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Author Topic: Looking for good DIY controller kit supplier  (Read 4056 times)

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Offline ZASto

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Re: Looking for good DIY controller kit supplier
« Reply #110 on: December 03, 2020, 04:07:11 AM »
0.1 uF caps are not needed if switches are NC.
Make no mistake between my personality and my attitude.
My personality is who I am.
My attitude depends on who you are.

Offline TPS

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Re: Looking for good DIY controller kit supplier
« Reply #111 on: December 03, 2020, 04:14:46 AM »
Wow :O Are those switches made from outback gold nuggets?

Parker Schnabel and his Team is coming over to mine the Gold for the contact's. .)
« Last Edit: December 03, 2020, 04:22:33 AM by TPS »
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 #112 on: December 03, 2020, 04:32:34 AM »
With ZASto's combo and MN300's rumba; how can I loose. I've come across pure talent here.
Thanks for the info fellas, will lob into jaycar with the purchase list as well. Save myself some money but won't forget the copper plated aluminium.
I'll check to see if the switches are NC or NO
TPS, have you just come rolling in from a party, stood next to some guys shrouded by smoke?

Offline MN300

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Re: Looking for good DIY controller kit supplier
« Reply #113 on: December 03, 2020, 08:16:14 AM »
I used to design controls for industrial equipment, $50 for an E-STOP switch would not have been out of line because a switch intended to last for decades of hard use costs money. However we are in the hobby world where things are much more relaxed. If something has crashed or is smoking having the second E-STOP contact to interrupt the power to the motors is not a bad idea. The E-STOP switches found so far have 1 NO and 1 NC contact but we need 2 NC's. Major vendors sell the contacts and the operators ala carte so you can make what you need. At this point the cheapest option might be to buy two and move a contact.

ZASto is quite right about no need for capacitors on NC switches that only open in emergencies. Additionally The 10 volt levels into a relatively high current input (the optos) will be fairly immune to noise. Your machine is small and you should be able to keep power wiring away from the signal wiring. These all reasons you should not need caps.

Here are some cables from Maker Store. Could you contact the store to find out if they are all copper? I imagine they are but aluminium wires that break under vibration would be no fun.
Limit switches - https://www.makerstore.com.au/product/2-core-cable-70-2/
Motors and maybe stepper driver inputs - https://www.makerstore.com.au/product/shielded-4-core-cable/

Offline MN300

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Re: Looking for good DIY controller kit supplier
« Reply #114 on: December 03, 2020, 11:25:33 AM »
It's kind of people not to point out the mistakes in the last drawing. Errors are bound to creep in. All the more reason for you Sherwood to go over it and ask about anything that seems wrong or you don't understand. Also it's amazing how much you forget after a year or two. The more detail we put in the easier it will be to repair or upgrade the system later.

I was going to use a solid state relay for the spindle but decided not to. It would have meant using P17 which is shared with the onboard relay, that's why the relay jumper was OFF. However I'm using the small onboard relay to control the spindle relay so it needs to be ON.
A copy and paste error affects the text for the limit switches. i forgot to go back and change "X AXIS LS" to Y and Z on their lines.

Some items will require more input to finish the drawing.
Details of the power supplies. I have drawn components in as semi-pictorial manner to make them clearer to beginners.
There should be a mains switch. Is there something now?
Verify the BOB relay common is connected to the 12-24V common.
Notes about where to use shielded cable.
Notes about shield grounding points. Generally they go to the ground of the equipment sourcing the signal.
Final selections for motor current and micro-stepping.

We'll catch up with these in later revisions.
Re: Looking for good DIY controller kit supplier
« Reply #115 on: December 03, 2020, 09:31:51 PM »
Buying quality is preferred, but Yep, true, in hobby world dreams meet the purse strings.

I looked at the Limit Switches, they stop current flow when activated .... that's NC, isn't it. If yes, it's a little counter intuitive as you can not walk through a closed door :-\.

The cables attached to the motors and switches are "Black Box Corp 6/C Type CMR (UL) c(UL) 75C E116394; is that a suitably shielded cable or best totally replaced?

In relation to the spindle control; I would prefer to initially keep my present set up, which is mains power and manual speed control by adjusting the potentiometer built into the spindle motor casing. I would certainly like to upgrade the spindle control to a computerised one as a future project.

A request for specs to determine quality, for all the required items yet to be purchased has been sent to a few suppliers. Awaiting a reply.

I saw the # X Axis LS and yes, did not understand .... will speak up next time.

I'll give you the specs of items (to be) purchased as they arrive.

What Mains Switch are you talking about, MN300, the wall switch for the 240V power supply?

Offline MN300

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Re: Looking for good DIY controller kit supplier
« Reply #116 on: December 03, 2020, 10:23:00 PM »
A main disconnect switch is turns off all the power when you're not using the machine. For you that could even be unplugging the power cord.

You machine worked at one time so the wiring must have been adequate.
The physical layout of the machine will determine the length of the cables and how hard it will be to keep good separation between the motor cables and the other wiring.
You may be able to reuse the encoder cables for the stepper driver inputs.
I looked back at the photo of the motor cable. It looks like it's 6 conductor unshielded. Buying new cable from Maker Store for the stepper motors shouldn't break the bank.
Re: Looking for good DIY controller kit supplier
« Reply #117 on: December 03, 2020, 11:45:19 PM »
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Re: Looking for good DIY controller kit supplier
« Reply #118 on: December 04, 2020, 12:04:59 AM »
OK, it arrived. That's the CNC; didn't know if the attachments would work this time.

Everything associated with the CNC including the computer is run via a dedicated power board. No piggybacking of any sort. One switch to turn it all on and off.

I can suspend the power cable for the Bosh overhead and well out off the way of other cables. The Limit and Motor cables will run through the drag chains, but once they exit I can truly separate them. Variations to the theme will be seriously considered.

Is a 0.4 mm 4 core cable suitable or is 0.5 mm minimum requirement. I'll replace all the cables as then I will not have to splice or fit contacts to extend them. One length of cable from the motors and switches to the TB6600s and BOB. Max length is for the Z axis motor and limit switches; 4 meters each. Each drag chain is approx 1.5 m and the distance from the end of the last chain to the best position for the control is 1 m. The last distance may be whittled down to 0.5 m, but I prefer the more distant position.

Offline MN300

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Re: Looking for good DIY controller kit supplier
« Reply #119 on: December 04, 2020, 04:27:03 PM »
The discussion about 0.1 uF capacitors and limits switches made me think about the noise immunity of an input connected to a normally closed switch, With the switch holding the input to ground it would take a very strong noise signal to cause enough voltage to falsely trigger the input. If the switch is operated the system shuts down and any noise that might get through during that state is of no consequence. This would explain why unshielded limit switch wiring was OK.
That would not be the case for a home switch that might be open during part of the normal axis travel. However you don’t use home switches.
I would still suggest using shielded twisted pairs for the motors when you rewire.
The cables from the BOB to the stepper drivers will be short and can be kept away from the motor cables so in this machine shielding will not be needed there.

This power supply is available from Digi-Key and Mouser.  LRS-350-24. They also have the relay and socket on the wiring diagram.

I sketched the main components in CAD and made an arrangement that minimizes wiring and keeps different signals separated. The rectangle I drew around it is 300 mm x 270 mm. The depth needs to be 80+ mm  to accommodate the stepper driver cabling. The enclosure you provide should be larger to allow for possible future additions.

A really proper box with an interior panel for mounting the components is a bit past your budget.
https://www.digikey.com.au/en/products/detail/hammond-manufacturing/EJ12146/2568630

Even a plastic version is not cheap.
https://www.digikey.com.au/en/products/detail/bud-industries/NBF-32026/2328539
https://www.digikey.com.au/en/products/detail/bud-industries/NBX-32926/2676759

I’ll leave finding an affordable alternative up to your imagination.