So - why not use an electromagnet for bolt control

[Lohman446]

Disclaimer - I state a lot of things in here as fact. They are my understandings of how things work, and they may very well be wrong. Feel free to correct me. THis may have been done, or may be being done in the past as well.. I don't know

Most blow forward markers fire the marker with air from behind the bolt, then use a force in front of the bolt (normally air) to reset the bolt. We are familar with the mag using a spring. The advantage of the air system is that the bolt does not have to overcome the constant spring tension that is there.

What if we appraoched this in a different direction? Why use spring or air, there has to be something else. What if we put constant regulated pressure behind the bolt - enough to propel our ball to 300FPS (or whatever). Now, rather than using air to control the bolt coming back, or a sear, the bolt is held in place by an electromagnet - either placed around, behind, or wherever in relation to the metal bolt or a piece of metal in the bolt. When you pull the trigger you interupt power to this magnet (or do they have electromagnets that work in reverse - ie power turns them off, lack of power turns themon) which allows the bolt to go forward. The magnet than turns back on, pulling the bolt back as the chamber refills.

Is it worth considering? The advantage I see is a possible increase in efficiency and a more relaible system with less moving parts than the air assisted ones. I also see the ability to keep the marker a true single tube design, as you only need air running to one spot.

Discussion?

[Chronobreak]

because people dont want an e-mag sized battery or larger

[Lohman446]

I thought about that as I posted. Do they make a "reverse" type electromagnet - defaults to operating as a magnet and then power turns it off? I don't know at all on that. And how much power would it take to pull a bolt back?

[BlackVCG]

So... basically whenever you're not shooting, the magnet is drawing current from the battery.

I see that is a very LOW battery life gun. Also, you'll have to use a pretty heavy material for the bolt inorder for it to have enough magnetism to get fast enough cycle rate out of the gun and therefore the magnet will have to use a lot of current to be able to cycle the bolt with its relatively large mass.

[Chronobreak]

So... basically whenever you're not shooting, the magnet is drawing current from the battery.

I see that is a very LOW battery life gun. Also, you'll have to use a pretty heavy material for the bolt inorder for it to have enough magnetism to get fast enough cycle rate out of the gun and therefore the magnet will have to use a lot of current to be able to cycle the bolt with its relatively large mass.


these are the issues ive head before being the main problems

i think it was brought up in tech before or deep blue

[SlartyBartFast]

Look at the size and power requirements for the Emag solenoid.

Now scale the whole thing up to consider the cycling requirements of a bolt. That's why it's a difficult concept to implement.

Now, there's that NPS electro-marker thing and Airsoft works on electric power only...

[Lohman446]

I take that as a no such thing as a reverse electro magnet. What I mean - no power magnetic; power applied - not magnetic

[TheTramp]

I don't think so as the Magnetic force is created by current running through the coil. No power, no current, no force.

[Lohman446]

Hmm... I wonder how much power it would take to hold the magnet back.. I don't see it being used for scenario games... nto fired a shot in XX hours and all of the sudden the bolt just jumps forward and you get a massive air leak because you dont have enough power to hold it... well theres another rambling idea that gets nowhere.

[VFX_Fenix]

What you're talking about is essencially turning the entire bolt assembly into a big selenoid. That could work, though as it stands now I don't believe it to be pratical with the current layout of the Automag Valve/Bolt system.

Now here's some food for thought (just came up with it actually)

If we assume that this new bolt arrangement would work like a 'noid, what's to say that you can't just use the 'noid to pull the bolt forward instead of relying on air pressure to drive the system.

Or if we still apply the blow forward design what if the bolt design changed and we got a longer stem on the center of the bolt with a 'noid mounted inside the valve such that the noid is just holding on to the guide rod in the center of the bolt when it's closed. The valve would need a make-over for this to work, a new bolt, new and creative wiring.

How about this, just use a 'noid to reset the bolt instead of a spring. Everything else would remain the same, relatively anyway. Sear would still catch the bolt and open the On/Off valve. With the ULT we could assume that a 9V can drive the sear tripper side and also drive the noid used to reset the bolt if it were made of... I dunno... Delrin or something lighter than the LX bolt.

[SlartyBartFast]

You'd probably be much better off using a stepper motor to move a bolt than a solenoid.

A high speed motor geared to the bolt could easily generate the required speed and force.

[VFX_Fenix]

yeah but that's noisier ;)

[steveg]

So... basically whenever you're not shooting, the magnet is drawing current from the battery.

I see that is a very LOW battery life gun. Also, you'll have to use a pretty heavy material for the bolt inorder for it to have enough magnetism to get fast enough cycle rate out of the gun and therefore the magnet will have to use a lot of current to be able to cycle the bolt with its relatively large mass.


It's common in clutch/brake assemblies, used in rotating machinery to use a
permanent magnet to hold the brake disc and friction material together,
then use an electromagnet of opposite polarity to cancel the magnetic effect of the
permanent magnet.

Still going to take one heck of a battery though!

[mag88888]

i would consider this if the magnets functioned good for say.......5000 shots then i could recharge them. and i wouldnt want them to be really heavy. but hey, anyone can deal with a few more ounces.

[txaggie08]

I take that as a no such thing as a reverse electro magnet. What I mean - no power magnetic; power applied - not magnetic


you wouldnt need a reverse electomagnet, you would need a realy that would only stay open and delivering power when it have power. then when it lost it it would close

[AGD202]

from what im understanding... u wont be able to make the bolt out of lightweight materials... and the battery would have to be massive.... after all of that the gun would probably end up weighing more than an emag does stock... and every1 knows emags are heavy stock... if u could make it lighter or maybe stick a battery in ur pocket w/ wire comming up to it? that would be all good.... but then whats the point if u dont have to use air? air and paint are the 2 things of paintball that make it the sport....

[txaggie08]

why not use a normal magnet for bolt return? it would eleiminate the spring issue thats for shure. plae t at the front of the chamber and use it to drive the boltback AFTER the gun discharges

[ApexAZ]

from what im understanding... u wont be able to make the bolt out of lightweight materials... and the battery would have to be massive.... after all of that the gun would probably end up weighing more than an emag does stock... and every1 knows emags are heavy stock... if u could make it lighter or maybe stick a battery in ur pocket w/ wire comming up to it? that would be all good.... but then whats the point if u dont have to use air? air and paint are the 2 things of paintball that make it the sport....

You would still need air to fire the ball.

[SlartyBartFast]

why not use a normal magnet for bolt return? it would eleiminate the spring issue thats for shure. place it at the front of the chamber and use it to drive the boltback AFTER the gun discharges

I believe the electrician already posted this idea in his boltless mag experimentation thread.

[Lohman446]

why not use a normal magnet for bolt return? it would eleiminate the spring issue thats for shure. plae t at the front of the chamber and use it to drive the boltback AFTER the gun discharges


To me the advantage of air over the bolt aws you had no resistance when the botl was trying to move forward (or minimal) The resistance to forward pressure could be "off" when the marker was firing. This is the big advantage to me over a spring (that and perhaps more controllability of dwell, I really don't know). A magnet would do the same thing as the spring, but offer little in the way of advantages I would think...

[hitech]

What you describe is an electrical solenoid. The bolt is the plunger.

You could use that idea (or a separate solenoid with a linkage to the bolt) to return the bolt instead of or in addition to the current return spring. Attempting to use it instead of wouldn't be practical. The power requirements are too high. In addition to is an interesting idea. However, to overcome the force generated by the air pressure against the bolt stem would still probably have a high power requirement.

:cheers:

[Glickman]

what do you think?(i "borrowed" the template from a certain ion diagram :D i tried from scratch and it sucked )

the first one is when its done getting reset by the magnets (yellow)

the second is when its firing


not practical at the moment, but is it feasable? (of course the magnets would be connected to a external power source)


http://img56.exs.cx/img56/599/thissucks2mo.jpg
http://img56.exs.cx/img56/599/thissucks2mo.jpg

[Lohman446]

In the first one, which is really what I had in mind when I started (but my magnets were at the back in my mind, same concept of operation though) but now realize the error of what is holding the bolt back? In my mind those magnets half to stay energized... which produced a battery life issue as others pointed out. I still think theres some way to overcome this though... just not sure what

[ICP]

I've been going over this in my head for about a 2 weeks. They have electro magnets that will run off of 3,6,9,12,18,24 volt (and higher of course). A 3/4" dia. X .66 long magnet has a holding force of roughly 5lbs with a 1 watt suplly of power, 2 watts = 7lbs, etc. all the way up to 13lbs at 10 watts. However, because I'm not any good at electronics, I don't know exactly what a 9v (or 2) will put out (in watts). Here is my idea for the design of the gun.


Single tube (1" OD, 3/4" ID), Body is 5" long (about the same length as your intelli), I would use a removable breech type setup(but that is another story at this point). Basically it is a poppit style valve set up.There will be a "breach seal" not a bolt made of thin delrin(or the like) Kind of L shaped to protrude into the body, behind the valve. This piece will have a small but strong(ish) magnet (earth maybe) set to be opposite polarity of the energized electromagnet. When the trigger is pressed, hits the switch, powers the EM and pushes the "breech seal" about .700 to close the feedport and stikes the poppit stem at the same time. As of right now there will be a valve spring in front of the valve (much like a spyder valve) that will seat up against the valve seal(damn, can't think of the name) and then against a ledge in the front of the body. Of course the valve spring will be changeable for tuning to specific function. And since the EM has a piece of steel running through the center (for mounting options) The earth magnet should draw enough on the EM to return the "breech seal" to original position and load for the next shot.

After all that rambling, this should prob. be in the tech section or mod section. But since it was already started here, I just decided to post it. Anybody that has information regarding how many volts will put out a certain amount of watts, please get in contact with, I would really appreciate it. I've thought hard about this, and will most likely try it, even if somebody finds a huge hole in my design concept. It's nice to be able to get working and sometimes makes it easier to think/change or redesign things for me.

Any imput? If it's hard to understand for a lot of people, I will try to get a sketch to explain with pictures.

[Glickman]

Watts = Amps x Volts

very well thought out.


its a great starting point, anyone wanna try? ;) :D

[Lohman446]

The more coils in an electomagnet the less power it takes.. what if we made coils the full length of the firing chamber? You could vary the composition of the bolt to allow it to pull only on the back of the bolt and not the front so it would pull it back taking less power?

Just throwing out ideas now, someone with a better understanding is going to have to work out the details if they want to try it

[ICP]

Watts = Amps x Volts

very well thought out.


its a great starting point, anyone wanna try? ;) :D


I'm still a complete idiot when it comes to electronics. As an example, I've got a 9v battery. How do I control the ampere output to get the watt value?

And yes I'm working on it now. I've got the body done and will use a spyder frame for now, because it already has a board that is outputing 9v. Should have my electro magnet in by the weekend. then will do some testing before completeing the body/barrel, etc.

[txaggie08]

To me the advantage of air over the bolt aws you had no resistance when the botl was trying to move forward (or minimal) The resistance to forward pressure could be "off" when the marker was firing. This is the big advantage to me over a spring (that and perhaps more controllability of dwell, I really don't know). A magnet would do the same thing as the spring, but offer little in the way of advantages I would think...

i was thinking of smoothness. allow the gun to cycle without the force of the spring driving it back. possibly even use a smaller electormagnet to "amplify the return force asthe bold moved away. just a thought. i also dont beleive the magnets that would be used in something like a full magnetic operation would draw as much energy as everyone beleives