# Print a Ball & Socket joint as one piece **URL:** \ **Category:** General Discussion\ **Created:** [January 4, 2017, 3:12am UTC](https://forum.formlabs.com/t/print-a-ball-socket-joint-as-one-piece/11176 "2017-01-04T03:12:00Z")\ **Posts on this page:** 17\ **Page:** 1
**Author:** ![Dudemeister](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/dudemeister/32/13812_2.png) [@Dudemeister](https://forum.formlabs.com/u/Dudemeister)\ **Post date:** [January 4, 2017, 3:12am UTC](https://forum.formlabs.com/t/print-a-ball-socket-joint-as-one-piece/11176/1 "2017-01-04T03:12:00Z")
I’m trying to print a ball joint in one pass, yet still have the parts movable. I’m printing a model of a mech, which has a ball & socket hip joint (see image below). The obvious way, would be to print the socket piece in 2 halves, and the ball separate, then glue the two halves after I put the ball inside. But I’d like to try to print them as one piece, with the ball inside the socket, and with just enough clearance between the parts, that they don’t stick together. Question: what is the minimum gap I need to leave between the ball and socket, so they print as separate parts (not touching), yet it’s still a relatively tight fit (not sloppy) ![](https://us1.discourse-cdn.com/flex025/uploads/formlabs/original/2X/e/e1efa1a7a62040fafbd4d83937a7b71cbdc34950.jpg) ---
**Author:** ![KenCitron](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/kencitron/32/1741_2.png) [@KenCitron](https://forum.formlabs.com/u/KenCitron)\ **Post date:** [January 4, 2017, 5:14am UTC](https://forum.formlabs.com/t/print-a-ball-socket-joint-as-one-piece/11176/2 "2017-01-04T05:14:22Z")
Not sure if you can clean the socket enough without a substantial effort in cleaning the uncured resin out. Educated guess try .01"? ---
**Author:** ![3DTOPO](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/3dtopo/32/6361_2.png) [@3DTOPO](https://forum.formlabs.com/u/3DTOPO)\ **Post date:** [January 4, 2017, 5:31am UTC](https://forum.formlabs.com/t/print-a-ball-socket-joint-as-one-piece/11176/3 "2017-01-04T05:31:11Z")
> [@Dudemeister](#): > > I’m tring to print a nall joint in one pass, yet still have the parts movable. FL’s design [guide](https://formlabs.com/media/upload/formlabs-design-guide.pdf) states to use a minimum of 0.5mm or about 0.02". ---
**Author:** ![fantasy2](https://avatars.discourse-cdn.com/v4/letter/f/a88e4f/32.png) [@fantasy2](https://forum.formlabs.com/u/fantasy2)\ **Post date:** [January 4, 2017, 8:49am UTC](https://forum.formlabs.com/t/print-a-ball-socket-joint-as-one-piece/11176/4 "2017-01-04T08:49:33Z")
I tried something similar with a hinge but without success. The play between the parts was something like 0.2mm. Resin between the two parts was cured. Changing the gap to 0.5mm made it successful. ---
**Author:** ![Zachary\_Brackin](https://avatars.discourse-cdn.com/v4/letter/z/4da419/32.png) [@Zachary\_Brackin](https://forum.formlabs.com/u/Zachary_Brackin)\ **Post date:** [January 4, 2017, 4:23pm UTC](https://forum.formlabs.com/t/print-a-ball-socket-joint-as-one-piece/11176/5 "2017-01-04T16:23:53Z")
Something with that small of a tolerance wouldn’t work because the laser would cure the material between the parts since the laser will cure a bit extra on the underside of parts. ---
**Author:** ![Dudemeister](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/dudemeister/32/13812_2.png) [@Dudemeister](https://forum.formlabs.com/u/Dudemeister)\ **Post date:** [January 9, 2017, 8:34pm UTC](https://forum.formlabs.com/t/print-a-ball-socket-joint-as-one-piece/11176/6 "2017-01-09T20:34:01Z")
I think I wasted about 150ml or more trying to do this, but it just doesn’t work. It should in theory, but not in practice. I even oriented the pats so they both print with their own supports (there are no interior supports touching between parts, I started with a gap of .3mm, then moved to .5, .75, 1mm. When I got to 1.25mm, the part still required some force to break it apart, and the part that is the socket outer shell cracked. At 1.5mm, the parts could move, but the surface was terrible and the gap way too visible. So I eventually gave up on this idea, and ended up printing the socket in 2 halves. ---
**Author:** ![billb](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/billb/32/5587_2.png) [@billb](https://forum.formlabs.com/u/billb)\ **Post date:** [January 10, 2017, 8:37am UTC](https://forum.formlabs.com/t/print-a-ball-socket-joint-as-one-piece/11176/7 "2017-01-10T08:37:31Z")
Well yes, you can only print this design if it is orientate so that there are no supports between the ball and socket. ---
**Author:** ![Zachary\_Brackin](https://avatars.discourse-cdn.com/v4/letter/z/4da419/32.png) [@Zachary\_Brackin](https://forum.formlabs.com/u/Zachary_Brackin)\ **Post date:** [January 10, 2017, 4:19pm UTC](https://forum.formlabs.com/t/print-a-ball-socket-joint-as-one-piece/11176/8 "2017-01-10T16:19:36Z")
Like I said, it’s because as it prints the underside of a print will cure material that’s stuck there, so the underside of the ball will cure extra material that’s trapped between it and the socket and would require a large gap for it not to cure that far. ---
**Author:** ![FredB](https://avatars.discourse-cdn.com/v4/letter/f/838e76/32.png) [@FredB](https://forum.formlabs.com/u/FredB)\ **Post date:** [January 10, 2017, 9:01pm UTC](https://forum.formlabs.com/t/print-a-ball-socket-joint-as-one-piece/11176/9 "2017-01-10T21:01:11Z")
If I was going to try to print these in place I would rotate the part so the ball is vertical and the socket is horizontal. You need to have all layers supported and that’s impossible with the socket vertical. So, with the socket vertical and a fairly decent gap it should work. Remember they recommend a 0.5mm gap between parts. I would bet that can be a little smaller with grey or black resin. ---
**Author:** ![Dudemeister](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/dudemeister/32/13812_2.png) [@Dudemeister](https://forum.formlabs.com/u/Dudemeister)\ **Post date:** [January 10, 2017, 9:13pm UTC](https://forum.formlabs.com/t/print-a-ball-socket-joint-as-one-piece/11176/10 "2017-01-10T21:13:24Z")
This was exactly what I tried, I had the the ball shaft oriented vertically, and the upper leg socket was horizontal, I also tried a few other angles where the ball and socket are basically independent, and there is no support between them, yet, in all cases, the 2 parts were fused together. Only when the gap reached about 1.25mm did the parts separate, but even then, the surface quality was bad, and the joint movement was very rough, so eventually I had to cut my loses and just split the piece. That worked just fine. [http://forum.formlabs.com/t/warhammer-40k-imperial-knight-paladin/10993/19](http://forum.formlabs.com/t/warhammer-40k-imperial-knight-paladin/10993/19) ---
**Author:** ![Zachary\_Brackin](https://avatars.discourse-cdn.com/v4/letter/z/4da419/32.png) [@Zachary\_Brackin](https://forum.formlabs.com/u/Zachary_Brackin)\ **Post date:** [January 10, 2017, 10:27pm UTC](https://forum.formlabs.com/t/print-a-ball-socket-joint-as-one-piece/11176/11 "2017-01-10T22:27:13Z")
The 0.5mm gap is likely to be a vertical gap ---
**Author:** ![Dudemeister](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/dudemeister/32/13812_2.png) [@Dudemeister](https://forum.formlabs.com/u/Dudemeister)\ **Post date:** [January 11, 2017, 4:32am UTC](https://forum.formlabs.com/t/print-a-ball-socket-joint-as-one-piece/11176/12 "2017-01-11T04:32:39Z")
Here is the layout I used that actually worked, but only after I reduced the diameter of the ball to increase the gap. The quality of the surfaces on the ball and the socket that faced each other was pretty bad. ![](https://us1.discourse-cdn.com/flex025/uploads/formlabs/original/2X/9/90fe1c3a8c9ae1f1484bd36960a2a64d3e4e7d22.gif) ---
**Author:** ![FredB](https://avatars.discourse-cdn.com/v4/letter/f/838e76/32.png) [@FredB](https://forum.formlabs.com/u/FredB)\ **Post date:** [January 11, 2017, 6:58pm UTC](https://forum.formlabs.com/t/print-a-ball-socket-joint-as-one-piece/11176/13 "2017-01-11T18:58:38Z")
Could you post up the STL? I’m interested in trying to print it on a FORM 2 ---
**Author:** ![Dudemeister](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/dudemeister/32/13812_2.png) [@Dudemeister](https://forum.formlabs.com/u/Dudemeister)\ **Post date:** [January 12, 2017, 5:34am UTC](https://forum.formlabs.com/t/print-a-ball-socket-joint-as-one-piece/11176/14 "2017-01-12T05:34:08Z")
Unfortunately, the STL is way to large to upload here (49MB). I’ll see if I can reduce it ---
**Author:** ![Bill\_Gibson](https://avatars.discourse-cdn.com/v4/letter/b/db5fbb/32.png) [@Bill\_Gibson](https://forum.formlabs.com/u/Bill_Gibson)\ **Post date:** [April 7, 2017, 2:26am UTC](https://forum.formlabs.com/t/print-a-ball-socket-joint-as-one-piece/11176/15 "2017-04-07T02:26:20Z")
I’d love to play with this model too. Please let us know if you find a place to host it. ---
**Author:** ![CraigBroady](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/craigbroady/32/6106_2.png) [@CraigBroady](https://forum.formlabs.com/u/CraigBroady)\ **Post date:** [April 7, 2017, 1:52pm UTC](https://forum.formlabs.com/t/print-a-ball-socket-joint-as-one-piece/11176/16 "2017-04-07T13:52:25Z")
[Pinshape](http://pinshape.com)? ---
**Author:** ![Dudemeister](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/dudemeister/32/13812_2.png) [@Dudemeister](https://forum.formlabs.com/u/Dudemeister)\ **Post date:** [April 7, 2017, 9:17pm UTC](https://forum.formlabs.com/t/print-a-ball-socket-joint-as-one-piece/11176/17 "2017-04-07T21:17:32Z")
Here is a link to the file. This has been reduced from the original 24MB, but it should still be quite usable for testing [Ball & Socket Joint test file](https://www.dropbox.com/s/nn6f7fis4qdlbsp/Left%20Thigh%20%26%20Hip%20-%20reduced_1.stl?dl=0) THis is hosted on my Dropbox account. Let me know if you have problems downloading it.