My attempt at controlling the Dephlem

[ShiFu]

To help others avoid the same mistake that I made, here is an updated sketch that includes the limit switch detail.

My attempt at controlling the Dephlem
Mega_Stepper PinOut.png (20.19 kB. 350x222 - viewed 1285 times.)

[Eucyblues]

Aha - so that's it....

Well I've just written it back to untripped HIGH (omg - internet roundabout)

So you can change your switches or change the logic in the sketch

You now will have another place to change it though - there's another one in the v0.6A AUTOHOMING routine

So now on startup
1/ toggle switch checked to ensure both directions are OFF (ie switch neutral)
2/ if that passes, the interrupts are loaded and the home limit switch is checked
3/ if the home limit switch is tripped - nothing to do
4/ if it is closed, the motor closes to home
5/ ready to go at your command

[ShiFu]

I'll go through your code line by line and try to set it to the state of my switches. Failing that I can rewire the limit switches to Normally Open instead of Normally Closed. The toggle should stay the same.  Far more sure for me to move a couple of wires than to jimmy with your code. 
But I'll try both. One or the other should work 

[Eucyblues]

wiifm and others...

I've moved posts related to the motorised ball valve to here:

http://eparrot.org/index.php/topic,378.0.html

[ShiFu]

I used Eucyblues latest code and rewired my limit switches to match his code.  Sorry for the limit switch wiring confusion, Eucy. Entirely my fault 

PERFECT     ... and autoHoming was a fabulous treat. Never got tired of playing with that today

Not absolutely happy with the $1 EasyDriver and have upgraded that to a different stepper driver.  MUCH more torque, stepping and power options, reliability, and A LOT less problems with a different stepper driver (big bonus, no change to the code to use the new driver).

Will publish the drawing and pictures after the next build.

This is WONDERFUL!

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For those that are curious, this project is to electronically control a condenser on your still by PID.
If you don't know what PID control is then please Google it.

1) Dephlegmator (or Reflux Condenser) electronic control for precise ABV output to the parrot.
2) Product Condenser electronic control to maintain a set distillate temperature output to the parrot.

This is true distilling Nirvana. Tell your still to produce a certain ABV and also tell the product condenser to maintain your outputting product at a certain temperature.
Oh yeah, baby. We all want that.

The first step is sorting out the hardware and testing it with software. We're about there now and will soon move to adding the PID algorithms . 

This will be the difference between futzing about and precision dialing in. 
Or we sputter and fail in the attempt.
Which are you cheering for?   

Follow along, I think you know where we are going. 

[Eucyblues]

I have a smile on my dial at the moment - very pleased to have been able to help and that you're enjoying it 

Onward and upward !

[ShiFu]

The work continues... 

My attempt at controlling the Dephlem
Mega_Stepper PinOut v0_6A.png (156.13 kB. 350x215 - viewed 1025 times.)

Revised the drawing to add the DC-DC step down board and upgraded stepper driver. 

Got a spool of red PLA for the 3D printer so printed the parts again. I like the new look.

My attempt at controlling the Dephlem
red PLA.png (284.75 kB. 350x262 - viewed 956 times.)

Breadboarded it all together and it works great. 

My attempt at controlling the Dephlem
StpNdlVlv Build2_0.png (166.73 kB. 350x262 - viewed 1008 times.)

This would be so easy to clean up by using a prototyping (solder) shield on the Mega. I'm just not ready to make it permanent yet. 

The stepper driver and motor do not get warm when I work it as hard as I can over two hours and it is set for about half of the maximum watts that is recommended by the manufacturer of the stepper motor. I started at the lowest power setting and gradually increased the power until it had very good torque. 

I read that stepper motors are made to run somewhat hot and what feels hot to you is actually normal. Not burning hot, just very, very warm. 
This leads me to think that the stepper motor that I'm using is too large and can be downsized. The stepper motors on my 3D printer are tiny by comparison but I'm loathed to take one off of it to experiment with. They never get hot either, even after a 3 hour print job.

The NEMA 23 stepper motor, steel mounting bracket and stepper driver (all shown in the picture above) were purchased as a set and cost $35 USD.
That's a good value for such nice gear but I am wondering if a smaller motor with a few more watts would give good results at a lower cost and smaller footprint.

[Eucyblues]

The typical ball valve motor has a torque cap of 2Nm - A Nema23 has a holding torque of 1.26Nm - the Nema17 torque drops to 0.36Nm -

Size-wise they drop from 57x57x57 to approx 42x42x40 - not a lot in it

This one would work:
http://www.ebay.com.au/itm/Extruder-Gear-Stepper-Motor-Ratio-5-1-Planetary-Gearbox-Nema-17-Step-Motor-Hot-/301743166517?hash=item46414b5435:g:sgQAAOSwQPlV-on3

Heaps of torque...

It's 42x42 but 67mm long - 10mm longer than the 23 you presently have

Hmm....not a lot of options maybe

[ShiFu]

I'm thinking you are right, Eucy.
What I have now seems to be overkill but the next commonly available size down is WAY down.
The little NEMA 17's on the 3D printer sure seem to be sized for the job. Never get hot or miss steps but on the printer they don't need much torque, just speed and a bit of stopping power.

A valve can require a bit of torque though. When the needle seats into the home position (fully closed) it takes a fair amount of torque to crack it back open again. The mains water pressure seems to add a bit more strain, too.

Searching through some manufacturers specs, they mention "normal housing operating temperature range 0 to 50C" but also state "Do not exceed 100C for prolonged periods".
The motor to control a cooling condenser needs a cooling condenser 

[swestill]

Must say I'm really jealous of you guys that have the knowledge to to this.
Just to be able to make a machine do as you want is quite impressing.
i could only dream of it and are happy that i can do the wirering from my bought controller
to my solenoid valve on my vm still.


Swestill

[Eucyblues]

Hi swestill

There is a learning curve to be sure, but I'd encourage everyone to have a go - start with a simple project - the parts a very low cost - You'll be surprised how addictive it gets to be. 
 
Ultimately I/we'd like to create some bolt-together solutions but there is still a need for decent assembly skills.. soldering, cutting, etc etc - and as I've said before, I think that doing that on a bespoke project for the first time is the most trying part even if it doesn't take up the time that software development takes.

Gather your bits and begin !!



 

[swestill]

Is their any progress Shifu on this gizmo?
I'm really intrested of a thing like this but as istill use it for controlling an lm. The principle is exactly the same but the opposed. when you open the valve for more reflux i want to close it for more reflux.

Iv used a solenoid valve for many years no for my Vm but am also very tired of the constand clicking at the end of the run.

The thing i am looking for is to have lets say 3 pidds in the column and when the tails reches the first pidd the valve closes a bit and the same on the second. if a certain dialed in temp reches the third pidd the valve closes and sets the column in full reflux until the temp goes down to the middle pidd then it start to open agen and so on.

that's what the istill robot does but en many more steppes.

[ShiFu]

... Is their any progress Shifu on this gizmo? ...

No progress on controlling the dephlegmator or the reflux electronically. Sorry.

There is still hope though. Edwin got interested and that usually leads to very good things.
See his thread here.