Solenoids

[bigegg]

Does anyone know anything about solenoids?

I'm after one that will "fire" about 20-30mm in <100ms with a force around 10-15N

Preferably running on 12v DC, but whatever...

I CANT use compressed air/co2 - it has to be electric

 

[andymfell]

look for a "push-pull" actuator loads on ebay but might not have load capacity

or

Linear actuators are available in 12v but might mot have the response time you are looking for

 

[bigegg]

look for a "push-pull" actuator loads on ebay but might not have load capacity

or

Linear actuators are available in 12v but might mot have the response time you are looking for

Yep
That's the issue I'm having.
Plus I don't know enough about them to know what to search for.

 

[bigegg]

I'm looking for something to make an impact, rather than push, if that makes any difference.

 

[Luke]

I've seen solenoid controllers that use a much higher voltage to get the core moving, then back off to a holding voltage a few 10s of milliseconds later. I think it was something like 60 volts for a 24v coil.

 

[bigegg]

After a bit more thinking, I think I might be able to use a spring and a solenoid operated trigger and a seperate solenoid to reset.
I only need one impact per minute.

A single solenoid solution would be much more elegant however.

 

[Robotstar5]

After a bit more thinking, I think I might be able to use a spring and a solenoid operated trigger and a seperate solenoid to reset.
I only need one impact per minute.

A single solenoid solution would be much more elegant however.

Why not use a spring forward operated solenoid that uses the coil to retract and hold it?.

 

[bigegg]

Why not use a spring forward operated solenoid that uses the coil to retract and hold it?.

Because I didn't know there *was* such a thing.
Can I get one with a powerful enough spring?
I'm assuming I can get a latching one? So it doesn't use power to hold?

 

[Robotstar5]

Because I didn't know there *was* such a thing.
Can I get one with a powerful enough spring?
I'm assuming I can get a latching one? So it doesn't use power to hold?

Not seen one like that they normally hols with power

 

[zzr1200]

You can get a 12 volt solenoid that has a pull in ampage (8>10 amps) and then has an automatic hold in of about 1 amp, spring extension.

Used on MEWP's as throttle solenoids, what do you need to hit/move with the solenoid?

You can also get unit that extend under power but without more details it hard to say much more.

 

[bigegg]

You can get a 12 volt solenoid that has a pull in ampage (8>10 amps) and then has an automatic hold in of about 1 amp, spring extension.

Used on MEWP's as throttle solenoids, what do you need to hit/move with the solenoid?

You can also get unit that extend under power but without more details it hard to say much more.

I'm going to make a rat trap.
Like the "good nature a24", but electrically powered.

The idea is that it's a baited vertical tube, just big enough for a rat to stick it's head up into.
When it gets far enough up the tube, theres a switch/sensor which activates the solenoid, hitting it in the head.
The body falls out of the tube, and will be disposed of by carrion eaters.
The trap then resets.

The original is powered by a c02 cylinder and can do 24 kills per cylinder. I want one that can be mains (or battery) operated.

 

[henry Kadzielski]

^^^ I think you can use 'fuel shutdown' soleniods. These are available in both 12 and 24v. They are available in both push and pull configurations. Look up 'woodward' or 'syncro start'. There is also coil controllers they control the power to the solinoid so it doesn't burn out. The most reliable versions now are the three wire ones. All, or most are now made in China and as such don't last as well as what they used to. These have generally up to a 30mm stroke and are rated for their push / pull in newtons. So exactly what you are after. They are used on genset diesel engines for the fuel control / protection of the set. If there is a problem the solenoid will turn the fuel off and shut the engine down.

 

[MCKDAVID]

what about the "hammer" coil / core etc out of a battery nailer, plenty force there, and dc.. if the spindle isn't long enough, you could just lengthen it to suit..

 

[Anguz]

Or a spring to fire, with something like a battery drill winder to pull spring back ....

 

[Anguz]

https://m.youtube.com/watch?time_continue=465&v=tbKGjRoSofA

Could do worse than the winder mechanism on that

 

[Dieselman 63]

I'm going to make a rat trap.
Like the "good nature a24", but electrically powered.

The idea is that it's a baited vertical tube, just big enough for a rat to stick it's head up into.
When it gets far enough up the tube, theres a switch/sensor which activates the solenoid, hitting it in the head.
The body falls out of the tube, and will be disposed of by carrion eaters.
The trap then resets.

The original is powered by a c02 cylinder and can do 24 kills per cylinder. I want one that can be mains (or battery) operated.

This wouldn't happen to be this one would it?

https://www.goodnature.co.nz/products/rat-stoat/

 

[bigegg]

This wouldn't happen to be this one would it?

https://www.goodnature.co.nz/products/rat-stoat/

That's the one

It's patented, but the patent doesn't cover electrically operated.

I'm going to call mine "TIITH" (pronounced "teeth")

Stands for "tw.. it in the head"

 

[Maker]

That's the one

It's patented, but the patent doesn't cover electrically operated.

I'm going to call mine "TIITH" (pronounced "teeth")

Stands for "tw.. it in the head"

Are you making a few to sell then?

I was going to suggest winding your own solenoid but that's not really practical unless you only need one or two.

 

[colnerov]

Hi, What about using a solenoid off of a starter motor? They shove the gear into mesh with the flywheel at quite a rate and force to ensure engagement. They have an internal spring to reset it. If the length of throw is not enough, use a lever for mechanical advantage.

Colin

 

[bigegg]

Are you making a few to sell then?

I was going to suggest winding your own solenoid but that's not really practical unless you only need one or two.

No.
Not to sell - just gonna publish plans.
I considered winding my own, but solenoids are only £1 - £10 so not really worth making - if I can source the correct size.