DIY Laser Cutter Project

[Things]

Z axis belt is in, just cut out a little housing for the stepper motor that allows me to use it for belt tensioning. Joining the belt was a bit of a pain, originally I tried glue and tape, however that quickly snapped under tension. Instead, I sewed it together, then melted a bit of scrap belt on top, followed by heating a piece of metal and pressing it down on top. This kind of sandwiched and melted everything together. It's holding fine so far, though the teeth are a little unaligned.

Dan

 

[MotionCAM Design]

Hi Dan,
I've just received a couple of stepper drivers from Lightobject the same as yours. Can you tell me how to connect them to the Lightobject DSP please.(what wires connect to what pin)

Cheers

Kevin

 

[Things]

Hi Kevin,

You need to connect DIR+ and PUL+ to their respective DSP pins, and the rest ALL need to be grounded, including EN+.

Cheers,
Dan

 

[MotionCAM Design]

Re: My (16 month ) holiday project - DIY Laser Cutter

Hi Dan,

I've got to the stage of testing my machine and wanted to know about the 445nm (1watt) laser you used. These are obviously quite cheap, where did you buy yours from and are they easy to hookup for power etc....

Regards
Kevin

 

[Things]

Hi Kevin, glad to hear it's working!

The 445nm laser I used was just purchased as a diode, I put it in a module and added a simple LM317 driver. The power is just switched to the driver and diode using a MOSFET connected to the DSP on the laser TTL pin.

It may be easier for you to purchase a TTL 445nm module, as then all you have to do is hook up power and the TTL wires

Would love to see some pics!

Dan

 

[Things]

Welllllllllllllllll, been a long and hectic past few months.

Ended up moving back to Cairns and my father driving the machine up to me. Upon putting it in the garage, the lack of space was a real concern. Living with family again meant the garage was already packed with other peoples stuff.

Even just getting to 1 side of the machine was a pain, and I had a lot of work that still needed completing, such as adding a case.

On top of that, I've also applied at University, planning to do Electrical Engineering. However, they only run the first year where I live at the moment.

I was in a bit of a dilemma. The machine was too big and heavy to move myself, and I now have to consider what I'd do if I had to move into a unit, live om campus etc.

So well, I decided to sell the setup as is Upside is I did get majority of what I put into it back. I had considered using the money to buy myself parts and build another one, but I really didn't think I could be bothered after so many attempts, and the new gear would have been about $2K to start off with. Then redesigning the Z axis, casing etc, argh, too much work for the limited tools I have!

So, decided to go the easy route and buy a smaller, complete machine. Not the greatest quality, however it is a lot better than those $800 "K40" type machines, and a much more usuable workspace of 500x300mm vs 300x200 for the K40 machines.

Not to mention it also has air assist, uses nice beefy motors, decent looking mounts, already built in Z adjustable table (Although it's manual - for now ).

It claims a 50W tube, however it looks like a stock standard cheapo 40W tube to me - On the other hand I've heard reviews from other people that it does perform a bit better than other 40W machines they've had, so who knows.

I went through many different machine options before finally settling on this one. However, the one main advantage is it actually ships from within AU. If I were to import something this price, I'd be up for over $400 in customs fees, no thanks!

Here she is:

Interesting to see how we're gonna get this off the truck

Technically it is still a bit impractical to move myself, but at least it won't take up my entire kitchen if I need to move into a unit.

Anyway, was listed for $2830AUD, managed to drag the seller down to $2556AUD shipped Toll.

Hoping maybe the end of this week, or early next week, Toll are pretty quick, but being such a big machine, it'll probably need to be moved around by machinery, adding some more delays.

I have heard some good reviews on these units, so I'm hoping it'll make a good platform for me to start off with, hopefully offering cheap SMD stencils to people, and upgrade it bit by bit as I need.

Exciting and scary times, not sure what to expect with Uni, but won't know till I try it

Dan

 

[Things]

Welp, my new baby landed today

Was a little bigger than I expected, the crate only just fitting in my car by a few cm! And it's still quite heavy, still a 2 person lift, but not nearly as bad as before

Was glad it came with an actual DSP rather than some "fake" DSP's I've seen other companies use on their machine, replacing the LCD display with a laser current meter instead of an actual display. I may end up upgrading it to one from Lightobject in the future, as the software is a little clunky, but it works fine for now.

In general I'm quite happy with it, especially for the price, can't really beat it. Were a few minor issues as you'd expect, like the water flow sensor has broken off it's welds, bottom of the emergency switch fallen off etc, but apart from that, not really any other issues so far.

Alignment was pretty good right from the box, only had to remove the ZnSe lens and clean a bit of burnt material off it that had obviously fallen in there during their aligning.

First thing to go will be the flat cutting table, it's already a mess from cutting wood and I've only had it for 5 hours!

Laser tube arrived intact, which is great. Not 100% sure how you're meant to adjust the tube height on those mounts however, but haven't had to yet.

The manual Z axis is a bit tedious, takes quite a while to move it to the full extents, but I intend on making this motor driven in the future too, shouldn't be too difficult.

It has an inbuilt exhaust fan, which isn't all that powerful, however it is sufficient, even with the extended tube.

It also comes with a rotary axis, which could really do with some rubber around the rollers, but that's pretty easy to add myself.

Basically came with everything needed to get up and running. Living in the tropics though, I'm using an aquarium water chiller to hold the lasers water at around 22C. I'd like to go lower, but condensation is an issue. The 10.6um wavelength being absorbed by water, the last thing I want is water getting on the output lens of the tube and cracking it!

Few little odds n ends I've done so far

Dan

 

[Things]

Have done my first few modifications, simply installing some LED strip. The fluoro is nice and bright, but it gets blocked by the X axis, so I put some at the front of the machine, as well as under the X axis itself:

Things I'm planning on doing when money permits:

Replace red laser attachment with a proper ZnSe combining lens, as at the moment it's practically useless.
Install a relay for the air pump so it only comes on when a job is running. It has a manual switch on the side of the unit, however it gets quite hot if left on for a period of time, and I've heard a few stories of these burning out.
Replace the cutting bed with eggcrate - this flat sheet is already a mess from cutting wood, and is basically hopeless on acrylic from reflections.

I'm gonna pick up some gangnails tomorrow and try them upside down until I can afford the eggcrate, see how that does

 

[Things]

Just a bit of a side note, today I was playing around trying to cut some ABS. Well, the first thing I noticed is it produced a hell of a lot of smoke, almost too much for the exhaust fan to keep up with. Because of this, some of it was also leaked back into my garage, and it was also still leeching out of the plastic for a good hour after I'd cut it. The cuts ended up messy and mostly a melted ABS mess, however the real worry set in about 5 minutes later with a crazy headache that lasted for a good hour.

During this time laying in my bed on my phone, I discovered that ABS actually produces hydrogen cyanide when it's laser cut. Yes, hydrogen cyanide, the stuff used in gas chambers!

So, I won't be doing that again until I can get a really powerful exhaust system going

PVC is also another nasty one, producing chlorine gas, it'll kill you within minutes, and rust your machine horribly over a couple of days, as it reacts with moisture in the air and produces hydrochloric acid!

Never cut ABS without serious ventilation, and don't even think about trying PVC unless your goal is to turn yourself into a doorstop and your machine into a pile of rust. Scary lessons learnt!

 

[MarioMaster]

I'm surprised the more expensive machine came with an axial flow fan - I tried using an axial fan with my laser cutter and the performance was horrible, the original centrifugal fan worked 10x better. I bet an argon laser fan would get rid of the smoke =P

Also I would recommend mounting the fan outside if you can, that way the entire vent tube is negatively pressurized. I quickly found that when cutting acrylic with mine that even small air leaks in the hose connections made the entire basement smell like burnt plastic.

 

[Things]

Yeah, that's where the problem with the ABS came in, would have been fine with my argon blower fan and mounting it directly on the window, and running pipe from the machine to it.

The fan does move a decent amount of air, but not really as much as I'd like, but unfortunately doesn't look like my argon blower made it here in my first lot of stuff

 

[Meatball]

Just sounds like you ought to replace that fan with a completely different setup - given you're concerned about its lifetime and effectiveness.

I hate to admit that I've come across that chlorine gas in person via the PVC method. It really is a deathly yellow.

I think MMs idea with the external is great!

Sorry you had to sell your masterpiece.

 

[Things]

Haha, all good. And yeah I'll replace the extraction system once I get my argon blower fan, or another fan, I'll just avoid cutting ABS for now. Copes fine with wood and acrylic.

I removed the crappy flat cutting bed this afternoon, was a bit of a pain as I had to unbolt the bed frame from the threaded rods. I ended up just snipping the corners off the flat sheet to get them out, as I couldn't be bothered removing the threaded rods. Don't really need it anyway. Turns out a piece of 35x55cm eggcrate will fit nicely, so I've put in a quote for that

 

[Things]

Installed a red aiming laser, using a combiner that was donated to me

It uses the original module that was attached to the cutting head, with a little custom acrylic mount I made for it. However, while trying to align it, just as I got it perfect and went to tighten the screw down, I shorted the module out to the case of the laser cutter and killed it

So I had to find a spare DVD writer, rip the diode, which was oddly soldered into it's heatsink, and pressfit it into the little 8mm module from the front, which was interesting. Wired up a LM317 to run it at around 60mA, and realigned the whole thing again. But works great now

 

[Things]

Few little bits n bobs I've made so far:

Also just completed a little container from 3mm acrylic to see if I could reliably make it waterproof, and seems to have worked great

Unfortunately acrylic is quite expensive, around $66/m^2. Managed to score all these offcuts (and cut down to size to fit in the cutter) for $100, so was pretty happy with that

Have also modified the wiring a bit to allow the water pump to run independently of the main power. Because I also have a 10L bucket in the laser water cooling loop, I needed to keep the water circulating through the chiller to keep it cool, ready to use. So now I can just turn on the water pump, and leave the rest of the machine off to save power, and because the fan is noisy.

 

[Things]

Eggcrate arrived today

Seeing as I got a scrap piece free, I had to cut it down to size to make it fit my machine. What was handy is it came with an outer frame that had risers attached, so it actually sits above the surface of the table a bit, which is perfect. Took a bit of mangling to get the frame right, as I had to cut the longer sides off and use 2 pieces of it to make up the back of the frame, but it worked