It's not very practical, unless the practice is artistic in nature, but
someone here might like this: https://www.brachiograph.art.

Daniele

On 14/01/2020 20:48, D.M. Procida wrote:
It's not very practical, unless the practice is artistic in nature, but
someone here might like this: https://www.brachiograph.art.

Daniele

It has a certain charm.

On Wed, 15 Jan 2020 16:26:13 +0000, newshound
wrote:

On 14/01/2020 20:48, D.M. Procida wrote:
It's not very practical, unless the practice is artistic in nature, but
someone here might like this: https://www.brachiograph.art.

Daniele

It has a certain charm.

Clever and imaginative IMO.

--

No deal? No problem! :-D

On Friday, 17 January 2020 18:45:37 UTC, Cursitor Doom wrote:
On Wed, 15 Jan 2020 16:26:13 +0000, newshound
wrote:

On 14/01/2020 20:48, D.M. Procida wrote:
It's not very practical, unless the practice is artistic in nature, but
someone here might like this: https://www.brachiograph.art.

Daniele

It has a certain charm.

Clever and imaginative IMO.

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

wrote:

On Friday, 17 January 2020 18:45:37 UTC, Cursitor Doom wrote:
On Wed, 15 Jan 2020 16:26:13 +0000, newshound
wrote:

On 14/01/2020 20:48, D.M. Procida wrote:
It's not very practical, unless the practice is artistic in nature, but
someone here might like this: https://www.brachiograph.art.

Daniele

It has a certain charm.

Clever and imaginative IMO.

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

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

On 19/01/2020 10:16, D.M. Procida wrote:
wrote:

On Friday, 17 January 2020 18:45:37 UTC, Cursitor Doom wrote:
On Wed, 15 Jan 2020 16:26:13 +0000, newshound
wrote:

On 14/01/2020 20:48, D.M. Procida wrote:
It's not very practical, unless the practice is artistic in nature, but
someone here might like this: https://www.brachiograph.art.

Daniele

It has a certain charm.

Clever and imaginative IMO.

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

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.

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

On Sunday, 19 January 2020 10:16:55 UTC, D.M. Procida wrote:
tabbypurr wrote
On Friday, 17 January 2020 18:45:37 UTC, Cursitor Doom wrote:
On Wed, 15 Jan 2020 16:26:13 +0000, newshound
wrote:
On 14/01/2020 20:48, D.M. Procida wrote:
It's not very practical, unless the practice is artistic in nature, but
someone here might like this: https://www.brachiograph.art.

Daniele

It has a certain charm.

Clever and imaginative IMO.

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

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 wrote:

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

No respect for monuments.

Daniele