how to control a dc motor-fluid pump?
Hello all. Im trying to make a robotic arm and control it not with servos but with dc motors working as pumps.
The board i will be using to control them is the parallax propeller.
After a lot of internet search i found some cheap pumps for this particullar use.
The only problem is that dc motors cannot be programmed and they just spin out if you plug them on a battery.
Is there a way to control them? I read about H bridge but dont have any idea how they work. Or how about esc for brushed motors? Will it work?
What about the power suplly as well? i need 4 in total, at least for now :-/
Has anyone done something like this in the past?
Thank you in advance.
The board i will be using to control them is the parallax propeller.
After a lot of internet search i found some cheap pumps for this particullar use.
The only problem is that dc motors cannot be programmed and they just spin out if you plug them on a battery.
Is there a way to control them? I read about H bridge but dont have any idea how they work. Or how about esc for brushed motors? Will it work?
What about the power suplly as well? i need 4 in total, at least for now :-/
Has anyone done something like this in the past?
Thank you in advance.
Comments
http://www.instructables.com/id/How-to-make-an-H-bridge/
There are many different H-bridge ICs to drive low power motors
and modules for higher power. just search EBAY.
and even if they write stepper motor you can use them for DC motors as well.
Voltage and Current values need to fit the requirements of your motors.
and then use PWM to drive them variably.
but usually in a hydraulic system there is one pump (pressure controlled or limited)
and servo valves for the actuators.
and the program in c? same command as the servo (although that i can find it by trying different speeds).
http://www.hobbytronics.co.uk/h-bridge-driver-sn754410
Would you be willing to share which " found some cheap pumps for this particullar use. " ?
and
What would be the approximate size of the robot you are intending to build using and what type of fluid are you
considering using.
Just Wondering.
http://forums.parallax.com/showthread.php/106382-4-State-Relay-H-Bridge
these are the water pumps.
the arm is a modified arm by lynx.
water pumps water to syringes and pushes the arm for more heavy load.
i want it to be controlled both forward-reverse (so that the syringe will retract) and to brake in order to not allow water flow back to the reservoir.
I would not expect too much pressure from this pump.
So you probably should check what pressure your arms / syringes need to work.
Also I would not expect it to work bidirectional or stall the flow if off ...
there are magnetic valves on EBAY
http://www.ebay.de/itm/TB-Electric-Solenoid-Valve-Magnetic-N-C-Water-Air-Inlet-Flow-Switch-N-C-1-2-US1-/390952698138?pt=LH_DefaultDomain_0&hash=item5b0698c11a
The hydraulic braking unit of modern cars has a hydraulic pump plus 8 valves, electronically controlled.
Maybe it is possible to hack such a unit.
BUT - this would require double acting cylinders ? - or maybe using the low pressure side makes them go backward ??
The most practical use I had for one of these recently was to evacuate the water out of a toilet tank so that I could make some repairs.... A plumber's dream actually ... but I'm sure you didn't want to hear that. :-)
We bought Nerf Electrostorm electric squirtguns to make flamethrowers (did I actually say that?) earlier this year. $7 at Big Lots, now closeout at $3.50, so I stockpiled more. They have a wonderful high pressure gear pump inside. Would work for you for a while, but it's all plastic, not sure how long it would last. Likely worth a shot for experimentation and yucks. Probably reversible, although I didn't test that. Stock was 6V (4xAA) but we hopped them up to 12V. There's a thermal shutdown circuit inside that you want to bypass.
Heck, if you find any for $3.50, buy them all for Christmas gifts or summer fun. They're lots of fun.
http://www.amazon.co.uk/Nerf-33693148-Super-Soaker-Electrostorm/dp/B005I4RQAA/ref=sr_1_1?ie=UTF8&qid=1416287974&sr=8-1&keywords=nerf+electrostorm