Electronic Lead Screw Project

[dcostaParticipant @dcosta]

Hi Phil,
Hi Limpet,

I'm sorry, it was a false alarm. I rushed in alarm without having tested what was within my reach and knowing how.
I did the computer reset and, in the end, the two serial ports were present and it was once again possible via the "Code Composer Studio" and again flash the program for the TI LaunchXL F280049C.

I also discovered that there was a broken cable that connects the LED & Key Display to the interface. Nasty coincidence!
I soldered it again and, finally, everything is working fine.

Tomorrow I will test the connection again.

Best Regards
Dias Costa

[Phil GrantParticipant @philgrant54580]

Posted by dcosta on 16/02/2020 00:31:26:

Hi Phil,
Hi Limpet,

I'm sorry, it was a false alarm. I rushed in alarm without having tested what was within my reach and knowing how.
I did the computer reset and, in the end, the two serial ports were present and it was once again possible via the "Code Composer Studio" and again flash the program for the TI LaunchXL F280049C.

I also discovered that there was a broken cable that connects the LED & Key Display to the interface. Nasty coincidence!
I soldered it again and, finally, everything is working fine.

Tomorrow I will test the connection again.

Best Regards
Dias Costa

Phew! that's good news, glad you sorted it out.

[dcostaParticipant @dcosta]

Hi Phil and others,

I finally managed to make an assembly of the system that works. And this time I didn't "burn" any components.
I used an 8-wire network cable to communicate between the control box and the interface board. I also used a network cable between the interface board and the DM542 driver.
As I said before, I used the DM542 driver and the motor spins when I move the rotary encoder.
I am currently using version 1.0.03 of the software.
During tests the stepper motor is stopped most of the time and, perhaps because of that, it warmed up a lot and quickly, and I tried to select 2.84A peak in the driver. Now it seems to heat up less and less quickly.

Questions:
1 – Should I follow any specific sequence when turning the TI LaunchXL F280049C and DM542 driver on and off? Is there any risk of turning on / off one before the other?
2 – The power supply for the driver / motor delivers 24V and goes up to 6.5A of current and the motor supports up to 2.5A. Should I be careful about the relationship between the power supply and the driver that only supports up to 4.5A even though it has over-voltage and over-current protections?
Any recommendations, please?

best regards
Dias Costa

[Phil GrantParticipant @philgrant54580]

Good news Dias,

As they are isolated with opto isolators they are electrically independant of each other having said that I would always power up the micro-controller side first so if there was any spurious signals prior to being in a steady state the should drive the stepper motor, not that there should be any spurious signals!

I'm my driver there is a jumper to set the stationary current to less than the drive current, does yours have one?

Phil

[dcostaParticipant @dcosta]

Hi Phil,

Thanks for your help.
The DM542 driver also has the option to automatically limit the current when the stepper motor is not running.
But to activate this option, it is necessary to switch on / switch off / switch on the SW4 and the effect on lowering the heat of stepper motor is not noticeable.
About an hour after being turned on it is unbearably hot!
I still don't know (I haven't researched enough…) if there will be any aspect of the driver configuration that can be changed to lower the engine temperature.

best regards
Dias Costa

[Phil GrantParticipant @philgrant54580]

Hi Dias,

I'm at a loss really, on my driver the SW4 halves the current in idle mode, it only needs to be switched once and left, this is from the instruction manual

"Standstill Current Setting SW4 is used for this purpose. OFF meaning that the standstill current is set to be half of the selected dynamic current, and ON meaning that standstill current is set to be the same as the selected dynamic current. The current automatically reduced to 50% of the selected dynamic current 0.4 second after the last pulse."

Maybe you need to get the DM542T

Phil

[Roger ClarkParticipant @rogerclark]

Hi Dias,

The off on off within 1 second is for auto configuration and is done with motor connected, that tests the motor to make optimum setting, after that sw4 should be set to off for half current to work.

Regards

Roger

[Johnboy25Participant @johnboy25]

Has any else made the mistake I made with led & key module? I measured the pitch of the led’s & tactile switches a couple of times and convinced myself they were on an 8 mm pitch! – Wrong! The switch are on the ‘industry’ standard grid of 0.1” (2.54mm) so the pitch for the switches & led’s came out to be 0.3” I only noticed this after I had milled the box lid in what I thought was quite an expensive little box! Should have know better – still ‘can’t win ‘em all’!

I’ve added the software mod from JonWoellhaf on github for the push button fast scroll mod – works great. A useful hack which I think improves functionality. The original hardware worked first time out of the ‘box’ after head some scratching with the TI ccs software. 👍Now to procure synchro belts & pulley’s to fit onto my metric Boxford 4.1/2” lathe. This is a great project it’s kept my attention from the first few YouTube videos. Well done James at Clough42!

John

Edited By Johnboy25 on 25/02/2020 14:32:52

Edited By Johnboy25 on 25/02/2020 14:35:59

[dcostaParticipant @dcosta]

Hi Phil and others,

Thank you for your help.
Maybe the problem is not with the DM542 driver …
The stepper motor I have been using was purchased at ArcEuroTrade several years ago and I must have missed the specifications as I cannot find them.
It was used, for a short time, until recently in a test application with the TB6560 driver and worked well for hours without overheating as much as it does now. The difference is that he was not idle that long.
It has eight wires and the connections that existed for the test and I kept for the DM542 driver, now, are the following:
YELLOW and BLUE pair connected to each other, PURPLE and BROWN pair connected to each other;
I connected the remaining four wires to the driver as follows:
the WHITE wire to A + and the GREEN wire to A-
the RED wire to B * and the BLACK wire to B-
The power supply supports 24V, 4.5A and is connected like this:
positive to the VCC pin and negative to the GND pin.
From what I remember the configuration of the connections is BIPOLAR.
Would another configuration of the connections from the stepper motor to the diver be better?

The only information I know about the stepper motor comes from the ArcEuroTrade invoice:
Item Code: 160-010-00400
Description: 220Ncm – 10mm Shaft – Hybrid Stepper Motor
More: it has a double axis, 115mm in length.
I would be grateful if any of the participants who have documentation for this stepper motor could share it with me.

The DM542 driver also has the functionality to reduce the current when the motor is stopped and also runs automatically, but only after being manually activated with the on / off / on maneuver.

best regards
Dias Costa

[dcostaParticipant @dcosta]

Hi Roger,

Thank you for your help.
Yes, this is writen in the documentation. But, activating the option, I didn't feel that the temperature of the stepper motor would rise less.

Are you, by any chance, using the same DM542 driver?
Can you please tell me which stepper motor you are using?

See if you can please the previous message addressed to Phil.

best regards
Dias Costa

[Phil GrantParticipant @philgrant54580]

Dias,

I'm at work at the moment so I can't check but what I can say is that with eight wires you have the opportunity to wire the four coils in series or parallel, maybe you've got them wired in parallel which will halve the resistance and double the current?

Use a multimeter to identify the coils and their connections and wire them in series by checking the resistance maybe this is your issue….. or not.

I just realised you've got them wired in series but just check the resistances to make sure the connections are correct.

Phil

Edited By Phil Grant on 25/02/2020 16:35:42

[Phil GrantParticipant @philgrant54580]

Dias,

See if this helps

how to identify coils

[dcostaParticipant @dcosta]

Hi Phil and others,

Thank you for your help.
With your encouragement, and based on the connections from another small stepper motor in another project, and using the multimeter to test, I tried a new connection that I think is called BIPOLAR PARALLEL.
So,
I connected the RED wire and the BLUE wire,
I connected the YELLOW wire and the BLACK wire – constituting winding A
I connected the WHITE wire and the BROWN wire
I connected the PURPURA wire and the GREEN wire – constituting the B winding.
NOTE: in the meantime I found an ArcEuroTrade file (HYBRID STEPPING MOTOR MODEL 160-010-00400) which also describes these BIPOLAR PARALLEL connections as possible.

Now, the stepper motor has been connected for approximately three hours and has heated up to, perhaps, 45º (the hand supports the temperature well) and, as far as I can see, it works as well as before.
Thanks to the help received, I am finally satisfied and will be able to move forward on the project.

best regards
Dias Costa

[Phil GrantParticipant @philgrant54580]

Dias,

That's great news, I suspected it would be the wiring of the coils.

Phil

[dcostaParticipant @dcosta]

Hello John,

Thank you for sharing information about your project.
I am interested in trying to add the functionality you refer to in your post to the program.
I have already started the process but, out of ignorance, I was forced to suspend the attempt.
I stuck in point 3. – here: "add this to UserInterface.h
int ButtonStateMachine (bool incrementButtonPressed, bool decrementButtonPressed) ";

Although I have professionally been a programmer / analyst for almost three decades, not having programmed in 'C', I am not sure where in the UserInterface.h file should I insert the line.

Could you do me a favor and tell me where that line should be inserted?

Thanks in advance
Dias Costa

[Johnboy25Participant @johnboy25]

Hi Dias

If you’re looking for the fast scroll mod/hack it’s here:-

**LINK**

It took me a while to get the code inserted correctly – I had help from a friend who’s an experienced C++ programmer as my C programming skill are a lot be be desired! 😳

I will look at the code file to find where it inserted for you.

I really think this is a useful mod.

John

Edited By Johnboy25 on 27/02/2020 09:48:10

[SillyOldDufferModerator @sillyoldduffer]

Posted by dcosta on 26/02/2020 23:41:49:

Hello John,

"add this to UserInterface.h
int ButtonStateMachine (bool incrementButtonPressed, bool decrementButtonPressed) ";

Although I have professionally been a programmer / analyst for almost three decades, not having programmed in 'C', I am not sure where in the UserInterface.h file should I insert the line.

Could you do me a favor and tell me where that line should be inserted?

Thanks in advance
Dias Costa

Hi Dias,

Though not into this particular project I am an ex C/C++ programmer.

Looking at userinterface.h I found a short file, starting with a comment section containing licence blurb. The action starts at line 27 :

#ifndef __USERINTERFACE_H
#define __USERINTERFACE_H

#include "ControlPanel.h"
#include "Core.h"
#include "Tables.h"

typedef struct MESSAGE
{
Uint16 message[8];
Uint16 displayTime;
const MESSAGE *next;
} MESSAGE;

class UserInterface
{

The new line can be inserted almost anywhere apart from inside any curly brackets!

I'd put it at the top just before the typedef, roughly line 33 thus

#ifndef __USERINTERFACE_H
#define __USERINTERFACE_H

#include "ControlPanel.h"
#include "Core.h"
#include "Tables.h"

int ButtonStateMachine (bool incrementButtonPressed, bool decrementButtonPressed);

typedef struct MESSAGE
{

…

H files typically contain definitions shared by a number of source files. In this case

int ButtonStateMachine (bool incrementButtonPressed, bool decrementButtonPressed);

means: 'A function called ButtonStateMachine takes two boolean arguments and returns an integer result.'

Boring explanation, if anyone cares:

The function is defined fully somewhere else in a code tree consisting of several source files, and the statement, it's signature, is a promise to the compiler that the full definition of the function will be made available later. So a project consisting of three source files, say A, B and D, will compile A even if it calls a function in D that doesn't exist yet. When the compiler hits an unresolved but explained reference, it leaves a gap in the code ready for the link phase, which is where A+B+C get glued together with any operating system and library calls. The linker, which can see everything, fills any gaps left by the compiler and completes the working whole. It's only an error when the linker can't fill the gaps.

Clear as mud? It's a mechanism allowing programmers to separate code into manageable blocks rather than one giant source file, and then assemble the bits into the whole later. It also allows code to be shared between different projects.

Dave

 

Edited By SillyOldDuffer on 27/02/2020 11:19:57

[Johnboy25Participant @johnboy25]

Dave…

‘Thanks for that – I’m just starching the surface with C++ so this is helpful to me.

John

[dcostaParticipant @dcosta]

Hi Dave,

Thank you for your help.
I took your suggestion, made a correction to a curly brace in a file and was successful.
The scope of the statement really had to be that. But as I lacked confidence, and as I'm not used to the development interface, I didn't dare.

I tried that feature and didn't like it. Perhaps because I did something wrong, the buttons randomly increase / decrease the value in jumps (not sequentially). Perhaps the function requires a short delay between each value …
Maybe I'll try to add it.

best regards
Dias Costa

[Phil GrantParticipant @philgrant54580]

Following a request on the Clough42 GIT hub I put my bracket designs I made for my small WARCO (Chinese) lathe and ELS on thingiverse Here

[JimmehParticipant @jimmeh]

It's been very slow progress for me on this project, but a recent change in my working arrangements has saved me 3+ hours of driving to/from work each day.

I now have the whole system working on the bench and am in the progress of sorting the hardware on the lathe.

I tried my hand at using a new (to me) gravograph and the result is actually alright (don't look to closely!).

Last night I fitted the drive system, which is a nema24 hybrid stepper with HDT3 belts and pulleys.

I'm hoping to drive the encoder with an HDT5 belt straight onto the headstock gear. I should be able to try the whole system fairly soon.

Huge thank you to Phil Grant for the circuit board and components!

Edited By Jimmeh on 26/03/2020 18:18:15

[Roy VaughnParticipant @royvaughn26060]

Nearing the finishing post now and starting to think about detailed functionality. It would be useful to see a visual indication of a stepper driver alarm on the control panel. James has included support for the input from the interface but I can't see any functionality attached to it in the code. Does anyone know any different?

Stay safe, Roy

[Martin ConnellyParticipant @martinconnelly55370]

If you have closed loop hybrid servo-stepper motors and drivers from Leadshine (possibly others as well) they have an error signal that is triggered by the position feedback differing from the demanded position by a set amount (that can be changed by the used if required). This signal would be fed back to the controller to either trigger a light, audible alarm or other action. If you don't have feedback encoders on your system then this warning may not be available to you.

Martin C

[Roy VaughnParticipant @royvaughn26060]

Thanks Martin, I'm familiar with the hardware requirement, it's what I have. My question concerns the software handing (or not) of an alarm signal. Roy

[Martin ConnellyParticipant @martinconnelly55370]

The problem of acting on the alarm signal is what to do? Stopping the lathe but letting the steppers run will cause problems. Stopping the steppers but letting the lathe run will cause problems. Stopping them both will cause problems unless they all stop instantly (or at exactly the same rate) which is unlikely so also a problem. If you have a spindle encoder that keeps the steppers closely aligned to the correct position if the spindle speed runs down then you would probably be able to stop the spindle knowing that the steppers will stop at the same rate as the spindle.

The best option for the majority of users may be to trigger an alarm light so that the lathe can run to a point where the operator can take some action that will not cause problems.

If you have some means of homing the movements of the lathe and use it at the start of a session you can easily reset everything by re-homing if there is an error signal that Is acted on by stopping safely.

Martin C

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