CNC advice please

[bilboburgler]

I'm working in a Maker Space in West Yorkshire. In our 2024 budget we aim to have £3-3.5k set aside for a 3 or 4 axis cnc portal miller for wood cutting. Since we have multiple users of varying skill ranges we need a fair bit of rubustness built in and would like proper slideways and ballscrew drives. Assuming that extraction, bench and any shielding was covered by other budgets and we wanted to be able to cut at least a 750x750mm area what machine would you look at?

Onefinity
Shapeoke
Bulkman
any other

 

[Ollie78]

I suggest a second hand more industrial one over any of those mentioned. Your budget is decent and you should be able to get something pretty good.
The machines you have listed all have fairly serious design problems.
When looking for a machine avoid anything with a belt drive or certainly with wheels running on aluminium extrustion, both of which are problematic.
I would also avoid anything that uses a router, water cooled spindles with VFD`s are pretty cheap and vastly superior.

What you are looking for is a stiff frame design, shaped linear rails on all axis, ballscrews or maybe rack and pinion drive system, ideally closed loop steppers but this is not essential. Servos will probably be out of your budget.
The "brand " is not as important as the repeatable accuracy figure, the maximum speed of the motion is also an indicator of the general quality of the machine, a weak frame won`t be able to move as fast as a strong one.

Remember you wan`t to use the machine to make stuff not spend time swearing at it trying to get it to perform well.

Quick look on ebay not many on there at the moment but something like this (I know its over budget but as an example ) will be so much better than the onefinity or anything like the Shapeoko.
https://www.ebay.co.uk/itm/29571526...Q0yStIfgW+ruEqJ9yzMFelztZe|tkp:Bk9SR7DSxouPYw
This is a good one and bonus as its vertical and has a cabinet. Only trouble with this type is you cannot feed long lenths through the machine as you can with some. Good for safety etc though and a very good bargain

https://www.ebay.co.uk/itm/33515360...1bDPecIP8E11lVByg%3D|ampid:PL_CLK|clp:4429486
Even this might be good but may need work, who kows.
https://www.ebay.co.uk/itm/36452831...MN0fHnCOB6mKEG819jIBqW5Bg9|tkp:Bk9SR5jI_ouPYw

Ollie

 

[bilboburgler]

Thanks, I'm a previous machine tool designer so well aware of basic structures etc. quality etc. I was really trying to get an idea as detailed in my question. The trouble with buying second hand is you buy the problems that the seller gave to the product as well as those given by the manufacturer.

Looking at those three manufacturers I can see that the Bulkman suffers from poor quality aluminium extrusions and far too much Chinese equipment. I'm not sure what the quality issue with the other two manufacturers are, but any advice appreciated.

I agree completely that using a router is not the way to go. With our users I don't think we need to go to the spindle solution as our up-time will be tiny, so I suspect a milling head will do better but I'm happy to be convinced by someone who has real experience of them both.

Thank you for the three company suggestions, I'll dig into them. Space and access are at a premium in our space and everything needs to come through a normal front door and be reassembled without lifting equipment which makes some of these impossible.

 

[Sachakins]

Worth looking at yt for James Dean Designs, has loads of info and clearly shown too.

https://youtube.com/@JamesDeanDesigns?si=QfW6S7rtbKz1cjrG

 

[bilboburgler]

Thank you, I've not been that excited by this range of machines, I don't like the wheels and the cogged belt, but the author is interesting enough with some good feedback and info.

 

[Ollie78]

Thanks, I'm a previous machine tool designer so well aware of basic structures etc. quality etc. I was really trying to get an idea as detailed in my question. The trouble with buying second hand is you buy the problems that the seller gave to the product as well as those given by the manufacturer.

Looking at those three manufacturers I can see that the Bulkman suffers from poor quality aluminium extrusions and far too much Chinese equipment. I'm not sure what the quality issue with the other two manufacturers are, but any advice appreciated.

I agree completely that using a router is not the way to go. With our users I don't think we need to go to the spindle solution as our up-time will be tiny, so I suspect a milling head will do better but I'm happy to be convinced by someone who has real experience of them both.

Thank you for the three company suggestions, I'll dig into them. Space and access are at a premium in our space and everything needs to come through a normal front door and be reassembled without lifting equipment which makes some of these impossible.

The issue I have with the shapeoko is that it uses wheels on an aluminium extrusion, dust gets in there the wheels wear and the aluminum is soft.
In comparison, profiled linear rail has wipers to keep dust out and many lubricated ball bearings in the carriages to keep everything smooth and in perfect alignment.
Also belts can stretch and move and I feel its a little underbuilt in general. It is not a bad machine but I feel for the money there is better value to be had.

The onefinty is possibly ok but I am unconvinced its structure is the best, it has used oversized round rail as both structure and bearing surface which would be almost impossible to shim back straight if it needed it, at least it looks like there is dust sealed bearings etc.
The other thing is that it has no structure in the base, its relying on your bit of mdf or plywood as a base instead of metal frame, the base is where it gets much of its rigidity, so you need to build a really good bench for it which is extra money and time.
The other thing is the control unit which looks like an all in one chinese (see ali express) unit which are not very well regarded. You may be better of with a PC and UCCNC or Mach3/4 which is how many systems are run.

For some context, my machine which I bought second hand is made from 90mm by 45mm aluminium extrusion and the gantry is 2 bits of this bolted together with 20mm tooling plate ends, I think I could stand on the gantry with no issue. I would not stand on a shapeoko.

The reason I recommend the water cooled spindle is because they are made to a higher tolerance than routers and are much smoother and quieter in operation, there are aircooled versions too. Make sure your milling motor will go fast enough as small bits want to go fast.

I was not specifically suggesting those companies but those types of machine, many will be the same under different names. The Denford machine is the exeption and probably costs at least £12k to buy a new one.

Avid cnc is a company that do a sort of modular system where you can upgrade and expand as you go. Stoney CNC have a range of decent machines so you can compare specs and why some are more expensive etc.

It can be a minefield but I am sure you can find something good.

Olie

 

[sploo]

Interested in this thread as an observer; as £3000 for a machine of that size with ballscrews and proper (ball circling) linear rails feels optimistic (at least for a new machine).

I bought a machine (900x600mm work area, servos, ballscrews, linear rails) about 17 years ago from the US (because it was cheaper than anything I could find in Europe for the size/quality) and that was still $6,400. The default/entry configuration for Avid's 24"x24" (600x600mm) machine looks to be around $8500; with the prices going up from there on the bigger machines.

I've seen some of the machines with belt drives and "3D printer like" rollers and... they... work. But I'm not sure how well they'd last. Ollie78's recommendation to look for used is probably the right route; accepting that there could be quite a bit of work in then getting the electronics and software going to your satisfaction.

 

[curryjunkie]

i think your budget is too small for what you are after, if its being used daily in a makerspace id assume at least 6 or 7 thousand for a decent machine. used is a toss up, unless you get lucky, remember unless you have expert knowledge in setup and repair it can be pricey to get it up to a good standard. similar to buying a car in used condition, you may get a bargain, or you may get a money pit.

 

[worn thumbs]

I suppose the usage of the makerspace has a large effect on the type of machine to look for.If the users are trying to earn a living,the machines listed are a step in the right direction compared to marking out and cutting by hand.They aren't hugely productive machines when compared to the larger commercial machines.Rectangular extrusions deflect under load as do simple guide rods.Far too many basic machines have gantry side plates that aren't triangulated to resist the loads along the gantry beam,even though it is usually powered by the same kind of steppers as the other axes.Something that might be a factor if any of the likely users have a rival with a more productive machine.A couple of weeks ago there was a Chinese made 8' X 4' machine on ebay for £4,000.A bit more of an outlay and space might be an issue,but so much more productive.



One other significant factor is likely to be software.The nature of a makerspace will probably mean a range of users and they will have to make some degree of adaptation to become accustomed to the software for creating the toolpaths.Has this been factored into the cost of getting a machine into use?Is the plan to cut outlines and pockets only or will there be some 3D usage?

One final caution,beware of recommendations from satisfied users as they are unlikely to have experience with other machines and are so impressed by the machine they have in their own workshop that objectivity is a bit lacking.

 

[Phill05]

Thanks, I'm a previous machine tool designer so well aware of basic structures etc. quality etc. I was really trying to get an idea as detailed in my question. The trouble with buying second hand is you buy the problems that the seller gave to the product as well as those given by the manufacturer.

Looking at those three manufacturers I can see that the Bulkman suffers from poor quality aluminium extrusions and far too much Chinese equipment. I'm not sure what the quality issue with the other two manufacturers are, but any advice appreciated.

I agree completely that using a router is not the way to go. With our users I don't think we need to go to the spindle solution as our up-time will be tiny, so I suspect a milling head will do better but I'm happy to be convinced by someone who has real experience of them both.

Thank you for the three company suggestions, I'll dig into them. Space and access are at a premium in our space and everything needs to come through a normal front door and be reassembled without lifting equipment which makes some of these impossible.

I am a cad designer, have you thought about building your own machine? this is what I did after buying my first machine that did work but not really to the extent of what I wanted to do up to 3D , so I sat down and designed a machine, found the best quality parts to use a lot from Germany and got on and made it and it has worked out so well for me, a have 4 axis machine with a cutting area of 500 mm x 500 mm I made an extended Z axis to cut 320 mm, I can slide longer work through the X axis.
I can cut in wood,metal and stone.

 

[bilboburgler]

Thanks to all, some great ideas above and I'm so glad I asked the question.

I think Shapeoko now have a proper slideway and ballscrew option.

Our MS is not heavily used and is physically small so not expecting a lot of usage. We already have a good basic range of wood working tools, sewing machines, laser cutters and 3D printers. In terms of machine tool physical side I think I'm the only Professional Engineer on site with high levels of precision machining experience which would make the project very vulnerable.

While just a few members use the space for a side hustle this is not the key use of the space, what we don't have is any sort of service engineer on site, so if the thing gets broken then getting it fixed is down to generous members stepping in. So far this has worked on other machines pretty well, but this machine will be a step up on complexity for us.

I do like the idea of group design and make to try and keep the price down and I'll bounce that idea past the team. The size issue is well defined above as well, smaller will always be stiffer with the same core elements.

 

[sploo]

One final caution,beware of recommendations from satisfied users as they are unlikely to have experience with other machines and are so impressed by the machine they have in their own workshop that objectivity is a bit lacking.

This is very true. I've been in a few industrial settings where they have several (huge) CNC machines, but I've never seen a hobbyist/maker with multiple budget level machines; so us "home gamers" rarely have experience with anything other than our own small machine.

 

[sploo]

I do like the idea of group design and make to try and keep the price down and I'll bounce that idea past the team. The size issue is well defined above as well, smaller will always be stiffer with the same core elements.

This is a much more realistic prospect than when I looked into it ~20 years ago; the wide availability of reasonable quality linear rails, and complete stepper + controller sets would make life considerably easier.

There's also the option of rack and pinion motion; which is quite common on larger machines as ballscrews tend to "whip" at high rpm over long lengths.

One thing to also consider is what's underneath the machine. Mine could not cut something below the bed because there's a ballscrew running the length of the machine, plus bracing for the gantry. Many machines now appear to have dual motors (one on either side of the gantry) and as such are open underneath. With planning, it means you could use it to engrave the top of cabinets, or even mount long stock vertically (e.g. for cutting tenons on the end).

BTW I'm just north east of Leeds. Where is your Maker Space based?

 

[jimbowley]

I was also going to suggest build your own. I started on that route myself because it's interesting to spec your own machine, but then I realised that a year long project wasn't what I needed, I just needed a tool to use.

I bought a 1800x900 Stepmores direct from China £4k all in. 3kW spindle. Vacuum holddown. Very happy with it, but aware that it could be a problem if it breaks down. Whereas if you design and build your own you will know it intimately.

Vacuum hold down is great for sheet products because you don't have to worry about collisions with clamps.

Size: Maybe go for 1200x1200, someone will appreciate the extra size at some point. Or 1200x800, something that divides neatly into 8x4 sheet material.

Because I'd been on a forum with some ridiculously capable machines, I started cutting with 10mm carbide cutters before I realised that's just more dust. Now I use 6mm for speed, or 4mm for more intricate parts. And 4mm/3.18mm for plastic. If you get a precise machine you can do plastic parts too.

 

[Phill05]

Have a look here for most of your linear parts: www.wmh-trans.co.uk

 

[Ollie78]

Thanks to all, some great ideas above and I'm so glad I asked the question.

I think Shapeoko now have a proper slideway and ballscrew option.

Our MS is not heavily used and is physically small so not expecting a lot of usage. We already have a good basic range of wood working tools, sewing machines, laser cutters and 3D printers. In terms of machine tool physical side I think I'm the only Professional Engineer on site with high levels of precision machining experience which would make the project very vulnerable.

While just a few members use the space for a side hustle this is not the key use of the space, what we don't have is any sort of service engineer on site, so if the thing gets broken then getting it fixed is down to generous members stepping in. So far this has worked on other machines pretty well, but this machine will be a step up on complexity for us.

I do like the idea of group design and make to try and keep the price down and I'll bounce that idea past the team. The size issue is well defined above as well, smaller will always be stiffer with the same core elements.

Shapeoko do have a model with proper guides and screws but it is actually over your budget.
This shows that they have realised the limitations of their original design and have in fact ended up designing a much more conventional system demonstrating that there is a reason for those conventions.

Designing and building your own is a great idea. I was going down this road having been in the same situation as you. I started looking at X carve and Shapeoko, quickly dismissed them because of the many issues, went on cnc forums, learned a lot and saw other people building very good machines for very much lower prices than anything you could buy ready made and getting excellent performance.
I was starting to design what I wanted but actually bought a second hand system which was a very good bargain and similar to what I would have built myself anyway.

You can buy a set of closed loop stepper motors and drives as a kit, all the ballscrews and linear guides, something like a CNC drive AXBB which will run UCCNC and perform incredibly well. Aluminium extrusion can be purchased ready cut to size and all the plates can be ordered water jet cut from all sorts of online sources.
Effectively you can create your own kit. If you have welding facilities at your shed then a steel sub frame is cheap and strong.

The trick I think is to stick to "standard" sizes so a 1200mm square machine for example so you don`t have to machine any ballscrews etc.
I was going to order my motion parts from BST automation in China ( well regarded in the community ) for much cheaper than you can get here even including taxes and import duty.
As a professional engineer it should be pretty straightforward to do a design, and in fact there are so many great designs on forums that you can basically copy a proven one and adapt it to your needs.

For inspiration look here
DIY Router Build Logs

and here
https://www.cnczone.com/forums/diy-cnc-router-table-machines/?s=bd2eae445bed9a9dbac479e56f8db3af
Ollie

 

[bilboburgler]

This is a much more realistic prospect than when I looked into it ~20 years ago; the wide availability of reasonable quality linear rails, and complete stepper + controller sets would make life considerably easier.

There's also the option of rack and pinion motion; which is quite common on larger machines as ballscrews tend to "whip" at high rpm over long lengths.

One thing to also consider is what's underneath the machine. Mine could not cut something below the bed because there's a ballscrew running the length of the machine, plus bracing for the gantry. Many machines now appear to have dual motors (one on either side of the gantry) and as such are open underneath. With planning, it means you could use it to engrave the top of cabinets, or even mount long stock vertically (e.g. for cutting tenons on the end).

BTW I'm just north east of Leeds. Where is your Maker Space based?

Otley Maker Space is based in the courtyard of the Courthouse arts centre in the centre of Otley. Basically if you remember the early Heartbeat series we are in the police station. Otley Maker Space | Otley Calendar

 

[bilboburgler]

Again, thank you so much for your thoughts, very useful

 

[sploo]

Otley Maker Space is based in the courtyard of the Courthouse arts centre in the centre of Otley. Basically if you remember the early Heartbeat series we are in the police station. Otley Maker Space | Otley Calendar

Had a look through your website and Facebook page; great stuff!

 

[Tweedy]

I am a cad designer, have you thought about building your own machine?

This would be my recommendation. When your standards are high and budget is small this is the way. I built my cnc mill and although not as attractive as commercial options, it cost a fraction for the equivalent capability.

Your budget is much higher than mine. You could build an exceptional machine.

In terms of work area, go big or go home. Make sure it's at least a sensible division of 8'x4' for your own sanity.

As far as routers for spindles, I'm not going to say they are premium, but they work fine. I use mine for aluminium and I use it HARD. Only killed one so far when i was still learning feeds and speeds, and at 40squid a go it wasn't a disaster.

On which note, anther advantage of building your own is knowing excactly what and where you can get spares without relying on the manufacturer.

In a makerspace people will make mistakes and break things, so inexpensive to replace and easy to repair is king in a way it doesn't matter so much in a commercial environment.