The usual question!

[walnutboydave]

Hi everyone,

I'm new to CNC and am going to ask the usual question - which machine should I buy/build? This has one slight difference from most of the questions on here though - I'm looking for a CNC machine that has an interchangeable head for laser engraving too. I'm looking at making signs for a local company from dibond aluminium, but also putting the machine to work when not making these signs by creating flat or 3D images from photographs in wood. I would also like to create laser engraved labels too, dog tags or house signs or similar.
I know I'm probably asking a lot, but when I delve into the internet to try and find machines that would suit my purpose I hit an absolute minefield of information that completely blows my mind and I end up not moving any further forward.
That's probably it for starters apart from saying the size of the signs I would like to make are around 400x500mm, oh, and I am reasonably handy so wouldn't shirk too much at having to put one together.

Thanks in advance
Chris

[walnutboydave]

Anyone?anything? Or am I barking up the wrong tree and such a machine doesn’t exist? Please help. I’m getting really lost in all the tech.

[A_Camera]

The only valuable data you have provided is the maximum size of a 2D object. That's not enough to start with, you need a Z movement also. Not only that, but what sort of budget do you have? What are your expectations? Is it for hobby or for professional use? Does it have to pay it's costs, or it doesn't matter? Are there other important limitations we should know about? For example maximum weight and machine size (floor space), tools and machinery you have, material you want to use and so on.

Yes, the Internet is a minefield, but it is also a gold mine. There is plenty of information freely available to start out with, and I honestly think that the best would be if you could limit your requirements and define more clearly what you actually expect to do with the machine and how much it should cost as maximum. Personally I think for full time job and professional use it is better to buy a serious machine, but that costs of course a lot of money. At the same time, anything worth to have will cost more than people expect it from the start. The fact that you can do some, or maybe all the work on your own does not automatically mean it will be cheaper than buying a similar, ready made one.

[walnutboydave]

First of all thanks for the reply! I would have included some more info on the original post but didn’t want to drone on too long.
In answer to your questions, the z axis would only need to be around 50mm, at least to start with. It would be mainly for hobby purposes, with an eye on expanding if I found it useful. It would also be great if it could fit on a bench top and budget is pretty tight I’m afraid, ideally around £750 - £1500 mark, but able to stretch a bit if the right machine comes along.
I also would necessarily need a new machine as I know that kind of money won’t buy a lot.
Materials would be mainly wood with a bit of aluminium every now and again.
I also understand that I might be asking a little too much from one machine, and if this is the case I would probably say that laser engraving and wood burning would be my priority.
Hope this gives a bit more clarity, and please try not to laugh. 👍🏻

[JAZZCNC]

If you want a router buy a router, likewise, if you want a laser then buy a laser. Mixing machines never work out well. Also, your budget isn't going to get you anything that's any good in either format.

My advise is look for a second hand machine that is well built because with £1500 your not going to buy anything new that is anygood. You'll need to double that budget if you want a decent router, laser I'm not sure about as it's not my thing but I think any decent laser will be in the 3K bracket.

[walnutboydave]

Thanks jazz, so if I wanted a second hand router for that kind of money what would I be looking at machine wise?

[JAZZCNC]

Thanks jazz, so if I wanted a second hand router for that kind of money what would I be looking at machine wise?

I can't tell you that I'm afraid. All I can say is lookout for something which appeals and falls in your budget range and if you are not sure if good or bad then drop me a PM with a link and I'll give you an honest assesment. Or if you don't mind the chance someone may Pip you to it post on here and we will all give our opinions. (and blow your mind..Lol)

[depronman]

there is a very common chinese CO2 laser sold on the likes of ebay, its know as a K40

It is only A4 bed size, so may be too small for your needs, but when you move up to A3 size then the cost goes well over the £1200 mark
The K40 can be had new for the £400 bracket

The mechanics of the machine are OK, but the control board and software is crap
I bought one a few years ago to engrave nad cut balsa wood and light ply for model making (Aircraft), I converted the control board to LAOS. However I think this project is now dead as GRBL has basically taken over and is a fair bit cheaper.
My LOAS laser has been trouble free for the lst 5 years, other then needing a new tube, so I fitted a 50W tube, the original being 35W
At 50W its not pushed as hard and cuts upto 1/4" birch ply easily. You need to install air assist which is basically a pipe connceted to a fish tank air compressor that is aimed at the spot the laser is cutting.
Also the bed on the std machine is rubbish, I fitted a ally honeycombe bed on a rise and fall mechanism, its manual to jack up or down, but only needs adjusting for material thickness.
It makes a great job of perspex cutting leaving a really polish cut directly of the laser, its also incredably accurate and repeatable, it will cut to +/- 0.001" all day every day

Also with any laser you need to manage the air coming from the machine, either vent it outside or arrange a filter unit to filter the air, mine is vented outside using 6" cloths dries flexi pipe
You also need to cool the laser tube using distilled water in a bucket with a pump forcing it through the tube, It will heat the water over use, so I made a chiller from an office water cooler (tiny fridge unit) so I can cut all day and maintain tolerance. If the water temp increase the laser is not as powerful, and therefore the cut line will vary over time, hence the need to maintain water temp
A rather more crude method is to have some freezer packs and place them in the bucket of water, replcing the cooler pack when needed for frozen ones.

If you need a bigger bed than A4 (320mm x 212mm is what I can cut, I can however hold slightly larger stock, but not by much) then you are looking attowards the £2000 mark, but you may get better software and therefore not need to change the control board
the one to avoid is moshi-cut / moshi-draw
I can use any DXF or SVG file to cut from, and can cut, mark and engrave all in the same job my using different layers or line colours to tell the laser cutter to either cut / mark / engrave
Engraving takes a fair length of time as the laser head is moved side to side and fires as it moves to engrave the work, its is advanced in the opposite axis a very small amount for each pass, engraving say a 1" square would take about 4 mins, engraving a line of text say 1" high and 6" long would take about 20 mins

Hope this helps a bit

BTW I fully agree with not mixing machines, a laser cutter does its job well, so does a mill or router, but neither is going to do a proper job of the others work


Cheers,
Paul