Finding a 40W laser business-end ? - Page 1
Forum section: electronics / general

author: Koen
author_rank: Frequent Contributor
timestamp: October 30, 2019, 09:09:34 pm
content: Hello,I have many custom made 3+ axis CNC machines. A lathe, a milling machine, a sewing machine, a pick and place. I used to buy time on a 80W laser but my last bill was 500 EUR and I figure it might be time to have this at home too now.I'm a bit lost with lasers though and especially with laser offerings on the usual websites like Aliexpress/Alibaba. I would like to buy the business piece of a laser and make the XY myself as usual.Would you know of kit providers ? With all the laser-related thingies in one safe and complete kit ?I plan on cutting 2cm thick foam (to protect objects in cases) and 2mm thick fabrics. All fine on a 40W. I can make many passes anyway if it's home.Thank you very much,Koen

author: Reckless
author_rank: Frequent Contributor
timestamp: October 30, 2019, 10:45:43 pm
content: I plan to buy a 40W Laser soon but I don't want to make my own. I want to cut carvings out of wood.

author: JPlocher
author_rank: Contributor
timestamp: October 30, 2019, 11:30:39 pm
content: The K40 crowd tends to get things fromwww.lightobject.com(K40 is the generic name for all those blue and red 40W $400 offerings you will find everywhere)The K40 is really a 25-30W device with really low quality components, but it makes a good donor towards a better DIY system: the tube, mirrors and lens/nozzle are OK, but most people replace the electronics and the laser bed/enclosure... Oh, and upgrade the software to use LightBurn... Of course, this turns your almost useless $400 el-cheapo into a nicely usable $1200-$1500 device.The 60W-80W systems out of China that have a DSP controller were in the $4k-$7k range a year ago are now in the $2.5k-$5k range, and are a much better "investment" than the K40, though they aren't in the same league as the $50k Epilogs...Note on power: a CO2 laser tube is rated at the maximum power it can produce, which presents two complications:You will quickly destroy the tube if you use it at its max rated level for an extended period of time, so you need to derate it ~20%. This mainly impacts itscuttingspeed/depth.A tube won't start lasing until it gets to ~15% of its power rating. This impacts the minimum power that it can produce forengraving.The net/net is that you want to top out at 60W-80W for an engraving heavy workload, and start at 60W-80W for a cutting one. If you want to cut thin sheet metal, you are looking at >120W and special nozzles...-John

author: Reckless
author_rank: Frequent Contributor
timestamp: October 31, 2019, 04:08:27 am
content: How much wattage to cut through 1/2" mahogany?

author: JPlocher
author_rank: Contributor
timestamp: October 31, 2019, 04:58:34 pm
content: probably > 100W, but I'm not sure how well that wood species will cut - many hardwoods, plywoods with glue, etc tend to burn/char instead of cutting cleanly if the laser settings aren't perfect. (The attached image shows avery good, cleanedge for reference)It may well be that a router table will give you better results than a laser if you are building furniture or making artistic products...

author: beanflying
author_rank: Super Contributor
timestamp: October 31, 2019, 05:50:05 pm
content: Quote from: Koen on October 30, 2019, 09:09:34 pmThe problem you will face with a 2cm cut into any material is the beam will not be focused. Providing you don't care to much about a taper on that cut caused by this then a 40W Laser will certainly cut most foams. ** Really important some foams SHOULD NOT be Laser cut due to what they produce as a by product.2mm of what Fabric?For a respectable source of bits have a look at Cloudrayhttps://cloudray.aliexpress.com/store/1513187For a good idea on what is involved in a DIY video then this recent series is highly recommendedhttps://www.youtube.com/channel/UCZ72zDm2feverqV7qAbNH7QLoads of great videos from Russ on Lasershttps://www.youtube.com/channel/UCqCyShJXqnElPTUnxX0mD5AAs to buying a Generic evilbay K40 DON'T unless you want a project to fix or upgrade to make it work. Much better options to be had for not a lot more without some of the pain. My toy is here with some of the resultshttps://www.eevblog.com/forum/reviews/40w-300x200mm-laser-cutter-engraver-vollerun/msg1665956/#msg1665956

author: Reckless
author_rank: Frequent Contributor
timestamp: November 01, 2019, 05:17:25 am
content: Quote from: JPlocher on October 31, 2019, 04:58:34 pmThanks, this is for artistic wall hangings and decorative swords. I have an instructables x-carve but I haven't been able to do anything more than manufactured plywood. Everything else is too hard and destroys bits.

author: beanflying
author_rank: Super Contributor
timestamp: November 01, 2019, 05:34:10 am
content: Look closely at the edge of the tile above. It dips in at the center.As with my reply on 2cm foam Laser cutting thicker Ply/Acrylic etc will see beam divergence through the cut resulting is a sloped edge. I have cut 1/2" ply with my 40W Laser at about 5-6mm/sec from memory but as it wasn't Laser grade I didn't do a lot. You can get a much better job with laminating thinner sections than using a lump. Today's marking gauge project shown below is about to be cut from 3mm ply sections then glued.These edges below on my recent PC Mini ITX case are 3mm Hardwood Laser grade ply cut at 80% of maximum power at 12mm/sec.So it can be done is the point but you will most likely want to post finish to straighten and clean up the edge.

author: Koen
author_rank: Frequent Contributor
timestamp: November 01, 2019, 05:38:57 pm
content: With reckless's direct reply I don't even understand my own thread anymore.Yes I did run into these issues with the thick foam but no I don't mind it at all. It's just to cut packaging foam conveniently. Thank you for the links !

author: beanflying
author_rank: Super Contributor
timestamp: November 02, 2019, 01:02:38 am
content: Just wanted to make sure you knew that Lasers are a travelling cone of energy not a straight uniform beam especially when you get deeperAlso double check your foam and Laser use some of the nasties are acids and other organics best not inhaled.You might also like to have a read/join herehttps://rdworkslab.com/

author: Marck
author_rank: Regular Contributor
timestamp: November 03, 2019, 10:36:32 am
content: I have a Gavograph LS100 35W laser that I picked up as unknown condition at a machinery auction I was at with a mate for well less than what it’s worth. The best part was no one was looking for a broken laser when they where shopping for a truck.And I can honestly say that yes it’s a cool toy but I wish it had more power. It’s fine for cutting foam, ply, acrylic and so on but I have found that I would like to get through other materials or engrave metals at times. Even cutting some off the shelf plastic enclosures can be interesting on thicker sections.If you go ahead with building one I would seriously look at as much power as possible you might not want it now but you might grow into itAnd defiantly be mindful of fumes from whatever you cut. My Laser has an extraction fan and filters but I still vent outside if I am cutting most things. On occasion if I forget to turn the extraction on and I am cutting something I find it cotes the lenses with crap. If you can build in some sort of extraction to pull contamination away from the laser.M

author: beanflying
author_rank: Super Contributor
timestamp: November 03, 2019, 10:45:45 am
content: See if you can adapt some sort of Air assist to the final and lense assembly?This is more than plenty of capacity for an air pump and on sale at presenthttps://www.aliexpress.com/item/32809039941.html?spm=2114.12010612.8148356.14.4aa52ffbwTKBR8All you need to get it to the head is some 4mm silicone hose.There is already some designs around for 3D printed air assist nozzles on thingiverse or roll your own custom one machined from Aluminium.

author: Marck
author_rank: Regular Contributor
timestamp: November 03, 2019, 11:35:28 am
content: It has air assist run from an airbrush compressor controlled from software so you can control it depending on laser path. The best use of the air assist seems to be stoping fires.The bed is fully enclosed so without the extraction on it just fills with vapour. I am still learning how to run it properly so no doubt I am probably doing something wrong but learning is half the fun.

author: beanflying
author_rank: Super Contributor
timestamp: November 03, 2019, 11:42:32 am
content: Cool you have air assist.Check out some of Russ's videos I linked above might help you along the way. If you haven't figured out how to checking your mirror alignment and focus might find some missing power if they are not right.Always run extraction for everything even if you think you don't need it. I also made some mods to mine to get the airflow working properly, it now draws in at the front across the entire bed and the only gap is the exhaust at the rear of the Laser. Some of the details are in my thread linked above in the second page but hit me up if you want more details. The improvement in cutting and engraving was really worth it.