Laser?

Hi,

my MPCNC was completed a couple of months ago (2ft x 2ft x 4inches), hasn’t seen much use due to health issues (getting old sucks - bits start to hurt!)

I’m all good with the router part, but would like to add a laser to it, but am not sure what type or power I should get.

My usage would primarily be to cut plywood up to 4mm or so (mostly 2-3mm) and acrylic up to 5mm or so. Parts mostly for model airplanes and boats.

What would be the color/wavelength and power rating I should go for? Funds are limited so maybe $200-$250. Something that is not to hard to get going?

Any tips very welcome as I know very little about lasers.

TIA

Gary

Hi Gary. Lasers are cool to be sure but…

To cut through that thickness of material you need a pretty high wattage laser ( = $$$) or Many passes with a low wattage ( 3 to 5w = in your price range ) laser. With this goes burned edges, smoke, maybe flames, colourful expletives, etc.

IMO, you are probably better to stick with the router since you don’t want to spend a lot, and focus on the right bits for the plastic (O flute single) with correct feeds and speeds. You will be off and running immediately.

There is a whole learning curve for laser wiring to be climbed depending on your control board, and you definitely need really good safety glasses. I feel the ones that come from across the Pacific are not worth using. Smoke evacuation needs to be good since burned plastics give off very nasty fumes as well.

Thanks Jeff,

I’ll take your advice and stick to the router for now :slight_smile:

cheers

Gary

Hey guys,

I'm wanting the same effects Gary is going for. Currently I have a 4.2W laser. For the cutting Gary described would a 7 watt laser be able to perform one pass or which laser kit from jtech would you recommend foregoing the price limitation?

I’m also trying to find past examples for hooking up a laser to the Rambo mpcnc setup. What wiring modifications would you recommend I make with my current pictorial setup?

Hi Chas. I am no laser expert for sure but I’ll venture a couple of comments.

To do the kind of cutting Gary was after, from what I understand you would need >40 to 60 watts of power. That’s why so many guys buy the cheap Chinese K40 type lasers. Mine is a 3 watt diode and it does a great job of wood burning on my projects. I’ve decided trying to cut any significant depth in wood or plastic would be too slow, get burnt edges, get lousy edges and generally not be worth the effort. Hence the comment to Gary. Some Old Guy Coding has some Youtube videos with his laser cutting stuff to consider.

The laser module I see in your pictures looks like the heat sink around it is quite small. I had a Chinese one like that which wasn’t supposed to run more than 20 min at a time. It fried in no time. I have a different one now with a Much larger heat sink and it can run for hours. Most threads will warn you not to buy one that mentions short run times. I also have a 15 watt laser that in light of past experience I expect to last about 20 min then die. Oh well. The JTech lasers seem to be good. I have seen poor reviews for a different, ‘east of Europe’ company though. Large watt numbers for diode lasers seem to be obtained by overdriving the laser. Looks like 7watts is about the reasonable max. Get protective equipment from JTech if you value your eyesight. I don’t trust the stuff that comes from far away - they don’t care.

Ryan has the correct pins identified for a Rambo based TTL controlled laser on his site. I have used that successfully. I prefer to run my laser now however with an Arduino Uno, GRBL, and Lightburn. Great combo if you don’t mind running a second wiring setup. Loads of features in Oz’s inexpensive software. It will run on Rambo/Marlin but not as well in comparison due to the GRBL 1.1+ Laser mode.

Thank you JeffH,

I was really hoping to cut a wikihouse kit with the mpcnc setup. For now it may be best to stick with the drill method and purchase a lasersaur in the future to upgrade or buy the 50W Chinese laser. I’d like to utilize customizable OSH open source hardware to maintain replicable modularity.

 

Chas

It looks to me like you’d want a Low Rider to cut pieces for a Wikihouse. I think the size constraints for a reasonable MPCNC build would mean cutting the larger parts a real pain. You would have to cut each piece in several sections.

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I also wanted a laser and after looking at the diode lasers a bit I just went the K40 route. It shows up tomorrow and I have a few parts I need to make for it with the MPCNC so I’ll post a thread about how it goes.

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@Bill,

Currently with my mpcnc I’m about to cut a toy scale model of wikihouse out. After successful attempts and scaling up I’d like to migrate to my lowrider2 cnc.

@clay,

Would it be a laser like this:

https://www.ebay.com/i/271238041852?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=271238041852&targetid=483851300373&device=m&mktype=pla&googleloc=9017429&poi=&campaignid=1497326549&mkgroupid=60666402907&rlsatarget=pla-483851300373&abcId=1139446&merchantid=101677629&gclid=CjwKCAjw8NfrBRA7EiwAfiVJpbiQA4jxo7SxKSqA_XP-CuHRRY-EY9PyU3y6dftNY58cRP0c_lKSBxoCwqIQAvD_BwE

 

Otherwise I’m looking forward to your thread. I myself am leaning towards the link or a lasersaur.

Yep, that’s the one. First time hearing of the lasersaur. From looking at their documentation it’s around $7000? I don’t know how it costs that much, I guess all the aluminum? Or maybe they’re just buying really high quality bearings and whatnot, it adds up. I’d love to see a conduit/steel tubing laser design by Ryan, worst part about the K40 is build area is extremely limited.

Surprisingly, the one I got was perfectly square and all the mirrors were aligned out of the box. No shoddy wiring either. The software available is pretty barebones but it works. A steal for $380. Only thing it needs is an adjustable bed which should be simple to do.