The inspiration
Some time ago I saw a video of a girl strapping herself into a spanking machine and this got me thinking about building such a device. I have always been interested in impact play and have enjoyed sessions both as a Top and Bottom. As an engineer with access to all sorts of equipment I figured it shouldn’t be too difficult.
The design
I wanted something that would work on a timer, so I would be locked in for a predetermined length of time. I thought about a mechanical device using sand, like an old-fashioned hourglass, but then I found an electronic timer PCB online for a few pounds, much better
In the video the girl locked herself in a pair of handcuffs, this would be OK when there was a film crew around to let her out, but I wanted something more automated. I settled on a simple stock design. This could be locked with a metal bracket held in place with a small electromagnet. The impact element would be provided by something flexible i.e., a belt or strap, using a horizontal rotary motion
The Build
I precured a 12v DC motor and power supply and designed a paddle attachment clamp for the motor, this was 3D printed. The stocks were made form a piece of wood from my off-cut box, and the lock made for a piece of sheet metal from my metal scrap bin. the only think I needed to purchase was the hinges and the electromagnet. I design a holder for the PCB that could accommodate a micro switch, this was 3D printed along with a trigger to activate the micro switch to start the timer. An old leather belt was cut in half and the two halves bonded together back-to-back to give a strong but flexible paddle
The Bench Test
First, I need to determine the speed of the motor i.e., the RPM (revolutions per minute). this was easily achieved with a small magnet and an app on my phone. the test was conducted with a long piece of wood in the clamp to which a leather belt was attached and counterbalanced with a lead weight. The result of the test was an average of 88 RPM. More importantly was the force delivered by the leather belt, when my hand was placed in its path the result was a reasonable slap against my palm.
The stocks and lock were also bench tested, with some fine tunning on the lock it worked very well. Once the lock was engaged there was no escape till the magnet was switched off.
The timer PCB has two settings for the time 1 for seconds and 1 for minutes, a little experimentation determined the relation between the settings. this meant I could set the time in seconds and know how minutes it would say on for
All the parts are 12V so could be run from 1 power supply, I just needed to work out the wiring and I was sorted
Play time
There is an old saying “when the cats away the mice can play” and so the time arrived when I got the chance to set up and play. Setting up didn’t take long as it had all been planned out. I repurposed my weight bench, the stocks were fixed to a board that sat under the bench and PCB and trigger were fixt in front with a short piece of cord that could be reached from the stocks, a few anchor points fixed to the board and that part was ready.
The motor was fixed to a piece of wood and stabilized with weights, and the power was connected.
The timer was set for 5 seconds, and an unmanned test run was triggered to check worked as expected. All was good so a second test was set up with me just over the bench with no restraints to check the alignment, a few adjustments were made to the motor position, and we were good to go.
All that was left to do was set the timer, it was adjusted to 20 seconds this would give about a 5 min run time when set to minuet mode.
So, all was set for the auto spank first run, straps were secured, I was completely immobile, arms placed in the stocks and took hold of the cord, one big breath and a quick tug on the cord and nothing!
A quick check found a loose connection, once this was fixed and I was resecured to the bench I was ready again. This time it all worked the stock locked with a click and the motor started. One downside of my design was all the strikes were in the same place, so whilst the force each blow was quite low, over time they soon added up, and after about 4 minutes I was looking forward to the end.
When I was released from the stocks, I check the damage and found 1 very red stripe across 1 cheek but not much on the other. It seems the belt needed to be a bit longer. O well always room for improvement
J
PS. Auto spank Mkll coming soon
