Steve Wards Rotary Table Controller

[john kennedy 1Participant @johnkennedy1]

Has anyone successfully built this unit ?

I'm struggling to get it working,mainly because I don't understand electronics.

When I put 5v onto the circuit board,the display lights up but no figures appear.

When I put 24v into the driver nothing happens?

I would appreciate some pictures if anyone has any to show where the connections go,and where from.

Hope someone can help.

Thanks, John

[john kennedy 1Participant @johnkennedy1]

[ZebethyalParticipant @zebethyal]

I have built it, but have yet to try it in anger.

I have also built the stepper adapter for my rotary table.

What I still have to do is print an enclosure for the controller and wire up the stepper motor.

When I apply 5V to my controller, it comes up with Steve's 'splash screen' and then moves on to ask for initial settings, so I am pretty sure the microcontroller is working ok.

I cut the design down a bit as I did not need all of the functionality and implemented on it a double sided perf board

Details of my version can be seen here

[john kennedy 1Participant @johnkennedy1]

Thanks for replying Tim. You obviously know what you're doing.

When I look at a schematic drawing it doesn't make any sense to me.

That's why I like photos.

John

[David lawrence 3Participant @davidlawrence3]

I have one of these stepper controllers, it works well. I did buy it ready made and tested. for the sake of any extra £ 20.00 or I could not see the point of building it myself and I have 40 years of electronics exp. I bought a driver from ebay for £ 12.00, stepper motor from ebay for £ 32.00, box from RS. The only down size is the keypad is 90' on its side, I understand that the latest version sorts this problem out. In use its very good, I use it too run a 6 " rotary table for cutting clock wheels on my mill. you just push a few buttons and of it goes. As to the problem of the board not working, can you measure the current being pulled by the pcb at 5 volts it should quite low say 100 ma max if its pulling lots more you may have a short on the pcb across 2 tracks, easily done. steve does have and email address for help.

[John RuddParticipant @johnrudd16576]

Posted by john kennedy 1 on 22/06/2016 15:50:10:

Has anyone successfully built this unit ?

I'm struggling to get it working,mainly because I don't understand electronics.

When I put 5v onto the circuit board,the display lights up but no figures appear.

Hope someone can help.

Thanks, John

 

I cant remember if there is a contrast pot for the lcd, if there is, have you tried adjusting it?

I just checked….there is, so try adjusting it..

Otherwise its back to basics, all components inserted in correct location and the right way round,……

No short circuits/bridges stray solder splashes across any adjacent tracks……

Mine worked fine after assembly.

Edited By John Rudd on 22/06/2016 16:55:45

[john kennedy 1Participant @johnkennedy1]

David, not quite sure how m amps are measured ?

John, yes saw that on Steve's fault finding page. Tried it all round.. still a blank blue screen.

Will get my magnifiers on and check the board as you suggest.

I am confused though where the 2 different voltages come in?

Need to see how people have wired theirs.

John

[ianjParticipant @ians]

John.

The 5v connection is to output 5v to the stepper driver if required. It's NOT for 5v in.

The in voltage of 24 v connection are to the left of the PCB as viewed with the terminal blocks along the bottom, this is regulated/dropped to 5v for the 5v output as mentioned above, & microcontroller power ..

You say when you put 24v into the driver nothing happens do you mean the stepper motor driver or the Steve Ward controller?

 

Have you programmed the microcontroller?

 

Are you using the latest PCB as purchased from Steve.

 

Maybe a photo of your 's would be helpfull.

Ian

Edited By ian j on 22/06/2016 17:41:25

Edited By ian j on 22/06/2016 17:53:25

Edited By ian j on 22/06/2016 17:57:19

Edited By ian j on 22/06/2016 18:00:13

[Gray62Participant @gray62]

John, if you are using 5v to power the board, you should omit the on board regulator. and connect the power to the 5v connection not the power connections that feed the regulator If you are feeding 5v into the regulator, the microcontroller will not power up correctly as the output of the regulator wil be less than 5V the ones I have built are all powered from a 24V supply but you must have a decent heatsink on the regulator as it can get quite warm, I also fan cool the enclosure with a small 5v fan.

Did you purchase the PIC pre-programmed from Steve or have you programmed your own?

I've built several of these using Steves PCBs and all work fine. Where in the country/world are you someone close may be able to help

[john kennedy 1Participant @johnkennedy1]

Ian, I think we're getting somewhere. I put 5v in that bottom left terminal block.

I'll try 24v

I have got the latest board from Steve about a year ago.

The chip came ready programmed.

Can't upload pics since I changed to win 10.

Will get back

John

[Mike PooleParticipant @mikepoole82104]

Hi John,

I have put this together for testing and it is working, just waiting to be boxed up,keypad not shown plugged in. I have a 24v supply on the brown and blue wires.

[john kennedy 1Participant @johnkennedy1]

Put 24v to the bottom left terminal and Success. The display read as it should and I went through the menu.

I have a Microstep driver M5045

**LINK**

On the terminal blocks to the left it shows High voltage DC in and DC earth.

Does this also need a 24v link to run the stepper motor.

Thank you all for your help so far.

Live in Grimsby by the way.

John

[john kennedy 1Participant @johnkennedy1]

Michael, just seen your post.Very helpful. My driver is different to yours but I'm sure we're nearly there.

Just noticed on your photos that 24v is linked to your driver.

John

Edited By john kennedy 1 on 22/06/2016 18:51:39

[Gray62Participant @gray62]

John,

Yes you will also need to provide a power supply to the stepper driver, the outputs from the controller board are only the 5v TTL logic to drive step and direction

[john kennedy 1Participant @johnkennedy1]

Fantastic.Thanks chaps for all your help. Linked up the driver and away it went.

Set it to jog 10 degrees. Nearly jumped out my skin when it went.

Can perhaps cut some clock wheels now.

Thanks again

(happy) John

[ianjParticipant @ians]

John.

Well done that's good news.

Ian

[John RuddParticipant @johnrudd16576]

Glad you got sorted with nothing major…..

I'm t'other side of the river just east of Hull….

[Enough!Participant @enough]

Posted by Michael Poole on 22/06/2016 18:43:35:

I have put this together for testing and it is working, just waiting to be boxed up,keypad not shown plugged in.

I would suggest using a motor with a double-ended shaft and fit some kind of handle/knob to the rear shaft. It makes manually setting a start position for the rotary table possible which is much easier than jogging it.

[Mike PooleParticipant @mikepoole82104]

I had not considered using a hand wheel for setup but fortuitously the motor has a double ended shaft so fitting a handwheel will be no problem if required.

Mike

[Gray62Participant @gray62]

Posted by Bandersnatch on 22/06/2016 21:51:56:

Posted by Michael Poole on 22/06/2016 18:43:35:

I have put this together for testing and it is working, just waiting to be boxed up,keypad not shown plugged in.

I would suggest using a motor with a double-ended shaft and fit some kind of handle/knob to the rear shaft. It makes manually setting a start position for the rotary table possible which is much easier than jogging it.

Just a word of caution, stepper motors act as generators when turned by hand and can pump considerable voltage back into a stepper driver which, if it is not adequately protected against back emf will fry the output drivers, had to repair a couple for friends who had suffered this. Best bet is to unplug the motor from the driver when hand cranking. I connect all my motors to the driver with a 4 pin XLR type connector for this very reason, good solid plugs and easy disconnect.

[Enough!Participant @enough]

Valid point, Graeme. In my experience it's been more theoretical than actual but it pays to be safe.

I too use a common connector series for all my steppers/drivers. In my case this series.

[ZebethyalParticipant @zebethyal]

Glad to hear yours is working now.

I chose to use an external switch mode dc-dc buck converter for the regulated 5V as these are around 95% efficient and although they cost a little more than the 7805 regulator (about £0.10 each), they are still only about £0.60 each and I don't need to worry about heat, I can also use it to supply the 5V side of my stepper driver, saving another 7805 and yet more heat.

The buck converter is good for about 2A without a heatsink and 3A with one, and neither item will be drawing more than a few mA, the 5V circuit on the main board works quite happily from a USB 5V power source which has a 500mA limit.

The 7805 needs about 7V to work and anything else is dumped as heat, 12V per 7805 (for my 19V supply) or 17V per 7805 (if you are using a 24V supply) all as heat.

[Douglas JohnstonParticipant @douglasjohnston98463]

I have built a few stepper devices which can be hand cranked and have been concerned about generating damaging back emf, but like Bandersnatch it has never proved to be a problem in practice.

I am a great fan of the stepper drivers of the type shown in Michael's picture above. They are very cheap from China and are well built. I have used them for a few years with no problems. When the stepper motor is hand cranked the on board LED lights up which is a bit alarming but no harm is done (or so it seems! ) At about £4 each for the drivers any failure would not be the end of the world.

Doug

[MuzzerParticipant @muzzer]

Posted by Graeme W on 22/06/2016 23:57:11:

Just a word of caution, stepper motors act as generators when turned by hand and can pump considerable voltage back into a stepper driver which, if it is not adequately protected against back emf will fry the output drivers.

It's the same back EMF that causes loss of torque with increasing motor speed when you are driving it with the driver. There will be a maximum speed at which the completely unloaded motor can be driven with your PSU. As long as you restrict the motor speed when driven to less than this, the back EMF will be less than the corresponding supply voltage and the drivers should be fine. All that's happening is that the back EMF is being rectified by the flywheel diodes but there's no danger to the drivers when the voltage is less than their max rated voltage. The back EMF waveform is a nice clean, predictable shape and you may even be able to find the Kv factor from the motor datsheet.

[ZebethyalParticipant @zebethyal]

On occasion I can be a bit of a cheapskate, as I objected to £38.00 for the built and tested module and also to £19.00+ (PCB+PIC+Components) + LCD, I certainly had no intention of paying well over £150.00 for a division master. I built mine for under £5.00 all in and had some fun in the process – I'm still relatively new to electronics so this was an interesting project for me.

My stepper driver also cost less than £5.00 and my stepper motor was about £16.00, PSU was free from an old laptop, enclosure will be about £3.00 to print on my 3D printer and custom made to fit my board, again because it is a fun project to design.

There are plenty of other areas where I probably engineer more with my wallet due to lack of knowledge and/or skill, but if it is something I think I can tackle, I will see how cheaply I can do it, and write it up for others to copy and/or improve on.

Edited By Timothy Moores on 23/06/2016 15:12:26

[Author]

Posts