTyranny/bu...ive/master.zip - Direct download link.

The procedure to flash the sketch is the same as any other Arduino sketch.

Everything you need to know about that is here: https://www.arduino.cc/en/Main/Howto


Software

Coming Soon!

I had a little trouble with this but it seems most people don't. I will write up what I did what this soon. In the mean time here are some links to what you need:

- Repetier Software - This is for sending your GCODE to the laser (yes it is software for 3D printers, but remember we are using modified 3D printer firmware!

https://inkscape.org/en/download/ - Free design software. You need this to run the following plugin

https://github.com/TurnkeyTyranny/la...nkscape-plugin - This is by the same guy who made the firmware. It is an Inkscape plugin that will export the GCODE for use in Repetier.

There are some installation instructions on this last link. Follow them exactly and pay attention to the versions numbers he specifies, I had to use the exact versions to get it working.

[hububalli]

Thx hububalli

More progress here. The axis are moving!
I have uncommented
in the configuration.h
recompiled and programmed. After resoldering every trough hole component.
Homing the axis seems to work. Both motors drive into them and then kind of back out.

Actually I'm trying to start my first program from the sd card. Generated by the Inscape plugin which is by the way really super work!

Executing this it homes ok, but then does nothing for quiet a long time. I thought it was not working but while typing here it started to move the mirror in the expected way.
Is this normal? Does it wait for the tube to heat up?
Finishing 10 minutes later and letting the mirror stay on the working area. But that seems ok because G Code ends with.


EDIT:

Another thing that crossed my mind. My Laser has a dedicated PSU for +24V which also supplys GND for the Marlin PCB. In order to not get static voltage in the way isn't it mandoratory to wire GND along with the signals to the Laser PSU?
Mine is connected to Earth & 230V. Perhaps this it the reason for some of you destroying their controllers?!

Does your laser have MAX end stops as well as MIN? Mine only has MIN end stops for homing. You shouldn't need to uncomment that if you do not have MAX stops.

My machine starts as soon as I press start. There is about a 2 second pause before it begins the job.

You could add G28 to custom GCODE to make it home at the end. I cant remember if mine homes at the end of a job.

That is a good point about the power supplies. That is one of the big problems with doing this conversion. There are so many different power supply configurations you really need to understand what you have in yours before getting started. Thankfully I have the latest version all in one power supply but that still didn't stop me killing the supply some how!

[Joeee83]

You shouldn't need to uncomment that if you do not have MAX stops.

No my machine doesn't have max endstops. So i disabled them by uncommenting.

Great post! One day earlier this would have saved me hours of searching and thinking! So the next ones will have a great time with it.

You are using the A4988 Drivers my Ramps kit came with DRV8825 - here jumpersettings are different. I've already edited my earlier post with information.
How much current are your drivers set to?

[hububalli]

"DISABLE" was the key word I missed there! yeah you are right. It is interesting that you had to do that to get it working. In my firmware DISABLE_MAX_ENDSTOPS is commented out still and it works as is.

I have not measured the current, it is as low as I could get it though. I moved the axis one at at time and lowered the current until you could hear that the stepper was struggling, that turned it up a little. Seems to work well like that and there is minimal heat.

That is a good point in regards to the Stepper drivers. I will add that to my post.

These lasers have such potential with just a bit of modification but not everyone has the knowledge to do the conversion. I hope my instructions will help those less techie to convert their machines and not pay out several hundred ££££ for ones of these conversion kits that are available.

[Rolf_K]

[snip]
Software

Coming Soon!

I had a little trouble with this but it seems most people don't. I will write up what I did what this soon. In the mean time here are some links to what you need:

- Repetier Software - This is for sending your GCODE to the laser (yes it is software for 3D printers, but remember we are using modified 3D printer firmware!

https://inkscape.org/en/download/ - Free design software. You need this to run the following plugin

https://github.com/TurnkeyTyranny/la...nkscape-plugin - This is by the same guy who made the firmware. It is an Inkscape plugin that will export the GCODE for use in Repetier.
[snip]

Great post huhuballi!

Looking forward to chapter 2, 'Software/Firmware Installation ' which has been my downfall.

[Kingjamez]

Hububalli: I believe your green and blue dots for laser PWM and laser fire differs from your "as built" photos and differs from TurnkeyTyrannys diagram. Which one is correct?

-Jim

[hububalli]

Hububalli: I believe your green and blue dots for laser PWM and laser fire differs from your "as built" photos and differs from TurnkeyTyrannys diagram. Which one is correct?

-Jim

You are right, the dots are on the outer edges. Should move into the middle. I will correct this. Well spotted

I don't seem to be able to edit my post. There is no edit button? I will have to make a new post and reupload all the images again which is as bit stupid.

[Kingjamez]

You are right, the dots are on the outer edges. Should move into the middle. I will correct this. Well spotted

I don't seem to be able to edit my post. There is no edit button? I will have to make a new post and reupload all the images again which is as bit stupid.

Well it's kind of silly that you can't edit the post now! I only spotted it because I'm following your instructions and replacing the NanoM2 board in my DC-KIII laser. Thank you very much for putting the guide up!

-Jim

[hububalli]

Yeah it is. I am going to ask in one of the help sections about it now. I cant delete it either so it is just stuck there giving people wrong information now.

I am glad it has been of help to you and my error didn't blow your board!

Did you notice the previous post from Joeee83 "You are using the A4988 Drivers my Ramps kit came with DRV8825 - here jumpersettings are different", that might apply to you too.

[Kingjamez]

Yep, I saw that thank you. I'm using DRV8825's and I'm going to see how well the MEGA can handle 1/32nd stepping, if not I'll dial back down to 1/16th steps. It's an easy change in Marlin.

-Jim

[hububalli]

So apparently you are not allowed to edit your posts after 3 days. If I want it changed I have to tell them what I want changed and they do it. Considering that it was meant to be gradually expanded guide it just wouldn't work like that. I think I will ask them to delete the post (as it has a couple of errors ) and I will put it somewhere else where I can have more control over it.

[Joeee83]

Sorry to hear that.
On the one hand seeing detailed information on such a complicated topic posted is a great thing but on the other relying on it even if the author has no way to update his guide can be a dangerous thing.
Seeing the information being spread on multiple websites and perhaps loosing the ability to discuss about it (forum) doesn't help the next builders.

Perhaps github and a link to it would be good.

[hububalli]

I think the best option would be to host it somewhere else (my website or Github maybe) and link to it from here so we can keep the discussion going.

[hububalli]

Coming soon! Pimp my K40

Featuring:

Honeycomb bed
Air assist
laser guide pointer
New control panel
Interior lighting
Single power point operation
Coolant flow sensor

:banana:

[Joeee83]

:banana:
:banana: Looking forward to that.
:banana: Getting inspiration for upgrading my laser bed is the thing i'm desperatly needing.
:banana:

[TroyO]

Wow, what an awesome thread, LOL. I have been eyeballing the K40 laser and reading up on it... the price is sure appealing. I am familiar with Arduino so this sounds right up my alley and cost-wise very doable. ($375-ish for the laser, then another $100 lets say in cables/boards/drivers? Under $500 for a fully functional and nicely capable laser cutter/engraver? Sold!)

Thanks to the pioneers who sorted all this out and made it work! Now, to come up with something I can make with my CNC machine that will pay for the laser... or at least something I can tell my wife will make enough to pay for the laser, LOL.

[tim_n]

Thread is brilliant.

I have got a cutter and all the gear mentioned. I'm hoping to hack it on the 14th Nov (no spare weekends until then!)

[Rolf_K]

Thanks for your generous time on this Retro. I am looking forward to messing with this mainly cause I want to be more in control of troubleshooting these kind of things.

Rolf I stole your thread but is this helping at all with your original problem?

It is hard to believe that it is now a year since I posted the start of this blog.........I have been checking in from time to time but that is about all. Have been busy building and flying quadcopter's when theweather allows. And I built a cheap Chinese printer kit, that is doing excellent after I have done a jillion modifications. Will probablymodify it to take a 2 W solid-state laser add on later.


Buddydog, I appreciate all the work you have been doing :-) Hopefully I will get back to my laser cutter problems soon.

Have to go . :-(

[buddydog]

Good to hear from you again Rolf. Been two back surgery's, sold the ultralight, resolved some family stuff, took up cigar box guitar building (6 for Christmas), building a hurdy gurdy, lot's of use for my laser (with my cheap table z axis mod. Haven't put any on the market yet altghough it's served flawlessly for a year), bought a big boat and rebuilt 2 Yamaha 250 horse motors for it, determined I needed bigger truck than my F250 to haul it so bought a 1977 F600 flatbed 2 ton and that is a current project to replace brake system and sort and fix 4 barrel Holley carb. Oh and spend some time contemplating fundamental physics and "time". Whew, a lot for an old man. Oh, forgot- took up "fine working" with hand tools exclusively. All this and more in the last year!

Miss Retro and if he surfaces I will be waiting to follow his advice on Arduino's again!