All new electronics

[LucDav]

I have recently purchased a NovaTurn lathe. Unfortunately missing all of the electronics. I have a Parker 508-01-20-00 DC drive, and stepper controllers. I am looking at using GRBL control and GRBLGRU as the main software. I am struggling with getting enough info on how the toolpost works. Any help would be greatly appreciated.

I am very much mechanically biased but have a friend who tends to help me with the more complex electronics and programming. If anyone has any advice it would be much appreciated also if the Parker drive will be acceptable as a stand in for a sprint 1200

thanks

Luc

[TDIPower]

if you have a good dig through the novaturn and starurn posts you will find quite a bit on the ATC, from stripping them down to the electronics.

Pete

[MadeForThat]

Definitely a lot to be said about the ATC, I am currently trying to diagnose a problem with mine blowing fuses and plan to make a circuit diagram. Inside the tool post turret there is a DC motor, and 3 sensors. The 3 sensors give a gray code feed of the current toolpost position. This 3 digit code is available in the novaturn electrical diagrams. The motor is either turning forward to index the turret, or it is reversing to lock the turret, it is always on. I don't know the voltages, but as I understand it uses full power to index the turret, and half power to reverse and lock. (24v and 12v I believe) I haven't looked closely at how the toolpost power supply is told which position to go to, but I suspect it requires the same 3 digit gray. ( in other words, if you can replicate the toolpost power supply, you need 3 outputs from your GRBL device to command it.)

As for the parker drive, I would look to see that the motor will get all the power it needs at max draw.. I don't remember if the motor is 180vdc or 90vdc, but your drive only outputs 180 if powered by 220. So if you had planned to make this machine run on 110v, and the motor is 180vdc, then you would need a different drive. Where are you from/what voltage comes out of the wall?

[MadeForThat]

Also the sprint drive is available in the classifieds, so that way you know it works
https://www.denfordata.com/bb/viewtopic.php?f=13&t=5863

[LucDav]

I have started making some progress with the lathe finally, i have been a little absent up until recently so seem to have missed that sprint drive.

I will be running the machine on UK mains so the 180V wont be an issue. I seem to have hit a snag with the encoder feedback on the machine from the spindle. Both the Sprint 1200 and the Parker 508 seem to suggest they require a tacho-generator feedback not an encoder.

My thoughts with the tool post are potentially to have GRBL treat it as an A axis for the control, it appears GRBL and tool changing are not yet working, but the correct macro or post processor could convert an M6 code to a piece of G-Code that activates the tool-changer.

I have been writing a separate piece of software for an Arduino Nano which detects and controls the tool post as yet im unsure what to communicate with it but i feel something could be achieved. I currently have control of the motor with speed and power through PWM and i can identify the tool position from the Optical sensors. I hope to have these working together this week.

Any more help and ideas are always appreciated.

[MadeForThat]

Sounds like things are progressing nicely! I suspect that tool changes are not handled by GRBL simply because of the huge number of different ways that machines have changed tools over the years. I dont know what is happening behind the scenes, but I cant imagine it would be too crazy hard to add a couple lines to say essentially :

toolChange(TCP){ //function called by main program, where the desired ToolChangePosition is passed to variable "TCP")
Switch (TCP){ //Check TCP and take the switch path that corresponds to desired TCP
Case T01:
do{
digitalWrite(1,High); //turn on motor "forward" to index turret
}while (digitalRead(3,Low)&&digitalRead(4,High)&&digitalRead(5,Low); //run motor until your 3 optical sensor pins return correct "gray code"
digitalWrite(1,Low); //turn motor off/reverse to lock
break;
Case T02:
same as t01, but different sensor pin code
Case T03:
same as t01, but different sensor pin code
Case T04:
same as t01, but different sensor pin code
Case T05:
same as t01, but different sensor pin code
................

Again I don't know how the GRBL program is handling lines, but I suspect M codes start their own function that handles whatever IO, so what I sketched above would simply take the tool change variable, and then turn the motor until the sensors matched that specific position. Not sure what level of programming you have experienced, but what I wrote above will take a lot of debugging and syntax hahahaha! If you would like any help feel free to ask, I have pretty minimal experience on arduino, but I had made a 3d printer with one a few years back, and dealt with a ton of BS in setting that up lmao

[MadeForThat]

Also if you haven't already, hit the "subscribe topic" button below under the topic tools drop down at the bottom of the thread. The check box is inverted, but if it is unchecked, you will receive notifications to your email. Makes it easier to snag those sprint drive deals

[LucDav]

My coding knowledge is terrible at best, i have a little help from someone at work with a far better understanding than me so im using this as a bit of a learning opportunity. (with enormous amounts of help needed )

thanks, any ideas of what the code needs to look like are much appreciated. I hope to have something toolchanger like working on my desk by the end of the week, i suspect the spindle feedback may now be a bigger issue than the toolchanger thanks to the encoder instead of a tachogenerator.

I do have 4 spare pins on the GRBL controller im using that are as of yet unused, i may be able to use them to send out a grey code for the tooling, unfortunately that is currently very far above my coding abilities.

I shall continue the slog

[Iron-Man]

I have started making some progress with the lathe finally, i have been a little absent up until recently so seem to have missed that sprint drive.

I will be running the machine on UK mains so the 180V wont be an issue. I seem to have hit a snag with the encoder feedback on the machine from the spindle. Both the Sprint 1200 and the Parker 508 seem to suggest they require a tacho-generator feedback not an encoder.

My thoughts with the tool post are potentially to have GRBL treat it as an A axis for the control, it appears GRBL and tool changing are not yet working, but the correct macro or post processor could convert an M6 code to a piece of G-Code that activates the tool-changer.

I have been writing a separate piece of software for an Arduino Nano which detects and controls the tool post as yet im unsure what to communicate with it but i feel something could be achieved. I currently have control of the motor with speed and power through PWM and i can identify the tool position from the Optical sensors. I hope to have these working together this week.

Any more help and ideas are always appreciated.

Hello LucDav

The encoder is simple. You can see my work at: https://www.denfordata.com/bb/viewtopic.php?f=42&t=4789

My situation was the same. I had a NovaTurn without electronics. I designed a new circuit board, repaired the spindle encoder,added Yaskawa AC Servos, PathPilot and new motor mounts. My lathe is fully closed loop, +-10V AC servos. The spindle motor is driven by a AMC DC servo drive. I finally obtained a 'BACK" Turret that I am in the process of modifying for the NovaTurn.
I may make these upgrades in the future: AC Spindle servo( 1.5 to 2.0KW) for C axis, 4th axis to make small dental parts.
In addition, I finally have most of the parts to start my Triac Mod.


Iron-Man

[MadeForThat]

How are you moving your tool post motor? If you have it connected so that you can control it with 1 pin, everything should be perfect. (ie, turning on arduino pin moves it forward, and it moves backward when not activated) Then the other 3 remaining pins can be inputs for the 3 optical sensors inside the turret. I would recommend researching into how to modify the GRBL firmware to adjust how it handles the M codes. I suspect it wont be that crazy complicated, but then again nothing is ever perfectly smooth when it comes to custom work haha!

[MadeForThat]

Iron Man-
What is the control board on that beast? How are you planning to control your toolpost?

[LucDav]

Iron-Man - thanks ill have a look through it to see what you did. Is it a tachogenerator feedback that gives the spindle rpm control in your setup? i assume thats what ill be using to ensure threading happens correctly. Im also half way through a mill conversion, though im on a starmill not a triac unfortunately, but brushless servos on X & Y and a spindle motor up to 1.8kW so a bit of an improvement. Lathe first though.

MadeForThat - i have a separate arduino nano running just the toolpost. That will have my simple program which hopefully will react to GRBL inputs then once its program is completed it will activate the resume button on the lathe.. i hope

[Iron-Man]

Iron Man-
What is the control board on that beast? How are you planning to control your toolpost?

I will be using PathPilot which is basically LinuxCNC using the HAL interface. A LPC1768 or PIC Micro will decode the PWM signals from PathPilot.
I will not be using the Emco Turret.

Configuration:
Denford NovaTurn
IBOB2, AMD GizmoSphere 1
Yaskawa SGDA 100W Servos, +-10V in Torque Mode
Control PathPilot (Loop closed within PathPilot)
MESA 7i77, 6i25

Hope this helps,

Iron-Man

[Iron-Man]

Iron-Man - thanks ill have a look through it to see what you did. Is it a tachogenerator feedback that gives the spindle rpm control in your setup? i assume thats what ill be using to ensure threading happens correctly. Im also half way through a mill conversion, though im on a starmill not a triac unfortunately, but brushless servos on X & Y and a spindle motor up to 1.8kW so a bit of an improvement. Lathe first though.

MadeForThat - i have a separate arduino nano running just the toolpost. That will have my simple program which hopefully will react to GRBL inputs then once its program is completed it will activate the resume button on the lathe.. i hope

Check out LinuxCNC there are several configurations to manage the Tool Post. There is no tach-generator. The spindle encoder feeds directly to the MESA 7i77. PathPilot which is basically LinuxCNC uses the HAL (Hardware Abstract Layer) interface to add PINS, Connections etc.
Check this example on LinuxCNC: https://forum.linuxcnc.org/49-basic-con ... otor-based

My Lathe : https://www.youtube.com/watch?v=FM0EkKyQHqM
There are a few more videos on YouTube.
I have posted my work on the Denford Forum, LinuxCNC and CNCZONE.

Iron-Man

[LucDav]

I was looking at using LINUXCNC but the mesa cards were a bit out of my price range. Also in all reality i wanted to use path pilot but couldnt see how to get it. did you get it direct off tormach?

[MadeForThat]

I definitely think the novaturn is a good base to make a very capable desktop machine, I have held some beautiful surface finishes on monel! Cant say I know how long an insert will last taking the cuts that I was, but the machine was as rigid as I could ever hope. Fortunately the inserts I use are dirt cheap, unfortunately monel is not! Perhaps some day I will go down the retrofit path with this machine, considering this is still so capable after 20 years makes me think it will still probably be worth the effort in a few more Having the conversational programming would be amazing for the odds and ends things I generally tend to make. Just typing that out makes me wonder if a stand-alone conversational programming tool is available... Gotta do some looking around!
Also I would definitely recommend one of these cheap kits for tools:

https://www.ebay.com/itm/4pcs-12mm-Lath ... Swjt1byDeM

as well as:

https://www.ebay.com/itm/1pc-MGEHR1212- ... SwygFeguHs

The same cheap inserts and all the tools are on the same height, so once your tool post height is adjusted, you shouldn't have to do much or any shimming for individual tools. If you are using this machine for making money or rely on it to produce, I would recommend buying some more valuable tooling, but at the minimum this is fine for assorted jobs.

[Iron-Man]

I was looking at using LINUXCNC but the mesa cards were a bit out of my price range. Also in all reality i wanted to use path pilot but couldnt see how to get it. did you get it direct off tormach?

I purchased my initial copy and upgrade 2.0, directly from Tormach.
There is no support for non-Tormach machines.

Iron-Man