[kwackers]

Fix

short-circuit limit2 with GND

Tanks

Hmmm, that's a 'feature'...

The short circuit you had will make it think it can't turn CCW, however once the attempt to move is complete it will then rotate CW to 'backlash' compensate which is OK because movement CW is allowed.

I think correct operation is if it stopped because of the limit switch it shouldn't backlash compensate.

I'll make a note of that...


As an aside, thanks to people for posting pics of their versions of the hardware - it's nice to see people are using my controller! And all over the world too!

[elforum]

Thanks a lot

It is a very useful tool. I put the pictures and after you finish

Have a nice day

[tonylu]

Thank you Mr. kwackers
A picture is worth a thousand words.

[elforum]

nyce keypad

[kmcwhq]

......tonylu
Where can I get a few of those keypads??

Thanks
dk

[tonylu]

......tonylu
Where can I get a few of those keypads??

Thanks
dk

I made it myself,It is nothing but just a piece of transparency film printed from a color laser printer and lay on top of a 4x4 smd switches with some duct tape,hot melt glue that's all.

[kmcwhq]

Thanks for the info......very nice looking job.

:cheers:

[bullethead67]

Would it be possible to feed NMEA input from a gyro and have this hold a constant degree?

Im on a Ship and am searching everywhere on how to get a stepper to take NMEA signal from my gyro and hold a steady heading (degree) regardless of whether the ship is turning or not.

Can this be modified to respond to my gyro. Or does anybody know how i can do this.

[kwackers]

Would it be possible to feed NMEA input from a gyro and have this hold a constant degree?

Im on a Ship and am searching everywhere on how to get a stepper to take NMEA signal from my gyro and hold a steady heading (degree) regardless of whether the ship is turning or not.

Can this be modified to respond to my gyro. Or does anybody know how i can do this.

My reply is based on a quick 'google' so appologies if it's not accurate.

The device as it stands couldn't. It wouldn't understand the NMEA data, however you could in theory change it to read this and rotate the table (or some other device) in response.
This response would either be to keep some object pointing permanently in a compass direction or to control say the rudder to keep the ship pointing in a constant direction. How accurate this would be would depend heavily on the gyro and it's update rate.
Also if you were controlling a ships heading - the combination would attempt to hold the heading if you wanted to turn the boat you'd need some method of overiding this, either by giving it a turn rate or by having a manual mode.

As I said my answer is based on very limited information...

[bullethead67]

Accuracy would not be a problem. The gyro is a 25,000$ unit. Dont need autopilot either im just looking to setup a rotary table to keep the Hughesnet dish pointed in the right direction. We have internet aboard, With a tracking dome, but it is ruled with a iron fist. So i brought my dish from home. and it works great....Until the ship turns.

I dont know where to start learning to figure out how to do this. I am studing Linux now. but im starting to believe i am going in the wrong direction. This is the closest thing I have seen to what i am doing. I would be appreciative of any guidance.

P.S. I just bought a Index Wells 810 Mill Im going to build one of these for my mill. Mabye one for my Machinist brother too

[kwackers]

Accuracy would not be a problem. The gyro is a 25,000$ unit. Dont need autopilot either im just looking to setup a rotary table to keep the Hughesnet dish pointed in the right direction. We have internet aboard, With a tracking dome, but it is ruled with a iron fist. So i brought my dish from home. and it works great....Until the ship turns.

I dont know where to start learning to figure out how to do this. I am studing Linux now. but im starting to believe i am going in the wrong direction. This is the closest thing I have seen to what i am doing. I would be appreciative of any guidance.

P.S. I just bought a Index Wells 810 Mill Im going to build one of these for my mill. Mabye one for my Machinist brother too

What you want to do is fairly straightforward - but would if be enough just to match the turn? What about roll and pitch?

Basically stepper drivers usually have two inputs 'step' and 'direction', if you're using a 90:1 worm and half stepping motor (400 steps per rev) then you'll need 90*400=36,000 pulses per rev (0.01 degrees per step).
So basically you write some code that reads your gyro and works out how many 'steps' it needs to move to correct any movement since last time - it then simply sets the relevant direction and pulses the step pin.

Feel free to PM me if you require any more information.

[elforum]

Finished the monster ...

[rajuraja123]

how much v on step, dir pin
plz help;
enable pin have 5v

[kwackers]

how much v on step, dir pin
plz help;
enable pin have 5v

Dir pin will depend on which way you turn, 5v in one direction, 0v in the other. Try pressing left/right to check if it switches.

Step pin depends on the polarity of the clock pulse. I think the default is + in which case it will show low, if you switch this in setup it will be 5v.
The step pin will pulse when the device is operating, but you'll need an oscilloscope or logic probe to see the pulses since they're very short.

[rajuraja123]

s

[rajuraja123]

artwork

[elforum]

working...

[dpaulson]

Hi Kwackers

What is Swap Clock Pulse? What is Enable Polarity? I am trying to connect your step generator to a Rutex R90H servo drive and having a bit of trouble. The pulse generator will reset sometimes and quit pulsing sometimes and other eronious faults results. The signals from the step generator (step and direction) are low while the step/direction pins on the rutex drive are high. Can that be the problem? How to fix? I should also add that the servo drive has its own power supply and the 0V from must be connected to the 0V on the step driver to get any response whatsoever.


TIA

[kwackers]

The clock pulse line is held at either a logic '0' or '1' (0v or 5v), when a clock pulse is sent to step the motor it flips state for a few microseconds.
Some controllers expect this state to be normally low and flip high, some expect it high and flip low. The 'Swap Clock Pulse' option simply allows this to be changed.
Some controllers will work fine in either position, some will be intermittent or not work at all in one position.
With regards to your controller I'm afraid I'm not familiar.

Enable polarity is the same, but for the enable line. When the divider wants to start to move the stepper it 'enables' the controller by pulling this line high (or low) depending on the setting in this option.
However, some controllers will stop driving the motor when not enabled and 'relax' this may cause steps to be lost or you may find it's possible to move your work due to the loss of motor braking. (Probably not an issue with a servo).
In my setup I use this line to put the controller into a low current state - i.e. it still drives the stepper but at a lower current.
Whilst trying to get the device working properly I would ignore the enable line.

Other things to check. You're not trying to accelerate the device to quickly? You're not exceeding the maximum clock rate for your device?

If in doubt set the max rates in the divider to smallish values (1000?) and try swapping the clock pulse polarity. You'd expect all but the weediest of systems to work properly with that.

When using steppers, another thing is to try to resist the movement of the table with your hand - if it mis-steps earlier then you're exceeding the maximum step rate you can get with that motor and power supply combination (higher voltage power supplies can maintain torque better at higher speeds - assuming your stepper controller is of the switching variety.)

Hi Kwackers

What is Swap Clock Pulse? What is Enable Polarity? I am trying to connect your step generator to a Rutex R90H servo drive and having a bit of trouble. The pulse generator will reset sometimes and quit pulsing sometimes and other eronious faults results. The signals from the step generator (step and direction) are low while the step/direction pins on the rutex drive are high. Can that be the problem? How to fix? I should also add that the servo drive has its own power supply and the 0V from must be connected to the 0V on the step driver to get any response whatsoever.


TIA

[mp3]

I have just finished my rotary table indexer attached to a Shoba 6" table. All the electronics is mounted in an Eddystone die cast box. The keyboard overlay was constructed from a colour laser print on paper sealed by a laminating sheet. The display window was cut out before lamination. The overlay was secured with 3M double sided cut from an A4 sheet. A 0.5mm plastic spacer sheet was sandwiched between the overlay and the box to allow clearence for the keytops.
There is a video of it on Youtube at:
[ame="http://www.youtube.com/watch?v=sIAeic1DEoc"]YouTube - Digital indexer added to Shoba 6" rotary table[/ame]

Thanks Steve, great design.