Kitamura Mycenter Zero - DELTA Ethercat Retrofit

[spikee]

Small update. The fanuc Z-axis has been removed. Now I'm waiting on a new coupler for the delta B3 motor -> kitamura Z axis ballscrew.
It differed from the ones on X and Y.

In the meantime I have bought a Celtic 14 lathe. so I need to re-organize the garage a bit so it has a place to part

[spikee]

Another big step completed. Got the z-axis servo mounted (finally).
Going to test it soon...

[spikee]

Motor is mounted. Aoon more to follow. Posted an update on the first page

[spikee]

After Christmas update!
Finally had some days where i couod make quick progess.
Everything is hooked up and is working individually.
Now i just need to combine it together.

I hooked up the 0.5um scales to the x-axis and now it is really perfect, all the time. At this scale one needs an interferometer to be able to messure the error. Hooking it up and getting it working was also suoer easy. In the hickory wizard, basically enable it, fill in two values... and it works!

I deceded to remove the delta b3 servo as the caroussel motor. The geneva mechanism on there is not accurate enough to be able to just run the position off the absolute encoder. So in the end it was simpler and much more cost effective to just throw a 20$ amazon dc gear motor on it. And voila an hour later it is turning and counting:
https://youtube.com/shorts/QGfIW7rwljk? ... yQ3Kwwqh0y

Tomorrow I will setup the b3 ethercat servo for the swingarm and at that point i should be able to make it do a fully automatic toolchange!

On thing i kinda noticed using centroid... is that it is kinda hard to crash. And you do it is super easy to recover from. Very happy about that. The software setup side has also been very simple so far.

Oh and before i forget, i also have the wireless 3d probe from robotdigg working and hooked up. I juat have to modify the centroid plc as it really wants a probedetect signal, but with a wireless probe you dont need that. I just need to make it so that when the probe tool is loaded , dont allow m3/m4.

[suntravel]

Good news.

yes scale setup with Centroid is super easy. Do you use them for home also?

Uwe

[Leo Voisine]

WOW so cool.

I remember that Mycenter from my days working at Winchester in the early 90's I saw it at the Chicago tool show and I wanted to buy it, but we ended up with a used Matsuura Tiger instead. The tiger had the Fanuc 0M controller. I was just learning Macro B at the time and the upgrade was $2000 in the early 90's

That Mycenter is a rock solid machine.

What a super cool project.

[spikee]

Good news.

yes scale setup with Centroid is super easy. Do you use them for home also?

Uwe

I have absolute encoders. So now it is just based on that but i guess you can also just go to the closes index on the scale from absolute encoder home and use that as your zero. I guess that would be more accurate. Somthing I'll look into when I mount my Z and Y scales. Those are a bit of a pain to mount

Do you happen to have M26 code example where you home towards the index of the scale?

WOW so cool.

I remember that Mycenter from my days working at Winchester in the early 90's I saw it at the Chicago tool show and I wanted to buy it, but we ended up with a used Matsuura Tiger instead. The tiger had the Fanuc 0M controller. I was just learning Macro B at the time and the upgrade was $2000 in the early 90's

That Mycenter is a rock solid machine.

What a super cool project.

Thanks man, so far I only did a little bit of cnc on the old fanuc controller. But the cnc'ing that i did was hardmilling a steel vice ( it was too long ) and it took it like a champ. I just had to slow down the DOC and feed as my endmill just could not handle it. The machine did not care.

I did a little bit of "manual" nc on the centroid setup so far, and aluminium just does not pose any challenge at all. The little steel i did with it, it did not care either.

[spikee]

So this morning I had a go at getting a tool switch done (manually) i.e. by jogging the axis, and it worked!
Well it worked in a sense that all the sensors do stuff and the motor turns haha.
I blew up my 3d printed shaft adapter cause I did not correctly manually drive the tool unclamp sensor.

There is one benefit of using a 3d printed shaft adapter as it works as a failsafe. But I think it would be better if I just lowered the max torque of the servo and use that as an error. I now put a 1:40 gearbox on it, but i think that is a bit too much. As my train of thought is that if I use a steel shaft adapter, that it is too easy to put 2-4nm * 40 gear reduction on the mechanism in case of a crash. So fat it seems easy enough to move it by hand. I have another 1:10 low backlash gearbox laying around. I think that would be a better match.

here is a bit of a snipbit of the ATC mechanism on the cnc:


And the mechanism is even simpler than I imagined. It just has a proximty sensor as " unclamp command LS" , that is your signal regarding when to clamp-unclamp the tool.

For reference I have added my current CNC12 report. I'm planning to first get the ATC logic working now. And finish the rest from there.
Additionally an unlisted youtube video regarding a quick physical overview of how the ATC mechanism works:

[spikee]

I had a try figuring out the plc code and i must say i found some things quite confusing. One example is lines like
"M101 /70320 ;Wait for ArmAtSpindleNewTool_M" when i look in the PLC code I can't find a reference of this.

So I did a DIY attempt and I must say that is kinda difficult when limited to G-code. I'm probably re-inventing the wheel here
and making up some DIY variables:

Code: Select all

 #9500 = current caroussel tool position - this is custom made by spikee :)
; #9501 = total number of tool positions on the carouse (mine is 16)

Code: Select all

;==============================================================================
; Swingarm Tool Change Program Starts
;==============================================================================
N700
#101 = <SV_POSITIONING_MODE>      ;Save Positioning Mode
M109 /1/2                         ;Disable Overrides
M5                                ;Disable Spindle
M9                                ;Disable Coolant
;M107                              ;Send PLC Tool Number --> no idea what this does so i commented it lol

;#4120 = requested T(ool) number in G-code; I.e. M6 T6 ; this value = 6
;#4203 = tool in spindle
IF #4120 = 4203 THEN GOTO 900; ; if requested tool is the same as the current tool... than terminate
IF #4120 != #9500 THEN GOTO N701 ELSE GOTO N702;if requested tool != carroussel position ; have to turn the caroussel

;==============================================================================
; Rotate caroussel to correct position
;==============================================================================
N701 
;#4120 = requested T(ool) number in G-code; I.e. M6 T6 ; this value = 6
;#9500 = current caroussel tool position
#9501 = total number of tool positions on the carousel

#100 = [[#4120 - #9500] MOD #9501]  (Calculate forward steps)
IF [#100 LT 0] THEN #100 = [#100 + #9501]

#101 = [#9501 - #100]         (Calculate backward steps)

IF [#100 LE #101] THEN     ;(Check if forward is closer or equal)
  WHILE [#9500 NE #4120] DO 1 ;while current caroussel tool pos != requested tool
    M50 ;Carousel Index +
  END 1
ELSE                       ;(Backward is closer)
  WHILE [#9500 NE #4120] DO 1 ;while current caroussel tool pos != requested tool
    M50 ;Carousel Index - 
  END 1
ENDIF
GOTO 701

What I find pretty difficult here is that there are M-codes to move the caroussel left or right (M50 , M51) . but it is for example not clear to me if this also has a target variable (i.e. pos 10 out of 16) or if it even does anything on the background relating to the toolcounter. I was not able to find a toolcounter variable that is auto updated. So the g-code above has some assumptions that it does

In the end i think this does not work. As at each stage you want timers and timeouts to make sure nothing went wrong. This is something that the default centroid caroussel already supports. After messing about for a bit, lets just say that this was to broaden my macro knowledge.

[spikee]

So i spent some time on drawing my machine in 3d. The major items are based on printouts that I found online of a (sparkchanger) configuration of this machine. Some small items I have edited with physical measurements on the machine. I will use this is a base to design my enclosure on.
From something like this:


To something like this:


Additionally i modified the swissi post processor so it can now do machine simulation: https://centroidcncforum.com/viewtopic. ... 100#p95100

FYI: There is something wonky in the machine kinematic file so the y axis is offsetted vs the table. Need to fix that at some point.

You can find the 3d model here:
https://grabcad.com/library/kitamura-mycenter-zero-1