Simpson lives!
![]()
This is the first (documented) dry run of Simpson. A RepRap 3D printer. There are some visible issues. The extruder will pitch and roll causing the extruder tip to be as much as 5mm from the expected position. I have ideas on how to fix that. Stay tuned. (Almost all the sound is coming from plastic pulleys grinding on plastic pulleys. I already have a redesign that should eliminate this. Additionally, the next source of sound is power supply's fan. I am going to crack it open and replace the fan with a more expensive one or a bigger one. If I can address those issues, the steppers with 1/32 micro-stepping are virtually silent.)
Interesting note: I don't think I will need any electronic end stops. As soon as the motors turn off Simpson zooms up to the top most position. I am planning on pulling each arm in 10 mm and then pulse the hold on the steppers on and off so Simpson can gracefully reach the natural home position without hurting himself.
The pitch and roll can be solved with multiple mount points. This will cause me to double up each arm. This will add complexity. I was pretty sure I was already going to have to do this but I am a big fan of not solving problems before they are problems. Can I fix it in 7 days and document in time for the Gada Prize? Probably not. I will try anyways. Heck, this was only an idea 16 days ago. In that time I have gone through 3 major redesigns, acquired all the parts, and have successfully built a functional prototype.
For those that are interested, the spring is perfect. If it was any weaker or stronger, there would be issues. When the extruder is close to the bed the springs are almost too weak and when the arms make a 90 degree angle, the spring is almost too strong. It is unlikely that I will be able to go with Nema14 motors unless I put a few more loops on the block and tackle setup.
This is the first (documented) dry run of Simpson. A RepRap 3D printer. There are some visible issues. The extruder will pitch and roll causing the extruder tip to be as much as 5mm from the expected position. I have ideas on how to fix that. Stay tuned. (Almost all the sound is coming from plastic pulleys grinding on plastic pulleys. I already have a redesign that should eliminate this. Additionally, the next source of sound is power supply's fan. I am going to crack it open and replace the fan with a more expensive one or a bigger one. If I can address those issues, the steppers with 1/32 micro-stepping are virtually silent.)
Interesting note: I don't think I will need any electronic end stops. As soon as the motors turn off Simpson zooms up to the top most position. I am planning on pulling each arm in 10 mm and then pulse the hold on the steppers on and off so Simpson can gracefully reach the natural home position without hurting himself.
The pitch and roll can be solved with multiple mount points. This will cause me to double up each arm. This will add complexity. I was pretty sure I was already going to have to do this but I am a big fan of not solving problems before they are problems. Can I fix it in 7 days and document in time for the Gada Prize? Probably not. I will try anyways. Heck, this was only an idea 16 days ago. In that time I have gone through 3 major redesigns, acquired all the parts, and have successfully built a functional prototype.
For those that are interested, the spring is perfect. If it was any weaker or stronger, there would be issues. When the extruder is close to the bed the springs are almost too weak and when the arms make a 90 degree angle, the spring is almost too strong. It is unlikely that I will be able to go with Nema14 motors unless I put a few more loops on the block and tackle setup.