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Brian,
Think the G-Rex encoder inputs are for use with the unstallable stepper controller Mariss is designing.
Might also be used to feed a DRO.
Mark
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Lost Tourist,
I am using mach 3 and the G100 plug-in. I did not have very much of a problem hooking up the G100. I just followed the directions from mach 3 for the most part. There were some minor issues, but I was able to figure it out and got it all running in a couple of hours.
Your diagram represents my wiring quite well. A few minor differences: my encoder wires are shielded, and my step/direction wires are not. However, I will buy some shielded wire for these as well, but am not sure whether i should include the +5V line in that cable too. Also, i don't have half of a limit switched wired up to my X-axis
I didn't pay much attention to your power supply before, but noticed that as of now you only have AC output. You will need to add a rectifier after the transformer to obtain DC output, and then a capacitor after that to minimize ripple voltage. Keep in mind that the capacitor will raise the voltage your voltage by 1.414 times if I remember correctly. So if you have 65V motors, you will need a 46V transformer and consequently, a 65V transformer will output 92V which is more than should be fed to the G320's.
I spoke to Mariss yesterday as well. In short he said it will not do anything to wire the encoders to the GREX, they only go to the servo drives. (He also then said that stepper systems don't need encoders either which made me want to ask "what the **** are they there for then?", but I didn't). I think that mach 3 can read the encoder inputs however, and this can be usefull down the road, so someday i'd like to wire them to the drive and the G-REX, but this is something to worry about later I suppose. He also said that the step/dir/+5V lines were wired correctly as well. As of now, I am confindent that my wiring (and your diagram above) is right for initial testing. I do want to incorperate an E-stop circuit, limit switches and encoder feedback to mach, so that wiring diagram will change down the road.
I'm interested in hearing yours and others input on the mach/G-REX/G320 system. I am currently having issues getting my motors to operate at full speed. It's nice to have contact w/ others that are trying to build the same system, and hopefully we can all help each other out in the long run.
regards,
Brian
Brian,
Think the G-Rex encoder inputs are for use with the unstallable stepper controller Mariss is designing.
Might also be used to feed a DRO.
Mark
Can anyone confirm that in fact G-Rex encoder inputs are for use with the unstallable stepper controller only?
I’m seeing the posts talking about closed-loop (or real-time closed loop) and they don't always mention stepper motors, thus confusing everybody.
Example:
"Look at the GRex. It is immature at present, but offers a host of advantages. In particular, it runs the nasty timing loop portion that we seem to feel is a problem for Windows on an embedded microprocessor. The performance being seen with it is apparently astounding. It comes with encoder inputs for all axes. Slightly longer term Mach will be enabled to work full closed loop with it."
Thanks for the comments everyone.
Yeah, I also noticed that I hadn't paid attention to the transformer when I drew it and have now added the bridge rectifier and capacitor, though I’m not sure of your maths Brian, I don't see how a capacitor could increase my voltage by 1.414 as it is only a smoothing capacitor and should raise my "average rectified voltage" As I’m using 65V motors I need to rectify a 2x65V sine wave which will give me 65V peaks when rectified, the capacitor is there just to keep near the peaks longer. Since I’m doing a retro fit I already have a 115V transformer output so I’ll probably use that (unless someone can confirm your maths) and rectify to around 57.5V
The problem I’m currently trying to understand is the spindle motor is 180V 2.5A. Looking at the circuitry I took off I can't see anywhere they supplied that so I’m not sure whether I will try running it at the 57.5V or go for something like a servo amplifier (which I also can't find in the old circuitry).
As for shielding, again since I’m only retrofitting I leave the encoder cables un shielded as they are unless i start encountering problems.
And because it'll probably pay off one day I will still wire the encoders to the G100 as well.
And yes I realise that the input switch is not wired correctly as I’m not sure which why to guess with that, whether it requires pull up resistor or not etc.
Lost Tourist,
Goto the Gecko website and down load the stepper motor basics pdf file.
Its an 18 page document on stepper motors, However, pages 11-12 cover sizing transformers for power supplies.
1.414 x AC Voltage (rms) = DC Voltage.
How are you wiring the encoders to both the G320's and the G-rex? If using the same encoder you'll probably end up with more problems.
On the 180 supply for the main spindle servo, the power came from the original servo drive.
Mark
Mark,
So clearly is has been far too long since i have done electronics
To keep things simple i'll probably just connect the encoders to the G320's
Now i am stuck with problem of running the spindle drive which is 180V, with a G320 rated to 80V. I have searched around looking for a servo amplifier however all i find is more servo controllers. I'm guessing the solution is more custom circuitry rather than off the shelf stuff.
Lost Tourist
Lost,
Sorry, to be late getting back with you. Fighting with broken machine at work.
Think an off the shelf solution is available. First, do you really need the speed that 180 supply? Think that servo motor speed is directly proportional to its voltage. What was the original top speed of the lathe?
The Gecko 320 should give 44% of that at 80 volts. Since you already have the 320 might as well try it out.
Another couple of options that use Step & Direction signals.
Rutex drives (the 2020) is spec’d at 200volt. Down side of Rutex being service and support problems. Upside is they are made in Australia.
Also have a look at Pico-Systems servo gear. Down side is you’d need a PWM controller, power supply and a servo controller card $375 USD, servo max voltage is 160v (89% of top speed) and Jon is a small business. Up side Jon really knows cnc, has EMC worked out for his system and is very knowledgeable on servo designs. Might be worth emailing him for an opinion.
What control software do you plan to run the machine?
If you were in Perth I'd liked to see the machine.
Mark
Mark,
Late getting back to me? I thank you for getting back to me at all.
The top spindle speed as spec'd on their website is 4,500rpm unfortunately not having paid attention to what actual rpm i've used before i can't tell whether this is particularly high or not.
I will probably try the G320 as you suggest simply because i already have it and see what it runs like. If it proves to be a problem i will investigate the other drives.
As for software i am intending on running it with Mach3 as this seems to be the preferred software around here.
Unfortunately Sydney is a long way from Perth so you'll have to be content with some pictures when i am underway.
Lost Tourist
Mark,
Late getting back to me? I thank you for getting back to me at all.
The top spindle speed as spec'd on their website is 4,500rpm unfortunately not having paid attention to what actual rpm i've used before i can't tell whether this is particularly high or not.
I will probably try the G320 as you suggest simply because i already have it and see what it runs like. If it proves to be a problem i will investigate the other drives.
As for software i am intending on running it with Mach3 as this seems to be the preferred software around here.
Unfortunately Sydney is a long way from Perth so you'll have to be content with some pictures when i am underway.
Lost Tourist
Lost,
When you get time for pic's send them to:
mark dot holycross at yahoo dot com
Thanks
Mark
I am new to this setup, so i will highly appreciate if some will help.
In Mach3 software, in “Ports and Pins”-->”Input Signals”, I have made configurations as described in the "manual of G100 for Mach3"
X++ 17
X- - 15
X Home 17
Y++ 17
Y- - 15
Y Home 17
Z++ 17
Z- - 15
Z Home 17
So if i have NC switches, shall I connect wire to “LIM” terminal then to NC switch and then to the GND available for each axis block on G100 terminals. I have also defined pin 15 in Mach3 software as X- -, so will I wire the pin 15 to the GND terminal labeled on G100 under “Digital Inputs”.
I want to use five limit switches on my machine axes, for X axis and Y axis on both sides as . X++, X- -, Y++, Y- - and for Z axis only at Z+ side, I don’t want to use Z- -.
Shah,
I'm probably not the best person to be commenting as i only just got around to connecting the motors the other night.
But as i recently started understanding things for the limit switches yes you wire them between the LIM terminal for the axis and GND. (Remembering that you can wire both limit switches in series for a single axis if they are NC, in parallel if they are NO)
I'm a little confused about the pinouts at the moment, I would have thought your X++ and X-- are wired in series and then wired to Pin 17 and similarly Y++ and Y-- to pin 18, Z++ to pin 19. I don't understand where pin 15 is. (but it is late and i'm not paying enough attention so it may be right in front of me)
I'm not sure what your home switches are. Normally I think you would use one of the limit switches as your home, but if you are using seperate switches then you'll probably need to wire them to a non axis related digital input and code for them in Mach.
Oh yeah and i should probably update the circuit drawing to include the ERR/RES as well. I'll do it later this week
Lost Tourist
I'm close now.
I successfully reloaded the firmware after installing the wrong one first and now Mach happily talks to the GRex and everything that moves moves as it should however i haven't figured out how to set up the spindle at the moment (step/dir drive) Anyone got any hints on this?
Lost Tourist
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