SMuFF - Servo Variant

thingiverse

# Here we go again...\r\n\r\nThis is a new option (or variant) for the SMuFF Revolver. The first picture above shows the complete SMuFF with this new option. In the second, third and fourth pictures you'll see all the new parts needed.\r\n\r\nIf you're not familiar with what a SMuFF could possibly be, head over to the main project and read all about it.\r\n\r\n\r\n# What's the gist?\r\nUsing a servo instead of the original Revolver comes with some benefits:\r\n- Fewer parts to print and assemble\r\n- Easier maintenance if something gets stuck\r\n- More precise pressure point on the upper Bondtech gear (means less interlocking and binding)\r\n- Not restricted to "only" 9 materials (make it as big as you need)\r\nYou can see it in action here:\r\nhttps://youtu.be/uA2HJwa0xys\r\n\r\nI've been stress testing the whole unit, just to make sure it's worth posting. The test ran continuously for 32.5 hours (whereas 24 hours was my goal), as you can see in the screenshot above. \r\nIn this time it performed a mind-blowing 7383 tool (filament) changes. In real life, this would compare to a almost 1.5 meter tall 3D printed something with one tool change per layer (at 0.2 layer height).\r\n\r\n\r\n# BOM\r\nTo build this thingy, you'll need:\r\n- The printed parts\r\n- A standard size servo\r\n- A servo horn (preferably Aluminum) with an overall length of 27 mm\r\n- An step down converter (to generate the 5-7V needed to drive the servo)\r\n- Two rods, 5mm in diameter (either steel, brass or - the preferred one carbon fiber)\r\n- 4 self-tapping screws 2.9 x 9.5 mm (for the servo)\r\n- 2 self-tapping screws 2.2 x 6.5 mm (for the lid)\r\n- A M3 x 6mm screw to mount the servo horn to the servo\r\n- The latest firmware version for the SMuFF (on Github)\r\n\r\n# What else?\r\nThe parts are named the same way as the parts in the main project (SMuFF). **R** stands for Revolver with a "-Servo" suffix (whereas this - from a technical perspective - isn't a Revolver anymore but I'll keep the term just to confuse you). So it's pretty easy to switch.\r\n\r\n# Firmware setup\r\nTo switch from the default Revolver to the servo version, go to the *Settings->Steppers->Revolver* menu and set **Use Servo** to **Yes**. Also, you have to define the On/Off positions of the servo in degrees in **Servo open** and **Servo closed**\r\n\r\n# Testing\r\nAfter you've assembled this variant, go to the *Testrun* menu and select the **Selector test** script to make sure everything is running smoothly and there's no binding between Selector and servo carriage.\r\n\r\n\r\n# Update 1\r\nI've added the parts for the mini servo version of this thingy. \r\nI wasn't convinced at all, that a mini servo has enough force to work as expected but, as you can see in the [video](https://youtu.be/JyuYnUzdIoI), I proved myself wrong in a test run of over 24 hours.\r\n\r\nThe main benefit - beside it's not as bulky as the other one - is that the cable management is better by far.\r\n\r\nIf you'd like to switch from the standard sized servo to the mini servo version, you only have to print the new 3 parts and you're ready to go.\r\nThe servo horn shoe I've added helps to put more pressure onto the lid as well as to get the right distance between servo horn and lid. I've glued mine onto the servo horn with a distance of 8.5 mm measured in between the top of the horn shoe and the bottom of the servo carriage.\r\nTo get the right distance of the horn shoe, you may have to shave off a bit of the servo horn.\r\n\r\n\r\n\r\n