Chineese Wiring Cnc Help

davidh

davidh

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i purchased a 4 servo set with controls for my home made gantry cnc and now am to the point of setting up the electronics and controls. i asked the supplier (longsmotors) on easy last night about wiring the limit switches and an emergency stop button.
"should the limits be normally open or normally closed, and what do they connect to from each of the control boxes. same with the emergency stop button. "
judging from the reply i got this morning, they were telling me how to make egg drop soup or something .
so i need to ask the group for a quick lesson in wiring. . . . do these micro switches connect to ground as normally open and grounded to stop the machine incase it gets away ? i could connect the emergency stop to shut all the power off but i don't think thats what they have in mind with the single wire attachment at each drive control box. .
does my questions make sense ?
ERROR BY ME.
the emergency stop & lim it switch connections are on the BREAKOUT BOARD
 
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I normally wire my limit switches as normally closed (active low). This causes the machine to stop in case of a broken wire and is much more noise immune.

For the E-stop. I would wire it to a relay, and use the relay to dump power to all of motors. Use a normal 3-wire control for the relay, that way the system won't restart after a power fail. You would have to press the start (control power) button to power it back up.
 
I'm starting to get this figured out now, then another question comes to mind. can my stepper motors be controlled with a switch that will turn them either left, right or off, and if so, what of the four colored wired would be used, and is this a good idea. i have lots of room in my control box for switches but I'm thinking about manual controlling without the computer hooked to it. . . going to finish the limit switch mounting plates, ill be hoping for a reply.. . thanks again.
 
The stepper motors are controlled by a Step (speed) and Direction signals to the drive. The step input is a pulse string. The direction is toggled by switching the direction input (high or low) Trying to switch the direction by changing the polarity of the motor wires is probably not the way you want to do it. If I wanted to run the steppers without a computer, I would (do) use a stepper speed controller. Something like this:

http://www.ebay.com/itm/Reversible-...893584?hash=item1c3f3aaa50:g:0fkAAOSwu-BWPCYC

The ones I bought cost about $10, but not as nice as the one above.

The speed controller connects to the stepper drive.
 
JimDawson said:
The stepper motors are controlled by a Step (speed) and Direction signals to the drive. The step input is a pulse string. The direction is toggled by switching the direction input (high or low) Trying to switch the direction by changing the polarity of the motor wires is probably not the way you want to do it. If I wanted to run the steppers without a computer, I would (do) use a stepper speed controller. Something like this:

http://www.ebay.com/itm/Reversible-...893584?hash=item1c3f3aaa50:g:0fkAAOSwu-BWPCYC

The ones I bought cost about $10, but not as nice as the one above.

The speed controller connects to the stepper drive.
Click to expand...


i ordered one, then thought, maybe i need three ? do i ? or does this need to be wired thru a selector switch? i finally have the rest of the wiring drawn out on paper, picked up some terminal blocks, made my 6 micro switch mounting brackets and have them painted and drying. except for this item above, I'm ready to start mounting things on the two panels and actually wiring the following days. my excitement is mounting. its been a long project with life scattered inbetween. . . . .
 
If you plan on running the motors without a computer, then I guess I would use three of them. Trying to control three motors by hand might be a bit of a challenge. I would probably get a computer setup and just use the keyboard to jog the motors, seems easier to me. I normally disconnect the motors mechanically from the lead screws until I am sure I have the motors under control and everything is doing what I expect. Just for testing purposes, one speed controller would do, get one motor running, then wire it into the next and so on.
 
ok, i understand that now. a selector switch would make it easier but why do that? i am ordering the relay for the power on to power supply and a E/M switch. another 15 day wait for parts. i've created a 12V and 5V buss bar for the inside of the box. . . next will be the connectors that will bulkhead thru the box to the motors and micro switches and the E/M that will be mounted somewhere by or on the gantry. all the micro switch brackets are made and painted and holes punched for mounting. . . .
I'm using a computer power supply that has the power that i require. . . (someone told me it would supply what i needed) and I'm laying out the two panels.
yikes, plug in connectors from the power box to the gantry, they will be about 15 feet apart, I'm still not sure where I'm going to put the computer / monitor or the laptop that may be sufficent. (SP). on and on we go. excitement grows. time seems to fly by. sheesh, I'm running out of saturdays one by one. . . thanks jim for your input. i really do need hand holding from time to time.
 
It sounds like you have it under control. I would love to see some pictures as you build. As for the computer, I'm working with one right now that is a little bigger than my hand. It's running a 3 axis machine (but not a machine tool, and it's proprietary so I can't show it either.) There are USB to parallel adapters available that are designed to work with Mach3. http://www.ebay.com/itm/like/121474800625?lpid=82&chn=ps&ul_noapp=true

There may be less expensive ones than the above example.
 
new question:
the wiring from the 3 drivers (?) to the break out board. . . 2 wires per axis / driver ... should / can they be 18 / 2 shielded or 18 / 4 shielded that i have left over from the driver(?) boards to the motors ? I'm not opposed to ordering another spool of wire.
i have made up three 18/4 cables from the box of electronics to the machines itself, for the motors. . . with disconnects connectors right at the machine itself. the controls and electronics will be maybe 10- 15 feet from the machine just because of the lack of physical space in my little shop. . . i'm getting closer and closer. . . . but the above questions are sorta holding me up for thursday. . . help please ? ? ?
 
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