Intro
I am an engineering major college student. Though I cannot afford a doll yet, I've been browsing the forum and it seems like the cleaning process can be improved. I developed this DIY device that hopefully could help you with cleaning by removing the need to move your dolls to the bathroom, as I know they can be pretty cumbersome.
I have seen similar devices being sold for a pretty high price ($300+), so I came up with this design with as many off-the-shelf parts as possible and minimal skill/tool needed to assemble. If anyone can share their advice for improvement it would be much appreciated : )
If you prefer watching the demo video instead of reading, please scroll down.
How it works
The device works by flushing your doll's love hole with a water pump and recycling the dirty water (with air too) with a vacuum. The following illustration shows the device's structure and water flow paths.
If the nozzle assembly is properly matched to the opening size, there should be minimal leak of water. Therefore, you should be able to do the cleaning without moving the doll to the bathroom. I tested it with a butt onahole and it worked pretty well. Just having an apron or bathing towel underneath for minimal leakage. This should still be better than moving the whole doll.
Off-the-shelf Parts
The following list has generic keywords because any model could work as long as they fit. I'm not sure if posting Amazon links (not affiliated, just what I bought) is allowed, but if you can't find them with these keywords let me know maybe I can send the links of the models I used in the prototype as a reference.
- 2 Sealed food containers
about 4L capacity will be sufficient for flushing two holes without refilling. ideally, a container with a spout opening on top will be easy for installing the connectors (see photo below).~$9 for two
- Submersible water pump
Any submersible aquarium water pump. I used a 150GPH one and it's roughly enough, but I think a higher flow (250GPH+) variant might be even better.~$15
- Mini vacuum pump
There are plenty of options: you can use your home vacuum just by attaching the nozzle to our device; if you want better portability, I recommend a "vacuum pump for storage bags (typically corded, 4000-9000Pa)", or a "desktop mini vacuum(typically battery powered, better pressure but short runtime)"~$15~30
- Tubing
Two pieces of tubing, one of larger and one of smaller diameter. The inner tube should fit onto your water pump. The outer tube should be able to withstand negative pressure. I do not recommend the corrugated type as the grooves may collect moisture and filth.~$9
- Outlet adapter with switch (optional)
The little water pumps often don't have a switch. I did some soldering to implement my switch, but buying this could be an easier option if you don't have the tools/materials to do electrical work.~$5
- Wine carton (optional)
Just to hold the two tanks together for easy lifting. I found the 6-bottle carton from any grocery store working perfectly, but you can also just tape them together, etc. Probably free if you politely ask to use it for "a school project".
3D Printed parts
This is where it gets a little tricky. While I tried using commercial parts to do the job, too many modifications were involved and the result wasn't very good still. I have a 3D printer, so I printed key parts with it.
- Custom 3-way T connector
This part seals the dirty water tank for vacuum and coaxially joins the water and air tubings. It is custom-made for the food container I had in hand, but it seems like plenty of products shared this opening diameter of ~60mm.
- Flushing wand
The center tube jets out clean water, and the outer tube vacuums dirty water and air back to the dirty water tank.
The flaps on the side hold the hole open to promote better fluid flow, and you can rotate it around to get full coverage. Its outer diameter is <36mm, which I believe should not damage the hole.
I plan to make maybe more variants in length increments. In the demo video, the rod is a bit longer than the hole depth.
*I initially intended to install the electrical switches on this handle, but it complicates the assembly process, and sealing 110V with water right next to it is somewhat challenging/costly for our lowkey DIY project.
Here is a photo of the assembled device. Not much to say about the assembling process, just plug things together.
Just gonna love how the wine carton perfectly holds the two containers with a handle. Demo Video
Here is a video showing the use of it. You can see there is minimal amount of water coming out so I only needed a bath towel instead of moving the doll to the bathroom.
Q & A for some design considerations
- High pressure vs. High flow?
For the smaller-sized pumps, the pressure is generally quite low (much less than a car washing machine's pump). I do believe a low-pressure flow with enough total flow is enough for cleaning purposes. Additionally, high pressure may pose a threat to some TPE dolls with a sealing "plug/ball".
- Why an air vacuum instead of a water pump?
These smaller-sized water pumps are typically centrifugal pumps that require being submersed to work properly. It would be an annoying process if we have to first fill up the tube with water for the pump to have sucking power. Plus, what comes back from the outer tube is a mixture of air, water, and other fluid (like lube) which are not ideal media for these water pumps.
- Protecting the vacuum from water damage?
There is no specific protection for this in this early prototype yet, and I plan to design some anti-splash structure onto the connector, or a floating valve to shut the passage when the water level rises too high.
Because the capacity of either tank is the same, if you empty the dirty water tank first and don't fill up the clean water tank too full, there shouldn't be enough water to reach the vacuum pump.
Thanks for checking out my little invention! I would appreciate any comments and questions.
* Dear moderators, I fully understand and respect the no-selling rules of this subforum. May I know if selling one or two 3D printed parts is categorized as "prototypes" and allowed here (if a member who doesn't have a printer requests the parts from me)?