DIY Laser Cutter Project

Re: My holiday project

Great progress, since the last time I looked at the project. This will be extremely useful when it's complete.

Re: My holiday project

I'm building a router table too, but I'm going all out on mine. Ballscrews and linear bearings all around. I'm using the giant CNC machines to build little routers though

I'm hoping to be able to cut stainless and more, even if it's just light cuts. I've got all the tools I need to build one super rigid, super accurate machine. Having access to all those industrial CNC machines has me spoiled though, I won't be able to deal with anything less than half a thou repeatable accuracy!

I've thought about making a laser "attachment" for my router, but I really haven't read up at all on controlling a laser cutter. It's gotta be possible!

Things - are you sure your table is going to move fast enough to use all of the power of your laser? If the table doesn't keep up with the laser you'll just burn your work up. You might try switching to a threaded rod that has a larger pitch. It'll decrease your resolution but increase your rapid rates, assuming the steppers have the torque needed to move the table that fast.

Also, it's probably not that big a deal in this case but you really don't want to use solid couplers like that. Even a tiny misalignment will eventually wear the stepper out from vibrations.

Re: My holiday project

Yeah I let him know about that fact, but he has not built the motor mounts yet. They sell helical shaft couplers that allow for a little play. That might be advantageous. The couplers were a pressie from me... so its not a loss for him if they don't work out.

Re: My holiday project

More bearings and the CO2 focusing lens arrived while I was on holidays. Back home now, so will start making some more progress. Although the trips to the hardware store are going to be only occasional, mum had a car crash before I left on holidays and still hasn't heard about her car

Re: My holiday project

Well, time for another update! Just finished off the Y axis :



I also made a video:



Just waiting on the motor couplers and CNC board from bobhaha, along with the 24V PSU I ordered. I also need to make a wooden frame for it, to give me somewhere to mount the motors etc, and also add some stability.

It also appears regular first surface mirrors work perfectly for Co2 wavelengths, so just need to devise some mounts and it's almost complete

Cheers,
Dan

Re: My holiday project

Just a question, if I were to use belts and pulleys instead of lead screws, how do you actually join the belt into a loop? I doubt I'm going to find any closed belts over a metre long, so I'd have to buy an open belt and somehow join it myself. I'm not really keen on using belts, mainly because the pulleys and belts will be over $100 alone!

I'm slightly worried, because my threaded rods seem to be fairly warped, which will interfere with precision greatly.

How do you join the 2 ends of a belt to close it?

Cheers,
Dan

Re: My holiday project

McMaster-Carr
a bit pricey but a nice last resort in case you don't find a way of joining.
using belts is a good idea, there's a reason professional cutters use them.

Re: My holiday project

Dan --
You might consider small steel cable like used in model airplanes. That's what is in my chart recorder and there is no stretch.
Some fishing line is also of stainless steel.
HMike

PS: Any flooding there on you? Algore promised draught with globule warming.

Re: My holiday project

TTW, I have found a source of "belting" in Australia, however I still haven't found how you are actually supposed to join the ends together.

HM, I didn't consider steel cable, sounds like it could work, although I'm not sure how it'd fit onto a pulley on my stepper motors without slipping?

Not so much flooding in my general area, however most of the state Southwards has had a beating! And we aren't even a month into the wet season!

Re: My holiday project

OK well, I took the plunge and ordered 7 metres of timing belt and 6 pulleys, total of $116.

Since the belt isn't actually going to go all the way around the pulleys, I'd just attach the 2 ends directly to the carriage, that way I dont actually have to glue the belt etc, just screw it down onto the carriage

Re: My holiday project

Well, got my belts and pulleys today and rigged up the X axis. One problem I think I may run into is my steppers not being powerful enough. I decided to use 2 steppers on every belt, totaling 6 steppers for the whole laser cutter. I need to order 3 more before I can continue though. But before I do that, I need to wait for my CNC controller so I can run these steppers, to test their torque.

Re: My holiday project

Looking very good so far! Can't wait to see the whole thing together and cutting. :gj:
I was wondering what it is that the carriage will be moving around.
Certainly not the co2 tube itself...
So I am thinking you will be only shifting around the mirrors, correct?
Doesn't that need on-the-fly refocussing?

Re: My holiday project

If i may suggest ..... don't forgot to place a wheel (pulled with a spring) also under the carriages, for stability

Re: My holiday project

anselm said:

Looking very good so far! Can't wait to see the whole thing together and cutting. :gj:
I was wondering what it is that the carriage will be moving around.
Certainly not the co2 tube itself...
So I am thinking you will be only shifting around the mirrors, correct?
Doesn't that need on-the-fly refocussing?

Click to expand...

Yes the CO2 tube will be sitting on the side of the laser cutter, and will use mirrors to bounce it to the topOnce correctly positioned, the mirrors don't need to be moved. I have used the optical sled from one of the Casio projectors to house the focusing lens, which also has a stepper in it to allow linear movement.

Re: My holiday project

I still somehow fail to see how you move the cutting laser dot across your workpiece
on the X and Y axes.
Or maybe you are instead sliding the workpiece around meanwhile the dot stays
always fixed in the same position.:thinking:
Sorry for not getting it and keeping on asking. :yabbem:

Re: My holiday project

Another good use of the Ca5io leftovers. +rep for that alone.

These CO2 laser cutters are a bit over my head but still a great read and thread and shows me once again what an incredible forum we have and there are so many generous members helping each other.

G L to all on your projects.
very cool DIYing.---hk