I seem to have gotten there, with even less ado and expenses:
After more than a year's of trial and error, I finally got my Venus2K clone act together and it's really excellent!
It's that good that even changed its name to: "Sophie 2000" 😃
The hardest thing was to find a strong, reciprocating motor cheaply. Finally, an $US80 (incl. shipping) Chi machine did it:
I swapped its motor for a Dodge window wiper motor and adapted the quite, geared Chi motor to my project, Now I have got both, the Chi machine and the Venus 2K clone working!
My "Sophie 2000" consists of:
1. Chi motor 220VDC (consuming 2A5= 550W of 22oV AC)
2. Pneumatic Cylinder 50x50mm (50mm stroke) $US30
3. Adjustable air valve
4. One-way air valve
3. Bridge Rectifier
4. 47uF/400V Electrolytic
5. Switch
6. Lamp Dimmer for 60 rpm (snail) to 280 rpm (rabbit)
I mounted all parts onto small piece of plywood and glued a piece of firm rubber foam underneath.
For frequent and comfortable use, I suspend the receiver onto a type of wooden bridge/ frame with a leather swing or place it between 3.5Kg of (cut-open) silicon buttocks, I used for years before and thus, put them to good use by enjoying something soft to hold on...
Result: The pumping action then pivots the whole silicon bum at the table's edge up and down, cradling the scrotum. - I can only describe the physical sensation as "ravingly insane!"
For best lubrication I regularly prepare a 1 liter bottle of Xanthan Gum + Guar Gum + water mix with a pinch of salt (as preservative). Even at +36°C it never turned bad.
The receiver housing I build myself from a tough, flexible (medical pill container) plastic tube, sanding its edges super smooth. Try different sizes...
As liner I use bicycle inner tubing 29 x 2.3 inches. Its firmness is welcome, for its pressure degree I control via that adjustable air valve.
To lubricate the motor's gearbox and the crank assembly, I use gun oil-thinned graphite grease or silicon spray. To lubricate the air cylinder's o-rings, I use special rubber grease.
Frankly, I don't think I can be happy anymore without my "Sophie"! Now at a young pensioner (71) I almost daily enjoy poking my new, hot "Sophie"! My dear wife is getting on in age and I hate to molest her with my sexy desires... So, I'm quite happy to share my physical joys with motorized Sophie and the exchange of virtues with my dear wife. That also keeps me home, safe from HIV/ AIDS! Last, not least benefiting my prostate it saves me bundles of money... End of my sexy problems!
Even though it works fantastically, I enjoy improving it. For instance:
1) Now I plan to build a light weight, small size "traveler version".
2) I now adapted the Japanese Rends Piston Liner and use it as the Receiver cup. It's even more effective and longer lasting than any rubber tubing.