DIY pen plotter

[D.M. Procida]

It's not very practical, unless the practice is artistic in nature, but someone here might like this:

. Daniele

[newshound]

It has a certain charm.

[Cursitor Doom]

Clever and imaginative IMO.

[tabbypurr]

Yes. I wonder why the print quality wasn't better.

[D.M. Procida]

Mainly: several degrees of hysteresis and dead-band errors in the servos, torsion and tendency to non-parallel movement in multiple parts of the mechanism, and generally, the fact the the whole thing is made of ice-cream sticks and a clothes-peg.

Daniele

[Steve Walker]

I built my own A2 pen-plotter in the late '80s. One stepper motor driving a toothed belt, moving the "head" along guide rods (all from a defunct printer). Another stepper driving a shaft with home-made knurled wheels to drive the paper back and forth (clamped between the wheels and rubber wheels). A solenoid to lift and lower the pen.

The steppers were driven by LM-298 H-bridges (IIRC), which were signalled by a Motorola 6821 PIA, with address block decoding by a

74LS138 and all connected to a Sinclair QL's expansion port.

It worked pretty well, but was soon made redundant by access to an HP-7475A 6-colour pen plotter.

I did ask my parents whether the home-made one was still in the loft recently, but they'd had a clear out.

SteveW

[tabbypurr]

:)

[D.M. Procida]

No respect for monuments.

Daniele