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Need some help for a first electronic project.

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one4stevo

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Hi all im new hear so please go easy on me

i would like to build a device that can squeezes a large syringe of 100ml about 4 inch long, over any period of time. "Don't worry im not a junky its for a planting experiment I'm doing" ill need something that can move the syringe, something that could be veritable say on a dial would be fantastic. i need something that could move say 4 inch in 1 min and have the flexibility to slow that speed down to over 1 hour.
now building the project i have no trouble at all, its just the electronic side of things i got nooo idea about, so if someone could give me a few pointers and stear me in the right direction i would be very great full.
Thank you
 
How fast does it need to go?

For slow controlled speeds use a stepper motor turning a screw which can be used to push the syringe very slowly.
 
Hi Hero999 Thank you for your response :)

well basically the syringe is about 4 inch long and it would need to screw down 4 inch and i was hoping for a high speed of 4 inch in 1 min and can slow it down to about 4 inch in 1 hour there about anyhow. o and it has to rewind too. Is there something out there i can hook up to a stepper motor? with a dial indicator for the speed settings? sorry but i am very limited with electronics the only experience i have is electric radio control cars. Building side of it thats fine. just need the electronic side of it sorted.
Thanks again Hero999
 
I don;t know much about stepper motors but i would of though you would be able to get a stepper with a gear box pre-attached, then find the appropriate controller for it. That's as far as i go with this!!
 
Interesting project. I would consider as Hero suggested. What you need is a linear actuator motor with at least a four inch stroke. A stepper motor could be configured to do this using what is called a ball screw or lead screw design.

You don't mention the liquid in the syringe so can we assume water? The question becomes how much force is necessary to drive the plunger. That will determine the motor size and other variables. The speed and direction driving the plunger in or out should not be difficult as long as the load (force necessary) is known.

I would start by working from Hero's suggestion as to using a stepper motor.

Ron
 
It's easily doable with a stepper motor.

Maybe the easiest solution is to attach the shaft directly to the screw which is inserted into a tapped piece of steel plate. The other end of the screw would need to be connected to the syringe. The motor would need to be on a carriage so it moves back and forth without spinning round.

If it's not clear I'll try to draw it.
 
If you use one of these; TSFNA57 - Permanent Magnet (PM) Non-Captive Linear Actuators All you would need then is a mounting bracket and a controller.

The screw is built right in on these. Inside the motor(where a shaft would be) is a nut that turns. That makes the screw move in or out depending on the direction the motor is turning.
Makes a kind of "electric air/hydraulic cylinder".
 
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That's brilliant but the price it per unit in quantities of 50. I assume the original poster only needs one.
 
You don't mention the liquid in the syringe so can we assume water? The question becomes how much force is necessary to drive the plunger. That will determine the motor size and other variables. The speed and direction driving the plunger in or out should not be difficult as long as the load (force necessary) is known.

this would be taken care of in the gearing if you used a powerful enough motor and the programming will take up anything else.
 
That's brilliant but the price it per unit in quantities of 50. I assume the original poster only needs one.

They give a single unit cost of about $29 (USD) and list the force as 24 Lbs. Anyway, really here nor there till the OP gets back with more information.

Ron
 
yes good option is step motor, select one with wide range of RPM.
maximum posible RPM and the minimum time for the stroke will determine the turn ration (torque ratio) for the gear. then the size of the motor can be selected depend on the torque ratio.
imput frequency of the pulse train to control the motor for maximum time and minimum time can be calculated based on the informations.
then the controller knob should generate the range of frequency for this.
 
They give a single unit cost of about $29 (USD) and list the force as 24 Lbs. Anyway, really here nor there till the OP gets back with more information.

Ron

Yes, you're right, I missed that they sell them in single units.
 
Wow Thanks everyone

You don't mention the liquid in the syringe so can we assume water?

it will be just different liquid fertilizer so yer basically water really

If you use one of these; TSFNA57 - Permanent Magnet (PM) Non-Captive Linear Actuators All you would need then is a mounting bracket and a controlle

That looks great, actually its perfect really.


yes good option is step motor, select one with wide range of RPM.
maximum posible RPM and the minimum time for the stroke will determine the turn ration (torque ratio) for the gear. then the size of the motor can be selected depend on the torque ratio.
imput frequency of the pulse train to control the motor for maximum time and minimum time can be calculated based on the informations.

Sorry mbarazeen but that just too confusing what do you think would do the job best?

What kind of a controller would allow me to change the speed easlys is there something out there that could do that?
also where do you get all these gizmos from?

Evey one thanks again i would of never found any of this :)
 
i told how it has to be calculated incase if you select the system to use your own gear to convert from rotary to linear action, as you said, the actuator TSFNA57 can be much easy for you to go with and it require only few more componets.

you have to work on how your entire mechanical arangment gonna be. then the controller for the actuator can be designed. from the data sheet shortbus= mentioned i counldnt find more information about the tun ratio of convertion etc.
 
The linear motor linked to would be a good choice. It delivers 24 pounds of force which should be more than adequate. If you look at **broken link removed** for the motor it tells you everything you need to know.

Since the sheet gives metric specifications I'll wing it a little and guess at a few things. The step angle is 7.5 degrees / step so if we take 360 / 7.5 = 48 or 48 steps equal 1 full revolution of the shaft. The travel per step of the shaft is 0.00098" per step or one revolution of 48 steps will yield a travel of 48 X .00098 = 0.047" per revolution. Each 1" of travel would be about 21 revolutions.

I will venture a guess here that in reality the screw is a 1/4" (.250 inch) screw with a pitch os 20. There are two popular standard off the shelf screw pitches for 1/4" stock threaded rod and they are 20 and 28 TPI (Threads Per Inch).

You want about 4" of travel and the linked to unit seems to have about a 6" stroke so you should be good on that note. Four inches of travel should be about 80 revolutions (give or take if I am right with the 20 TPI).

This link is to a simple and easy to build stepper motor controller that should run under $15 USD to build. If you look at the Pulse in line, each pulse is a step. It also allows for direction to be switched.

There is a little more to all of this but what you have is an overview so at this point you need to decide where you want to go with things.

Ron
 
from the datasheet, it requires 4082 steps to move a 4" stroke. so the controller will have to drive 68step/sec to 1step/sec to achive the stroke time of 1min-1 hr.

i doubt wheather it is possible for the morotr to handle 68 pulse in a second.
 
What leads you to conclude that the motor wouldn't handle 68 pps? The time constant of the motor winding is just over a millisecond.
 
What leads you to conclude that the motor wouldn't handle 68 pps? The time constant of the motor winding is just over a millisecond.

yes i was wrong, i think maximum rpm of the motor can be 8000? in this case it wil handle more than 100 pulse in sec.
 
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