Machsupport Forum
Third party software and hardware support forums. => Third party software and hardware support forums. => Topic started by: penkomitev on August 25, 2013, 01:18:58 PM
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Hello guys!
First of all, let me say several words about my experience with Mach3. A friend of mine owns a machine running Mach3 and it is the place I have the possibility to get used to Mach and get familiar with the various capabilities the system has. This encouraged me and my colleagues to build our own machine and decided to base it on Mach.
Now that the construction is almost ready, we need to consider buying the hardware in terms of a PC and the external device(be it a breakout card or a motion controller). We are not sure yet what is best for our case, I've read several discussions and have gathered some data.
Here is what is known about our machine:
- 6 axis breakout --> (we will start with 3 axes but plan to have another rotary two in the future). PUL+/PUL- DIR+/DIR- is what our drivers have.
- 0-10V, 0-5V spindle control. --> My friend's machine is using ModBus to control spindle speed. This results in delays of up to 4-5 seconds for the spindle to change its speed. That's not real.
- Several relay outputs --> Flood, Mist and Servo enable are what I have in mind.
- As many inputs as possible --> 2 limit switches and 1 home position for X, Y, Z is just the theory. With parallel ports we have 10 inputs so some extension or another general approach is needed. Another solution I considered is using the limit switches as home positions, that is supported by Mach3 as far as I read. My friend's machine all limit switches are wired to the same pin. That doesn't sound good to me, he overrides the limit switches from the special button on the Mach3 to get away from a dangerous situation.
- Real feed back if the servo motors are moving - we were away with my friend for a moment and after we got back, the machine was cutting the part on a place it shouldn't. As we checked, the servo driver for Y had a failure and Mach3 was sending pulses to no one. I imagine the three servo drivers's ALARM outputs to be connected electronically in an OR way so that Mach3 stops if any driver fails(I mean we get a single input pin occupation for all three). I've read somewhere Mach3 can stop the execution on external signal. It is safe enough for us. We can resume the program execution manually after we get rid of the servo failure.
After my research, I"ve found several breakout board items on Ebay from the seller "cnc4youstore". I won't post a direct link as it may be considered as an ad. I saw several threads from them in this forum too. They vary in price $100-$500. The latter are with a smooth stepper and Ethernet-controlled if I am not wrong. On the other hand, for a first machine, I am not feeling sure enough to go for the most expensive, most powerful, most colorful solution if you get what I mean.
Getting feedback for a particular product would give me more self-confidence to carry on and get the best ratio price/quality/reliability/needs coverage/
To summarize, we would like to build a simple in design but a reliable machine covering our needs and not much more than that.
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My advice would be to start out simple (and cheap) with a basic PC (with parallel port) and a basic breakout board.
Once you have your machine up and running (having learnt about the way in which your motor controllers are connected, limit / home switches configured and Mach3 is setup etc.) you will know it’s full potential together with any possible limitations.
You then have a base to work from and can improve (perhaps at a cost) the areas that need improving.
(Although I have a Smooth Stepper motion controller, for 99.9% of the time I am still using the parallel port and basic PC running WinXP).
Tweakie.
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I wanted to build a CNC router just for the fun of it and I am getting along OK and thought that the best way to go would be to learn as best as possible Mach3 and have downloaded the generous but limited software. I have also put together the electrical equipment including a 5 axis breakout board and all the power supplies, connected three X,Y and Z M542 stepper drivers and a couple of Nema 24 motors (I haven't got the third one yet).
All seemed to be going well except that the motors wont run. The digital display fed off the breakout board runs fine. I'm sure this is a software set up and wonder if I have misunderstood the instructions. I do not seem to be getting any pulses out of the breakout board even though I have correctly, I believe, allocated the correct pins etc in the configuration menu. My stepper drivers seem to be asking for a common 0volt and the pulse, direction and enable are +ve going. Have I missed something. This probably isn't a Mach3 problem but I thought I might ask.
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Hi Exhausted,
Welcome to the forum.
Perhaps if you give us some details of the actual breakout board / stepper driver you are using we may be able to help you to get it sorted.
Tweakie.
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Ok, The breakout board is a five axis although I only plan to use x,Y and z. I.m not sure of the make but it is common on ebay and has a normal 25 pin parallel port one end and the smaller plug the other end for external hand control which I do not have. It has also got three plugs for digital display, three axis, four axis and five axis. (Does ECG sound correct). The Stepper controllers are M542H.
I have configured Mach3 in the motor output configuration to
X axis Step pin 2 Direction pin 14
Y axis Step pin 16 Direction pin 3
Z axis Step pin 7 Direction pin 9
Step and direction Port 1 both
Output Signals
Enable 1,2 and 3 as Port 1 Pin 1
Not sure what digit trig is so left that unchecked
(The current ebay item number ebay.co.uk is 171116789211 which may help)
There is a circuit diagram included which can be seen down the listing which I have followed.
Thanks for your quick reply
Brian
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Hi Brian,
As the details on this breakout board are pretty poor (with errors) my best suggestion…
Check that your parallel cable is indeed wired Pin1 to Pin 1, Pin2 to Pin2 etc.
Check that your USB cable is providing the necessary 5 volts to the breakout board.
In Mach3 configuration (change just one thing at a time and observe the results)…
Try changing the Active Hi / Low state of the Enable signal LPT Pin 1 (you really only need one enable signal but as you may have them all enabled then the active state of them all needs to be identical).
Try changing the Active state of the other axes (just the step pins).
That’s all I can think of trying just at the moment.
Tweakie.
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Tweakie
Thanks for your help I was encouraged to keep at it.
I think I have solved the problem which I think may have been with the way that the breakout board was configured. I had a different basic board which I bought ages ago and never used because I didn't understand the pin configuration. A bit of setting up in Mach3 'configuration' and using the board which identifies pinouts instead of codes, and I was nearly there. What I hadn't sussed was that of the four outputs for each motor driver, only one was a pulse, the spacing between pulses dependent on the speed/axis movement from Mach3. The other two are straight +5volt when the motor is enabled and polarity 0v or +5v for direction. The 4th connection is of course 0V(Common ground).
Armed with that eureka moment, I was able to get the motor driver to work. Connecting to the stepper motor, at first the shaft hardly moved but then I went back into Mach3 and looked at the motor tuning and realised that I could set the motor pulses much higher than I realised and hey presto with a bit of fiddling with the dip switches I'm confident that I am in business and can put the lid on my control center and start building the mechanical bits.
Regards
Brian
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Good news Brian, I am pleased that you are on your way to making chips. ;)
Tweakie.
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I have what I hope is a simple question. breakout board or motion controller. Why are the prices so far apart?
I ask cause I am trying to finish a small homemade cnc using a Dremel as the tool. I know it will have limits but thats fine. I am on a budget and understand from what I have read. But I just can't se the difference but the 2.
Once I have things up and running I buy Mach3 but for now the trial should get things cutting, no pun intended.
Thx for the feedback.
Greg
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Hi Greg,
In very basic terms..
If you PC has an LPT parallel port then a breakout board could be used - if you PC does not have an LPT parallel port then an external motion controller will be required.
Tweakie.
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HI guys. I built a machine a couple years back, using Xylotex hw for the breakout board. I have an XP parallel machine, and got it working fairly well with generated gcode. I couldn't get the limit switches set due to my limited experience and the lack of capability or instructions. I can configure a PC pretty well, just not very electrical. I have, I think 23 and 45 steppers installed, three axis so far. Is there a more common and easy to set up breakout four axis with limit switch controls? Not tied to parallel, but I can make it work. Yesterday, Geko was suggested. No direct phone there. I'd like a supplier that I could spend a few minutes talking with or has something more turnkey? Appreciate the help.