Here are details on everything but the filament drive which will be easy enough to finish up this weekend. The 12 pieces that make up the arm will get laser cut on monday and I should have enough vitamins by Monday or Tuesday to do a simple motion test. Very exciting times.
Image may be NSFW.
Clik here to view.
Here I placed some rough boxes to make sure I can fit the power supply and the controller. I will have to print some mounts but I will wait until I have the physical objects.
Image may be NSFW.
Clik here to view.
This is a bottom shoulder joint. Both sides of the arm are identical. I also included Nema14 mount points if it ends up that I have an excess of power. You can also see my bed complete with a silicone heater pad, glass, retainer clip, and spring. (The spring is just barely visible and will allow for easy leveling.)
Image may be NSFW.
Clik here to view.
Here you can see the block and tackles setup. I also included a static mounted cylinder for the termination of the string. The termination cylinder will keep the math from getting complicated. The one thing that I don't like and am going to fix is that this joint has not retainers on the bearings. However, I am going to use a thermal interference fit so those bearings will never budge. (Polypropylene has a very large coefficient of linear expansion. I will heat the arms up and will freeze the bearings. They will then just drop in and then very quickly get stuck.) You can also notice in the middle of the arms are torsion blocks to boost the rigidity. My mock up showed that to be the number one weak point but not anymore.
You can also see the hall effect sensor and the magnet. I actually did some science/math to get the optimal placement so that the stop is close but not too close to the physical limit of motion.
Image may be NSFW.
Clik here to view.
The only thing to really see here is the torsion block/ bearing retainer.
Image may be NSFW.
Clik here to view.
Here all the arms meet with some oversized thin section bearings. Right now I have no quick release for the bowden tube so that will have to be fixed. You can see that wires can freely be routed through the middle. I also have a magnetic angular encoder insert designed to embed right in the center of this guy so that we can get all the benefits of direct drive with a bowden tube. (I have printed the parts and ordered the encoder but I am going to leave it out until I get over all the other hurdles to getting this up and running.)
Image may be NSFW.
Clik here to view.
I like the look of everything but the extra holes make it look more complicated than it really is. However, the ability to have mounting holes for just about anything appeals to me especially when this isn't a proven design. The holes stay and I will get over it.
Image may be NSFW.
Clik here to view.
Here he is in the flesh. He watched a little TV tonight with the family. It is amazing how quickly you learn to love your children. On his bed are all the parts needed in front and all the reject parts in the back. You can also see a squirrel that was lending some emotional support.
Let me know what you think? If I have done something stupid, I would like to know. I have two days until this initial design will get baked in.
Thanks,
Nicholas Seward
Image may be NSFW.
Clik here to view.
Here I placed some rough boxes to make sure I can fit the power supply and the controller. I will have to print some mounts but I will wait until I have the physical objects.
Image may be NSFW.
Clik here to view.
This is a bottom shoulder joint. Both sides of the arm are identical. I also included Nema14 mount points if it ends up that I have an excess of power. You can also see my bed complete with a silicone heater pad, glass, retainer clip, and spring. (The spring is just barely visible and will allow for easy leveling.)
Image may be NSFW.
Clik here to view.
Here you can see the block and tackles setup. I also included a static mounted cylinder for the termination of the string. The termination cylinder will keep the math from getting complicated. The one thing that I don't like and am going to fix is that this joint has not retainers on the bearings. However, I am going to use a thermal interference fit so those bearings will never budge. (Polypropylene has a very large coefficient of linear expansion. I will heat the arms up and will freeze the bearings. They will then just drop in and then very quickly get stuck.) You can also notice in the middle of the arms are torsion blocks to boost the rigidity. My mock up showed that to be the number one weak point but not anymore.
You can also see the hall effect sensor and the magnet. I actually did some science/math to get the optimal placement so that the stop is close but not too close to the physical limit of motion.
Image may be NSFW.
Clik here to view.
The only thing to really see here is the torsion block/ bearing retainer.
Image may be NSFW.
Clik here to view.
Here all the arms meet with some oversized thin section bearings. Right now I have no quick release for the bowden tube so that will have to be fixed. You can see that wires can freely be routed through the middle. I also have a magnetic angular encoder insert designed to embed right in the center of this guy so that we can get all the benefits of direct drive with a bowden tube. (I have printed the parts and ordered the encoder but I am going to leave it out until I get over all the other hurdles to getting this up and running.)
Image may be NSFW.
Clik here to view.
I like the look of everything but the extra holes make it look more complicated than it really is. However, the ability to have mounting holes for just about anything appeals to me especially when this isn't a proven design. The holes stay and I will get over it.
Image may be NSFW.
Clik here to view.
Here he is in the flesh. He watched a little TV tonight with the family. It is amazing how quickly you learn to love your children. On his bed are all the parts needed in front and all the reject parts in the back. You can also see a squirrel that was lending some emotional support.
Let me know what you think? If I have done something stupid, I would like to know. I have two days until this initial design will get baked in.
Thanks,
Nicholas Seward
