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Author Topic: Looking for good DIY controller kit supplier  (Read 4061 times)

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Re: Looking for good DIY controller kit supplier
« Reply #70 on: November 27, 2020, 11:14:10 PM »
Just to get my mind straight:

The 'Interface' is the device that is connects the 'Controller' to the computer via a parallel port, USB or ethernet cable, such as a BOB.

The 'Controller' is a collection of devices (hardware) that comprise circuitry that facilitates functions such as:

Limit and home switch inputs – more IO ports allows separate input of switches to help with troubleshooting.
E-Stop input
Stepper motor drives
Relays for Spindle On/Off - direction, Coolant, etc
Analog output for spindle speed
Probe – set tool height
MPG – manual pulse generator to manually move the axes
LASER

and there are 'Power Sources'.

Both the 'Interface' and the 'Controller' hardware has to be built to allow particular software such as Mach3 or 4, or any other chosen software.

The Computer, Power Sources, Interface and Controller have to be electrically isolated. In fact, there are Interface and Controller components and parts of their circuitry that should not have a common current flow. 'Energy or information can still be exchanged between the sections by (other) means such as capacitance, induction or electromagnetic waves, or by optical, acoustic or mechanical means' (wikipedia), and these 'means' are built into all the devices.

I would like to maintain all the functions my CNC has at present, inclusive of MPG, as a minimum. I'll also keep my motors and their Encoders as they seem to be working well at present. My router does not have a coolant facility, but who know, might need it in future.


Please advise which Windows O/S would be most stable for Mach3. I presently run on Vista, but maybe another would be more stable?



Offline ZASto

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Re: Looking for good DIY controller kit supplier
« Reply #71 on: November 28, 2020, 03:37:56 AM »
Just to tangle the strings a little bit :)

Controller is, in case you are using parallel port, your computer running Mach3 or similar software which generates Step/Dir signals. In case you are using USB or Ethernet devices, these are controllers as they are generating Step/Dir pulses derived from data that your computer sends in form of PVT (Position Velocity over Time).

BOB: in case of parallel port, a dumb piece of electronic circuitry for interfacing between parallel port and motor drivers and various switches (Home, Limit, Probe, ...). In case of USB/Ethernet, those controllers are BOBs at the same time.

Mach3/4 are open loop controlling programs so you can not use encoders that are mounted to the motors.

If you want to use MPG with Mach3 without external controller, you will need a second parallel port and some "brains" to be able to use it (I do have it on my machine).
Make no mistake between my personality and my attitude.
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Re: Looking for good DIY controller kit supplier
« Reply #72 on: November 28, 2020, 04:41:42 AM »
Strange thing is, ZASto, The original circuit board fitted between my computer and the CNC has encoder plugs and the encoders were plugged into them. If you go back a few pages on this post you'll see the circuit diagram. Are you telling me that Mach3 made no use of that info, or that the encoder info was not fed back within that circuitry to fine tune the stepper to prevent stalling? I'm so confused.
Also, my 6 wire motors are configured into a 5 wire Unipolar manner. Should I change the wiring config to Bipolar? And should it then be series, half coil or parallel? I have to fully understand these concepts first to even make a choice.
Could you send a labelled diagram of your set up and all the functions it provides to the CNC? I need some visual input.

Offline TPS

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Re: Looking for good DIY controller kit supplier
« Reply #73 on: November 28, 2020, 07:45:25 AM »
-in your Special case (MaxNC controler board) the PIC is reading and handling the encorder, and only the PIC,
Mach3 knows nothing about this Encoder.

-in a good tuned stepper System it is normaly not necessary to use encoder's

-anyhow there there are stepper Motor drivers on the market witch can handle Encoders. then they are
closed Loop. Leadshine is only one example:
http://www.leadshine.com/ProductSubType.aspx?type=products&category=closed-loop-steppers&producttype=closed-loop-stepper-drives&subtype=general-closed-loop-stepper-drives

but also here, only the stepper drives reads/handles the Encoder, not Mach3
anything is possible, just try to do it.
if you find some mistakes, in my bad bavarian english,they are yours.
Re: Looking for good DIY controller kit supplier
« Reply #74 on: November 28, 2020, 08:20:43 AM »
Thanks for the link TPS
I have just found 'CNC Router Source' -  http://www.cncroutersource.com/homemade-cnc-router.html and will read my way through that. Seems to give a good overview of all the control and driver criteria.
ZASto's set up seems simplicity itself and I do like simplicity. I just have to come to terms with my 6 wire stepper motors, their technical specifications, whether or not to use them as a uni or bipolar setup, if bipolar then series, half coil or parallel or even if I should totally replace them; whether or not to use the encoders and how to connect the limit switches and router / spindle. I also have to decide if I want the option to install some extra functions in the future, as MN300 suggested. Will I update Windows, and if yes, which Mach version would be the best to use on that O/S; will I use the parallel port, USB or an ethernet cable; will I use the computer as the main controller or use an external controller etc. etc.
Cost will determine most decisions but I need to first educate myself.

Offline MN300

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Re: Looking for good DIY controller kit supplier
« Reply #75 on: November 28, 2020, 09:50:42 AM »
The CNC Router Source was a good find!
Yes, simple is good. It will get you running and give you the experience to decide what to do next.
The stepper drives in ZASto's earlier post look like good value for money but I would do further research before committing to the no name breakout board. The chinglish description in the AliExpress site is hard to interpret. Compare that information to the manual for a similar BOB.
https://www.cnc4pc.com/pub/media/productattachments/files/c11g-r9_user_manual_2.pdf
If ZASto has used it and can support you then it sounds like a suitable device. Does your computer meet the requirements for using that board?

The stepper drives are for bipolar motors. Ignore the center taps on your steppers and connect the ends of the windings to the drive.

We need more information to decide if/how the breakout board can control your spindle. The picture of the breakout board shows a relay but I would hesitate to run mains power through it. Does the spindle have a variable speed drive?

Offline ZASto

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Re: Looking for good DIY controller kit supplier
« Reply #76 on: November 28, 2020, 01:45:53 PM »
The BOB that I use is perfectly suitable for a beginner and intermediate user.
Nothing special on it. It has a possibility to "control" 5 stepper motors or 4 motors + spindle.


As you can see from schematic, if jumper is placed on dedicated pins it controls the relay which can be used for switching spindle On/Off. PWM is available at the terminal P1 buffered from pin1 of LPT port and as 0-10V at dedicated output near relay output.
So it is Mach3 that controls spindle THROUGH BOB  ;D

Another thing, this BOB needs two power supplies. One 5V connected to PC 5v and PC GND and a second one, 12-24V (if stepper supply is not higher than 24V it can be used), for input side (Home/Limit/Probe).

Chinglish? Attached manual is quite easy to understand.
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Offline MN300

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Re: Looking for good DIY controller kit supplier
« Reply #77 on: November 28, 2020, 02:27:45 PM »
Thanks to ZASto for providing the missing documentation. I looked for links in the AliExpress item but could not find them or a model number with which to search the web.
It's good to see the 12 to 24 volt side of the circuit is isolated from the parallel port. This includes the 12V switch inputs, the relay common, and the 10V analog output. The TB6600 stepper drive is opto-isolated completing the isolation between the parallel port and the rest of the CNC controls.

Offline ZASto

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Re: Looking for good DIY controller kit supplier
« Reply #78 on: November 28, 2020, 05:06:32 PM »
I use the same BOB with Mach3 and with Arduino running GRBL (when playing with 2.5W laser module). Just unplug cable from LPT port and plug it to Arduino BOB that I made.
Make no mistake between my personality and my attitude.
My personality is who I am.
My attitude depends on who you are.
Re: Looking for good DIY controller kit supplier
« Reply #79 on: November 28, 2020, 10:03:28 PM »
Thanks for all your input, people.

My computer is a ACPI x 86, 2 x Intel(R) Core (TM) 2CPU 4300 @ 1.8GHz each. Memory a paltry 2046MB. It runs Vista, which during it's time was regarded as a giant virus.
I can install XP if that would be better.
My router is a Bosch 1617 EVS, 120V, 60Hz, 12A and 2.25HP. It's power supply is a stepdown transformer 240 to 115V. The Router was supplied with the CNC and US rated. So was the CNC. It is a variable speed but manually controlled
I now have the opportunity to gear control componentry to 240V mains.

I have looked into the TB6600 steppers and ST-V2 BOB. The BOB is regarded as one of the 5 best for Mach3 while the TB6600 presented quite some problems in the early 2010s. Problems such as overheating and not supplying the rated current. That seems to have been resolved but it still seems to be a case of buyer beware of cheap imitations.

BUT, I've committed and bought the stuff from a reputable Oz supplier.

?What is a jumper and a PWM? I looked it up online but could not find a ref as to what they actually are, only that the are used.

So now I wait till the goods arrive.