Adding Servo support to an UM1

[drayson 74]

Hi all,

recently I found a entry at thingiverse where a guy soldered an additionally connector onto the UM shield to connect a servo for auto bed leveling.

http://www.thingiverse.com/thing:225584

Now my question: would it be possible to address the same pins to e.g. trigger an automated build platform, kick prints off the plate, trigger a laser... - basically have an additional output for doing something...???

This would be interested especially if you have used all available stepper and temperature I/O´s...

Any hints/answers appreciated... :smile:

 

[gr5 2,005]

If you only have one extruder then you already have a spare stepper driver. You might have to buy a pololu but it just slips into the spot for "extruder 2".

You then control this with G1 commands. No software changes necessary.

T0 is the default extruder

Doing T1 switches to the other extruder.

T1

G1 E15

Moves the second "extruder" to 15mm position.

I already kick prints off the plate using the fan shroud on the UM Original - but only for bracelets. UM does this for robots also so they can set up a printer to print out 60 bracelets or 60 robots and come back a few hours later and they are all over the floor. They give these away at trade shows. I gave away 100 bracelets last weekend at a local sci tech expo.

 

[aviphysics 9]

I would love some instruction on kicking prints. My daughter's birthday is coming up and we have been talking about printing favors. Does it work with blue tape or do you need a glass plate or what?

 

[dashhunter 0]

I would love some instruction on kicking prints. My daughter's birthday is coming up and we have been talking about printing favors. Does it work with blue tape or do you need a glass plate or what?

 

Recently there was a post about it: http://www.ultimaker.com/blogs/news/2013/03/14/start-your-own-mini-factory-with-autoprints

They used 3M 3434 Scotch tape instead of the 2090 scotch, because this was too sticky.

 

[drayson 74]

Yea, the possibility to use the second extruder connections is clear... BUT:

unfortunaltely I don´t have this possibility because I already mounted a second head :-)

My fault as I have not clearyl specified this in my question

Nevertheless, to automate a few things more would be a interesting thing. I found a laser set for TOM, where the laser is controlled via the automated print platform output.

Of course, another thing would be to create a servo arm for kick off prints...

But basically, the question is how to controll this additional things...

 

[anon4321 16]

You can only control the outputs within the limits of the firmware. You need to find a function you can leverage.

Peeking at the firmware changes for the Z probe stuff. It looks like you would rebuild the firmware for the number of servos or PWM outputs you require and then you can use in your GCODE.

M280 P{servo number} S{angle}

Servos are numbered starting at 0.

There is a little more info here:

https://github.com/ErikZalm/Marlin

Search for leveling

Oh, here is a better link: http://3digitalcooks.com/2013/12/setup-servo-with-marlin/

on the UM1 shield, the servo connectors appear to be next to the two 10 pin connectors in the middle of the board. Appears that only two servos are supported and the pins are not populated so you will need to solder them on.

Be careful with large servos. The connectors appear to be tapping into the 5V line to power the servos and I believe the 5V line comes from the Arduino's 5V regulator and that doesn't support much current. Probably about 500ma in total so if the servos are consuming more than 75ma * 2, you might be stressing/heating the 5V regulator.

 

[drayson 74]

Thank you for this hint - that´s similar to the functionalityI have in mind...

 

[drayson 74]

More than 1,5 years left until I hooked up the servo.

Just for our records: NOW it works :-)

Marling FW version from 06/2014, enhanced with the code from http://www.thingiverse.com/thing:225584, servo hooked to Pin13 and addressed via M280 P0 S0 up to S180 code...

So finally mission accomplished :-)