[xNuno]

Hi all,

I'm trying to make a CNC myself using the information on the net.

To start I buy 4 Axis TB6560 CNC Kit 24V PSU + Control Handle + Mach3 on ebay.

I will make a 3 Axis CNC but since I need 4 Stepper Motors I buy this KIT.

My design will be something like this one



I will use wood since is more easy for me because I don't have tools to work with another materials.

My first question is How can I power the 2 stepper motors X axis?

Can I use the C channel of the driver or can I plug both motors to the same output X channel?

Regards,
Nuno

[doorknob]

You would treat each X-axis motor as if it were a separate axis, and then configure Mach3 to "slave" both axes together.

[xNuno]

You would treat each X-axis motor as if it were a separate axis, and then configure Mach3 to "slave" both axes together.

So you are saying that I will to use the 4 channel that the board driver have?

[CarveOne]

Yes, for the G540 it has all four drivers in it that you need. That's one of the many reasons it is so popular. Slaving motors has become a popular way to minimize racking issues on machines with wider gantries.

Most of us assign the X and A axis letters for slaving the two motors together. You could also use B or C. Note that one of the two motors needs to be configured in Mach3 to run the opposite direction so that both ends of the gantry travel in the same direction. The motor cables will be wired the same way.

CarveOne

[xNuno]

Well some updates, after some changes during design because something don't work as expected...

[Phife]

What do you plan on cutting with that?

[xNuno]

I hope I can make some electronic PCB's...Or at least use this machine to cut pieces to another one more accurate...

[Phife]

I hope I can make some electronic PCB's...Or at least use this machine to cut pieces to another one more accurate...

Ya you can probably do PCB, although your accuracy may suffer from the all thread screws.

You'll have a hard time doing anything other than engraving though, Single bearings, unsupported rails, and MDF is just no where rigid enough to make accurate parts, your machine will bounce and shake while it cuts, and it will be slow too.

[xNuno]

Well, I'm trying to do my best, already waste some money with this MIN 500€...

[allesg]

Rigidity is everything when it comes to CNC machines. The more rigid you make things,
the more accurate your product will be.

There are a number of similar designs at CNC-Router - 3D- CNC-Routers - CNC-Milling Machines - CNC-Engraving - CNC-Engravers - CNC-Engraving machines - CNC-PLASMA Cutters - Plasma-TORCH - New, cheap, exact, made in Germany
Some differences are that they use larger rails and ballscrews instead of threaded rod.
Accomodating supported rails would also be a big improvement.

MDF can be made rigid. All MDF is not created equal. MDF made of hardwood and a
strong waterproof glue as opposed to pine and a water soluble glue makes a difference.
Multiple layers and or a metal sandwich construction are sometimes the answer.
Review what microcarve does in his thread "My newest desktop machine".

Using MDF to mock up a prototype was definitely a good move. Sometimes one
just doesn't see things quite the same way when working with CAD designs.
It also gives you something you can see and touch and measure your progress with.

[xNuno]

Just finished hardware stuff...

Now I need help to configure Mach3...Already try but I don't see any to move the axis to a position I want and them set home...

[IMG=http://img804.imageshack.us/img804/2184/imag0032qc.jpg][/IMG]

[riche543]

Hey Nuno,
I started with a mdf machine & threaded rod, still using it but building full aluminum & steel machine after 2 years or so using mdf one. I did get mdf running not too bad I can cut 12mm thick Ali with 3mm end mill, but lots of passes & slow feed , you will learn a lot about what you will be able too cut & not cut & whats needed in your next machine, but if you look at as a learning curve this machine will be ok I think, I will admit I do spend more time fixing or tweaking my mdf machine as I do fine engraving on it & one day will be fine & another day will miss the material on one end, its just not solid enough, almost any type of wood will expand & contract which I think is happening too mine, good luck with it & keep us posted.
Cheers
Riche

[xNuno]

Hi riche543,

Yes I will use this one to learn more about this stuff. My problem now it's how to start with Mach3, I want to setup my limits and homing but don't know how to yet...

Can you help me with this?

Regards,
Nuno

[riche543]

I'm
Not too clued up on Mach setup as it was over 2 years ago since I done mine, had to go over the mach3 manual lots of times, it will be along the lines of setting up correct pins etc in Mach settings, I'm sure someone will help you on this but give full details on motor type breakout board type & the pins you have connected if you have connected any, most motor suppliers will send you a data sheet on installation, or can be found on the net, I was the same at the beginning , go slow read twice i
.

[neurofen]

good luck with your project, that's a pretty cool little cnc kit you found. how much was it?

[xNuno]

You mean 4 Axis TB6560 CNC Kit 24V PSU + Control Handle + Mach3 on ebay.

[adprinter]

Hi riche543,

Yes I will use this one to learn more about this stuff. My problem now it's how to start with Mach3, I want to setup my limits and homing but don't know how to yet...

Can you help me with this?

Regards,
Nuno

It's good advice, to read the Mach manual. But doing so, won't really do much to help in wiring up the limit switches. The main thing to pay attention to, is that you can wire them all in a series circuit. The reason for this, is because anytime a limit switch is triggered, it stops Mach3 from running until you click the Reset button. Mach3 doesn't care WHICH switch got triggered, only that A Switch was triggered, so it stops. The thing about wiring them in a series circuit, is that it can reduce the number of Input pins used up on this to ONE! The reason being, that when you Home your machine, Mach3 goes through each axis, one at a time- Z first, Y second, X third. This is important, so that Mach3 has a point of reference to work from on each axis. Once you succeed in properly wiring the limit switches, and a successful Homing of the machine, at that point you will be ready to play! After the Homing operation, the limit switches will perform as just that: LIMITS on each axis. If one gets triggered, it stops your machine. It is best to wire all of these using the Normally Closed configuration -which creates a continuous series circuit. If a switch is triggered, it stops your machine. The advantage of wiring Normally Closed, is that it becomes a self-diagnostic system which will alert you if a break in your wiring (somewhere) occurs. It won't tell you where the break is, only that there is a broken wire somewhere in your circuit. Again, READ the Mach3 manual for the details. I offer this info, as I know how confusing it can be starting out, with ONLY the manual to go with. Hope this helps!
-Michael

[xNuno]

I'm making some tests and I think something is not right...I setup on Mach3 settings to make A axis as Slave of X axis, I make some tests with shortcut keys and works fine, the problem is when I load some G-Code Sample and start the process I can see sometimes A axis moving without X moving and X moving without A...is this normal? I think not because the normal behaviour is A move when X moves...Some BUG of my BOARD?

[neurofen]

You mean 4 Axis TB6560 CNC Kit 24V PSU + Control Handle + Mach3 on ebay.

i must have miss read somewhere in the post, i thought you'd bought the entire starter kit to start with and then modded it/reworked it, i think it was the first image in the thread i was referring to , the one with the cnc with white plastic support posts. edit.. looking back again i can see you've used it as a template.

hope you get your slaving problems worked out, i havent installed my second y axis ballscrew yet so cant help much im afraid, sorry.

[CarveOne]

I'm making some tests and I think something is not right...I setup on Mach3 settings to make A axis as Slave of X axis, I make some tests with shortcut keys and works fine, the problem is when I load some G-Code Sample and start the process I can see sometimes A axis moving without X moving and X moving without A...is this normal? I think not because the normal behaviour is A move when X moves...Some BUG of my BOARD?

It is not normal. They should both move in the same direction at the same time. Mach3 is sending the same step and direction signals to the X and A motors. The A motor needs to be reversed from the X or the gantry will rack. Mine are set up as follows:

Ports and Pins tab:

X,Y,Z,A are enabled
X,Y,Z,A Step and Direction are active high

I reversed the direction wiring of a motor coil (phase) that is not moving in the correct direction, but you can do the same thing by making the direction active low by not checking the check box.

It is also possible that the signal level is too low for the motor driver to operate correctly. Use a volt/ohmmeter to see if your parallel port is putting out around 4-5vdc.

CarveOne