Electronics my weakest point!

[mmukhaizeem]

Hi,
This is my first post on this great forum, and I want to say Hi everybody ,

I have been reading and reading for years now, I have built a CNC router long time ago which was bad in all aspects, bad structure and wiring,

although I have good motors, BOB and of course geckos, the result was I lost confidence and lost interests for some time.

Now, I have a lot of space in my new home workshop and have been dreaming of a CNC router and inspired by the Madvac CNC, I want to be back but there is one problem, I am soooo confused about the electronics things, I have managed the power supply needs for my motors but regarding fuses, emergency switch, precharge resistor, diodes, solid state relay, pole switches ….. I am totally lost!


what I have now is a custom transformer 240v/50v 1500VA , 3 Nema 34 1200 oz stepper motors, Campbell BOB, and 3 gecko drives, 85,000uf 100v cap.

My plans are full size steel structure CNC router, and without your generous help and advice I am sure I will not achieve that goal.


Thanks and appreciate your input.

MSD

[LeeWay]

You will need a multimeter and a box to mount the electronics in. It can be pretty much anything as long as it's large enough. Leave plenty of room around the components for wires and fans.

That will get you started.
You will also need a computer.
What software will you run on this computer?
You have to make some type of decision here first.

[mmukhaizeem]

I do have large electrical box, a multimeter, and a PC, I am considering mach3 to run this machine.

Note, I have disassembled may first machine and electrical enclosure just to start all over again right.

MSD

[LeeWay]

That is a good start then.
I concur with your Mach 3 choice.
It is wicked for the price.
Does your computer have a printer port?

Download and install a trial of Mach 3 and get it set up to that printer port and then run a driver test.
You will find the driver test in the Mach 3 folder.
Just double click the file and hold on a minute or two to see the results. Only maybe 10 to 20 seconds actually. Look for spikes on the graph.

[mmukhaizeem]

i have desktop computer with two printer ports, the test is smooth with a couple of small spikes.

FYI, English is not my native language so I may ask stupid Qs that's because I did not understand all what I read.

Thanks

[LeeWay]

Your english is fine. My Arabic is non existant, though I do speak German as a second language.
No worries about stupid questions. Asking questions is a smart thing to do.

I am hoping some others here will chime in. I am no pro at this either, but I have been down the road with it a few times now.

I think the driver test is fine for now.

Tell us which Gecko's you have and which BOB.

[mmukhaizeem]

I have combo board from Campbell designs and 3 X 210 and one 212


My concerns are:

I do want to put fuses between cap and drives, but what type of fuses - fast or slow blow- and how to determine the amps of those fuses?

do I need charge pump, precharge resistor or pullup resistor, I even don't know what they are!

emergency stop! what type if there are types?

I do want shield twisted wire! 18awg and 4 core is my best for all 3 or 4 axes?

what about the bare wire (the fifth wire in case of 4 core shielded cable), is that right? how to ground it? both ends? where?

one end should be grounded to gecko drive body?terminal? what about the other end! just leave it untouched and just cover it?


I am soooo confused


MSD

[LeeWay]

It can be overwhelming at first. Just relax a bit.



You are now getting to the root and asking some of the right questions.

I don't have any experience with any of your electronics. I use C10 BOB's and Gecko 201's and 203V's.

They should be similar enough though I think.

Here is a link to the 210 PDF.

The 212 here.

Someone more familiar with those drives will have to give you clues on fuses and setup options for those.

Bob has more than 1 board available. Specifically which do you have?

Your wire choice sounds fine. The 5th wire is your ground or sheild wire. It should only be connected to the ground at one end. The cse ground that the gecko's are mounted in. Just leave it disconnected at the motor end.

I use 5 amp automotive fast blow fuses between my power supply and my Gecko's. Not had any issues with those.


We will get to the charge pump later. For now, just skip it.

An Emergency stop can really be just about any type switch.
U use a simple mushroom switch that is momentary. In other words, it activates when I push it and deactivates upon release.
Lots of guys use the twist lock switches.

http://homanndesigns.com/store/index...bbd8ab73e4945a

Even the switches on the Chinese made mills and lathes would work okay.
I actually use a machine toggle switch on my lathe.

Originally Posted by mmukhaizeem I have combo board from Campbell designs and 3 X 210 and one 212 My concerns are: I do want to put fuses between cap and drives, but what type of fuses - fast or slow blow- and how to determine the amps of those fuses? do I need charge pump, precharge resistor or pullup resistor, I even don't know what they are! emergency stop! what type if there are types? I do want shield twisted wire! 18awg and 4 core is my best for all 3 or 4 axes? what about the bare wire (the fifth wire in case of 4 core shielded cable), is that right? how to ground it? both ends? where? one end should be grounded to gecko drive body?terminal? what about the other end! just leave it untouched and just cover it? I am soooo confused MSD

[DaveKennedy]

Hello, This is my first post too. I have just aquired my stepper motors and bits for the first time. Nema 34s 4.2 Nm.

I have it all on my desk top and it's working with Mach3.

I used car inline fuses with the common blade type fuses found in cars. Each driver has it's own fuse of 15Amps. Don't know if it's right, but it works.

The wire I used I striped out of a standard 3 core electrical wire.. the type you have on a kettle or washing machine or.... no shielding.

Then I followed those great videos on http://www.machsupport.com/videos/

and I'm off! building a frame and fitting linear rails and ballscrews is easy for me and I now treat that mass of wires as a package to be used to drive the mechanics.



I can order 2 glasses of white wine in Greek, but that's not much use

[DaveKennedy]

Originally Posted by LeeWay It can be overwhelming at first. Just relax a bit. An Emergency stop can really be just about any type switch. U use a simple mushroom switch that is momentary. In other words, it activates when I push it and deactivates upon release. Lots of guys use the twist lock switches.

Hi LeeWay,

Our good friend Art says use 'normally closed' switches, because Mach3 can tell you if there's a break in your circuit. If you use a 'normaly open' switch Mach 3 thinks all is well when there is no current flowing. So if you get a break in your circuit Mach 3 thinks all is well, even when the limit switch/ emergency stop is pressed. Using a 'normally closed' switch makes sense to me. I'm no expert.

[LeeWay]

Right.
That is the best practice. Wire it so that the switch is closed at rest and active when open. Some switches like some limit switches can be wired either way.
This is the switch I use on two machines.
http://www.surpluscenter.com/item.as...tname=electric

[srcmadison]

If you choose a momentary e-stop button like the nice one suggested by LeeWay, you will need a relay to cut the motor power when the switch is activated, otherwise the power comes right back as soon as your hand leaves the button. Your drives may have an internal circuit which does this for you but the safest bet would be to use a maintained switch or a relay circuit so that you are sure that the motor power is off when the switch is pressed in.