Which CNC router for aluminium sheet?

[user 26575]

OK, I think we've focused our minds on a CNC router (after my posts on a printer and then mill conversion in this part of the forum). This is partly to learn cnc, and partly to make some bits for motorcycle modifications using 2mm aluminium sheet.

Making one is beyond us (just to get that out the way!). So it's either buy new or used. The operations are pretty simple/ don't need to be terribly precise. This kind of thing:


(It's to replace a heavy instrument panel/ fairing mount on a bike - 2mm 6082 ally).

I know it's best to find a setup that's not overly flexible, but apart from that have no real idea what to get. Lots of names of manufacturers, different models, different prices. Where to begin?!
The maximum would be £2000 for new, I'd prefer much less, and not sure about what to expect to pay for used (and, presumably a bit outdated?) Realistically, in the long run, if we get on well with what we buy we'd likely upgrade once we've got the hang of things. But equally we don't want something that'll annoy us.

Sooo! Any recommendations?

 

[ChaiLatte]

A router works in three dimensions. You have provided only one dimension (2mm) in your specification. The photo of the bent piece you show is very roughly 200mm left to right. Is that the maximum you will ever want? And what of the front-to-back dimension?

Whatever machine you buy, you have to hold the aluminium sheet onto the bed of it before and during machining and then remove it afterwards. Some approaches to solving that issue may have budgetary implications after the initial purchase cost of the machine.

 

[sploo]

Size and rigidity (usually mapping to weight) are important factors. If the parts you want to cut are relatively small (e.g. a work area no bigger than 30x30cm) then you'll likely get away with a fairly budget machine. You can use something like a 1/8" (3mm) single flute spiral cutter and have decent success in 6082T6 ally (without needing mist or flood lubrication). NB I've found other grades of ally (common for sheet goods) to be very "gummy", but 6082 is usually OK.

You'd get something like the Ooznest Workbee (https://ooznest.co.uk/product/original-workbee-z1plus-cnc-machine/#size-colour) in a small size for under £2k; or less used (one on eBay now for £899).

One of the Stepcraft models might also be worth considering (https://shop.stepcraft-systems.com/cnc-construction-kit-d-series).

The Denford Microrouter is reasonable too; but only used, and you need to get one that's been converted to run available control software as the Denford proprietary stuff isn't usually an option.

There are various sub-£500 Chinese machines (e.g. google "3018 cnc") but I'd probably avoid those.

 

[ChaiLatte]

You'd get something like the Ooznest Workbee...

Thanks for pointing that one out.

Has anyone remarked here previously that the router motor they offer is a clone of the Makita/Katsu one but with an ER11 spindle?

That means in principle it should fit all standard router bases for those brands and have the ability to take a much wider range of cutters (a full set of ER11 collets is not a lot of money and can be had in 2-7mm as standard, with 8mm, 1/8" and 1/4" also possible).

 

[Ollie78]

I suggest a second hand industrial machine over a home style machine like a workbee etc.

A smaller machine is easier to keep stiff and that is important.
For metal machining you will probably want coolant and so will need some kind of tank and pump system and chip tray.
This would lean more towards a cnc mill or a fixed gantry style with a moving bed rather than moving gantry.
I would not bother with a trim router as the motor but a proper water cooled spindle, these days they are pretty cheap and worlds better than any router.

You will need to think about what is the biggest thing you will need to machine, how you will hold the material, how will you design the things you want to make and how will you generate the g code.

you can make most older machines work with a new uccnc and an axbb http://shop.cncdrive.com/index.php?productID=1009

 

[user 26575]

Thanks all, that's really helpful.
@sploo - 30 x 30cm is plenty for now, if we really need to my lad can weld sections together but that's very unlikely.
@Ollie78 - we've talked about it and can't think of when we might need more than 2mm thickness ally - except when much thicker and then it'll need to be done the old-fashioned way on the mill. (I did look into cnc-ing the mill but it's going to take more time/ effort and probably understanding than I have.)*
The Ooznest ones look nice Sploo - I saw the ebay one, do they usually have cables hanging off the gantry like that? Made in England sounds good, too.

eta *I forgot to write my question, Ollie. Do you think 2mm aluminium will be too much for the Ooznest style kit?

 

[ChaiLatte]

For metal machining you will probably want coolant...

On 2mm aluminium, on a machine in the class of those shown above, coolant could be a great disbenefit.

With the chip size and volume that such a machine can produce, either a light air blast or a vacuum extraction will suffice. A solid wax lubricant applied to the outline of the part would be another alternative.

Liquid coolant is likely to produce a silver coloured slurry that will be quite challenging to manage.

 

[Ollie78]

On 2mm aluminium, on a machine in the class of those shown above, coolant could be a great disbenefit.

With the chip size and volume that such a machine can produce, either a light air blast or a vacuum extraction will suffice. A solid wax lubricant applied to the outline of the part would be another alternative.

Liquid coolant is likely to produce a silver coloured slurry that will be quite challenging to manage.

This is true but I know how these things go.
You will start by doing a bit of 2mm sheet then, you know, since you have a cnc machine you will start making other stuff pretty quick.

This is why I think it is important to decide what you really want to do, not just the first job but the 10th job or 50th job.

 

[user 26575]

This is true but I know how these things go.
You will start by doing a bit of 2mm sheet then, you know, since you have a cnc machine you will start making other stuff pretty quick.

This is why I think it is important to decide what you really want to do, not just the first job but the 10th job or 50th job.

It's definitely for up to 2mm aluminium, Ollie.

 

[user 26575]

I noticed that the Ooznest ones use a leadscrew. As I said above, it doesn't need the greatest accuracy, just wondering if not being ball screw is an issue?

 

[Ollie78]

Thanks all, that's really helpful.
@sploo - 30 x 30cm is plenty for now, if we really need to my lad can weld sections together but that's very unlikely.
@Ollie78 - we've talked about it and can't think of when we might need more than 2mm thickness ally - except when much thicker and then it'll need to be done the old-fashioned way on the mill. (I did look into cnc-ing the mill but it's going to take more time/ effort and probably understanding than I have.)*
The Ooznest ones look nice Sploo - I saw the ebay one, do they usually have cables hanging off the gantry like that? Made in England sounds good, too.

eta *I forgot to write my question, Ollie. Do you think 2mm aluminium will be too much for the Ooznest style kit?

Ok as you already have a mill and it is strictly for thin aluminium. I think the ooznest style kit would be capable of cutting it.

However it is my opinion that you still should not buy one unless cheap and second hand.
My issue with the design is mostly the fact that it runs on an aluminium extrusion with wheels. This is a situation asking for trouble with swarf and dust getting in there, and also belts are a possible failure point. The Shapeoko is a slightly better version of the same idea which has some improvements.
The Stepcraft ones are a better.
To be fair the chinese 30/40 ones are possibly better than the ooznest because they use rails and basllscrews, the trouble is more often it the electronics on these and getting a reliable supplier. My mate had a 60/40 one and it was mechanically fine but he had to change it to uccnc which sorted it out.

Roland do some neat small machines similar to the denfords as well, often used in schools and stuff, again software might need updating.

 

[Ollie78]

I noticed that the Ooznest ones use a leadscrew. As I said above, it doesn't need the greatest accuracy, just wondering if not being ball screw is an issue?

Leadscrews are fine for accuracy purposes and better than belts. The advantage of ballscrews is more the longevity and easy peasy maintanance.

 

[sploo]

The Ooznest ones look nice Sploo - I saw the ebay one, do they usually have cables hanging off the gantry like that? Made in England sounds good, too.

I don't know I'm afraid - I've never used one (I just know of the brand). My CNC machine is ~20 years old, and from a US manufacturer that unfortunately no longer exists.

My machine is (now) fitted with a 3hp spindle, has ballscrews, and weighs around 100kg. However, when using a 1/8" single flute spiral bit the limit is really the deflection on the cutter; not the spindle power. Taking 1mm deep cuts works ok; with a bit of care to clear chips with a vacuum cleaner. It takes a long time, but I have cut shapes from 20mm thick aluminium with success.

 

[user 26575]

I just had a quick browse of FB and ebay and now have a much better idea of what we're looking for. Still not clear on new vs used but it's clear used saves a lot. Maybe the downside of older ones is software compatibility, which is probably bad for us - the lad has used Fusion360 for CAD in school but we really don't know about what works with what, so a new(er) setup is more likely to be nearer to plug and play.

 

[sploo]

I just had a quick browse of FB and ebay and now have a much better idea of what we're looking for. Still not clear on new vs used but it's clear used saves a lot. Maybe the downside of older ones is software compatibility, which is probably bad for us - the lad has used Fusion360 for CAD in school but we really don't know about what works with what, so a new(er) setup is more likely to be nearer to plug and play.

Fusion360 will have a CAM module. I think 3 axis is free (or it was the last time I heard). As long as you've set up the machine in your software (dimensions, tools, feeds and speeds etc) then you ask the CAM program to output gcode for the controller you're using. A "Mach" postprocessor is fairly common in CAM tools; given the wide use of Mach3.

I am a dinosaur though; I used an ancient version of AutoCAD to make simple 2D DXF drawings, and output gcode using a similarly ancient version of SheetCAM (https://sheetcamshop.myshopify.com/). Basically this is because almost all the machining I do is simple 2D contours, with the occasional pocket; and whilst the above is very manual, it's also simple.

I have had a play with the CAM module in Solidworks; which is massively more powerful (it'll generate all the right toolpaths based on your model; depths, inside/outside cuts etc). However, it melts my ageing brain so I've yet to have the courage to actually use gcode it's output.

 

[ChaiLatte]

Basically this is because almost all the machining I do is simple 2D contour...

I do not know if this is splitting hairs, but perhaps what you describe (and what the OP seeks) could be better thought of as 2 1/2D.

There are variable moves in Z (up and down) involved, but not simultaneously with any X or Y moves.

Something like a pen plotter could be closer to a strict definition of 2D (where it only has 'pen up' and 'pen down' for vertical movement).

 

[Ollie78]

I just had a quick browse of FB and ebay and now have a much better idea of what we're looking for. Still not clear on new vs used but it's clear used saves a lot. Maybe the downside of older ones is software compatibility, which is probably bad for us - the lad has used Fusion360 for CAD in school but we really don't know about what works with what, so a new(er) setup is more likely to be nearer to plug and play.

Fusion 360 will do the cam no problem it will limit your maximum cut and rapids speed as far as I remember unless you subscribe. This limitation may be unimportant to you as it will still work fine. You can "post" to mach 3 or UCCNC or any number of other machines and standards.
So Fusion will get you going no problem. Otherwise Vectrics cheapest product is called cut 2d which is ideal for sheet cutting. One great thing about the vectric software is you can try it out as fully functioning software, the only thing you can`t do is actually generate g code at the end. So download some stuff and have a go.

The actual G-code is basically a text file so as long as you can get it into the machine it should work

"Plug and play" is a bit of a pipe dream, there is always a learning curve. It is a bit confusing initially but once you have cut something it will make sense.


have a look on here, https://www.mycncuk.com/

 

[user 26575]

Thanks Ollie - I'm more than happy to learn how to use it, I guess I'm just trying to avoid those problems where you hit a brick wall and the info/ software we need is very out of date - I have that repeatedly on my desktop imac and it's really frustrating. My son's is newer and can function as mac or pc so we'll use that to learn to bridge the gap between Fusion360 and our sheets of ally!

It's just a question of which one to go for now, and what to pay. Well, that and my complete ignorance of Fusion - it's on his laptop, so I'll start playing while we hunt for the right setup.

I'm really grateful for the advice you fellas have given us.

 

[sploo]

I do not know if this is splitting hairs, but perhaps what you describe (and what the OP seeks) could be better thought of as 2 1/2D.

There are variable moves in Z (up and down) involved, but not simultaneously with any X or Y moves.

Something like a pen plotter could be closer to a strict definition of 2D (where it only has 'pen up' and 'pen down' for vertical movement).

Exactly that - "2 1/2D" cutting covers 99% of what I've done with the machine (hence it not being a huge problem to work with simple 2D DXF drawings, and manually enter the cut depths in a separate (simple) CAM application.

The modern CAM packages are incredible; you can essentially give it your modelled 3D part and they'll work out all the cuts that are needed to make the part (using your available tools). However, you appear to need to do much more work to define your fixturing (because otherwise it essentially assumes the stock is just "magically" held in place). They are also (understandably) far more suited to large milling machines with tool changers; rather than smaller hobbyist kit (that almost never have an automatic tool changer).

 

[Steve Mehrlich]

see below link to a thread on here last year.
https://www.ukworkshop.co.uk/threads/cnc-machine.147508/

the chap was making planer blades i think from steel and bought his machine as a kit for i think £1300 . although there is a bit of putting together i think it was pretty much a full machine.

might be worth reaching out to get some feedback now he's used it for a while.