[wontpontificate]

Hello folks!

For a while, I've been glancing at the cheap chinese lasers on the eBay, and doing my homework on what makes them tick, and what their strengths and weaknesses are.

The general consensus seems to be that the software is terrible -- not only is it counterintuitive, and a pain in the butt to use, it doesn't support vectors. Additionally, the hardware doesn't play nice with any other software.

I have read though, that once you can tame the software, the raster output is actually fairly decent.

When people here, and elsewhere ask about the machine, I tend to hear some variant of these three responses from people:

1) The whole shootin' match is awful, and should be avoided at all costs -- save your money and buy a better unit.
2) The software is so terrible it will make you give up cnc and take up knitting
3) The machine runs much better after replacing the drivers and running it with Mach/EMC2

These imply that the software is terrible, but aside from the first blanket statement, say nothing of the hardware. I'd like to hear some more detailed information about the guts of the machine -- The quality of the design and construction of the moving parts (e.g. amount of play/slop in the axises, design of the bearings and drive mechanics, etc.), the quality of the laser/PSU, and the design of the housing, and the quality/ease of adjusting the optics.

At the price they're asking, It seems like it'd be worth it to buy with the intention of giving it a brain transplant from jump -- assuming the mechanics are reasonably sound, and would stand up to light hobby use with occasional weekend sprints.

I know you can't make a silk purse from a sow's ear, and I fully understand that this is not a professional production machine, but it sure seems to make a good glorified parts kit.

-C

[mondo50m]

I have had one of the 'cheap lasers' for about 2 years. I would believe they are cheap due to the fact that they may be using factory seconds for the tube and power supply. That is just my opinion. I had to replace my tube about 4 months after having the laser, and the power supply after about a year. I have since upgraded to a DSP from Light object. I never had a problem cutting vectors with my unit or doing engraving, you just can not do them both at the same time without upgrading to the DSP. The software is very difficult to get used to, but it is possible. I have replaced the nuts on the mirror adjustment screws with springs, this makes it very easy to align the mirrors. I know there have been upgrades to the software, but I have not used Moshi software in quite some time.

Milt

[herby08]

OK the mechanics:
first all the rails and the gantry (X Axis) need to bealligned to be square
speed settings should not go over 350mm/s
the laserhead carrier has four rolls which need to be adjusted that they are not to tight and not to loose
all belts need to be tight but not to tight like a guitare string is to teight
all the three end pulleys need a second bearing
the X Axis motor is to week
overall for a hobby is good after the above.
greetings
waltfl

Hello folks!

For a while, I've been glancing at the cheap chinese lasers on the eBay, and doing my homework on what makes them tick, and what their strengths and weaknesses are.

The general consensus seems to be that the software is terrible -- not only is it counterintuitive, and a pain in the butt to use, it doesn't support vectors. Additionally, the hardware doesn't play nice with any other software.

I have read though, that once you can tame the software, the raster output is actually fairly decent.

When people here, and elsewhere ask about the machine, I tend to hear some variant of these three responses from people:

1) The whole shootin' match is awful, and should be avoided at all costs -- save your money and buy a better unit.
2) The software is so terrible it will make you give up cnc and take up knitting
3) The machine runs much better after replacing the drivers and running it with Mach/EMC2

These imply that the software is terrible, but aside from the first blanket statement, say nothing of the hardware. I'd like to hear some more detailed information about the guts of the machine -- The quality of the design and construction of the moving parts (e.g. amount of play/slop in the axises, design of the bearings and drive mechanics, etc.), the quality of the laser/PSU, and the design of the housing, and the quality/ease of adjusting the optics.

At the price they're asking, It seems like it'd be worth it to buy with the intention of giving it a brain transplant from jump -- assuming the mechanics are reasonably sound, and would stand up to light hobby use with occasional weekend sprints.

I know you can't make a silk purse from a sow's ear, and I fully understand that this is not a professional production machine, but it sure seems to make a good glorified parts kit.

-C

[wontpontificate]

first all the rails and the gantry (X Axis) need to bealligned to be square
...
the laserhead carrier has four rolls which need to be adjusted that they are not to tight and not to loose
all belts need to be tight but not to tight like a guitare string is to teight

Is the alignment procedure a royal pain in the butt (i.e. is it designed to be adjusted, or do you have to fiddle with it?) and does it stay aligned, or does it drift back out and need frequent readjustment? I'd expect to have to realign everything after transatlantic shipping, but hopefully not again after I got it all "dialed in"

speed settings should not go over 350mm/s
...
the X Axis motor is to week

Is the maximum speed related to the weak x-axis motor, or another limitation? Would replacing the motors with better ones solve the problem? Are motors standard (I presume NEMA 17 frame) steppers?

all the three end pulleys need a second bearing

What sort of bearings are these, and what sort of modification is required to add them?

Thank you for your response! I appreciate the input -- At the very least, I'll be able to put together a rough cost analysis of what is necessary to do in order to get one of these machines up to snuff post-purchase, to help others decide whether the added expense makes it a poor purchase option.

Cheers!

-C

[Robin Hewitt]

At the price they're asking, It seems like it'd be worth it to buy with the intention of giving it a brain transplant from jump -- assuming the mechanics are reasonably sound, and would stand up to light hobby use with occasional weekend sprints.

I have one but I don't have another laser to compare it with. Have some random information, I'll try and give you a feel for it.

The Moshi software comes with a dongle. You can cut text in outline. Outline box checked = cut, unchecked = engrave. It seeems to have lost it's dxf input.

The new Moshi driver board looks to be using a single 8051 family CPU where the older version had two.

The case is 1mm steel, powder coat with the occasional rust spot. Held together with 6mm bolts, not a waher in sight. Inside there is a plate to separate laser from electronics and an L shaped plate at the back to hold the laser. To remove the laser plate you need to remove the separation plate. To remove the separation plate you need to remove the XY assembly. There is one hole in the case bottom best covered over unless you want to set fire to your table top.

The laser framework appears to be lacquered aluminium extrusions.

The Y axis uses two belts with an axle across the front. A double shafted NEMA17 motor has a pulley on one end and connects to the axle at the other.

One turn on an XY motor moves the head 40mm. I have heard that the driver have two intermediate voltage levels for stepping.

Inside the case you have the Moshi board, a 24VDC supply, a bare PCB laser PSU, a bare mains distribution PCB, and a wiring loom tied up with spiral wrap.

The mirrors are sprung back against 3 adjust screws. One of the lock nuts is hard to get at. The screws are prone to rust and prone to turn when you lock them.

My laser mounts were set 6mm too low with what looked like a piece of 3mm tractor inner tube for packing.

The water cooling is by a fountain pump which gives you 43W of heat before you even turn the tube on.

The fume extractor is designed for a larger machine and has a crude air duct. It is surprisingly quiet .

If you want to replace the Moshi board, the laser PSU seems to have an opto isolator input. It gets 5V and a transistor pull down through a 33R resistor. It seems to get 5V off the 24V PSU using a fat resistor and a Zenner.

There is no "air assist" so keep cleaning the lens. It is a gunge magnet.

If you like tinkering then the K40 is for you. Everything you do improves it, it is totally gratifying. I love mine to bits

[herby08]

hi there
OK I replaced my original motor with a nema 17 1.5A,
the bearings are miniature two side sealed ones from ebay 5x8
the beam adjustment is a bit tricky but only the first time, then its pretty easy and only needs adjustment after
some hard bounce.
overall I can say its wioth to convert to a DSP with the stepper driver and a PWM laser powersupply and if you wana do more heavy cutting you could use a GaAs lense what gives you about 30% more cutting power
greetings
waltfl