Need Some Advice On Adding A Laser To A CNC Plasma Cutter

[ZarlosJari]

I have a friend who wishes to modify and add a laser to his CNC plasma cutter table he has. He has this for in his own personal work shop and not in a commercial environment. He wishes to be able to cut up to 1/2" acrylic/Lexan and up to 3/4" UHMW. As well, he mentioned he would like to be able to cut thin aluminum sheeting sometimes if possible, too.

Because the table will continue to be used as a plasma cutter, he will need the laser module mounted on the transit and head of the table rather than stationary and beamed into the head via mirrors. He said he has not problem having a cooling pump and power supply being remote mounted and plumbed/routed in to the head.

He has also requested that the laser be controlled by the computer code as well.

So my questions are as follows:

-What laser diode or tube would be best suited for this application and would also be cost effective considering the intended usage in a home workshop?

-What power supply is best suited for the laser module recommended?

-What, if any, cooling system would be recommended...even if it's home made?

-How does he give his PC authority over the laser...Is that accomplished all through the power supply or is there a separate controller?

-How would you recommend mounting the laser to the head so it will be well supported but not hard to service as needed?

Thanks ahead of time for your help with this!

[RodolfoWen]

Do a little research on CO2 lasers and you will find what he wants to do is really not feasible. Laser machines use a system of mirrors and a moving carriage with optics to focus the beam. I do not know a laser diode that exists today that has enough power to cut 1/2 acrylic at least in one pass anyway. It would take a minimum of 80 watts to do so. Before a bunch of people jump in with yes you can, I have owned laser machines going on two years and run a sideline business. I know what a US made and Chinese made machine can do.
If he has a lot of money to invest, Kern makes a large flatbed machine that will do what he wants.

[Jessieea]

If he uses a RF laser tube he could focus directly straight down into his lens. no mirrors envolved.

[Williamhaxy]

Have you ever seen a RF tube? My ULS RF tube window is near the top on one side. My guess a 100 watt RF tube, which will not cut metal would cost outright $10-15k. Not counting the power supply and you still need optics to focus.

[ZarlosJari]

Thanks for the advice!

The big hurdle is the size of his shop. He already has the large plasma cutter in the shop and does not have enough practical space for another machine that large...hence the desire to make his plasma table a dual-purpose machine.

Pardon my ignorance here, but what would be the problem with mounting the CO2 tube securely in a vertical stance on the head and beam the laser straight down through any required focus lenses and then onto the table? Or what about mounting the tube horizontally on the head frame and using a single right angle mirror and a lens down onto the work surface? In both of these scenarios mentioned, the laser tube would move with the head frame across the table.

I'm interested to hear your thoughts.

Thanks!

[Howaredug]

The main issues of monting the tube directly is weight.
If you consider the water cooling you can get over the 2kg mark quite easy - this would require changes or at least tweaking of settings unless the machine itself is already a bit overpowered for the normal CNC operations.
I the tube is located off the moving parts and only mirrors and the lens head is used these masses simply don't exist so the machine can operate as normal.
For my the main concern of a tube mounted onto moving bits is that it can cause stresses wich in return can casue failure that are quite costly.
The easiest way to check if the machine can handle a directly mounted tube is by placing a weight of a few kg onto the moving axis.
If there is no problem moving this without loosing steps or other unwanted results it would be fine - still I advise against it unless you want to invest into a RF driven tube wich comes in a metal housing.

[kagtinyzs]

RF tubes don't use water to cool and even if they did there is not that much water in the tube He wants to be able to cut acrylic not metal

[Michealpync]

A water cooled CO2 tube moving is not really possible or practical. It depends on a water pump and hoses for cooling and the tube moving would cause water flow issues inside the tube. A RF tube is very expensive and the lens is on the side near one end as I have stated above, at least on mine anyway. I don't think the vibration of the gantry would be good for it either. These tubes depend on mirrors and electronics inside (RF) to work.

I think the Kern, and someone will need to check is a tube at one end and the typical flying mirrors setup.

I think your trying to invent something here that will be very expensive.

So what is the budget for the plasma cutter to laser conversion?

I have said a number of times, with enough time and enough money anything can be done!

BTW the OP did post
As well, he mentioned he would like to be able to cut thin aluminum sheeting sometimes if possible, too.