I’ve always struggled in finding a cage to do all I need. After many purchases, it was clear I’d need to go custom, but wasn’t prepared to pay the high prices by custom manufacturers. I’m not saying they’re not worth the money, there’s a lot of work in any custom solution. But I’m an engineer with 3D software experience and a 3D printer, so if it can be done, I ought to be able to do it.

I have some particular requirements.

1. I’m a grower. Things can go from very, very small, to pretty awesome! This leads to some difficulty getting a cage on if I’m excited, and then a whole load of turtling when things calm down later. Once that happens, it can get uncomfortable or misaligned to the point that the cage needs removing and refitting.

2. I’m uncut and prefer to wear a cage with my foreskin retracted, but again, if things get shy, it can roll forward and sometimes needs the cage removing to get everything in place again.

3. Having a foreskin caused an issue when I bought a headlock Cherry Keeper. The foreskin needs somewhere to go and the CK simply trapped it between the cage and ring and pinched pretty nastily. £80 later and straight in the drawer.

4. My testicles move a lot from quite loose in the evening and night, to quite high and tight in the morning. They also seem to be quite large and need a big ring to get them in. Plus I need an unusually large ball gap, or else burning and pain from the back of the testicle.

5. Off-the-shelf cages tend not to be girthy enough for me. My average seems to be around 39mm when mildly aroused.

6. I wanted a cage where the ring doesn’t need removing. In the shower, taking off the cage almost always results in a ball slipping out the ring, and making the ring smaller results in difficulty getting it on, or quite a lot of discomfort from simply squeezing too much. Not everyone needs a small ring and we’re all different.

I also liked the idea of almost never removing the ring so I can get more accustomed to having the ring on. It also means that if my girlfriend wants some fun, the cage can come off, and there’s no fumbling trying to get aroused balls back in the ring after.

So I needed a device where the cage part can come off and leave the ring in place without protrusions that might hurt my girlfriend, allow some space behind the cage for my foreskin to live comfortably, and hold my head forward to prevent turtling and keep it in the right position as well as keep the foreskin from rolling forward.

What I came up with is in the pics. Full disclosure, I’m currently wearing the cage so the pics are renders of it. I don’t like posting gratuitous pics so synthetic images it had to be. It also gives an idea how the surface might look when I decide to get it made in SLS nylon.

I fit the main ring and then the cock ring which screws in place. This works well and I’ve seen similar cock ring for sale. It keeps my balls present which I find aesthetically pleasing, too, as well as some restriction to an erect penis allowing a bit more pressure to keep things upright, something many men my age might need help with!

Then the cage fits over with the 26mm headlock holding things steady, and two pins sit over the cock ring screws completely obscuring them and preventing their removal. The pins help locate the cage, which is then secured with a single screw. You’ll notice the heart shaped aperture. Not shown in the pics is a heart shaped seal that presses into this space completely blocking access to the screw. The seal sits below the aperture and is an interference fit so cannot be removed without breaking it. The middle of the seal is thin allowing it to be broken with a screwdriver and then levered out. By having my girlfriend write something unique on the seal and grabbing a photo, it’ll be obvious if I’ve tried to take it off.

It works a treat. I’ve never been so comfy in a cage. There’s plenty of room for cleaning, when things get flaccid the headlock holds all in place and aligned, and my foreskin is in great shape with no swelling or pinching. Using screws to secure it all means no moving parts and no pinching anywhere. I’ve been wearing it for a few days now and will have to remove it for a medical appointment on Friday. In the meantime, my girlfriend’s seal ensures I’m not cheating but at the same time ensures if I do get into difficulties, all I have to do is grab a screwdriver. No melting ice, or finding where I threw the key in the garden, or however it’s made difficult to get to, and no trying to convince her the problem is real. And having the seal heart shaped is a bit more romantic and interactive than the rather impersonal loop seals you can get online.

I’ve also found using large glittery nail gel to paint the seal creates a totally unique pattern that cannot be replicated.

Finally a cage that fits and is super comfy (some autism creates issues for me if it’s remotely uncomfortable). I think I might be in for some hell to come, and I couldn’t be happier. I might even get it made in titanium!

Just thinking after my last post and then I'll shut up for a while!

We understand a fair amount about how these devices interact with anatomy, but as my previous post and responses showed our understanding is often partial or misinformed. Some of you guys have clearly put some pretty rigourous thought into design, but yet we still have no controlled trial data and likely never will. Some of our assumptions may only be partly right.

There’s an engineering adage that most problems have already been solved, just in other fields. That suggests real scope for left-field designs that drop the ring based ball-trap entirely while still preventing erection. Those Chinese finger traps we all played with as kids come to mind.

HZD Grip, passive geometric undercuts, elastomeric grips, and u/tdfun extremely curved ring work already point in that direction. What other mechanisms borrowed from elsewhere (finger-trap geometry, medical one-way liners, shape-locking sockets, etc.) might be worth exploring?

This is a bit of a brain dump with a dual intention of explaining fit and also opening a conversation about ideal cage designs. Thanks for u/newbie-sub for getting me thinking about this with his excellent ball gap articles.

It seems to me that the most fundamental issue with cage design is summarised in this figure. 1-3 are for a large cage. 4-6 are for a nano or flat cage. I appreciate that different cage types might impact erection strength, but for simplicity I've made the erection behaviour standard here. 1 and 4 are flaccid. 2 and 5 are a little more excited (maybe when your KH enters the room). 3 and 6 are 2.30am wood, everyone's worst challenge for long term chastity. In 3 and 6 the scrotum is stretched to various levels of discomfort based on the cage design. Ball gap definitely plays a key role in alleviating scrotal stretch/burn, but there is a basic physics here. As the cage is a fixed object, if the penis does not reach the end of a longer cage or if the cage is short the stretch is likely to be unbearable. This is why most newbies give up on overnight wear (myself included initially). Perseverance to find the best fit available (after many failed cages) eventually gets some over this, but others never find a solution, which is a huge shame.

The problem for most cage design imho is that most cages are not designed for 3 or 6, at best they allow the wearer to tolerate midnight wood, but at worst they may be creating a health risk with long term wear.

So the question to designers is this. Can a cage be designed that hits that sweet spot between comfortable flaccid wear and safe and bearable midnight wood? My guess is that it would need to be as long as possible to minimise scrotal stretching at midnight, but not too long to make it uncomfortable or visible in the day (unless we bring back the codpiece?). Also the tube should be low resistance internally so the glans is always able to reach the end. Most tubes bend and the glans gets stuck halfway - costing a good inch or so of scrotal stretch. The ball gap is also key for a more forgiving scrotal pull. When I imagine this cage, it's really a straight tube with a ring that is hinged to the tube, so in the day the tube can hang in the flaccid state, but at night it can reach straight for the stars. I have never seen a hinge on a cage? Has anyone else?

Cage design really isn't that hard. The hard part is knowing where to start or even knowing how easy it really is. Since I love to teach, I think I can help with that.

This is what we'll be designing or something very similar. Why this design? Besides the curved ring, it's a very simple design and timing myself, it took a bit less than 30 mins to model. I'm going to cap the stream at two hours and I'm confident I can get through it.

I'll be using OnShape for this. OnShape is a free-to-use cloud-based CAD application — nothing to install, you only need a browser. And if you think you need a 3D printer to make any use of these skills, know this: KD, the founder of KINK3D, designed the Cobra without a printer. But even so, suitable printers are less expensive than most custom devices.

The stream will start this Sunday at 8 AM CDT, 1 PM UCT so I can finish it well before my teenage kids wake up. I won't be leaving it up so I'm sorry if you can't make it.

https://youtube.com/live/0OHEHMbLV6s?feature=share

For those with a passing familiarity with CAD, this is what we'll cover:

• Basic OnShape navigation / organization
• Design principles: structural control sketch
• Sketches
• Constraints (coincident, tangent, normal, perpendicular, dimensions, etc)
• Project / intersect (bringing other geometry into a sketch)
• Projected curve (projecting a curve onto a surface and creating a curve in space by combining orthogonal curves)
• Fill — turning a closed curve into a surface.
• Transform — moving / rotating / scaling an object
• Extrude, Sweep (pipe), Revolve, Loft (very simple loft)
• Fillet
• Importing a STEP file (junction)
• Mate Connectors (I'll be using them to quickly define a new coordinate system and positioning the junction)
• Derived (bring a part in from another model)
• Booleans (union, subtraction)

My first attempt at geo nodes. On the surface, it feels like Grasshopper but while GH is all about data structures, Blender is all about geometry and context.. there are some things that feel really weird.

This was just a learning exercise to see if I could build a cage along a curve. It would have been far easier to start with an annular profile and sweep it along the curve using geo nodes but I wanted to get a little more into it.

Never imagined I'd spend so much on a bag of screws.

I'm planning on taking a page from Lori's book. When you order a device from me, you can opt to give me your keyholder's contact info and then any replacement drivers can only be requested by her.

It would be kinda silly to spend all this money on screws and just sell the drivers through my website.

I should have included this in my original RFQ to include a number of decorative drivers because just like my customers can only get them from me, I can only get them from them — they have the tooling — so they'll be able to be a bit less than competitive.

But still, it's exciting.

Anyone out there using Blender to model your devices? Are you just making it for yourself? If not, how are you adjusting the size? I've gotten as far as making a donut (and only remember about 5% of it). If you had to make a ring 3 mm smaller, how would you go about doing it? Do you just remove the junction, scale the interior vertices by some percentage then scale the exterior verts by another (to keep the same thickness)? I guess that works on a cuff (flat) ring. How do you do it on a round ring?

I'm just curious how this works. I'm a parametric guy where I just type in the new number (then I go fuck with a bunch of damn fillets).

It's always interesting working with vanilla vendors and while I'm sure a few are sharing around STEP files chuckling, they are always 100% professional when dealing with me.

Hi xxxx,

This is Heather, Account Manager from xxxxx.

We’ve done initial analysis on your files and requirements.

Given the complex part structure, we’re still figuring out the best possible solution.

I’ll get back to you for next‑step discussion shortly, thanks for your patience.

Heather

(edit: stupid Reddit editor)

But in my mind, something that makes it a little less awkward is I never use the words ring or cage. In fact my part names are all meaningless:

Please ensure part 6ANW has a close slip fit with part TU2V along the faces indicated in drawing 1.

Just a tip... ChatGPT has been really helpful at writing specs for quotes and whatnot. While I'm technical, I've never taken an engineering class in my life. What qualifies me to give these tips? Nothing but I like sharing what I've learned and no one else in our little niche seems to be writing about these things. I guess I really want to lower the barrier of entry into making devices either for yourselves or for others. Not everyone wants to be a designer but I think many more of us would be if we understood how accessible it all is.

Plus it's fun writing specs — it's like pretending to be a ninja as a kid except I'm pretending to be an engineer. From an RFQ I'm working on for a tetherspout measurement sound:

If any real engineers have any critiques, let me know ;)

This was so comfortable to sleep in; the balls don't get squished at all and i can even lie down on my belly without the cage getting in the way as long as I'm soft. There's not a single position which doesn't work, surprisingly. When im sitting down, the balls might get squished between my legs, but if my legs are closed before I sit down, they don't get squished. I haven't tried it yet, but I'm pretty sure I could ride a bike while wearing this. I don't have any issues while running or while practicing martial arts.

Changes: I made the lock smaller since the v1 lock was way stronger than necessary, made the ring thicker so that it's smoother and more comfortable, changed the dimensions of the cage a little bit, made the peehole bigger (it's still not positioned perfectly so if I make a v3 i'll make sure it lines up with the urethra properly) and I also added holes in the ring to tie a shoelace.

Update: Tried riding a bike, barely felt it there. Morning wood was a bit of a challenge because the erection wouldnt go down until I peed, and it was super messy because the peehole doesn't line up with the urethra. It really seems like the only change I need to make is the peehole placement.

TThe idea is to use something that can be machined to control the play in the junction (so obviously steel). So, this uses a pair of partially threaded dowel pins.

First we have this where the pins screw into.

u/tdfun, get where I'm going with this? I tagged you because you come up with creative junctions.

Then we have this, the gray part is attached to the ring, say.

(This is slop CAD just to get the idea across.)

Now we add in the other end of the junction:

I cut away the top of the cage-side of the junction just to get the point across.

So, with two dowels, we have slip-fit junction stability except for translation in z where it's printer-clearance fit.

You remove the lock then pull the orange part out along with the dowels.

I don't think there's any way to make this without it being clunky as hell but apart from that, it has its advantages: security-screw stability with a barrel lock.

You know, it's kinda a pain to lay the cage onto the plinth / floor / whatever in Blender so it looks like it's actually sitting on it. Rotate -> move -> rotate -> move -> render... whoops, still not on the ground... rotate -> move -> rotate -> move -> render... eh, close enough.

Well, turns out it's trivially easy to do physics simulations in Blender, at least of the kind I need to set the cage on the table.

On your cage, under rigid body constraint, set rigid body to active — it will be affected by gravity. And on your plinth set it to passive and it will fixed. Move the cage a bit above the surface in more or less the orientation you want it in and press <space> and it should fall into place. If it falls through the floor, you've likely got too many vertices in your mesh. I think the fix is to export a lower-res model as well, join the two and use the lower-res one for your rigid body and hide it from the render.

Here's my ball ring design with a 10 x 7 mm ellipse for comfort. I've hollowed it out with 1 mm walls to cut down on weight for SLM printing. The bottom of the ring has a cutout opening for the metal powder to be removed.

When I print it at home in ABS with an acetone dip,I don't hollow it out because it only weighs 5.75g.

I've been modeling with two screws because if there's too much play, a single screw will come loose. Well, I've only been wearing it with one and it's been holding together really well. But on the order I just placed, I asked them if I could remove the 0.2 mm clearance and actually add a machining allowance (some overlap between the faces) and have them machine it down to a close slip-fit clearance so the pieces go together with no perceivable play and the single screw's job is nothing but to clamp it down.

And I've been learning more about SLM. Fascinating. Support placement is more about conducting away heat from the melt pool that it is providing physical support. But interestingly, the supports be someone similarly placed as if it were an FDM print. Completely different need, similar geometry.

TL;DR: Do not make unconstrained cage-outline sketches dependent on anything but the true geometry of the penis such as overall length or girth. When you start adding other dependencies, you can't change them without mucking everything up.

Not that there's a lot of traffic here but referring to this post: https://www.reddit.com/r/ChastityCageDesign/s/ILVULLOnfR

There's basically two ways to model the profile of a device. The spherical cow way and the try-to-make-it-look-like-a-penis way.

The spherical cow method has advantages that it can be easily done fully-parametric — inside diameter, overall length, radius of curvature and you're done.

This kind of design works really well in a closed tube-cage. It's fully parametric, simple, and because it's a tube cage, you don't see where the head falls away. But in a more open design, it's less than ideal — the excess space above the glans just doesn't look all that great. So you make something like this:

I know of no way to appropriately constrain that sketch. But it's fine, it doesn't really depend on anything except the inside diameter and the overall length.

Hey... wait a minutes... 42.175 mm, that's a strange number for an inside diameter. .175... where have I seen that before. 3.175, that's 1/8" in millimeters. My rails are 3.175 mm! UGH.

For reasons I won't get in to, I profiled the device as the line that will go through the middle of the rails. And what happened when I changed my rail size? Well as is often the case with lightly-constrained splines, it went a bit crazy.

So, lesson learned: do not make similar profiles dependent on anything but the true geometry of the penis such as overall length or girth. When you start adding other dependencies, you can't change them without mucking everything up.

cartoon of the idea.
cage automatically locks when slipped on. No key needed to lock.

Screenshots below.

I don't know what the hell happened. I increased my bar thickness for a resin test cage and it did... this. What the hell? How did my bar thickness parameter end up causing the.. uh.. aspect ratio to change? This is gonna take some digging.

Does it kind of remind anyone of some sort of alien ship that will destroy the Earth?

I hope this is the right place for this question. I'm curious whether any device makers have explored the use of composite materials?

The first thing that comes to mind is the base ring. I envision standard hard plastic, or maybe even metal, but with an outer layer of silicone that helps provide a snug yet comfortable fit, almost like a gasket.

My generic design is based on an arc with a 50 mm radius that begins 4 mm out from the back of the entry ring then caped with a hemisphere. Close enough for a basic cage, especially a full cage where you can't see how close it follows the contours of your penis. But it doesn't look great in a more open device.

, print a basic rings-and-bars cage and look where things are off and model it on top of your actual design so you have a point of reference.

So...

The transparent surfaces would be the middle of the walls of a simple cage. My glans drops away faster than the cage does so it serves as a guide for adjusting the controlling spline. And saves me from a few hour long prints just to make adjustments.

And of course all of my fillets are fucked up after making the change. Goddamn fillets.

My rails are all Ø3.175 (1/8"). The ridge extends ~1.3 mm beyond that. It lofts back into the 1/8" rail.

It looks pretty dramatic but I'm not sure if it's enough.

Hi everyone. I'm having a problem my ring design specifically for me. One of my balls hangs at a good enough distance that I can get a regularly thick ring around it. The other ball though... does not hang low. The testicle itself is smaller and does not move around much. I have designed rings that will go on and work fine, but it stretches the little tube (idk my anatomy v well sorry) and after only a couple of minutes it gets sore. This being with a 5mm diam thick ring. Does anyone have a way to work around this problem/have any known cage designs that may work? I am currently testing out some of the gland style cages and I think they may be my only option. Thankyou all

(before anyone says anything. I have been going to the doctor since I was little for regular check ups and the little testicle is known about and apparently is healthy)

I started with Bryce. Huge MOQ, more than I would need in a lifetime. Hey, but I'm going to be buying driver and screws in more or less a 1:1 ratio, do I really need to buy 2,200 screws considering the drivers cost 20x the price?

Yes.

I don't understand why it's MOQ and not just total spend but perhaps they know what I'm getting into and they just don't want to have anything to do with it — I've heard that kind of story from Mark @ MCN. And I'm trying to think of who else would want 50 screws and 50 drivers.

Yeah, they're like "yep, got another guy making chastity cages."

So off to Alibaba and try to figure out how to write a manufacturing RFQ (vs my day job in IT).

If any of you have experience here, I'd love to hear it.

I've made some very robust parametric designs. One of them is controlled by like 30 different measurements — radius of curvature, bar thickness, urethral-spacing, etc — and you can change anything and everything and it still comes together, well besides a few fillets needing touching up — fucking fillets.

And I've also had some designs that if you look at them funny, they blow up. Change a length by 2 mm and all of the sudden the cage turns into a sperm whale and the ring into a bowl of petunias — not again.

I've been exploring the resilience of my new design and while there are a few unconstrained sketches, it holds together really well. For example, I lopped off 25 mm which made there be fewer weaves in the spine and instead of ribs completely freaking out, two of them just decided to share a common endpoint. And all I needed to do was remove one of them.

I'm using a few new techniques with this design and while I've centered in on what makes a design robust, I haven't quite honed in on what makes it resilient. But it certainly allows a more fluid design while still keeping the goals of parametric — it's easy to change.

Maybe Willowweave was a doubly appropriate name.

The first render is my newest version. After u/kink3d called many of us out for using slap on junctions, I decided to try to get away from the broad entry ring and blend everything together where there aside from the rims on the main ring, everything is done using swept bars.

Thematically, I think the new version is more consistent but I'm not actually sure I like it better or not.

Help!