110V Reciprocating Saw conversion to mounted sex machine. Need help with speed controller.

[Capital_Kink_Couple]

My sub has fallen in love with a video she saw of Rain DeGrey fully restrained with a high-speed sex-machine driven dildo positioned below her and mounted anally.  Upon watching this video, I can tell that they were using a modified 110V/120V reciprocating saw with a vac-u-lock toy attachment.  The modification though is that it was being speed controlled to either go very slow (approx 40-80 RPM) and then was turned up to approx 900 +/- RPM.  This intense speed mixed with its shallow thrust depths can create the surrounding body to vibrate at a frequency that will cause the other nearby areas to also vibrate to orgasm (vaginal & clitoral).  I have been watching other like-kind videos and have seen where they were able to get the appropriate rpms to create this affect again and again.

This is where I am stuck.  I purchased a new Craftsman corded 110V/120V  7.5A  CMES300 reciprocating saw.  It came with a variable speed trigger, but this was pretty useless as it didn't offer much control (as you could expect) so I removed it.  I fully removed all of the body work until I was down to the mechanics of the saw itself.  Now with the trigger and cord removed, I should be able to wire a variable speed controller to it.  So, I purchased a Variable Fan Speed Controller AC 120V 15A (max 15A) for Fans and Vent Blower.  It had a Low/Medium/High dial and a Variable or Full switch.  But, no matter what level or setting I put the controller on, it only gave me full speed (which is 3,200 RPM on this model which is pretty normal). Any ideas on how to properly control this to lower-mid speeds?  What type of variable speed controller can be used to control this to the speeds that are needed?  It is not a brushless motor (if this helps).

I fully understand that by slowing it down, it can and will overheat but I am going to address that separately by building it into a box with cooling fans directed on the motor itself.  Not planning on keeping on that long either.  

Thank you for any help with this.  If it ends up working out, I will post the parts and process on here for possibly making your own

[Ar****]

I'd consider posting this query on some tech/engineering forums (you wouldn't even have to mention the purpose if you want to be discreet, just your issue), I'm sure somebody here has the experience and know-how but it might be a long shot as to whether they'll see this. Good luck either way.

[PanamaJoe]

I think you'll need a 0-130V variac.   It should work on all equipment - including vibrators.   No guarantees though.   I've used one before to control everything from light sources to mechanical equipment - but never tried one with a reciprocating saw.

[Jimmmy]

If it’s an induction motor then you need to control the frequency really, otherwise you’re just going to get a reduction in power and speed but with a massive reduction in torque also. If it’s a brushed motor then you’re best converting to DC and varying the voltage, because that will still maintain a reasonable amount of power and torque whilst giving you the controlability. It’s not just dead simple…

This is why most commercially available machines use DC motors driven by a DC speed controller. That’s also why electric vehicles use DC motors, because of their controlability. The variable speed controls that we get on AC power tools are okay within a certain range of speeds, but when you want to get down to really low speeds, which for this application you do, things become not so good. Try looking on eBay for a 1/2 hp (375W) rated single phase inverter, which will drive the motor at the appropriate speed by controlling the frequency. They’re actually not that expensive nowadays and this will do the job for you, most likely.

[on****]

It may be the case that in the video only the case was retained and everything inside was replaced. Personally if I were doing it I'd go with a brushless DC motor, connected to step down gearing to reduce speed and keep the torque up. Control via microcontroller, probably an Arduino. Whole setup would run on safer voltages rather than mains/line voltage

[Capital_Kink_Couple]

Thank you to everyone that has replied and with ideas on how to possibly make this happen.  I am expecting to start work on the chair & restraints in 1-2 months and will start messing around with modifying the motor and control unit(s).  I have found other brands with higher amperages that offer a separate speed-control dial on unit.  The one like I have has it integrated into the trigger.  I may try one of the others and maybe replace their small dial with a separate, large unit that would give me more control.  I have been researching these online since posting and have found a few vids of users with them in action.  Have also found a custom metal fabricator that makes a vac-u-lock adapter that is looks to be strong enough to take the rapid *** (they have a tendency to break, even at lower speeds).  I ordered one and it is superbly built.

Once I have something and it is working consistently, I will post it on this forum.  Have a feeling this is going to be some trial and error before I have something that can repeatedly be used for extended periods of time without overheating (low speeds seem to be the heat enemy of these motors), so I will figure in a cooling system for it too without grossly over engineering it.

Thanks again everyone!