Low voltage, high current Elec. Magnet

[Pax Writer]

Hi experts

I'm just thinking about starting a new project, where I want to either push or pull a piston with a neodymium or similar magnet in it using a low voltage electro magnet in an H-bridge so I can change polarity at will. Compressed air is not an option but I do have the possibility of using a relatively effecient battery.

I don't yet have the specs for the thingy, but my design limitations are, so far:
Voltage: Max 15V (but preferebly 12V)
Current: Up to 40A
Stroke length: ~7.5cm
Stroke frequency: 15-25 strokes/second

Apart from not knowing whether such a project can even be realised (due to currently lacking knowledge of magnetism and mechanics - But I'll study up on that), I wonder if I'll have to make the electro magnet myself or if there's somewhere I can find such a fella (by fella I mean electro magnet, but I guess since I now spent many more words explaining my abbreviation, I might as well not have abbreviated it in the first place... Dang... ).
So what do you think:
- Is such a project possible, judging from the few specs I have?
- Should I make my own electro magnet or buy one (and if so, where? Links are appreciated).

Thanks in advance for your thoughts.

Pax

 

[JimB]

....if there's somewhere I can find such a fella (by fella I mean electro magnet, but I guess since I now spent many more words explaining my abbreviation, I might as well not have abbreviated it in the first place... Dang... ).

Dont you just hate it when that happens!

Regarding the electromagnet, I think that you need to know the mass of the thing you are trying to move.
Only then can you know how much force you will need to move it, and hence the current you will need in the coil.

JimB

 

[Pax Writer]

The weight is estimated at 200-250 grams.
The piston is around 100-140 grams. The rest is the magnet...