I am going to build a CNC machine, What do I buy?

[northwest]

One more question, 3 axes I see plenty of talk about, could a rotary table or dividing head be added, if it were needed?

If you are converting or building a Mill, it is almost a prerequisite to have four axis available to you. The fourth axis on my mill was an afterthought and was one of the reasons for me going down this rebuild route. Even if you have no use for one today, if it crops up in future you are going to regret not having it.

 

[mtt.tr]

In terms of controllers, I've never been a fan of the LinuxCNC approach.
They were hell bent that unless it's realtime, it's not worth it, which means until very recently, they've relied on dedicated internal PC hardware.
As somebody who runs my machines to make money, I know the PC is likely the weakest link. If a PC fails, I don't want to have to faff around swapping hardware in the hope whatever has failed hasn't wiped out the controller cards. I just want to connect another PC, load the software/machine profile, and get running again.

I'd also echo @Hood 's comment about dedicated controllers.
I quite like the dedicated controller my new lathe came with, but I'm not sure I'd like the same on a milling machine, unless it was a production machine, where it would have a limited number of setups. PC based controls still give you a lot of flexibility, and often nice graphical displays for the lesser used functions. I know a dedicated controller can do edge/centre finding with a touch probe, but if you only do it every few weeks will you be able to remember the required code to do it?

My personal preference for controllers is the Dynomotion KFlop with the various optional boards, as it lets me do quite a lot things you'd struggle to do with other controllers.
Things like my little CMM runs standard steppers on all three axes, but two of which run closed loop via linear scales and returns the encoder position for probing points.
My last lathe ran a KFlop with analogue servos, a customised spindle output to handle the spindle VFD, and talked to a PLC via MODbus for the turret control. The PC is simply there as a user interface, and to send code when required.
My current mill runs three axis step/dir, with the spindle running an analogue servo and capable of rigid tapping.
The biggest problem with a KFlop is you need to understand C in order to configure them, but understand that, and it'll do things you'd normally need a far more expensive controller to do.

Every controller has pros and cons.
Anybody who tells you differently is either lying, has a vested interest, or thinks how they done something is the only way to do said something.

Mach3 was revolutionary for it's time. It still has a huge user base, big community support, and lots of compatible controllers. For new users, it is still a good option.
Mach4 is still good software, but it's now pretty expensive, and you still need hardware to go with it, which makes it even more expensive compared to other options.
Centroid Acorn is a good option, if the hardware meets your requirements, but by the time you buy the extra software options, it can get pricey.
UCCNC controllers are also a good option, again if the hardware meets your requirements.

As I said in a previous post, most controllers will manage to run a basic 3-axis machine. Where the cheaper options will often become unsuitable, is when you start to do more complicated things that require critical timing, or lots of inputs/outputs.

Missed this thanks for the input.

 

[northwest]

The CSMIO/IP-M that the OP is putting on his mill is only capable of 4 axis.

This is not a bad thing, not good either as my brain only works in one_at_a_time!

:-)

 

[Hood]

This is not a bad thing, not good either as my brain only works in one_at_a_time!

:-)

Not a bad thing at all and it is a very capable wee controller.
Sadly not capable of rigid tapping but with careful programming and a floating holder it should be possible.

I probably would have put an IP-M on the plasma if I hadn't already had the IP-S left over from the wee lathe that I was using to experiment with. Then again I use a lot of I/O and the IP-M can't be expanded sadly, it is a shame that they don't allow using the expansion modules and the Enc module (needed for rigid tapping and single point lathe threading) but I suppose they have their reasons.

 

[m_c]

Those are some seriously good prices for servos even with the postal cost and the duty they will no doubt incur. I don't have any need for servos or drives at the moment but I will be keeping a link to them

There are quite a few cheap servo options available now.
When you can get servos that cheap, I think it removes most justification for even considering big stepper motors.

Thanks for that really in depth answer - before I buy anything, and I'm a long way from there yet, I will consider carefully. The performance thing - I guess, as long as the motor is strong enough, it's speed we're talking about. Well this project will be hobby only, maybe supply a few request items, so speed is not of the essence for me really.
One more question, 3 axes I see plenty of talk about, could a rotary table or dividing head be added, if it were needed?

As Hood says, it's positioning that can make it monotonous. Take something like 2 m/min might sound fast enough, but if you need to move 30cm, that will take around 10 seconds.
In terms of cutting moves/speeds, the big benefit is from maximising acceleration. It's all very well having a machine that can do 10m/min, but if it's slow getting there, that means it's also slow at achieving cutting speeds.

If you'd like to add a 4th axis, then you need to consider that when selecting a controller.

 

[northwest]

Sadly not capable of rigid tapping but with careful programming and a floating holder it should be possible.

I have no toolchanger so not the end of the world and besides, I am very interested in thread milling, something I am trying to get my head around.

 

[Hood]

Thread milling, in principle, is easy, feed the axis in the desired diameter and feed down at the pitch at the same time.

 

[MCKDAVID]

Thread milling, in principle, is easy, feed the axis in the desired diameter and feed down at the pitch at the same time.

as usual that's the key word, sometime the transition to practice isn't quite so straightforward....

 

[northwest]

as usual that's the key word, sometime the transition to practice isn't quite so straightforward....

I have absolutely no idea as to what you are saying, it's just computaz, innit?

 

[MCKDAVID]

I have absolutely no idea as to what you are saying, it's just computaz, innit?

I generally have absolutely no idea what I'm saying either........

 

[mtt.tr]

See it all the time on the wood working, its cnc'd anyone could do that.
Haha be my guest

 

[m_c]

See it all the time on the wood working, its cnc'd anyone could do that.
Haha be my guest

Most idiots can load parts and push buttons.
The skill is in making the machine be able to take those parts, and do what you want when the buttons are pushed.

 

[northwest]

Most idiots can load parts and push buttons.

I would take exception to that, unless you have worked with a better quality idiot

 

[m_c]

I would take exception to that, unless you have worked with a better quality idiot

You're already ahead of those idiots, or is that behind those idiots?
You've at least already got a functioning machine, and managed to do things with it

 

[Hood]

@m_c did you use the software to set up and tune the A4 drives? I loaded it but just get an error when trying to open it. Not sure if I clicked all the right buttons when installing as it was all Chinese

 

[northwest]

Panel layout. The breaker is just there to give me a guide, it is totally unsuitable:



Just waiting for the trunking.

 

[m_c]

@m_c did you use the software to set up and tune the A4 drives? I loaded it but just get an error when trying to open it. Not sure if I clicked all the right buttons when installing as it was all Chinese

Not got that far yet. I bought a new lathe instead of building one, so I've not actually needed to get the Matchmaker running yet.
It's on my list of things to finish, as I have nearly all the parts needed and it would mean I can sell my Triac (2nd CNC mill I've bought since buying the Matchmaker..), but I have more pressing uses of my times just now.
One of the servos is currently being used as a foot rest next to my desk, as I brought it in to get the dimensions for machining mounting plates, and it's been sat there since :-/

I will however ask somebody who's fitted a few of these if he's used the software.

 

[Hood]

Not got that far yet. I bought a new lathe instead of building one, so I've not actually needed to get the Matchmaker running yet.
It's on my list of things to finish, as I have nearly all the parts needed and it would mean I can sell my Triac (2nd CNC mill I've bought since buying the Matchmaker..), but I have more pressing uses of my times just now.
One of the servos is currently being used as a foot rest next to my desk, as I brought it in to get the dimensions for machining mounting plates, and it's been sat there since :-/

I will however ask somebody who's fitted a few of these if he's used the software.

Ha ha you work fast, must only be about 10 years ago that you got the matchmaker

 

[northwest]

Ha ha you work fast, must only be about 10 years ago that you got the matchmaker

Oh Boy! Is that what happens? Should I start building now? How much are second hand shipping containers?

 

[m_c]

Ha ha you work fast, must only be about 10 years ago that you got the matchmaker

It's one of those things that I'd like to get running, but other jobs keep getting in the way.
All the basic mechanical stuff has been done, so it just needs motors and electrics fitted.
In the time I've had it, I've bought a Denford Cyclone. Then a Denford Novamill as I needed something quickly to make tool holders for the Cyclone. Then sold the little Conect lathe, as it was no longer needed.
I then got a Denford Triac for a reasonable price, and sold the Novamill.
Then last year I blew up the turret on the Cyclone, so started designing a lathe, which meant I'd need the capacity of the Matchmaker, and ordered all the bits to get the Matchmaker running, but I then discovered i could get a complete lathe for pretty much the cost of building one myself, so I've still had no real need to finish the Matchmaker.