Pulling an old HP printer to bits for parts, and it suddenly turned into a CNC machine conversion. Took me 4 days, but there were a few small hurdles to overcome. The brains of it is an Arduino Uno with a Protoneer CNC shield running GRBL. (Big shout out to https://info.protoneer.com/1)
The Z and X axis runs on ball bearing drawer slides, and they have absolutely no vertical or horizontal play.
The threaded rods run through MDF thread inserts and using a small piece of 6mm acrylic for a ‘nut’ to lock it into the mounts. The inserts don’t seem to have the same amount of backlash as a standard nut.
All electrics (incl a PSU) is at the end where the ink carts used to be.
The X axis is a bit noisy because it is mounted to the printers steel base plate, but some nylon washers should dull that down a bit.
The dremel flexi-shaft runs down the inside of the 1″ square tube (the bit the pen was zip tied to) on the Z axis.
PS…I’ve never attempted anything like this before, I’m still learning about the whole CNC thing (spot the sticky notes to remind me what axis I was moving!). The fact that I could use the original bodywork (panels) was more good luck than good design….except when it comes to drilling holes for USB cables. That was just crappy “eye-ometer”.
UPDATE: Here is a blog I wrote up about the build, including the first runs.
https://justcheckinm8.blogspot.co.nz/
We show you how to galvanize metal objects to protect them rust.
First we get 30g of zinc sulfate and dissolve it into 100mL of water.
Zinc sulfate was made back in our video on making a copper sulfate and
zinc battery: https://www.youtube.com/watch?v=Id3tL2iI0Vw
Then connect the item you want to galvanize to the negative terminal of a 5 volt power supply. Connect the positive terminal to a strip of zinc metal.
Zinc metal was obtained from our video on getting useful materials from batteries: https://www.youtube.com/watch#%21v=knc1lSupAwQ
Immerse both electrodes into the zinc sulfate solution and keep them from touching. Then turn on the current and run it for about one minute to give the metal a zinc coating.
Remove the object and now it’s galvanized.
To test the rust protection, place it on top of a paper towel soaked in saltwater. You should also place an unprotected item next to it for a good comparison. Cover the towel to prevent evaporation and wait a day or two.
The treated object should remain rust-free, perhaps developing a white crusty coating. The untreated object should start to rust.