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Explain me how to make an "Electromagnet Solenoid" more powerfull Answered

I bought something like this off Ebay:


Turns out it wasnt as powerfull as i need it to be but it has the right amount of travel and is nearly perfect in size...

Notice that the body where the coils are is fairly short. What if i made my own? But MUCH longer body, (theres plenty of room in my aplication LENGTH-wise) will it get more powerfull? Can i make it more powerfull by adding more coil?

Turns out i have plenty of coil like the one used in my solenoid, i have plastic pipe similar size and i can CNC the central "plunger" rather easy as well. Or make it different shape etc...
The solenoid i have has a metal body, does that affect how strong the solenoid is? 
The coils are wrapped around a plastic tube, the plunger is rather loose inside it and the tube could be thinner. Will thicker plunger and thinner tube improve the power?

Im using a 11.1V lipo battery, something you can find in RC-cars. Increasing voltage/amps IS NOT AN OPTION. 

So, in simplicity, if i make a solenoid like mine, but longer, can it pull greater load than the original or do i need to do something else as well?

The actual aplication itself in simplicity is the solenoid pulling certain object back around ~10mm AGAINST a spring, not very powerfull spring might i add. It pulls the object back, then lets go. It will be controlled via a circuit later but right now just a battery and nut-job holding a red button.
I just need a solenoid powerfull enough to overcome the spring. The object needs some force  to return to its position so putting in a smaller spring is not an option eighter.


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5 years ago

20N is around ~5k or so. I need MORE POWAH!


5 years ago

There's always the option to use a car rear hatch door actuator. they usually have about 3.5-4.5Kg of power.


5 years ago

Check some old commercail laser printers and copy machines.
These big towers use quite a bunch of these relays in different configurations and lenghts.
But you have to keep in mind that an electromagnet does not really work the way you might think (judging by your post).
They are used to hold things but not to push or pull them ;)
Take the printer as an example:
One of those things is connected to a mechanism that pressed a roller on paper for transport.
There is a weak pring to hold it all up.
Once the relay is activated it pulls the plunger in - the roller is locked in place by the holding force of the now closed relay.
Even a soft 5mm thick foam piece will be enough to overpower this relay as there is not enough strenght to pull.

If your existing one is already next to perfect try this out:
Make a new plunger of the same diameter but shorter.
The lenght it need to be shorter is determined by the thickness of two rond neodymium magnets you will add.
To make sure all stays together add a drop of 2K glue.
Just to be clear:
The new one should be same length and diameter as the original, just with one magnet on either side - distance between magnets is the length of your coil.
You will need a plastic spacer inside the hole for the plunger to prevent it from binding too much at the end.
Alternative would be to drill out the end and to place a plastic cover over it.
With the magnets the system could be about 3 times as strong in terms of pulling power, if the coil receives enough juice.
With the hole added you can use it push and pull by reversing the polarity on the coil.

So that enough writing for today for me ;)


5 years ago

Shame, because increasing volts briefly is the best answer, charge a nice fat cap to 3 or 4 X the nominal DC rating of the solenoid, then whack it hard.