Feeback on cnc design

[handlewanker]

Wow, ain't you the lucky dog.....must be a good scrap yard.

[ger21]

Careful when taking the blocks off the rails. All of the balls may fall out.

[metiz]

Careful when taking the blocks off the rails. All of the balls may fall out.

Didn't have any fall out when I removed them from the rails but I thought you had to take them fully appart to properly clean them. Not doing that again. Took me 2 hours to reasemble one block. The bearing balls won't stay in place without those plastic bits on the inside but those won't stay in place without the endcaps, and you can't put the balls in after you've reassembled the blocks. Ended up using a piece of cardboard to hold the balls in place, reasembling the block and then cutting out the cardboard....First one is the cleanest of them all though so I've got that going for me, which is nice...

[metiz]

Found some 10mm steel at the junkyard for the gantry and stepper motor supports. I have access to a flow jet so hopefully I can use that to cut the plates. I also found another piece of heavy quality T profile, so now I can build the Y and X supports out of the good stuff and reserve
the crappy stuff for the bed and legs. Left profile is good and heavy, middle profile is light and crappy, right profile is good and light (and rare, can't find it online anywhere)

[wizard]

Nice to have a junk yard that actually will sell you stuff, i dont know of any around here that even allow access.

[metiz]

I'm in the process of ordering things and I'm wondering if for the Y direction I can use 1204 ballscrews instead of 1605, to cut cost a bit. My reasoning is that the force is only in the length direction so a huge diameter shouldn't matter that much?

[metiz]

For the stepper motors, how's this listing? https://tinyurl.com/yaq6jtpk 3 motors, 3 drivers and a power supply

*edit* or this listing for 4 of everything. I'll just use a nema24 for the Z too https://tinyurl.com/ydbgvxyv

*edit 2* and this for the spindle https://tinyurl.com/y92pyd3z

[wizard]

I'm in the process of ordering things and I'm wondering if for the Y direction I can use 1204 ballscrews instead of 1605, to cut cost a bit. My reasoning is that the force is only in the length direction so a huge diameter shouldn't matter that much?

They will work but the question is, is 1204 good enough for you? In a light weigth router i dont see this size lead screw having any trouble lifting and lowering the Z but long term reliability might be an issue. Also accuracy might not be ideal as you can get twist in the leadscrew with that twist backing off when you dont want it too.

[metiz]

Good point.

[LeeWay]

Your Z axis ball screw probably does more back and forth traveling than the other two screws combined. If I was building one again, I would put a higher quality screw there instead of lesser or smaller.

[metiz]

Alright I'll get the beefy stuff. What's another 100 bucks at this point
Any feedback on those listings? Considering the package deal I'm thinking about using 3.1Nm Nema24's on all the axis

[metiz]

Got the spindle motor, frequency converter, pump and stepper motors with controls in today! steppers were from china but I didn't have to pay taxes. Score!

[metiz]

I suppose I'll post this question here. I have build this cnc and the mechanical construction is completed. I am now working on the stepper motors and I can't get them to work. Can anyone here help me with that?
I use:

M542T drivers
Nema 24 stepper motors (x4)
A Mach3 breakout board
A 36V, 11A output power supply
A 12V, 0.5A power supply

The mach3 breakout board is connected to a 12V power supply, 0.5A
The mach3 breakout board is also connected to 5V through USB

The stepper motors are connected as follows:

Black (coil 1) to B-
Green (coil 1) to B+
Blue (coil 2) to A-
Red (coil 2) to A+

drivers, DC+ and DC- are connected to my 36V power supply.
Further driver connections:

ENA- Not connected
ENA+ Not connected
DIR- Not connected
DIR+ on all 4 drivers (separately of course) connected to Adir Zdir Ydir Xdir on the breakout board
PUL- Not connected
PUL+ on all 4 drivers connected to Aclk Zclk Yclk Xclk

To connect the board, I use a serial to USB converter cable
The USB connector is used for 5 volt
12V is connected to the ground and +12V connectors on the side of the breakout board.

When I turn everything on, I can hear a faint whine coming from all the stepper motors;
The cable is installed (windows 7) but I can't find it under device manager. I would expect to see it as an LPT connection(?) If I can't find the cable, I can't find the port and I can't set it in Mach3;
On previous (incorrect) attempts, when I plugged in the mach 3 breakout board (usb) A relay would close and the relay light would turn on. It does not do that anymore, even if I short the pins manually (in case of a broken jumer). When I plug in the 12V, the 12V led lights up, as does the 5V led. When I then plug in the usb cable, the led's are a bit brighter.

My questions are:
Is my setup wired correctly? (currently mounted on a piece of wood for testing)
Is the 5V from USB even required? You would think they'd just use a voltage regulator and convert the 12/24 volt
Assuming everything is connected correctly and the port has been set (and nothing else), can I test the steppers in Mach3 using the jog function?

[ericks]

Got the spindle motor, frequency converter, pump and stepper motors with controls in today! steppers were from china but I didn't have to pay taxes. Score!

Well done! you have made great progress

[wizard]

I'm not familiar with the M542T drivers so this might be a wild guess but are the ENA terminals Enables? Most drives have some sort of enable input which has to be in the correct state for the drives to operate. Also there should be a common connection some place on the drives. If not you need to connect to both the '+ & -' inputs making one a common for your control signals. in other words you need a full electrical path.

[metiz]

Alright I'll give that a try. Any comments on testing in mach3 and the usb to serial cable?

[metiz]

So after some googling I found out that, apparently, mach3 won't work with a lpt to parallel adapter. Can anyone confirm? Any alternatives? I hooked everything up like this (but with the breakout and not the arduino And I still hear a high pitched wine coming from the motors and still nothing works

[wizard]

I dont run Mach so take this with a grain of salt. In any event i believe most users these days use an exernal pulse generator like Smoothstepper or similar external devices. The best reliabilty seems to come from Ethernet connected device though the USB ones do work.

Basically due to the lack of real printer ports and very bad real time performance from Windows, the solution has become an external pulse generator box that handkes the realtime signal generation and I/O. Id suggest looking at all of the Mach solutions out there that solves this problem.

As for Mach 3 understand that it is getting old real fast!!! It would pay to investigate all of the competeing solutions out there. I think it is fair to say that many have completeky out classed Mach 3.

[metiz]

I've changed pace a bit and am now using an Arduino uno. I loaded GRBL to it and am using Universal Gcode Sender. I can now get the motors to wine on command, but not rotate. When I rotate a stepper, it sounds like it is moving, it feels like it is moving, but it is not, in fact, moving...The controllers were set at max current so I decreased them to the minimal setting. This results in a less loud whining and nothing else...

[wizard]

[QUOTE=metiz;2201776]I've changed pace a bit and am now using an Arduino uno. I loaded GRBL to it and am using Universal Gcode Sender. I can now get the motors to wine on command, but not rotate. When I rotate a stepper, it sounds like it is moving, it feels like it is moving, but it is not, in fact, moving...The controllers were set at max current so I decreased them to the minimal setting. This results in a less loud whining and nothing else...[/QUOTEte
1. My personal opinion is that you always set a setpper drive to the correct current for the motor connected to it. This especially in a machine tool where loads can vary dramatically.
2. The noise you hear is it when you command a move or is ti thete all the time the stepper is powered up? If the stepper is making noise only when commanded to move and it isn't actulaly moving I would review your motor wiring to make sure it is correct. I'd also put a flag on the motor to allow you to verify that the rotor is turning or not.