Hello Guest it is May 16, 2021, 04:30:48 AM

Author Topic: Looking for good DIY controller kit supplier  (Read 4047 times)

0 Members and 1 Guest are viewing this topic.

Offline MN300

*
  •  243 243
    • View Profile
Re: Looking for good DIY controller kit supplier
« Reply #100 on: December 01, 2020, 07:06:00 PM »
Here is a start on a wiring diagram. We can improve it when we learn more about the power supplies and any features you want to add. If you decide to use the 4 pin connectors instead of the terminals for the stepper drivers I could revise it for that.

I couldn't see the legends for the BOB relay terminals in the available information. Also it would be useful to verify the relay common is connected to the 24V common.

If the stepper motor windings are run in twisted pair and kept well away from the other wiring it will greatly reduce the change of problems with noise. Of course the spindle motor wiring need to be separated too. 
https://audiouniversityonline.com/twisted-pairs/

The 10 volt powered opto-isolated inputs give you better noise rejection than the usual 5 volt BOB wiring.
If the four wires to the stepper driver inputs are twisted together that will reduce noise pickup too.

When you decide where to mount the new equipment you will be able to determine if longer wires will be need.
Re: Looking for good DIY controller kit supplier
« Reply #101 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?
Re: Looking for good DIY controller kit supplier
« Reply #102 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.

Offline MN300

*
  •  243 243
    • View Profile
Re: Looking for good DIY controller kit supplier
« Reply #103 on: December 01, 2020, 09:24:47 PM »
The drawing was made with the classic version of ExpressPCB software. I've used it for well over 10 years to design PCBs.

Let me discuss the most rigorous method of wiring. To get some idea of cost I found an eBay site with cable that looks to be a reasonable prices. This is just to get a general idea and not a recommendation. I know someone who bought inexpensive cable only to find out it was copper plated aluminium and not suitable for his use.
https://www.ebay.com/itm/RVSP-2-4-6-8-10-12-14-16-20-Core-Double-Twisted-Shielded-Cable-485-Signal-Wire/254397336055?hash=item3b3b4349f7:g:JE8AAOSwgqZdrqCW

Motor wiring would be done with shielded 2 pair cable.
4 core 0.5 mm2  5 meters US $13.30

Stepper drivers would be connected with 3 pair shielded cable, one pair for each of the three optos.
6 core 0.2 mm2 5 meters  US $11.02

Limit switches would be connected with twisted pairs, individually shielded or grouped into one cable as the physical configuration requires.
More of the 6 core or 2 core 0.2 mm2 5 meters US $5.87

24 volt power would connected with loosely twisted hookup wire to each stepper drive from a distribution terminal block. This is because if they were daisy chained the first part from the supply would be carrying all the motor current and need large conductors. I should change the drawing to reflect this.

There would be many commons and shield grounds going to the same places. On a industrial machine we would use lots of terminals the cost of which adds up fast. For hobby use they could be spliced together. You may have to learn how to solder.

This is a a belt and braces approach to the job. You might get away with extending the existing wiring with whatever scraps of wire you can find but...
Short runs need less protection so you may not need the expense of all that shielding but I don't know the details of your mill. I'd like to hear about the mill and what materials you have on hand. Who are the reputable vendors in your part of the world? Can your friend make recommendations?

Offline MN300

*
  •  243 243
    • View Profile
Re: Looking for good DIY controller kit supplier
« Reply #104 on: December 01, 2020, 09:35:53 PM »
Here is item I forget to mention. If your E-STOP switch has two contacts we should use one to interrupt the 24 DC to the steppers.
Re: Looking for good DIY controller kit supplier
« Reply #105 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.


Offline MN300

*
  •  243 243
    • View Profile
Re: Looking for good DIY controller kit supplier
« Reply #106 on: December 02, 2020, 08:32:16 PM »
Here is a second draft of the wiring diagram.

Stepper input signal wiring changed to use the 4 pin connectors. Do you have a place to buy the cables or the materials?
Second limit switches added.
Wires grouped to indicate cabling.
Second E-STOP contact used to break AC mains to the 24V supply and the spindle.
Optional Relay added to start and stop the spindle under MACH control. The selected relay has a test button so the operator can run the spindle manually.

I would prefer to use a major supplier for some parts like the relay and socket. Minimum order value or minimum for free shipping might make that impractical. Candidates are element14, Mouser and Digi-Key.

Maker Store may have the best price on cable but one item has aluminium conductors, others don't specify. That's something to check before ordering.
Re: Looking for good DIY controller kit supplier
« Reply #107 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.

Offline ZASto

*
  •  373 373
    • View Profile
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 #109 on: December 03, 2020, 03:52:09 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.

Hey Sherwood, fellow Aussie here. Cairns, Nth QLD.
I've been watching this topic but haven't waded in because you've been getting an amazing amount of input from others.
I just thought I'd chime in and direct you to the Emergency stop switch that I use on my home made router.
https://www.jaycar.com.au/latching-emergency-stop-switch/p/SP0786
It can be set up as NC or NO contacts.
Not sure if anyone has mentioned this before, but I'd also fit a 0.1Uf capacitor across each of your limit and emergency switches.
This solved an electrical noise issue that I and some others have had with our set ups.
https://www.machsupport.com/forum/index.php?topic=26182.0
These guys might be of help to you.
https://core-electronics.com.au/search/?q=0.1uf