One of the cool things about vacuum based milkers is that they can suck in their own lube and if set up correctly never run dry. So in theory one could leave a sub on the milker for days 😈 (Well, please don’t in reality, there may be other things causing issues).

Lube

As I had mentioned in part 2 already, there’s a third hose for the lube supply going to the receiver. I’m using a transparent 3mm hose.

 

On the receiver-side I added a clamp to shut off and regulate the flow of lube and a simple hose connector. I’m planning to upgrade to a PMC connector though.

On the “machine”-side, I’m using a cheap PE bottle and a custom printed cap. The vacuum in the receiver sucks in the lube from the bottle. You need to restrict the lube flow carefully using the clamp. Otherwise you will run out of lube in just a minute.

Before playing I prepare a mix of roughly a quarter table spoon J-Lube powder and 500ml water in the bottle. Use a mixture to your own liking or any other kind of lube, but make sure it is fluid enough to be sucked in through the hose. If I want to be fancy, I add a drop of food coloring, so it’s easier to see how much lube is left and how much has already collected in the coffee can.

This concludes the description of the basic milker. More extensions will follow though.

This is how it looks when in use 😈

BOM

• 1 Coffee can
• 1 Pressure regulator
• 1 Pulsator
• 1 Vacuum gauge
• 6 M8x1 Nuts
• 6 10mm ID O-Rings
• 6 hose fittings
• 1 3D-printed support for the pulsator
• 3m 8mm hose color 1 (constant suction)
• 3m 8mm hose color 2 (pulsating suction)
• 3m 3mm hose (lube supply)
• some 8mm hose color 3 (to pump)
• 3 PLC male hose coupling without valve
• 5 PLC female hose coupling with valve
• 1 PLC male hose coupling with valve
• 1 PLC male hose coupling 90° with valve
• 1 straight connector (for lube, alternatively use a male and a female PMC connector)
• 2 valves
• 1 vacuum pump
• 1 receiver
• 1 bottle
• 1 3D-printed cap

Since we covered the heart of the milking machine in part 1, it’s time for some of the other parts.

The receiver

Of course something needs to “do the work” 😈. I went for a standard “SPT” receiver from SeriousKit. Their build quality is fantastic and absolutely worth the money. They keep adding new options and I’d love to eventually try out more.
I would highly recommend just going for their receivers. They just work, I never had any issues and their customer service is great and friendly. I was thinking of building a receiver myself, but I’m lacking the tools. So considering everything buying a reasonably priced SPT was the best decision for me.
When selecting which one to get, make sure you get the right diameter. You want neither too large because it will lead to air streaming around the penis which leads to very weird sensations. You also don’t want it too narrow, because things simply won’t fit or be too uncomfortable.

The pump

You will need a vacuum pump that has a throughput of at least 60 l/min. I went for the one from SeriousKit as well, which is a Chinese GM-1.00. The benefit is that it’s oil free and therefore requires no maintenance. On the other hand there are cheaper options, especially when import taxes, handling fees and other 🏴‍☠️🌪☠️ costs after Brexit get added. You may even find ones that have a higher throughput on eBay, AliExpress or some other local source.

If you are into making your own silicone toys as well, you probably have a pump already anyway 😜

I added a short tube and a PLC female coupler without valve.

The pump is quite loud and certainly not something I want to have anywhere near when playing. So I put the pump behind as many closed doors as possible and run a 10m long “extension” hose to the play area. It has a PLC male connector and a PLC female connector on the ends. This connects the pump with the coffee can aka. milker.

To turn on and off the pump without having to run to wherever it is, I use a Shelly Plug S.

I got a recommendation from a friend for this pump. It actually seems much better suited for a milker as it has higher throughput and is much cheaper than the one I have. He successfully used it. I haven’t experienced it myself yet.

Hoses

You guessed it, there needs to be a connection from the milker to the receiver. We will need three tubes. One permanent suction, one pulsating suction and one for the lube supply. I color coded the tubes on the milker and the hoses. Black for permanent, red for pulsating. I did use transparent for “clean” to the pump and for the lube supply. In retrospect I should have chosen four different colors. But since the transparent lube and the transparent “clean” suction to the pump have different diameters, this is not too big of an issue. The color coding helps when you are playing with people who haven’t used the milker too often yet or are not very technical. Just tell them to follow the colors.

My hoses are around 2.5m long. You don’t want it too long to not have too much air volume in the hoses. But you also want them long enough to be able to easily position things. I would prefer a tad longer ones, maybe 3m, but 2.5m works most of the time.

You will need valves to gradually restrict air and lube flow. For the vacuum hoses I used cheap valves from amazon. For the lube these clamps.
I have a short acrylic tube in the black “permanent suction” hose to gauge how much lube and possibly other liquids 😈 are getting sucked out. I got the SeriousKit Venus conversion kit, and therefore had the tube. But I would argue that it’s not really necessary, so you should be fine without.

The black hose for the continuous suction has straight male PLC connectors on both ends. This will allow to easily flush it with water after use. For the red one for the pulsating suction I used ones with a built in valve. In normal operation they should never see any liquids and when cleaning the valve helps keeping them dry inside. I used an angled one on the receiver side and a straight one on the milker side.

All three hoses are tied together with cable ties, so you can run them neatly to wherever you need them.

In the next part I’m going to cover the lube supply and a complete BOM. Stay tuned.

Next to chastity I have another quite recent weakness: Milking Machines. Isn’t it just great to teach a sub that they must not cum for most of the time. But when they are allowed to, they should be made to cum as often as possible by a machine?

So to cut a long story short, I wanted a suction-based milking machine like the SeriousKit one, but without the price tag. So pawsy pup got going and built one.

It’s a very compact version of a standard milking machine as SeriousKit or GenerationF sell. Overall it comes at around 200€ and a time investment of an afternoon. It consists of all the key parts like a pressure regulator, a gauge and the pulsator mounted on an airtight coffee can. Hence the name “coffee milker”.

Parts

Here’s a parts list and the sources I used. Of course you may need to swap a few depending on your location or availability.

1. 1 Coffee can You may use any airtight container that has a (mostly) flat lid which you can drill holes into.
2. 1 Pulsator This is the key part. There are tons of cheap options. I tried a few different ones and did not notice any significant differences.
3. 1 Pressure regulator Depending on your vacuum pump, you will want this.It allows you to reduce the suction to a level that is comfortable. You may be fine without one, but I painfully regretted not having one in the beginning 🙈.
4. 1 Vacuum gauge Same as for the regulator. You don’t strictly need one, but it’s helpful. Especially when you use the milker on someone else.
5. 6 Hose fittings
6. 6 10mm O-Rings
7. 6 M10 Nuts, fine threaded with 1mm pitch
8. 8mm silicone hose you will need a few short pieces for the actual milker plus some longer pieces to connect to the receiver and pump. I used different colors for the different types of connections.
9. 1 PLC male hose coupling without valve
10. 4 PLC female hose couplings with valve
11. 3D-printed support for the pulsator

Build

The build is pretty straight-forward.

Lid

You need to drill 10mm holes into the lid and mount the hose fittings into it. The trickiest part is arranging the holes in a way such that you can fit everything on it without too much bend. Here’s the arrangement I used. 

The arrangement needs to consider that the Pulsator needs to sit flat on the lid and you’ll need to be able to access the back to adjust the speed as well as have enough clearance at the front, where the hoses to the connectors stick out.

Use the O-Rings to create a good seal around the couplings. Fit an O-Ring around the fitting, push the fitting through the hole and fix it with the nut from insider the lid.  Contrary to the picture shown on the left, don’t mount the one for the pulsator quite yet.

Pulsator

Next is preparing the pulsator assembly. This takes advantage of the thickness of the hose. The outer diameter fits just into the O-Ring inside the pulsator. Prepare a 25mm long piece of the hose. I used a sharp kitchen knife to get a very clean and flat cut. Put the hose into the pulsator as far as you can.

Next you stick the support for the pulsator to the bottom. I used three strips of 3M’s 5952 VHB tape.

Once you did that, push the hose fitting into the tube. The length of the tube should be so long that the bottom of the hose fitting is aligned with the bottom of the pulsator support. The O-Ring you put around the fitting should be slightly higher than the base of the support.

Last you put three more strips of double sided tape to the support and stick the pulsator assembly to the lid. Make sure you align it such that it does not collide with the tubes sticking out. Carefully fix the fitting with a nut. You need to do that carefully to create a tight seal with the O-Ring but without turning the fitting which is only held by the tube.

Last, put all the hoses and connectors to the lid and double check that you have a tight seal. Mount the lid on the can again and also check the tight fit there.

Voila, you built your very own coffee milker.

Next you should test whether everything is air tight by connecting your vacuum pump. Depending on the setting of the regulator you should easily get to -0,7 bar.

Part 2 is about building the hoses, the pump and some other parts you’ll need.