Hobby lathe with AC servos

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Stephan
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Re: Hobby lathe with AC servos

Post by Stephan »

Hello Uwe,
Something has opened up again where I can't get any further, so I would ask you again for help.
I'm still totally hooked on the centroid for the lathe.
In the meantime, I have also successfully tested thread cutting with G76 and thread cutting with a tap works really well. (It's fun to see that HIHI)

Anyway, I started changing my Maximat to a milling machine yesterday.
A few problems have arisen in the process. Most were already addressed here in the forum, so I was able to fix everything relatively easily. Only one is left.

When turning I have a function that I think is absolutely cool with the Centroid. This feature is one of the main reasons, besides cycles, why everyone should have centroids.

It's about:
If I turn and I make the mistake of feeding too much, the spindle motor either stops immediately or it first slows down and then stops. In every other software I've had so far, this means destroying the indexable insert. Since I've had Centroid, the software just freezes and I can restart. Of course I think that's great...

This means, of course, that the encoder controls or readjusts the feed.

Then yesterday I set everything to the best of my conscience or according to the videos from Franco and Martiesgarage. I thought.
Then I eliminated all other errors and your videos were very good for eliminating errors.
The only thing that has remained is that the machine does not stop when milling or readjusts if I feed too much.
Do you know what I did wrong?
Thank you greetings Stephan

Hallo Uwe,
Es hat sich mal wieder etwas aufgetan wo Ich nicht weiter komme deshalb würde Ich dich nochmal um Hilfe bitten.
Ich bin immer noch total begeistert vom Centroid für die Drehmaschine.
Mittlerweile habe Ich auch das Gewinde schneiden mit G76 erfolgreich getestet und auch das Gewinde schneiden mit Gewindeschneider geht richtig gut.(Ein Spaß das zu sehen HIHI)



Jedenfalls habe Ich gestern mal angefangen meine Maximat umzustellen auf Fräsmaschine.
Dabei sind so ein paar Probleme aufgetaucht. Die meisten waren hier im Forum schon angesprochen daher konnte Ich alles relativ einfach beheben. Nur eins ist geblieben.

Beim drehen hab Ich eine Funktion die Ich absolut cool finde beim Centroid. Diese Funktion ist einer der Hauptgründe neben den Zyklen warum jeder Centroid haben sollte.

Es geht darum:
Wenn Ich drehe und Ich mache den Fehler das Ich zu viel zustelle dann bleibt der Spindelmotor entweder sofort stehen oder er wird erst langsamer und bleibt dann stehen. In jeder anderen Software wo Ich bisher hatte hat sowas das zerstören der Wendeplatte bedeutet. Seit dem Ich Centroid habe bleibt die Software einfach stehen und Ich kann neu starten. Das finde Ich natürlich super....

Das heißt natürlich das der Encoder den Vorschub steuert bzw nachregelt.

Ich habe dann gestern alles nach bestem Gewissen bzw nach den Videos vom Franco und Martiesgarage eingestellt. Dachte Ich.
Dann habe Ich alle weiteren Fehler beseitigt auch deine Videos waren sehr gut zum Fehler beseitigen.
Das einzigste was geblieben ist ist das beim fräsen die Maschine nicht stehen bleibt bzw nachregelt wenn Ich zu viel zustelle.
Weißt du was Ich falsch gemacht habe?
Danke dir Gruß Stephan
suntravel
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Re: Hobby lathe with AC servos

Post by suntravel »

For milling there is no encoder feedback. To stop the CNC you must use the ALM function of the axis drives and the spindle. So if one of them stalls from overload Acorn stops with Spindle fault or Drive nok. The original setting for ALM stop is 1000ms, I reduce this to 100 on my machines.

Uwe
Spartan117
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Re: Hobby lathe with AC servos

Post by Spartan117 »

suntravel wrote: Mon May 30, 2022 3:19 am For milling there is no encoder feedback. To stop the CNC you must use the ALM function of the axis drives and the spindle. So if one of them stalls from overload Acorn stops with Spindle fault or Drive nok. The original setting for ALM stop is 1000ms, I reduce this to 100 on my machines.

Uwe
Thank you for that addition regarding the time.
I wired up my stepper drivers today and pulled the ALM-connector on the drivers to test the fault-function. And i wondered, why it reacted that slow^^

Does anyone know if there is a reason, why it is set that slow by default?
What are the drawbacks of a shorter reaction-time here?
suntravel
Posts: 1967
Joined: Thu Sep 23, 2021 3:49 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 6433DB0446C1-08115074
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
Location: Germany

Re: Hobby lathe with AC servos

Post by suntravel »

Spartan117 wrote: Mon Jun 06, 2022 6:38 pm
suntravel wrote: Mon May 30, 2022 3:19 am For milling there is no encoder feedback. To stop the CNC you must use the ALM function of the axis drives and the spindle. So if one of them stalls from overload Acorn stops with Spindle fault or Drive nok. The original setting for ALM stop is 1000ms, I reduce this to 100 on my machines.

Uwe
Thank you for that addition regarding the time.
I wired up my stepper drivers today and pulled the ALM-connector on the drivers to test the fault-function. And i wondered, why it reacted that slow^^

Does anyone know if there is a reason, why it is set that slow by default?
What are the drawbacks of a shorter reaction-time here?
You should also take a look how fast ALM is triggered on the drivers for spindle and Axis....
I have some drives which put out ALM after 4000 pulse position following error by default, quite useless for me :D

Uwe
Spartan117
Posts: 101
Joined: Mon Apr 11, 2022 3:37 pm
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Re: Hobby lathe with AC servos

Post by Spartan117 »

I already noticed that value can be changed, but i have to admit, i have to clue what could or would be right here...?

The stepper-(online-)software doesn't offer a useable scope where i could have a look at "normal" deviations to determine good values.
I will have to test that, lowering the value from time to time and see if it will still work
suntravel
Posts: 1967
Joined: Thu Sep 23, 2021 3:49 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 6433DB0446C1-08115074
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
Location: Germany

Re: Hobby lathe with AC servos

Post by suntravel »

For CL-T drives I use the leadshine Pro tuner to figure out the max. position following error during acceleration. Something between 40 and 400 should work, depends on the complete setup of the machine. With JMC servo drives it is a little more complex....

Uwe
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