Chinese 40W eBay engraving laser

I ended up trading some LTC/BTC for a 40W laser from china, even though I have a 100W laser at Null Space but I wanted something for making PCB stencils and so on. I fully expected to get back a hodge podge machine that would need work, since it was $599.

 

They took just over a week from purchase on eBay to shipping via Fedex, it arrived in a few days, going from China, to Japan, to Hawaii, Oakland, to LA. The box just about made it, when I unpacked it, the box was being held together with the cling film outer wrapper.

My phones SD card was corrupted, but this is the top of the box

 

 

That blue box notes the first problem I noticed, its 220V/50hz and USA uses 110V/60Hz, the eBay listing wasn’t super clear but there was an image with the 220V shown on the label.

Quick trip to Frys and I picked up the 2000W step up transformer, this will be plenty. 

The left side is 110V, that’s plugged into the water pump (see later)

Inspecting the machine is the first order of the day, and for good reason.

 

This terminal block sends 220V to the rear panel for the water pump and squirrel fan. The two terminals on the left side in the middle are loose, they’re never been actually connected, so they didn’t come loose in shipping, how do I know? the screws on the terminal are screwed down tight. So first easy fix, but not a great start.

 

I noticed the Y direction had a small plastic tube and o-ring as the hard stop

 

 

But its not long enough, so the mirror adjustment screws hit the frame before this stop works, so add a short length of tube til it no longer hits the frame.

One the back the pump and fan are connected, they won’t sit together, shave off some of the squirrels plastic and it’ll sit better, but they’re the wrong style plugs (also 220V) for a better fir they need to be the round style of metal pin not the flat blade type, they just fall out otherwise.

 

 

water pump and air assist hookups

 

 

laser tube, interesting mounts

 

The water pump I got with the machine, couldn’t pump the water not sure if a problem with the Hz difference, or just a crap pump, luckily as with most hackers I had at least one water pump in the garage, and not only that the plastic fittings were exactly the same so I swapped it out, since it’s a 110V pump I didn’t use the rear panel. this pump is also very quiet and pumps a lot more water. Make sure you get all the air bubbles out of the laser, so as not to make hot spots.

 

The squirrel fan didn’t boot either so, but it was just stuck so cleaned it out and it was fine, not the most powerful fan but its quiet.

 

The transformer came with a small blade to pin adapter, it worked really well with the rear panel and fan.

I have a spare laser tube in the background that I’d picked up a couple of years ago, I believe it should fit.

 

Interestingly the wires for the LED crosshair runs through the tube, it limits the airflow I found, so I rerouted it to the outside. Also there is a hole,a nd a slice in the tube at the quick connects for the wire to get into, so the air leaks there too.

 

 

 

runs back here

 

unwrapped the spiral wrap

 

mark the wires so you know which polarity is used.

 

I undid them and unwound the orange pipe, this makes it easier to remove the ribbon cable from inside the tube

 

 

hole in the tube

 

I cut the tube to remove both holes and rewound, then reattached it so that it didn’t foul.

 

the original tie wrap routed the tube so it limited air flow, so I moved it.

 

 

Lightly tightened to allow it to move a little.

 

This is how I mounted the cable, til I pick up some new wiring, I’m planning to change out all the wiring since most of it seems to low a gauge for the voltages used.

 

 

rewrapped and tied back

 

the air flow is much better now, but the end needs a new nozzle to help jet the air

 

The mirror adjustment is interesting

 

jumping around a bit, i ‘d engraved some plastic sheet

 

interesting clip art that moshidraw is supplied with.

 

I’ll add more to this as I go along, there are a few blogs already about these styles of laser cutters , most people replace the moshi electronics, as moshidraw is probably some of the worst  software you’ll use. Though I’ve never had software that’s had a specific icon for Mongolian text.

 

I downloaded and installed MoshiDraw 2012, that works a lot better there are some warnings about MoshiDraw 2013 bricking controllers or USB drivers, my interface board is v4.6 so it seems to be earlier versions that are affected, there’s a debricker for the 2013 version too. I’ll try the 2013 version later today.

 

http://www.moshisoft.com/soft_200/repairusb.rar

http://www.krasner.de/RepairUSB.rar

I haven’t had to use it yet. MoshiDraw 2012 stopped once during an engrave, but only once so far. The software writers though have used the wrong windows message handler for the numerical input boxes though, so every time you type a character into the move control, it sends it to the machine instead of waiting for the input box to be moved away from or enter press, it’s a common windows GUI newbie mistake that affects a lot of software though you may never notice, but its critical for CNC stuff, you can change 80.000 to 80000 by mistake, and the machine will try to move to 80000mm. A side effect is if you type 8 0 , it’ll move to 8, then 80 but since it’s a quick move, the machine wont respond correctly and you get an error. I’m going to see if I can change the message handler code.

No need to change it, moshidraw 2013 fixes that problem, but it introduces another one, I’ve done two engraves and its only made it through about 20% of the task. I reset the machine on one of the crashes tasks, and the laser immediately came on and cut a diagonal line from home til I turned it off again… One of the reasons I’m going to add a defeat switch on the main panel lid and laser tube access panels. 

Yep tried a few times, only makes it part way through the job before stopping and homing or just stopping altogether., might be a buffer size issue?

With MoshiDraw 2012 you can use the machine as laser cutter, and not just a laser engraver though, the MoshiDraw 6/7 that comes with it will really only engrave, if you draw a line, it’ll draw around it, if you draw a circle it rasterises it so you get the draw left, move , draw right, move back, down, draw left, move, draw right.

 

Air assist as you’d expect, really helps keeps the flames down and improves the cuts no end. I just have to change out from my supersilent aire airbrush compressor which can’t keep up the air demand, to a cheap diaphragm compressor which can, just make the tubes long enough so it acts as a reservoir and stops the putt putt airflow.

 

I pulled the 8051 and tried to read it back in an eprom programmer. its likely locked or not the atmel/win AT89 but its definitely a variant, schematics match up , it has a serial 4 pin isp port on the board too..

 

So far it cuts just fine. Engraves nice too.

 

Primarily I wanted to use this for eagle solder stencils.

 

I used cream-dxf.ulp which outputs two dxf’s of tcream and bcream. Since its primarily designed for vinyl cutters , I click off the cut two times, and set shrink to 0.1mm ( None of the other DXF outputters I used could import properly)

cream-cdxf

 

After that I open it into Illustrator, set the scale to 1:1 millimeters, watch out when you select mm, it’ll change the Units(s) number

illustrator-open

 

My board is centered at 0,0, so I move the artwork to the bottom left, which is where AI has its coordinate system.

Then “Save As”  .AI format, version 8

ai_out

 

Then I import it into MoshiDraw 2013, File/Import

 

moshi

 

For the 40W I set speed 20-30 and power 25.0 to 20.0 (on the cutters control) 25 I find scorches and melts the plastic sheet, you want the fastest with the least amount of power.

moshi2

I’m still fine tuning the power/speed and reduction settings, on the TQFP64 its removing too much I need an inner cut of the pad..  But its real close.

 

Oh and if you just output HPGL directly from an Eagle CAM job, you’ll get this…

The HPGL is one contiguous line.So the laser never turns off, Etch-A-Sketch style

 

mmca suggested not using air assist.

Straight off the cutter. Like I said needs some tuning. I do these stencils on our bigger GWeike 100W laser no problem.

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