6040 7i76 Conversion

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3 years 5 months ago #271131 by my1987toyota
Replied by my1987toyota on topic 6040 7i76 Conversion
Thanks for clearing that up PCW.

spacestate1 if you use the TB6600 use a 36 volt power supply ( say Meanwell LRS-450-36 ). If you use something like the DM556
you can use a 48 volt ( say LRS-450-48 or NDR-480-48 which is din rail mountable) and you will have more top end speed in your
steppers but check the motor temps
when under load  If the steppers get hot enough that they get uncomfortable to hold your hand on
drop your amp setting on your drives until they get warm but not uncomfortable to hold. Also the
DM556 has the setting for half current when idle ( I think dip switch 4 ) so your motors will cool
when not turning . The TB6600 doesn't have that feature so they hammer your steppers with the
max set current as soon as the drive is powered.
 

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3 years 5 months ago #271136 by my1987toyota
Replied by my1987toyota on topic 6040 7i76 Conversion
E-Stop.
The way I do it is the circuit is always connected or normally closed unless I hit the E-Stop switch or
in a rare case of the wire failing, the E-Stop will be triggered. How I normally do it is I use a multi
contact relay that when the E-Stop is triggered it cuts power to the relay coil which in turn-
1 shuts off power to the coolant,
2 disables the spindle drive,
3 tells the computer an Estop event has occurred, (through the 7i76)
4 disables the stepper drives

You could wire in more relays to do more things if needed but in my case this covers all my bases.
I prefer hardware type of E-Stop over software so that in the event of a program crash when an
E-Stop button is triggered the machine will stop moving regardless of what the computer is doing.
When designing any machine it is always best practice to fail safe.

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3 years 5 months ago #272070 by spacestate1
Replied by spacestate1 on topic 6040 7i76 Conversion
I can connect and flash the 7i92 with a bin file for the 7i76 board, and it seems to apply things as expected. But now I'm not sure what to do to get the steppers going. I know there's a ton of info out there on this, but I think I'm missing something simple.

I bought a DM556 and wired it up a 48volt power supply with the stepper coils wired, and the step pins to the 7i76 like this:

Step 0-  -> PUL-
Step0+  -> Pul+
Dir0-      -> DIR-
DIR0+    -> DIR+

I then used steppconf to get the board and settings into the ini file, but I cannot get the X-axis to move in LinuxCNC, or in the test menus.
Am I missing something like an enable switch or another pin? Or is the 7i92 not setup correctly? 
Attached are ini config files and the readhmid output

thanks again

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3 years 5 months ago #272112 by my1987toyota
Replied by my1987toyota on topic 6040 7i76 Conversion
first things first . Don't use steppconf when using a Mesa board use pncconf. The rest of the board setup should be pretty easy.
Personally when I did my first one I made the simplest setup possible then played around with adding more stuff so I didn't hit information
overload.

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3 years 5 months ago #272118 by PCW
Replied by PCW on topic 6040 7i76 Conversion
Also, as a quick sanity check of the setup,
check that the direction pins on the 7I76
change states when jogging in different
directions.

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3 years 5 months ago #272122 by spacestate1
Replied by spacestate1 on topic 6040 7i76 Conversion
Typo, I set it up with pncconf

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3 years 5 months ago #272125 by spacestate1
Replied by spacestate1 on topic 6040 7i76 Conversion
Just double checked my wiring I had the DB556 wired wrong, moved the wires down a peg and now it works. Thanks for help once again though.

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3 years 5 months ago #272143 by my1987toyota
Replied by my1987toyota on topic 6040 7i76 Conversion
Something else you may want to take a look at is some of the Tormach manuals.  More specifically their electrical wiring and
schematics near the end of their manuals. It will give you an Idea of what should be used for a more reliable and more
importantly safe machine . It helped me a lot .

link for PDF download of the 24R Operators manual
tormach.com/support/router/24r-cnc-router-documents

Link for PDF download of the 1100M Operators Manual
tormach.com/support/mill/1100m-documents

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3 years 5 months ago #272432 by spacestate1
Replied by spacestate1 on topic 6040 7i76 Conversion
Posting to see if there's problems with this plan on how to wire up the E-stop, and also just from my own reference. This is based on what I've read on the forums and from the hardware I'm working with.Again any input is appreciated.Note: So far the DM556s have been great they're very smooth with tons of power.  
 

Attachment not found

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3 years 5 months ago #272457 by my1987toyota
Replied by my1987toyota on topic 6040 7i76 Conversion
Just making sure I am understanding your diagram. Are you tying in the DC ground from your relay to A/C Main ground?
if so don't. just return all of the DC- or Common  back to the DC negative of your 24 volt power supply. The main reason being is
you want to avoid creating ground loops which introduces electrical noise into your controller (7i76). I would recommend
checking out this link for Wiring Best Practices
linuxcnc.org/docs/stable/html/integrator/wiring.html The wiring from the 48 volt power supply to the Stepper drives looks ok but I would recommend adding  fuses in line . 

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