I read that you can get stepper motors from old dot-matrix printers. What about plain old ink jet?
so my main X and Y axis motors came from an old Oki 9 pin dot matrix. they are pretty good for the job but still a little underpowered.
all the Inkjet printers i looked at didn't have anything very good.
they seem to use DC motors and high resolution encoders rather than stepper motors. i presume this is because the ink can be sprayed very quickly meaning the printer does not need to hold the print head in position, it just sprays as it goes past.
i did get a big 3 phase brushless motor out of a large office laser printer which would be great if it was bi-directional.
not quite as precise as a stepper motor but it would make up for that with better torque due to it's size.
unfortunately the control PCB is built into the motor chassis and the control PCB only contains circuitry for rotation in one direction.
i did consider completely re-building it but that would take as long as the rest of the CNC machine put together.
the most interesting motors i found in ink-jet printers were the small stepper motors that park the print head when it is not in use.
they are small stepper motors. really nice motors but not powerful enough for my application.
i am having to use one of these anyway for my Z axis in the absence of owning a better motor... (it's the one in the vid that moves the Dremel up and down.)
i saw these on a few different cheap HP printers. presumably other manufacturers use stepper motors somewhere as well.
For one weeks building thats incredible. I'm in the process of making a rapid prototyper but it's going a lot slower.
it helps that i have a friend who has a computer scrapping/recycling business so could get a few broken printers to strip.
i've been planning the build in my head for about a year now though so it really was just a case of cutting out the parts and assembling.
it's still really nice to see that it works as planned though.
i don't believe it has to be that hard as long as you can come up with a system of rails that only allow movement in 1 dimension.
assemble 3 of these rails and all the rest of the structure can easily be designed on the back of a beer mat. (well, i used Sketchup but you get my point.)
after lots of thought on the matter, finally coming up with a design for rails that could be built cheaply and easily but still with reasonable precision.
then today in a DIY store i saw a pre-made item that cost about the same as the bearings i bought: kitchen draw rails.
they were about 500mm long and very little sideways movement.
if i ever make CNC_contraption_2 i will be using these.
couplers are always a pain.
i'm using pieces of plastic hose. get a piece that you can barely force over the 2 shafts. mount the 2 shafts in their final position so they can only move as they will once in operation then gently heat the plastic hose. while the hose is hot, run the motor.
heating the hose has 2 effects:
1. it shrinks the hose onto the shafts.
2. as you turn the motor and other shaft together it aligns the axis of the partially melted hose with the axis of the shafts being coupled.
anyway, i'm rambling again.
stuck on a ferry bound for Scotland at the moment.
at least ferries have internet these days.