www.BoundAnna.com

These are now available :- http://www.amazon.com/Master-Lock-Dialspeed-Electronic-Combination/dp/B009THBSUG and take a sequence of up to 12 presses to open, given that a randomly generated 12 press (of 4 buttons) sequence would be very hard to remember the idea is :- Arduino/similar generates and di...

Sir Cumference wrote: Ok, thanks.

I have been looking into the pulse valves used for beating dust of filter bags.

They are very interesting..... And correspondingly pricey.

I looked at them briefly, basically a pimped up servo (piloted) valve by the looks of them.

Just so everyone knows... There are portable air tanks for use to fill car tires and such.... Some even come with their own chargers... and some are even 12v DC powered for use while you are on the road... Not available in all parts of the world, certainly not common in the UK. If you're not famili...

...... I'm currently modifying some old CO2 extinguishers for use as special effects confetti canons they have a test pressure of 200 BAR but they will only be used at 10 BAR or less which I'd say is a pretty good safety margin. Interesting! What kind of valve do you intend use? Sorry for the delay...

Note if you are intending to use commercial gas cylinders and try and re-fill them many (depends on type and country) have non-return valves and some also have excess flow valves (mostly on propane cylinders). The non-return valve is there partly so that back pressure in a mixed gas system can't for...

To use the motor to do the spanking is the hard/hi-tech way to do this... In this case, the low tech is the way to go... And potentially very dangerous, if you are feeding a High torque High speed motor (as in the example above) with 30V for several 10's of ms what happens if the control circuit fa...

For that sort of machine, I strongly prefer a servo or stepper motor... similar to the Pain4fem machine but with actual computer control so it's not limited to a shoelace-style effector. You need the ability to change acceleration arc and profile to match a range of implements. Servos/steppers with...

Agreed there is simply no such thing as a "simple" spanker. The only realistic methods are either very expensive high speed/high torque motors (along with very careful control! you really don't want a spanker using them going wrong) or storing energy in a spring/bungy using a relatively ch...

Another simple way to seed a random number generator is to have a fast loop running through seed values, when the user presses a "start" button the seed is chosen. If you wanted a motion sensor could re-seed the PRNG regularly.

Well sprag clutch and pinion gear finally arrived, the pinion gear happens to be a nice fit on a windscreen wiper motor shaft but needs a way of locking it onto the shaft, probably a grub screw. (The thing on the right hand side of the motor is an slotted opto sensor that I fitted for a previous job...

A scenario I would like to try is this :- Number of strokes is randomly decided (between limits you set). You will only be released once that number of strokes has been delivered. You decide when strokes are delivered by pressing a button but of course have no idea how many you need to receive befor...

lj wrote: perhaps you need to find a sub who also happens to be an Engineer ?

Hello! Trouble is I'm in the UK. Any Doms need a sub engineer?

I know this is quite an old thread and I've not been around here for quite a while! But re. the pain4fem machine, I've been looking into this and it looks very much like it uses a "sprag clutch" sometimes known as an over run clutch. Specifically it looks like one used as the starter on ma...

lj wrote:

Jeanette wrote: Does anybody know that a 12 volt battery can put out ungodly amperage, - under the right circumstances?

That's what fuses were invented for !

Powdered graphite it the best lubricant for locks (You can buy it specifically for this purpose) WD40 and silicone oils are OK but many oils can cause more problems than they solve as they attract and cause dust/dirt to stick thus gumming up the mechanism. If you use padlocks to lock yourself to som...