Web Cam Positioner – Ball Joint
At the end of my last post I mentioned I was already printing a ball joint. It’s not very big, it’s only intended to hold a web cam after all, so the print finished before I tucked in for the night. First I’d like to note that it printed without any issues, none of the start print, spaghetti, stop print, clean adjust and try again stuff, it just worked. Maybe the bet was more out of alignment than I thought. In any case I got a good print the first time.
I removed the support structures, gave it a quick shine and put it together, well, almost. I put the ball with the rod into the socket and slid the cap on but the cap was this much too small. Oh well, everything looked good otherwise. The ball fit nicely in the socket, the rod was able to move quite well so all I needed was to make the cap a bit bigger and, as you know from the last post, that’s something I know how to do. But it would wait until the morning.
The next day I opened fusion, selected the cap, and scaled it. In the Fusion 360 section below I’m going to detail a nice feature I need to get better at using (you’ll see what I mean in a bit.) When I re-printed the cap for my threaded cylinder print I actually copied the Fusion 360 project and deleted the other part before exporting. But I learned that you can hide objects from a project and that hidden objects are not exported. This means if a piece of a print goes wonky I can adjust it and export an STL file with just the updated part while keeping the overall project together. So, I hid the other parts and exported just the scaled cap.
In my last post I noted that the Fusion has uniform and non uniform scaling options and that when scaling a round thing use non uniform and be sure to scale both the x and the y axis, or x and z or y and z, whichever your round thing is in or all three if it’s a sphere but then you might as well use uniform scaling. So, I scaled both x and y by 1.05mm … baby steps, I want it to fit but I don’t want it looser than a three dollar wh… I’ll stop there before I get in trouble. I don’t want it too loose.
Exported to STL, loaded to Cura, using the same configuration as the previous print I sliced it and saved the gcode, pulled it into OcotoPrint and hit the print button and watched the streaming feed as it printed the cap without any issues. When it was done, I removed the support structure, gave it a quick rub down, not that there were any major problems with the quality and it screwed on like it belonged.
I made the rode coming out of the ball about 2mm in diameter with threads. In hind sight this was way to small but I will say that surprisingly the threads appears to be there and good. I think I could have added a nut if I had one. The other problem was that it was fragile. I gave it a little pressure test and it broke right off.
I went back into Fusion 360 and made some adjustments. My first thought was keep the smaller diameter base and put a bigger threaded rod on that because a smaller rod at the base meant the ball could rotate a little more and there would have a little more range of motion. This was not my best idea. I made the threaded rod 6mm attached it to the 3mm rod coming out of the ball about 3mm up. I also printed a nut to fit on the threaded rot to test the ability to use these smaller threads.
Export to STL, loaded to Cura, slice and save as gcode, load to OcotoPrint and hit print. Oh, and yes, I cleaned off the printer bed between prints but I was not making any adjustments or using alcohol, just a dry cloth. I was pleasantly surprised when it worked the first time.
The nut didn’t fit perfectly, I had to do a little cleanup with a knife but it did eventually start to thread and then the small rod broke off the ball. Sad… I used a plier to hold the small rod while I tried to thread the nut further on the rod and it broke off the larger rod. Sadder… Back to Fusion 360.
This time I did away with the smaller rod and extended the 6mm rod into the ball extending the threads all the way down as well. I also scaled the nut by another 1.05 in the x and y axis.
Export to STL, load to Cura, but I noticed that where the rods had connected to the ball there wasn’t much material, which partly lead to the breaking. I increased the number or rows to print at the top to 8 from, I think 4 and increased the fill from 20% to 50%. Then sliced the model, saved the gcode, load to OctoPrint and hit the print button. Then ran downstairs to clean off the printer bed which I noticed when I looked at the streaming feed and saw I hadn’t done after the last print. Thankfully, it takes a few minutes for the bed and extruder nozzle to get up to temperature so I didn’t have to stop the print or anything. A little while later, print complete.
The nut screwed on relatively easily. I had to clean a little off what was the bottom side of the print because it was binding a bit but after that it screwed on relatively well. Tight, no wiggle but easy to thread. I stuck it in the socket and added the resized cap and, well, ball joint! I applied some pressure to the rod once the ball was locked down in the socket and it didn’t break off so I think the extra fill and thickness settings helped.
I’m calling this a victory.
Happy with the general design I wanted to see if it would scale, that is, if I could literally just scale it up if I needed something bigger. I also thought it would be nice if the cap had some texture, something to help keep it from slipping when I tried to loosen or tighten it. So, I added little … bumps? raised thingies? Anyway, added texture to the cap in Fusion 360 and exported to an STL file. Loaded it into Cura. I selected the objects, all 3 the cup, ball and cap. Then I selected the scaling menu and made sure Uniform Scaling was checked and changed the values to 120%. The preview grew appropriately so I saved to gcode, loaded in OctoPrint and press the print button.
It printed great. Looked good but there was a problem, everything basically scaled up and out, the hole in the cap did as well so the hole got disproportionately large to the point where the ball will pop past it :(. Lesson learned about scaling, There may be something I can do in Fusion 360 but this was already a bit of a side track for me.
Fusion 360
What’s next
I think I have a workable and flexible enough joint for my adjustable support arm. The arm should just be a series of these with arms or rods of some sort between them. Since the design includes a screw in coming out of the ball, I’ll add a place to screw it, or a bracket on the arms to attach them. That should be relatively easy (famous last words). But I also need a way to hold the base down, some sort of clamp, I think. So, my next endeavor is to make a flexible clamp base of some sort and some sort of clamp to hold the camera with, maybe the same thing, maybe not. I guess I’ll find out. Maybe I’ll have this done in the next week!
For the long view, the part that holds the camera will be made to hold a couple of high power (3 watt) LEDs. I’m waiting on the high watt resistors needed but my plan is to have 1 or more of the lights attached to the camera mount and rig it so I can turn the LED on and off from OctoPrint.
After thoughts
I’m probably going to start doing more of the Fusion 360 mini-demos. I found it very helpful. The example as shown was not exactly what I had done to get the texture added to my lid because for that I was hitting YouTube, reading other blogs and experimenting. It was, however, helpful for me because I did the original several hours ago and this helped cement the ideas and techniques. I think I’ll do more of these types of demos and explanations.
I’m getting excited. Hopefully I’ll have a better camera stand and can get a good angle of my prints. Right now the camera is pointing down from the side so the extruder blocks most of the print. I can tell if it goes really wrong but other than that mostly see the extruder jumping around and going in circles.
For fun today, I printed a name … plate? A thing with my name for a desk or wherever. It was fun to do and I like how it turned out. I find it interesting that I bought the printer because I was curious but I was worried I wouldn’t know what to do with it or wouldn’t be able to make anything work. Now I’m frustrated (and tired) because there isn’t enough time in the day to work on all the things I want to work on.