[mike-oz]

No doubt been asked before, so happy to be guided to the right thread.

I am retired and live in Tassie. I have a small mill, metal and wood lathes etc etc and been making model brass steam engines for a while.

I would like to have a play with CNC which may be able to cut some small brass parts. I use a lot of brass plate up to 5mm thick. I am OK with CAD software having extensively used Autocad and Turbocad.

My CNC research seems to hit a brick wall unless I have an odd $20,000 to spend, not possible as I am not only retired but on a pension also :-). Is about $4000 a doable budget.

Have also been doing a lot of woodwork lately and hand cutting ply gears and stuff. Maybe a machine that could also handle clock making.

Any suggestions on a reasonably priced machine that will fit my criteria please or am I asking too much.

Cheers
Mike

[Vlod]

You could build one or retrofit an old milling machine

[ardenum2]

probably the fastest and within budget would be to use your existing structure and cnc it otherwise $4000 will probably get you a decent router at best with linear guides and ballscrews.

you could build one yourself on a granite surface plate using aluminium extrusions, that's probably as simple as it gets unless you have a weight limit. something like datron m7

[joeavaerage]

Hi,
given that you already have a mill you'll be acutely aware that the rigidity of the machine is paramount to accurate and acceptable results. A CNC mill
is just as demanding of rigidity as a manual mill.

The prospect of building a mill of sufficient rigidity on a budget of $4000 is a big ask. I think the compromises that you'd have to make to meet that budget will end up with a machine
that misses the accuracy target that you want.

Could you not convert your existing mill? While its nice to have linear rails and cars....its not strictly necessary either. Plenty of CNC mils run dovetails....but what a CNC machine
really needs is zero-lash ballscrews. Any lash very much compromises CNC operation. Could you conceivably squeeze ballscrews into your existing mill?

Craig

[machinehop5]

Hi,
given that you already have a mill you'll be acutely aware that the rigidity of the machine is paramount to accurate and acceptable results. A CNC mill
is just as demanding of rigidity as a manual mill.

The prospect of building a mill of sufficient rigidity on a budget of $4000 is a big ask. I think the compromises that you'd have to make to meet that budget will end up with a machine
that misses the accuracy target that you want.

Could you not convert your existing mill? While its nice to have linear rails and cars....its not strictly necessary either. Plenty of CNC mils run dovetails....but what a CNC machine
really needs is zero-lash ballscrews. Any lash very much compromises CNC operation. Could you conceivably squeeze ballscrews into your existing mill?

Craig

X2 Craig

+ my 2cents..... you might find a old Knee Mill type CNC.like a Tree 325 that you can still get spare Electronics for the Control and Drive systems....or an older Fadal Bed Mill might be possiblly available in your area. Fadals are easy to work on and great free documentation.... The main thing is you're going to most likely have to repair and/or work to maintain anything you buy in the $4000 range.

DJ

[mike-oz]

Thanks guys, will continue my research, a lot to learn :-)

[peteeng]

Hi Mike - Look at cnc3D machines (gold Coast Oz) and turn your messages on. Peter

CNC3D Home | CNC3D | Gold Coast | QLD | Australia

[curiosity22]

Hey Mike,

Your obviously experienced at using a lathe and mill. How about a picture or two of some of the things you have built already?
If you intend continuing your hobby building model engines but just want to automate the process a little.
I would add to Craig's statement, why not convert your mill to CnC? That would more than meet your budget with plenty of change.
What type of Mill do you have?
The only new thing you would really have to learn is the software how to make it work without you handling it so much.
If you can build steam toys I'm sure it wouldn't take you long to learn how to use some software.

Cheers,
Steve

[mike-oz]

Thanks for past help
In case anyone still watching I have built a CNC and posted a new help thread - this is it
CNC Electronics Advice

I have built the mechanical part of a CNC, my first effort. I wanted it to be able to do a bit more than carve wooden signs or circuit boards so have tried to build stiff & strong.

Main parts 16mm aluminium plate, 40 x 80 alum slot rails
20mm ball screws and rails, 12mm ball screw Z axis
Travel approx X 700mm Y 700mm Z 145mm

I have not purchased any electronics and need some advice please as my internet research brings up a mind boggling array of stuff. It seems that the package needs to be compatible and balanced.

Please keep in mind I live in Australia so do not have access to US or Europe stuff. My main suppliers have been Ebay.au Amazon.au and local Australian companies.

Also I do not have access the 3 phase power and my little workshop runs off of the 240 volt 10 amp house mains.

All help and advice gratefully received :-)
Kind Regards Mike
76 year old new comer to CNC, with lots of CAD experience so the software should be OK!

[peteeng]

Hi Mike - Have a look at the Nighthawk or Scribe from CNC3D at Nerang Qld. One box solution excellent support, made in Oz. I haven't used it yet, I'm wiring one into a small router now. But feel confident they are doing things right. Peter

Nighthawk CNC Controller | CNC3D | Gold Coast | QLD | Australia

[joeavaerage]

Hi,
the system that peteeng has recomended is a glorified GRBL controller. Many Gcodes are just not supported.

I use Mach4 and an Ethernet SmoothStepper as motion control. The ESS is available ex Homann Designs in Victoria.

Mach4Hobby ($200USD) is a full blown CNC software and is almost an exact copy of Fanuc21i Gcode excluding MacroB. Mach4Industrial
includes MacroB...but is unnecessary for hobby machines.

Craig

[peteeng]

Hi Craig - Sure its a GRBL based controller (so what) they are adding more codes and features all the time, they provide very good support and it has a development language so you can write your own routines. Until I use it for a little while can't really comment further. It is wifi wireless and you can drive the machine from your phone no need for a MPG... Peter

[joeavaerage]

Hi,
I expect a CNC software solution to have all the common (ANSI) Gcodes, if you are happy with GRBL then good luck to you.

It is wifi wireless and you can drive the machine from your phone no need for a MPG... Peter

And you think that's a good thing????? Wireless is always subject to noise and you think that's a good way to communicate with a machine????

My wired pendant has about a 12 foot cable, but guess what......I don't need anything like it. Do I walk 12 feet away to touch off a part in my mill......NO..... I'm standing right
there to see whats going on.

To my way of thinking a wireless MPG is a complete waste of technology....and was no doubt invented or proposed by someone who has
never actually done any CNC machining. Anyone who has will tell you that with even a modest cable so you can stand close to where you can see the action is entirely enough.

The correct thing to enquire about a motion control solution/CNC software solution is how does it handle out-of-band axes? How does it handle master/slave axes? How does it home, and can it home
master/slave axes? Can it do single point lathe threading? Can it handle backlash compensation? Can it handle THC? Can it do rigid tapping? Can it do laser rastering?
How does it handle G93/G94? How does it handle all the canned cycles?

How about programming your own macros? How about Ladder logic/PLC behavior?

I've been using Mach4 for eight years and I know how Mach4 handles each of these questions, and while not all of those features is seamless, it does have a solution for all those questions.

Craig

[joeavaerage]

Hi,
how many industrial CNC machines have you seen that don't even have a pendant? They all seem to have an MPG, but often its built in to the controller panel, its not like you can carry it around.

This solution seems adequate for many an industrial machine....but we need a wireless pendant with countless features and modes?? BS!!
What we need is an perfectly reliable MPG, with a silky smooth action. Nice to be able to swap axes on the pendant, and maybe select incremental or velocity jogging,
but anything else is pure marketing BS.

Craig

[joeavaerage]

Hi,

This is what I mean, look at this Fanuc pendant, look how simple it is, just two rotary switches, one for jog increment and one for axis select, and one
silky smooth MPG, that smooth 'it'd put a horn on a jelly fish'....that good!!!. What more do you need in a pendant?

https://www.ebay.com/itm/31398265465...3ABFBM_KaZ37Vi

Craig

[elfrench]

LinuxCNC installed on a small NUC for the controller is one of the least expensive options with the most extensive functions.

[mike-oz]

Thanks guys, really appreciate your time. However you have started a bit too high up the learning curve for me :-)

I have checked out the 2 websites you mention

However still need some help with what I need to complete this build. The following is what I think I need not necessarily in the correct order

Spindle (been looking at the Vevor 1.5kw)
Power Supply for spindle?
Stepper Motors x 3 ( Nema 23 closed loop?)
Stepper Motor Driver Boards
Controller for the stepper motors (the only computers that I can use to drive CNC do not have a parallel port only USB. My main CAD computer is in my study)
Limit Switches
Power Supply (No idea)
Cooling Fan?
Main Emergency Switch
Software (integrated or separate programs?)

[Vlod]

It depends on your plans for the machine and your budget.
You can buy a cnc kit on Amazon that includes all the motors, drives and usb Mach3 controller (some kits come with demo Mach3 software to start with) and buy a router to start with…
It works… especially if you have limited power supply.
Later when you feel the needs to upgrade you would know what you need.
I would recommend “Vectric “ software if you work mostly with wood. They have different packages and a demo that you can try.
Powerful and easy to use I like it.

[joeavaerage]

Hi,
the spindle you mention is an asynchronous 24000 rpm spindle and requires a VFD. Most buy a 'cheap as chips' Chinese made VFD and then blow them up. If you want
to buy cheap the Chinese make it for you.

I buy Delta, a Taiwanese brand made in China, better quality, support and documentation. I've bought twenty or so over fifteen years for various projects and retrofits and not a single one
has blown up.

Closed loop steppers and their matching drivers are fair, but not a patch on what the manufacturers claim, 'go faster, more powerful, never lose steps'....all BS. Good low inductance open
loop steppers are every bit as good.

23/24 size 1mH-2mH, 1mH preferred, reject anything over 2mH
34 size 2mH-4mH, 2mH preferred, reject anything over 4mH

Whatever you do don't waste your money on high inductance steppers say 4mH or over in 23/24 size or 6mH at 34 size, they are just rubbish manufacturers make cheap to sell to people
who don't know any better. Don't be that twat!

Get 80VDC capable driver and an 80VDC supply, a linear supply is preferred. You don't buy good steppers only to try to drive them at 36V or 48V......you want 80VDC minimum.
This power supply is 1000W and will power your steppers without demur for decades no matter what you throw at it:

https://www.antekinc.com/ps-10n80-10...-power-supply/

If you want genuine closed loop performance then buy AC servos...they'll eat any stepper ever made. I buy Delta B2 series:

https://www.fasttobuy.com/flange-80m...er_p28084.html

I've bought a dozen or so, both for my own machine and other retrofits, and at $438USD they kick arse!

There are cheaper Chinese made servos but they have poor documentation and support and no set up and tuning software. If you've never used servos before....pay the extra and get a brand
like Delta or DMM that do have free set up software....you'll come to love it.

If you've got boatloads of money don't shag around get Yaskawa, Delta is about half the price and approaches Yaskawa in performance.

I have already suggested Mach4 and an ESS, and another post has suggested LinuxCNC on a NUC presumably with a Mesa board, and I know peteeng uses UCCNC and one of their
controllers with satisfaction. Any of these three would work well for you. As for the GRBL based board that peteeng has recommended, I think the jury is still out...they have had such little
use in CNC machines, no one can answer any of the questions I posted earlier. Your money, your call.

I personally use Omron roller plunger snap action microswitches for both limit and home switches. My preference is to have a separate home and limit switch, but many combine both into just one switch.

https://nz.element14.com/omron/z-15g...pdt/dp/1181279

Power Supply (No idea)

If you use 750W Delta servos as I do you don't need a power supply, they work direct off 240VAC mains.

Cooling Fan?

What for? A fan is bloody hopeless for cooling beer....that's what God invented fridges for!.

Main Emergency Switch

Good set of shoes to run like hell.....other than that any Estop switch will work. Dirty b******s want untold money if you buy one....any old push button will work. Better to save for servos than a
'you beauty' Estop switch.

Software (integrated or separate programs?)

I use Fusion 360, and have had a subscription (approx $700NZD inc GST/year) for several years. I have just renewed the Machining Extensions which gives me simultaneous four and five axis, collision avoidance,
toolpath editing. I managed to wangle a nice discount so it cost $2034NZD (inc GST) for a year, whereas the normal price is $2440NZD (inc GST) If you have a need for simultaneous four and five axis.....that
really costs a fortune.....other than that Fusion 360 Basic is a good package and fairly priced. I'm not a fan of either subscription software nor 'cloud based software' but I have to confess my attitude is changing,
it just plain works, and I get good software for a fraction of what I'd have to pay for perpetual software.

Craig

[mike-oz]

Thanks again, lots of www trawling to get my head around it all. However I am happily retired and have nothing better to do and all day to do it in :-)

Cheers
Mike in Sunny Tasmania!