Thanks LightObject - K40 DSP Upgrade Completed

Post Reply
daveman
Posts: 31
Joined: Wed Jan 09, 2013 10:07 am
Location: Frankfort, Kentucky
Contact:

Thanks LightObject - K40 DSP Upgrade Completed

Post by daveman »

I know there are a number of posts about successful DSP upgrades but I wanted to share some of my thoughts on this awesome upgrade to this otherwise cheap K40 Laser Engraver. Maybe someone will find them useful.

First step in the journey, getting the thing to my house. This was shipped in a monsterous amount of packaging, I was very impressed. Unfortunately it was so large after all the padding that my mail carrier couldn't fit it in their vehicle. I had to go pick it up at the post office where the postal workers affectionately nicknamed it the "giant dog bone" package. I think you will see why:

Image

Out of the box (and multiple layers of tape, 2" of foam, and 15 layers of bubble wrap) it looked good and worked well when the Moshi software would let it. I immediately placed my order for the DSP controller!! The Moshi software was way too unstable.

Image

Inside it was clean and the wires were well routed with lots of room to play with. with DSP controller in hand it was time to let the games begin!!

Image

Step one, mounting all the goods, there are notes after the photo about some of the issues I dealt with. This is not nearly as neat as I like for my projects to be but it is functional.

Image

Notes:
1. I elected to leave the "green giant" resistor. I have seen a number of posts that say it can go but I figured it did bother me to leave it.
2. I had to move the power supply back about 1.5" to make some extra room. It looked like lots of room at first but got a little cramped when I started adding things.
3. I used Marco's conversion PDF. Great work Marco!! Thank you.
4. My unit did not have a fan in the back. There was one in the power supply but it just moved hot air around the inside of the case. I grabbed a PC case fan out of the junk box and mounted it in the back.
5. The small board at the bottom is a custom 3 way power board. It supplies isolated 5 volts for the meter, 12 volts for the PC fan I added, and 3 volts for a laser pointer that will be added soon to the laser head so I can see where the laser will fire.
6. I added a new 6A 24v supply, the stock one was too weak for the motors and controller.
7. With all the tinkering in the electronics compartment, I think I bent the metal around the tube in the back. It didn't look bent but on full power it wanted to arc between the positive on the tube and the metal case. I fixed it by rotating the tube a few degrees to maximize the air gap between the positive and any metal.

Next step, making the panel look good. I used 1/8" lexan (no I didn't cut it on the laser, like Nancy Reagan said . . Just Say NO!). Anyway, I cut it on my scroll saw to mount all the components and covered it with white vinyl for a finished look.

Image

Final step was to improve a little on the X-Y stage. The way the limit sensors were positioned and the garden hose "stops" were positioned, a lot of useful travel was lost (mainly on the Y axis). Notes to follow the photo.

Image

Notes:
1. To the left is the garden hose stop for the Y axis. I trimmed about 3/4" off of it to increase positive travel.
2. To the right, there is a custom PC board I made to replace the optical Y limit sensor. By eliminating the optical sensor and making the custom board as small as possible, I gained an additional 1/2" of travel.

So now I have a very functional laser cutter fairly cheap, I'm ready to make a few more modifications before I move on to making my own from scratch.

1. I want to add the laser pointer to the laser head to indicate where the laser will fire on the material being cut or etched.
2. Air assist is in my not so distant future.
3. Adjustable table. There is one listed as out of stock on LightObject that looks awesome, I would love to buy one if anyone know of one available. If not, I would appreciate any ideas on implementing a movable table on these K40 laser engravers.

One more thing, not that anyone would be interested but I have added the EagleCAD files for the custom pc boards for the power supply and limit switch boards.
Attachments
EagleCAD_Files.zip
(44.67 KiB) Downloaded 266 times
daveman
Posts: 31
Joined: Wed Jan 09, 2013 10:07 am
Location: Frankfort, Kentucky
Contact:

Re: Thanks LightObject - K40 DSP Upgrade Completed

Post by daveman »

Before someone spots the mistake on my schematic for the power board I made, let me correct myself a little. The laser pointer power section is wrong. Under no load, the two diodes levels the power out at about 3 volts which is what I was looking for. Unfortunately, under a load the diodes will cause a combined voltage drop of 1.2 to 1.4 volts. That will bring the 3.3 regulated voltage down to 2.1 or so which is well below the operating voltage of the typical laser pointer module. I don't have a clue what I was thinking. Instead, I will replace one of the diodes with a wire jumper and the other with a 10 Ohm resistor. By doing that, the resulting voltage drop across the resistor will be about .4 volts putting about 2.9 volts at the laser pointer module. It's obvious mistakes like that which will teach you not to play with EagleCAD when you are short on sleep. :roll:
theking
Posts: 19
Joined: Mon Sep 10, 2012 11:08 pm
Contact:

Re: Thanks LightObject - K40 DSP Upgrade Completed

Post by theking »

Verry Good works please if you have other picture send to me at [email protected] i order kit and i wating packeg for remplacemnt moshidraw board and i think i made from you Thanks.
Dany.
daveman
Posts: 31
Joined: Wed Jan 09, 2013 10:07 am
Location: Frankfort, Kentucky
Contact:

Re: Thanks LightObject - K40 DSP Upgrade Completed

Post by daveman »

theking wrote:Verry Good works please if you have other picture send to me at [email protected] i order kit and i wating packeg for remplacemnt moshidraw board and i think i made from you Thanks.
Dany.
I would be glad to. Unfortunately I don't have many before photos but if there is any particular area that you would like to see more detail on I will be glad to post some for you. Just left me know the main areas you would like to see and I'll get them to you this weekend.
Dave
theking
Posts: 19
Joined: Mon Sep 10, 2012 11:08 pm
Contact:

Re: Thanks LightObject - K40 DSP Upgrade Completed

Post by theking »

Thanks you Dave , i see you keep a red bouton on top is this laser fire on off ??? if yes let me know how do you make a wiring ? is it whit wp on ps . ?
Dany.
daveman
Posts: 31
Joined: Wed Jan 09, 2013 10:07 am
Location: Frankfort, Kentucky
Contact:

Re: Thanks LightObject - K40 DSP Upgrade Completed

Post by daveman »

theking wrote:Thanks you Dave , i see you keep a red bouton on top is this laser fire on off ??? if yes let me know how do you make a wiring ? is it whit wp on ps . ?
Dany.
Yes, I liked the idea of keeping a quick kill switch for the laser itself. Here is how I have the power supply wired:

Image

It does use the water protect connection. In the DSP Interface guide, it shows WP just jumpered to ground but placing a switch in line (like the original K40 laser wiring) serves the quick kill purpose. I will eventually add a water sensor and door open switch in series with the red push button. They will both be normally closed contacts that will break the circuit if the door is open or water stops flowing. I just haven't planned how to do the water flow sensor as of yet. I know I can buy one but the real fun in this type of project is testing my skills and making it myself.
daveman
Posts: 31
Joined: Wed Jan 09, 2013 10:07 am
Location: Frankfort, Kentucky
Contact:

Re: Thanks LightObject - K40 DSP Upgrade Completed

Post by daveman »

Dany it just hit me you were talking a about a switch to fire the laser. You won't need one of those, there is one on the DSP control panel. My switch is for enabling/disabling of the laser.
theking
Posts: 19
Joined: Mon Sep 10, 2012 11:08 pm
Contact:

Re: Thanks LightObject - K40 DSP Upgrade Completed

Post by theking »

THanks for this update :) i receive my kit last week and i'M excated :mrgreen:
daveman
Posts: 31
Joined: Wed Jan 09, 2013 10:07 am
Location: Frankfort, Kentucky
Contact:

Re: Thanks LightObject - K40 DSP Upgrade Completed

Post by daveman »

New update coming soon. I have backordered the motorized z table that is due first week in February. I know Marco's stock of these things will be in short supply (I saw on another post that said 20 or so) so I hope I can snag one this round. In the mean time, I lowered the stock table and added honeycomb to the existing table but I really look forward to an ajustable table where I can tweak it for different material thicknesses. I will post pictures of the motorized z table if I am lucky enough to get one, until then here is my lowered stock table with the honeycomb I bought on this site. I didn't like that it wasn't framed so I took some scrap aluminum and made my own:

Image

In addition to the motorized z table, I also added on the stepper driver for it and a air assist head as well. I ordered a 60lpm air pump off ebay, we'll see how that turns out. Also I'm still trying to figure out the laser pointer for the laser location indicator, but my first attempt failed at that but I'd rather mark it up as a learing experience. :D

So based on my investment tonight, here's my upcoming to do list

1. Adjustable table if the back order gods smile on me (based on the measurements on the site, I may have to trim back the vent some)
2. Air assist (trying to figure out the tubing routing, I have cable drag chain but haven't worked out the details yet)
3. Revisit the laser pointer mount

At some point, I will actually start making some cool laser cut stuff on this thing but for now I am really enjoying just making it the best machine for the money. My girlfriend laughs at me when I get in to things like this and I already have a half dozen ways figured out to improve it before I even take them out of the box. I'm up to about $1300 so far and with what I hope to end up with, I don't think you could touch it for that amount. More updates to come soon.
daveman
Posts: 31
Joined: Wed Jan 09, 2013 10:07 am
Location: Frankfort, Kentucky
Contact:

Re: Thanks LightObject - K40 DSP Upgrade Completed

Post by daveman »

New events today, power table has arrived and I'm pretty pumped about it. It was quite a surprise to see that it came fully assembled. The description when I ordered it made it appear to require assembly. I will post some pictures in the near future of the install. I have to do some mods to the machine to get it to fit and I want to add a home switch to it. This is a VERY well made bit of hardware. If it works as good as it looks I know I will be pleased.

I got my air assist head too and I was pleasantly suprised there as well. Finding the metric tubing that I though I was going to need for the pressure coupling was looking a little challenging in my area. I was very happy to see that what was delivered actually has your everyday nipple on it and not the pressure fitting. It is much less bulky and really will make it much easier to source the tubing at my local hardware store.

I want to give some credit to LightObjects. I know they were in a rush to get these out to the customers that had back ordered them and accidently left out the wiring for the stepper motor. They were very pro-active and mailed the cable separately to ensure that I had everything needed when it arrived. I certainly like doing business with a company that identifies their mis-steps and corrects them before I even know about them. I got the cable yesterday and the table today so they went the extra mile to ensure that there was abolutely no impact to me. Good work!!

I'm really looking forward to making these final updates to my K40 and I will share photos and experiences with them over the weekend.
kculm
Posts: 3
Joined: Sat Mar 02, 2013 2:22 pm
Contact:

Re: Thanks LightObject - K40 DSP Upgrade Completed

Post by kculm »

Would you still happen to have the template for the face plate if so would you mind posting it.
ivantandy
Posts: 51
Joined: Tue Feb 12, 2013 9:04 pm
Location: CANADA
Contact:

Re: Thanks Daveman for WP wiring tip

Post by ivantandy »

I have wired the Test laser switch on my similar K40 with excellent results. thanks.
Post Reply

Return to “D40/K40 small chinese CO2 laser machine”

Who is online

Users browsing this forum: No registered users and 66 guests