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View Full Version : I need Help I need to get a decent CNC machine don't have to much to spend



theceo
02-04-2016, 03:47 AM
I need a decent Cnc machine to cut my letters I just needs basic letters cut and don't have a ton to spend on a machine i just need some good feedback I know everyone has something bad to say I need to hear something useful and also need to know what type of software is needed as well as computer thank you in advance.

AndyGuid
02-04-2016, 07:12 AM
Afraid it strikes me that you're simply refusing to hear what people are trying to tell you!
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And opening multiple threads on the same topic in the hope that somebody will eventually say what you would like them to say will probably also will not work, other than really pee people off!
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Maybe you can find a website whose membership is comprised solely of adoring 3040 fans?
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Btw, we tend to be blunt and to the point down here on the other side of the world.

Doddy
02-04-2016, 09:45 AM
theceo,

As AndyGuid says - there's a lot of blunt responses here - it's nothing personal, it just seems to be the nature of the beast that is a machinist, that they'll say it as-it-is.

BUT, read what they say - there's an awful lot of experience here. For what it's worth, I came here after buying a second-hand Marchant Dice router (similar to a 3040, but UK build). I got much the same response from the forum as you are getting trying to discuss 3040s. After a year, I gave up the MD crap and had to admit that they were right all along, and I had thrown good money after bad trying to get it to do what I wanted (one goal - isolation routing of PCBs - that's taking 35 micron (sorry, US speak = 1.5 mils) of copper off fibreglass substrate - the machine wasn't stiff enough, and had too much backlash to do even that).

That experience, between purchase price, tangible cost to modify (ignoring time, wasted material, broken cutters) and resale price probably lost me 500 ($700?). The less tangible costs were a year of frustration, confusion and grey hair. As a hobbyist, that I can afford. As a business, could you?

I ended up replacing that with a 30 year old Denford StarMill, pre-converted to Mach3 (the CNC control software). That's taken some time and money to get to where I want it, and there are very real limitations with it, but it's a known entity for me know, and I'm confident with what I can and can't do with it - which is half the battle.

That cost me 500/$700, which probably was usable out-of-the-box.

I'm not suggesting that this is the best route, but you should at least consider it - you'll get an awful lot more machine for your money than buying new, and there's likely people here that could comment on a machine before you commit (although, over the pond, you tend to have an awful lot of US-build machines that rarely travel over here). If you can find one that's already converted to Mach 3 (or EMC2) then you'd have something that you could get up and running with a wide range of software fairly easily. Another way of looking at it, with your limited budget you're not likely to find a suitable solution buying new.

You probably need to consider the whole tool-chain if you're looking to start up. If you was to go down the second-hand market then you might find that you can tick off a few items with your purchase at once. This was the most confusing bit for me when I was first in the market - understanding all the items that you need between an idea, and a lump of machined material. I'm not trying to teach you to suck eggs, but it might be worthwhile understanding each element that when you look at an advert you can understand what you're getting, and what you're missing.

* Cutting tools - end mills, etc. There's a view that a rough rule of thumb that half your start-up costs could be expected to be eaten by cutters. I think that's perhaps a bit excessive, but don't underestimate your tooling costs.
* Clamps - simple things - that can cost a lot of money. With your application you might be able to fabricate something yourself, or bolt directly to the machine bed. Think about what you need.
* Tool holders - How are the cutting/engraving tools fixed to the spindle? Will you have to go out and buy a bunch of tool holders and at what cost?
* Machine - CNC Mill, or CNC router (the former, the spindle is in a fixed position and tends to be a stiffer design, the latter tends to support a larger cutting area).
* Spindle Controller - often part of the Control Hardware (below) - can be as simple as an on/off switch or relay, through to a 3-phase speed controller. Used to control, obviously, when the spindle is running/cutting.
* Control Hardware - normally you'd expect a solution with 3-axis stepper drivers, integrated with a Break-Out Board (BOB). The former convert the logic-level signals to high voltage/high current drive signals for the stepper motors on the machine, the latter interfaces the host computer to the control hardware - often via a Parallel port (your computer has one?) or increasingly common via USB or Ethernet (those options being in ascending order of desirability... and cost). Oh, and there should be a hefty power supply in amongst that lot.
* (Optional) Motion Controller - alternative to the BOB, typically provides greater capability (in terms of number of I/O pins), and provides localised intelligent control over the signalling to the steppers - it moves some of the real-time timing overhead from the host computer to dedicated hardware in the control hardware - nice to have, but not essential!
* Interface to the host computer - depends on the BOB/Motion Controller. Most entry level systems use the standard 25-pin parallel port. These are increasingly rare with new-build computers, and USB/Parallel adapters would rarely work. If your BOB is USB or Ethernet, you might find support for this more readily available with modern computers.
* Host Computer - for EMC2 or MACH3 (see below) there's nothing particularly arduous required here - any half-modern computer should be able to support the requirements for EMC2/MACH3 reasonably easily. Worth considering the O/S requirements...
* OS - EMC2 requires Linux - free (usually). MACH3 requires Windows XP - not available now. There is information on ArtSoft's website that Vista or 32-bit Win7 is supported - you'd need to Google yourself to understand if that is a viable route for yourself (there's a lot of noise on early integration with Vista that isn't very polite). This choice is driven from your CAM solution, which may be driven from your CAD/design requirement.
* CNC Control software - I've mentioned EMC2 and MACH3. The former is freely available and has a good reputation, the latter costs $175 and probably has the largest user base and support. This takes the output from the CAM software (below) and translates this to motion information to be transmitted to the BOB/machine.
* CAM software - Converts your design (e.g. dxf) files into a machine toolpath, this is the part where you specify how a tool will e.g. plunge into the material and cut the outline of your letter. Sometimes integrated into the design software (e.g. Fusion 360), otherwise you'll need to buy a dedicated piece of software. Many options around, one being CAMBAM for windows.
* Design software. Where you start - designing the object that you're trying to machine. Your needs are very different to mine - I've heard that Vectric is well suited to what you're looking to do but that comes at a hefty price. I typically use software like DraftSite and (as of last night) Fusion 360 - both available for free for private use, but you'll need to check the costs for commercial use.

Much of the above is available bundled together, but at least with reference to the above you can understand (hopefully, and I'm sure someone else will correct the list if I've got it wrong) all of the elements that you need to consider when you're costing how much CNC is going to cost you.

Personally, in your situation, I'd now evaluation honestly your requirements - start with your working platform size, your budget, and I'd be looking at used machines on eBay.

theceo
02-04-2016, 09:13 PM
thanks Doddy that's the feed back I have been looking for I admit yes it sucks to hear what you guys have to say about a machine I just knew should work, but wont but what was worse than that is no one gave a solution until now so thank you for details and not just saying pay more or build one because if I could do either I wouldn't be here.

Doddy
02-04-2016, 09:59 PM
theceo,

I think I saw one of your threads where you mentioned others in your field (your supplier?) has a similar machine to what you're looking at. Why not try to have an open and honest conversation with them to understand how their experience has been, what modifications they've made and why. Obviously they may not want that conversation but if you don't ask...

It may be that the limits of the machine are tolerable for you - if this same machine is used for the same application then logically you might be able to get the same results, but I, for one, would try to get the experience of those that successfully use them, before parting with a sizeable lump of cash and a time sink. But, please understand that these machines have a significant lack of strength/rigidity, your results will be variable.

Doddy
02-04-2016, 10:08 PM
if I could do either I wouldn't be here.

I'd come back here even if I could do both. Never underestimate the value of experience.

theceo
02-04-2016, 10:29 PM
I did reach out to them, but the tech only knew so much about the machine that was being used or she just didn't want to tell me but I can go back and see if I can get someone else who may know or tell me more.

komatias
02-04-2016, 10:44 PM
As we said in another thread. If you are cutting wood, you are proably lookng to get some good detail in the corners. The only fast way to do this is by getting a laser cutter.

Here is a sign I cut the letters for on my Chinese 50W laser. The sharp corners would have taken an absolute age to get right on an industrial router never mind a 3040 with a shitty DC spindle.

A 50W laser wil cut through 1/4" ply ok. 1/8" it will cut with speed. If you go to 80W you are in proper business and in fact I am looking at getting one myself. The wood in the photo is 3 layers of 1/4" ply.

https://lh3.googleusercontent.com/-EXLs07Xih7c/VwAuhvnqhrI/AAAAAAAAIsU/IuHH_E-e4Q8KhkAu03e8fAxkO01widLcgCCo/s800-Ic42/12490363_10153335345847844_484612968_o.jpg

theceo
02-04-2016, 11:06 PM
Ok you got me that looks great, so what's the cost of the 50w laser cutter

komatias
02-04-2016, 11:09 PM
Take your pick. Also have a look on the Facebook for the group "Laser engraving and cutting"

Assuming you are in the USA: http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR3.TRC2.A0.H0.X50W+la ser+cutter.TRS0&_nkw=50W+laser+cutter&_sacat=0

theceo
02-04-2016, 11:29 PM
I am in the US

JAZZCNC
02-04-2016, 11:32 PM
Here is a sign I cut the letters for on my Chinese 50W laser. The sharp corners would have taken an absolute age to get right on an industrial router never mind a 3040 with a shitty DC spindle.

So what cutting length do these 50W lasers have because that looks like long sign or is it optical illusion.? Most cheap lasers I've seen have only been 500 or 700mm max and that looks longer or is it Joined.?

Doddy
02-04-2016, 11:32 PM
Just to throw a curve-ball here.

Komatias - how do you find cutting wood affects the optics? (I'm thinking resinous smoke deposits on the mirrors) - Not necessarily a game-changer, but I'm thinking that it needs to be considered here. I would agree if you can cut with a laser this must be a good, viable solution, but I have avoided particle/laminate boards up to now with my 40W chinese (not that acrylic is particularly clean).

I'm surprised that 50W will cut 1/4" - but will take your advice on this. Perhaps I need to grow a pair and get some ply in mine - I've plenty of 1/4" knocking about and a project that needs an enclosure (ironically, to contain a laser - but only 1W 450nm... though that nearly set fire to my shed). Maybe a couple of passes will get through.

theceo
02-04-2016, 11:38 PM
Ok Komtias I looked at one of these machines looked small is that big enough to make a 11inch tall and 10inch wide letter plus what type of power does it use.

komatias
02-04-2016, 11:46 PM
The total sign was 1.4m long. I split the letters and nested them on multiple 600x250mm sheets. The designer I did this for, then tacked and glued all the letters together.

Wood makes a lot of smoke but that is why you will need to buy a good extractor fan.

Most lasers nowdays come with air assist. This is basically a nozzle that allows air to come out where the focused laser beam exits. It also ensures that you dont start a fire while cutting. You really only clean the final concentrating lens once a month.

komatias
02-04-2016, 11:48 PM
Just to throw a curve-ball here.

Komatias - how do you find cutting wood affects the optics? (I'm thinking resinous smoke deposits on the mirrors) - Not necessarily a game-changer, but I'm thinking that it needs to be considered here. I would agree if you can cut with a laser this must be a good, viable solution, but I have avoided particle/laminate boards up to now with my 40W chinese (not that acrylic is particularly clean).

I'm surprised that 50W will cut 1/4" - but will take your advice on this. Perhaps I need to grow a pair and get some ply in mine - I've plenty of 1/4" knocking about and a project that needs an enclosure (ironically, to contain a laser - but only 1W 450nm... though that nearly set fire to my shed). Maybe a couple of passes will get through.

Doddy,

40W will cut through 3mm ply in one pass but 6mm in two or three depending. You need to have a look at getting an air nozzle on you machine if it is the chinese 40W one.

komatias
02-04-2016, 11:53 PM
Ok Komtias I looked at one of these machines looked small is that big enough to make a 11inch tall and 10inch wide letter plus what type of power does it use.


Although not 80W this one is one that I would definitely consider buying it has 700x500 cutting area (27"x19"). Again at the price you will need to ensure you are up to the task of maintaining it.

http://www.ebay.com/itm/1-Value-USB-Laser-Engraving-Cutting-Machine-Engraver-Cutter-60W-Co2-700x500mm-/111952105056?hash=item1a10dd8e60:g:C3AAAOSwHnFV2tp 4

I see that the 80W are roughly twice as expensive and considering you can get most of the work done with 60W, I do not think you need any more than that.

Doddy
03-04-2016, 02:03 AM
Doddy,

40W will cut through 3mm ply in one pass but 6mm in two or three depending. You need to have a look at getting an air nozzle on you machine if it is the chinese 40W one.

Yup, mine came with an air-assist nozzle - and a handful of coiled rigid air pipe. That quickly got replaced with an energy-chain to contain a flexible (ok, aquarium) 4mm silicone air tube, as well as a 2-core ribbon to supply the two laser line-generators that a 3d-printer bracket held to provide x-hairs (don't think to use a x-hair lens/laser assy, as you can't guarantee the focus/alignment, you really do need two single line generators, one on each axis).

My real problem with chinese lasers is the absolutely crap software. I need to adapt the machine to be driven from g-code, but I've struggled to justify the cost.

theceo
03-04-2016, 05:08 AM
i hear you on the laser but it just seems like to me that a drill bit would cut wood cleaner and better than a laser maybe not metal but definitely wood,

dodgygeeza
03-04-2016, 10:31 AM
absolutely not, a laser will cut it faster and a lot cleaner than a router.

komatias
03-04-2016, 10:34 AM
i hear you on the laser but it just seems like to me that a drill bit would cut wood cleaner and better than a laser maybe not metal but definitely wood,

You get charring due to the laser that can be minimised by selecting the right feeds and power.Then a normal flapper type sanding wheel will take care of the rest. A Drill bit however is only used to drill holes. It cannot cut. An endmill or router bit will cut. The issue I see is that you cannot have a sharp internal corner due to the diameter of your cutter and that is one reason I did the job on my laser. And changing bits out, say from an 1/4" to a 1/10" cutter is a pain. If you are engraving, fine but then you may as well get a proper machine.

The software used for lasers is much simpler than the one required for cutting too. You do not have to worry about parameters, homing, ensuring the GCode is good. For someone that is pretty new to all this, looking to make money cutting out wood, then there is no beating the laser. The learning curve is minimal as opposed to CNC routers/cutting machines where you need a months/years under your belt before being able to confidently say you are any good at it.

Ultimately though it is your money to spend as you please. CNC is rewarding and a good skill to have but a cnc machine is by no means a Santa Claus machine.

theceo
04-04-2016, 03:22 AM
looked at the laser cutter at work it does cut very clean and fast the only two things now that i have to find out about is how much power does it use and the cutting size and space.

theceo
19-04-2016, 07:16 PM
Komatias wanted to know what do you use to smooth out your letters like that and to get that finish on them

komatias
19-04-2016, 10:43 PM
From what the client told me, he did nothing to the sides apart from brush them with a hard nylon brush. Then they applied varnish to the whole thing. If you get the speed and intensity of the laser right there is very little post process needed.

theceo
20-04-2016, 10:56 AM
Thank you for the response I will apply that thanks again

theceo
29-04-2016, 08:38 PM
Last question I hope what type of software do I need to run the 50w laser machine or do I need anything at all

komatias
29-04-2016, 08:54 PM
you need a grapfic software to make vector graphics and the one that is packaged in with the laser to turn the vectors into machine readable code. You should join the facebook group too.
https://www.facebook.com/groups/441613082637047/

theceo
02-05-2016, 01:46 PM
ok I will join but question based off the feed back this is the machine I decided to buy ( Water Cooling 50W CO2 Laser Engraving Machine Engraver Cutter Build-in Air Pump){http://www.ebay.com/itm/like/121545233041?lpid=82&chn=ps&ul_noapp=true} what do you think

lucan07
02-05-2016, 01:56 PM
Advice for when it arrives water cooling is vital letting the tube get over temp will kill it very quickly, operating at 100% will reduce life of tube so use minimum required to do job, there are suppliers of MDF and PLY for laser cutting that cut much easier and better than standard supplies couple fo examples just first to come up on google below these have been manufactured for laser cutting and some older PLY etc is difficult to cut with laser. Make sure mirrors and lenses are always kept clean and aligned and protect eyes at all times.
https://hobarts.com/sheet-materials/wood/laser-grade-mdf_124_15_55/
https://www.kitronik.co.uk/materials/laser-plywood/poplar-laser-plywood.html?gclid=CjwKEAjw9Zu5BRCS_OuVibujhQ0SJAD 7t4KrqNgtK7v59kv3SGf1VaD24MUTnhcgAoNLUeZ8HlxkxRoCq _rw_wcB

komatias
03-05-2016, 12:21 AM
And for the love of machinery, use deionised water and 5% automotive antifreeze as coolant. Not tap water.

theceo
04-05-2016, 08:04 AM
thanks guys you have all been a huge help and have saved me a lot of time money and headache i thank you all for the great advice.

theceo
05-05-2016, 12:22 AM
By the way is there basic software that will allow me to do different font letters and different shapes.

komatias
05-05-2016, 11:12 AM
By the way is there basic software that will allow me to do different font letters and different shapes.

yes, get inkscape or adobe illustrator or corel draw, create vector graphics, export as DXF, then import into the software that comes with the laser. You can do very basic stuff on the lasers software too, I use it for quick jobs all the time

lucan07
05-05-2016, 11:31 AM
Don't use a lot of the other software mentioned but inkscape has many plugins that tend to be missed, but I use inkscape to generate G-code directly for my engraver/cutter powerful program once you get to know your way around and its free.

theceo
05-05-2016, 01:48 PM
thanks again guys

theceo
26-05-2016, 10:23 PM
Hello guys got my machine and will be putting it together over the Holiday weekend, I am excited to try it out and see what it can do, I will let you guys know how everything goes thanks again.

komatias
27-05-2016, 12:04 AM
Hello guys got my machine and will be putting it together over the Holiday weekend, I am excited to try it out and see what it can do, I will let you guys know how everything goes thanks again.


Pics or it never happend!:beguiled:

theceo
02-06-2016, 01:15 PM
My CNC machine the journey begins 18540

theceo
02-06-2016, 01:26 PM
Now I need to know how to use inkskape to design with my machine

lucan07
02-06-2016, 01:30 PM
Remember to treat temperature of coolant as essential if not fitterd fit a thermal cut out to coolant system, and use minimum required power to maximise tube life, 30 minute running hot or over driven can kill the tubes. Also buy the laser quality MDF and PLY as they cut easilly compared to standard products also maintaining tube life.

lucan07
02-06-2016, 01:34 PM
Using inkscape is like any other software you need to read manuals and practice, it handles many formats for import and export but as with any other software there is no magic shortcut around the learning curve.

theceo
02-06-2016, 01:36 PM
ok thanks working on that curve now

theceo
02-06-2016, 03:56 PM
Do i have to download some software to get my computer to see my cnc machine because i cant get them to connect

lucan07
02-06-2016, 04:10 PM
It should come with necessary driver but best not to plug in before installing drivers it may well install wrong ones, if you have done this may need to go into the device manager identify device uninstall and remove drivers. Should all be in the destruction manual that comes with the machine.

RTFI (Read the flipping instructions) is the polite version, we all tend to plug in and try but often not the best solution.

Doddy
02-06-2016, 06:49 PM
Do i have to download some software to get my computer to see my cnc machine because i cant get them to connect

I could be very wrong here - and probably am - but from the photo this looks like a chinese laser (I can't seen any obvious safety interlocks - but again, I might be wrong).

Anyway, if it is a Chinese laser, it might be like mine (I bought a cheap 40W Chinese special) - and no software was supplied. When I queried this with the supplier they provided, via email, the dodgy copies of Corel-esque software that provided the direct interface with the machine... there wasn't an explicit driver.

theceo
03-06-2016, 02:33 AM
yes its the chinese laser cuter 50w the one i was advised to get by this panel but yes they gave me software that doesnt work bad desk, but no saftey issue here :encouragement: wanted to see if i could get the drivers another way

theceo
03-06-2016, 08:16 PM
Figured out a work around to download the software for my machine with a bad desk I GOT SKILLS

lucan07
03-06-2016, 08:20 PM
spelling is not one of them it's a bad disk :thumsup: the desk is what you put under the computer not in it.

theceo
06-06-2016, 06:37 AM
why lucan07 your cool :stupid:

theceo
06-06-2016, 06:39 AM
question what is the best way to adjust my cutting dept with my cnc machine i'm thinking cutting power let me know thanks in advance

lucan07
06-06-2016, 08:53 AM
Yes depth is adjusted by adjusting power but I would advise to try and stick below 70% of max recommended to try and extend tube life and watch temps more power may require more cooling.