Mesa 7i92 Installation, considering old ATX psu for I/O voltage source...

Very long day, finally got a chance to slow down and check in here to post updates, then forum ate my post 3/4
of the way thru. Just one of those days i guess...  So here goes again.

Good information on the LAM, and yes I want to go closed loop with encoders but need to figure out a valid
encoder that will work on the dual shaft steppers I end up with. Honestly tho, the stepper drives with all the active
amperage/efficiency management are rather interesting when you think about it. I have read alot of posts of guys
mentioning midrange performance boosts using the better gecko options too, so it sounds like either make is up
to the task.

Honestly I am leaning towards the geckos due to them being based out of the states and there appears to
be more documentation/support for Taig mills with the gecko drivers on them over here. But, on a different
build, I would really like to order a LAM drive to see how they handle as well.

I certainly would like to have found an available Japanese or German made stepper here in the States, but after
a second session of mucking thru the catalogs of the major regional suppliers here, I was left with only the
questionable and recently acquired keling name, so I took THAT risk... Didn't like that decision, but I am trying
to keep to a rather tight timeframe with this machine build and it was taking way too much time finding another
option. I intend to upgrade away from this set of ordered steppers sometime later, they were cheap enough to
justify the compromise for now.

Keling nema23 dual shaft hybrid stepper specs:
p/n: KL23H276-30-8B
282oz/in rated holding torque
1/4" / 6.35mm shaft with a flat    (idk if the flat will slip in the Taig couplers, but we will find out/make it work...)
4.2A
0.46ohm
~2.2mH (this is what they were claiming at least)
8wire bipolar parallel, no connector, just leads with a grommet... Back case doesnt look encoder friendly either...

So ya, not my first choice of motor, but I can probably work around these things to get this machine operational.

np on all the info, I will utilize the data I can gather and rationalize my final choices with consideration to available resources.
 

ATX psu progress...

Sat down and split up / tested all the wires on this old unit today, overall it went rather well. After I got through
the sorting and color code identification for this particular example, I regrouped the wiring to better suit my
current application. (various I/O supply for my Mesa cards and auxiliary electronics)

The longest available wiring on this unit had been for the various molex connectors that ran to dvd drives and
the like. I cut the chain of molex connectors off the end of this group of wires and then also did the same for
the adjacent wire group that had ran to the hard-drives in the original application. While either of these groups
were not terribly long, they should be adequate to reach a couple of common terminal blocks that I can branch
out from in my wiring enclosure, and from there supply the Mesa cards. While I could have tried to implement several
direct wiring paths by utilizing more leads from the main wiring group that had the 24pin motherboard connector,
i believe the terminal block approach (using the longer wiring groups) will ultimately be more organized and allow
easier service in the future.

Once I had cut the groups of connectors off, reordering and bundling similar wire groups was just a function of time.
Any extra wiring I didn't plan to use I moved out of the way and just capped off any loose ends in those groups.
On the 24pin connector there was a -12v (Blue) , two -5v (White), and also a small (Brown)
wire that had shared a pin with a larger 3.3v (Orange) wire (I just left that pair connected for now as I wasn't too sure
of the Brown wires function...) these were the outliers that I didn't have much interest in. Most of the rest of the
main 24pin connector was an assortment of Red or Orange positive wires, and Black common wires. However this
left just...
 

... THE 2 MOST IMPORTANT wires on the 24pin connector: The Gray and the Green, these two get connected together with a switch to power up the power supply.

Remember, the color coding i have listed is just what I happened to find on this unit, others will vary. Of several other similar power supplies i have, the GRAY and GREEN are the same however.


General wire color coding and Voltage on this old dell ATX psu:
Gray ---> Green (these two turn the unit on)
Black: Common
Orange: 3.3V
Red: 5V
Yellow: 12V  (Not in the main 24pin connector on this unit, used in some of the other connectors however)

Blue: -12V (low Amp rating)
White: -5V (low Amp rating)
Purple: 5v (low Amp rating, this one is special, it functions different than others when on standby I believe)

Brown: ? idk on this one, left it with the Orange 3.3V it was paired with originally.
 

A meanwell MDR-60-24 power supply would be much more compact than the PC one. You may need to buy a similar 5 volt supply
Maybe a MDR-20-5

If you want a high quality stepper motor look at moon's industries. They are way above the average stepper online standard. They have stock or an office in the US.

I have paired these with LAM drivers. The Lam boost function is driven by a custom component that monitors the velocity of the drive. if it is constant (eg not accellerating), it drops the current to a defined value say 30-50% of the actual. This allows the drive to cool when its not working. Some drives we profiled only used 12% of rated power once the motor was at speed.

Good points Rod. The stepper options listed on moon's webpage did include several useful models.

The form factor on the DIN mounted Meanwell supplies are certainly more efficient, and I hadn't realized how
affordable the MDR series was...

I'll go ahead and order a MDR-20-5 on monday from Mouser, they have them listed for about $25us, so
at that minimal cost it will be easy to isolate my logic level power from any other general relays and such.
Should be money well spent, and drop some btu's inside that hardware enclosure.

My ATX psu will still be useful for testing/running other components but that MDR is a good fit with the Mesa cards.

*EDIT: I did some more research and answered several of the questions I had when I made this post, took out the
less relevant text to keep this post more concise and updated.

Long weekend of Linux Limbo wrapping my head around more bash commands and then reading thru the
Mesa Manuals several times more...



Stepper drivers and the other Power supplies have been ordered, I ended up going with;

Gecko G214 stepper drivers

Mean Well MSP-600-48, SDR-120-24, and MDR-60-5 power supplies

The 24v and 5v supplies will be specifically for the Mesa cards.


With regard to the Mesa hardware, I have a 7i92TF, 7i85S rev.B, and a 7i84 rev.A, all
of which have been mounted down in that order with aluminum risers to ground out to
the frame. I do not intend to connect the 5v common or 24v common to that frame ground.

(My current focus is now on the Mesa hardware install, but I am not powering any of it
until I have verified the following information...)


Mesa hardware configuration tree for my system as I currently understand it:

7i92TF:
    J1 <-- RJ45 Jack on Computer Motherboard
    
    W1 - UP, W2 - UP (Is this correct for DB25 connection to 7i85S ? )
    W3-DOWN, W4-DOWN (Pins 22-25 grounded on P1,P2)(Local 5v from P4)
    W5-DOWN, W6-DOWN (Default 192.168.1.121 address, may need to set W6-UP
              to ping 10.10.10.10 from EEPROM ? )
    
    P1 --> not currently used (may expand I/O later)
    P2 --> 7i85S (J1)
    
7i85S rev.B:
    W3-DOWN (J1 Pins 22-25 grounded)(Local 5V from P4)
    
    TB3 --> Differential Encoders 0,1,2(not connected yet)
    TB2 --> Differential Encoder 3, Stepper Drivers 0,1(not connected)
    TB1 --> Stepper Drivers 2,3(not connected)
    
    (TB1 Pins 17-24 --> 7i84 J1)(Smart Serial/RS422 ? )

7i84 rev. A:
    W1-LEFT (VIN connected to VFIELDB)(Can this introduce interference to internal logic?)        

    TB1 <-- (VFIELDA) 5V PSU, (VIN/VFIELDB) 24V PSU
                (should VIN have a dedicated psu?, all TB1 grounds are common?)
    
    TB2 --> 5V I/O (VFIELDA PSU)
    TB3 --> 24V I/O(VFIELDB PSU)
        


Additional questions/notes:

Should I do some form of power-on testing of the psu's for the Mesa cards to verify
there is not an excessive spike at power-up, or should the Capacitors in those
units take care of that?

What sort of input resistors/capacitors/diodes/fuses may be needed to keep these cards safe
with common I/O connections?

There will be various typical inputs/outputs to setup after these Mesa cards are connected, and
I do intend to source some form of differential encoders for a closed-loop feedback system, but
these items shouldn't have too much impact on the initial config. files for the Mesa cards?

When I do finally power up the Mesa cards, what should I watch for from the Led outputs?

Should this Mesa hardware combination be configured/powered on together or sequentially?




Once I have the information above verified, my focus will shift to handling Mesaflash, card
drivers, and Hostmot2.