Messages

51

General Mach Discussion / Re: Looking for good DIY controller kit supplier

« on: December 03, 2020, 02:15:35 AM »

I'll cost all the required items from the 3 suppliers you mentioned; they have good Aust online stores so all good.

Had a look at the E Stop switches and was surprised by their cost Aus $ 50 to $300 and more.

Will discuss item specifications with you prior to placing the order.

52

General Mach Discussion / Re: Looking for good DIY controller kit supplier

« on: December 02, 2020, 04:58:24 AM »

Prep time, OK;

I'll use the 4 pin connectors instead of the terminal, I've decided to use cable, I know where I will install the equipment and will measure the cable length required for the Motors, the three TB6600s, the Limits Switches; I'll use a terminal block to connect the three TB6600s to the 24 V power supply. I do not have an E Stop switch

I will visit Jaycar electronics to purchase the lot. If they do not have it I'll source it online most probably from Maker Store. The E Stop shall have 2 contacts.

I have been soldering for a few decades now but will purchase an iron or tip that will allow for finer work.

The CNC mill is a basic set up; table, X,Y and Z gantries with lead screws directly attached as extensions to the stepper motor shafts. It has two Limits Switches for each axis. I have no relay and the Bosch motor/spindle is mains connected, and only has a manual dial RPM potentiometer built into the router casing. It has a 3 pin plug - mains earthed.

53

General Mach Discussion / Re: Looking for good DIY controller kit supplier

« on: December 01, 2020, 07:45:08 PM »

Did you draw that circuit diagram MN300? 

You could make a tute out of the sherwood cnc saga; must be plenty other newbies who would like to install ZASto's combo.

54

General Mach Discussion / Re: Looking for good DIY controller kit supplier

« on: December 01, 2020, 07:38:53 PM »

Thanks for the road map to the circuitry, makes what I'm seeing more meaningful.

Twisted pairs are good, follow the reasoning from the link

I will have to dismantle the harness as there are now encoder and central tap wires in it that will not be used. Should I remove the encoders from the motors?

All other motor wires will need to be extended by 50 cm to 60 cm, will that affect information travelling between the motor and control?

I'll follow the 'User Manual of 5 Axis BOB' wire attachment with the MN300 alteration. How do I identify Stepper Pulse and Direction wires?

55

General Mach Discussion / Re: Looking for good DIY controller kit supplier

« on: December 01, 2020, 04:31:21 AM »

Good to hear from you ZASto, I have no doubt that you have not experienced any glitches.
Being the adventurous type, I would not mind trying it as per MN300's suggestion, but any difficulties and I'll default your way.

From the BOB circuitry diagram you attached some time ago, it seems to my untrained eye that the BOB has 6 opto couplers and the diagram states that they are for pins 10, 11, 12, 13, 15 and the 6th for the spindle control maybe?? What is the significance of that as related to using pin 14?

56

General Mach Discussion / Re: Looking for good DIY controller kit supplier

« on: December 01, 2020, 12:39:17 AM »

Can the voltage and current be measured with my you beaut QM1529 Digitech multimeter?

Since I won't have encoders attached I'd like to reduce the chance of missing steps in every way.
How would you see the TB6600s hooked up to the BOB, your before mentioned 1st or 2nd alternative?
If afterwards it somehow caused an issue, I can always connect the units as ZASto did

Suitable equipment location is available

57

General Mach Discussion / Re: Looking for good DIY controller kit supplier

« on: November 30, 2020, 10:16:43 PM »

Once I have the items, will I be able to provide you with the voltage and current to the opto input?

So you are saying that the BOB IC (is this the SN74HC245 Octal Bus Transceiver?) needs to put out more current than it is rated for, to bridge the communication gap of the TB6600 opto coupler. So if I connected them as ZASto does, what is the worst that could happen, BOB blows up or TB6600 blows up ....... or both??? What damage could occur if the BOB IC was overloaded??

Do either of you have circuit diagrams of both the BOB and the TB6600? If Yes, could you attach them? I'd like to follow the processes.

58

General Mach Discussion / Re: Looking for good DIY controller kit supplier

« on: November 30, 2020, 05:36:00 PM »

Good tutorial, thanks
I'll let you two come to terms on the issues raised by MN300, in the mean time I'll read up on the componentry and processes mentioned.

If necessary, could always obtain a more suitable BOB.

59

General Mach Discussion / Re: Looking for good DIY controller kit supplier

« on: November 30, 2020, 07:25:43 AM »

Yes MN300, challenging

As far as the stepper electronic magic is concerned, I'm reading and comprehending more.
I see how you arrive at all the values. I see how the 24 V power source sets up the stepper winding's potential energy (PE) and how the stepper drive is basically a switch that raises the PE levels (Voltage) required to start the Flow of electrons (Amperage) to generate the Power (Wattage) required to rotate the stepper motor 1 step at the time.

Question: Was the 2.5 Amps per winding or per motor (2 windings)?

Question re: "When the inductance of the winding sees a change in current it creates a back voltage which resists that change" How does that occur, is that an opposing electromagnetic force?

I'll have a good view of the entire process depending on the answers to those questions.

I'll provide the 5 V and 24 V of the BOB with a reliable separate power supplies.

60

General Mach Discussion / Re: Looking for good DIY controller kit supplier

« on: November 29, 2020, 09:33:08 PM »

Yep, I follow the formulas mathematically; conceptually somewhat hazy but that will settle.

What do you think of some of the cheaper ebay transformers from China at about AU$20 to $25. I bought a 240 - 110V step down transformer from China quite some time ago and it's still working.

Also, the 5V power supply, any particular wattage to consider?