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Member postings for dcosta

Here is a list of all the postings dcosta has made in our forums. Click on a thread name to jump to the thread.

Thread: Optimum products?
19/10/2020 10:12:19


This is a photo taken from an Optimum catalog that shows that, at least in 2015/2016 their factory was in Yangzhou.
If anyone is interested in the catalog (220 pages, 21MB), I can make it available for download.

I have had a BF20 milling machine from Optimum since 2008 and I am satisfied with it.

Dias Costa


Edited By dcosta on 19/10/2020 10:14:10

Thread: A Virtual Meet Up on Zoom
16/10/2020 19:09:45

Hello Neil,

I would like to participate if possible. Possibly only lurking. Spoken language is a barrier.

Dias Costa

Thread: Overseas Distribution to restart
20/07/2020 14:55:24


In the 1980s I made a purchase for the first time from a supplier in England. I bought a set of propellers for boat models. At the time of purchase, the price was lower than the price in the catalog and also in the order, but without the dynamics that the WWW allows now, I only knew that the price of the propellers had dropped some shillings / pences (?) when I received the propellers, the invoice and a note asking me how I wanted to receive the difference and informing me that, to minimize that difference, the supplier had decided not to charge shipping costs. My admiration for the supplier grew and, at the time, I thought that, in general, all (?) English traders would behave similarly. I was then thirty years old and I took it as a lesson.

A few minutes ago I paid £ 16.89 for two issues of a magazine (293 and 294) that I had paid in advance.

P.S .: During the pandemic I continued to receive products purchased from England, from other suppliers, at no additional cost and with only slight delays.

Did not like.
Dias Costa

19/07/2020 20:47:18

Hi Neil,

I also received MEW number 292 and it was the last one I received.
And, like Peter, I want to know if I am not going to receive numbers 293 and 294 and, moreover, whether I will have to look for them and buy them somewhere.
Will I be able to buy them from MTM?

Best regards
Dias Costa

Thread: Electronic Lead Screw Project
15/06/2020 16:23:00

Resuming this project, I verified that the synchronization between the rotary encoder and the stepper motor was not correct.
The rotary encoder (B E6B2 - CWZ6C) has a resolution of 1000P / R.
The motor stepper completes a rotation in 200 steps (1.8º per step) and the DM542 driver is configured in DIP switches for 8 microsteps (1600 Steps / Rev).

In the Configuration.h file, following Clough, i have


But, if I change the STEPPER_MICROSTEPS variable to 12, and test 40 rotations on the rotary encoder, the synchronization with the motor remains correct.

Although the sync remains correct, it seems to me that there is something wrong with this configuration.
Any opinions are welcome.

greetings from
Dias Costa

Thread: Corona virus testing
24/04/2020 09:52:40

Hi Mr. Robert Eggleston,

You wrote:
"Heaven above only knows we have enough of CV info 24 hrs per day on this side of the pond without having to view it from your side of the pond also."

If I understand correctly what you mean, I, who am the main side of the channel, opposite to your side, am in doubt as to whether your segregating will also applies to those on this side?

Dias Costa

Edited By dcosta on 24/04/2020 09:59:55

Thread: Fantastic British engineering
23/04/2020 16:33:34

Apparently it's a shaper. In **THIS** enlarged image, it is possible to see the groove where the shaper feedrate governing mechanism runs.
Also, in horizontal alignment of Father Christma's hand, to the right side, the T-groove of the fixing table appears to be visible.
Finally, to the right of Father Christmas's knee, what appears to be the manual feed handle of the table and the connection that transmits the rotary movement for the automatic advance of the table is visible.
Just an opinion

Dias Costa

Edited By dcosta on 23/04/2020 16:35:11

Thread: BF20LV problem
11/04/2020 16:24:03

Hi gary,

Some time ago I had a problem similar to yours and the cause could be the same.
Using the browser, please, search for the following, full, string:
site: https: // dcosta bf20
Perhaps you will find useful information ...

best regards
Dias Costa

Edited By dcosta on 11/04/2020 16:25:24

Thread: Websites contacting you
10/03/2020 17:27:06

Hello all,

I received from Firefox a message with this banner: "Keep Facebook off your trail".

For those concerned with abuse of the privacy of their data.
Firefox offers an extension that allows you to avoid spying in the context of their browser.

greetings from
Dias Costa


Edited By dcosta on 10/03/2020 17:33:19

Thread: Electronic Lead Screw Project
27/02/2020 20:19:22

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

26/02/2020 23:41:49

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

25/02/2020 20:21:23

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.
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

25/02/2020 16:25:28

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

25/02/2020 16:22:02

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

25/02/2020 00:21:15

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

23/02/2020 21:08:26

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.

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

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

15/02/2020 23:22:30

Hi Phil,
Hi Limpet,

I really appreciate your quick help.
There was a "disgrace" ...
Is there a way to test the integrity of the TI LaunchXL F280049C?
I think I just burned one more, the second.
I connected the DM542 driver to the interface, as suggested, and when I powered on the interface, the display showed nothing. The DM542 driver was not connected.
As it is the second I burn in similar circumstances, I must have made some mistake in the interface.
The two serial ports that the "Code Composer Studio" software uses to communicate with the F280049C are no longer present in device management as they did when I burned the first board.

Thanks and regards
Dias Costa

Edited By dcosta on 15/02/2020 23:25:06

15/02/2020 21:58:06

Hi Phil,

I really appreciate your quick help.
Please consider the wiring diagram for the DM542 interface driver, ***HERE*** .
Which interface pin do I connect to VCC? It seems to me that it should be the positive 5V output. Am I right?
I assume that Pulse should be connected to Step, Direction should be connected to DIR and Enable should be connected to EN.
What about the negative pole? Can I understand that it is passed by each of the STEP, DIR and EN? And so, in addition to ALM, do I also ignore GND?

Thanks and regards
Dias Costa

15/02/2020 21:46:48

Hello Limpet.

I really appreciate your help.
For someone like me who is a "turnip" in electronics and does not have English as his native language, it is sometimes difficult to discover the meaning of some words, especially if contained in idiomatic expressions, let alone acronyms!

Best regards
Dias Costa

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