Odd lines on Printer output

[redgatemodels]

Hi All,

I've recently been working on replacement printer belts with an online purveyor of all things Speccy and have today tested the first 3D print of a belt. To my surprise, given that the printer I bought was clearly spares or repairs I was pleasantly surprised to get this:

Given the age etc especially of the paper, I did not expect perfection, but what about the odd lines at the right hand edges of the print? they look like score marks and occur even when pressing the paper advance button. Can it be improved?

[Moggy]

Something mechanical I would have though making an imprint on the paper so possibly something stuck to the roller which what ever you do don't attempt to clean with any kind of substance especially fluid types as the roller is conductive and forms part of the printing circuit electronics. Cleaning the roller in said manner will render it useless.


Printer service manual found here...

https://spectrumforeveryone.com/wp-cont ... Manual.pdf

[redgatemodels]

which roller, the long shiny metal one on that paper carriage?

[Moggy]

No the rubber paper feed roller.

The official Sinclair service manual can be found here and includes diagrams, page 20 shows a blow up diagram of the printer including the paper feed roller.

http://www.retro8bitcomputers.co.uk/Con ... Manual.pdf

[redgatemodels]

Thinking about it, as part of the design, instead of a plastic peg for the stylus to fit onto the 3D prints have a hole to take a section of staple, to do this the wall on the outside of the belt where the hole is has been made wider. It is possible that the stylus is a fraction futher towards the outside edge of the belt, could this make the stylus tip too close to the paper as it comes round the end wheel?

clearly before cutting down to 2.5mm

[Moggy]

It's possible I suppose but as a dedicated Alphacom user, one who thinks the Sinclair printers are pile of junk I'm not best qualified to answer any deeper into their workings which would need a gurus touch and the half dozen I have had the misfortune to own did about a dozen listings between them before going tits up and are currently in my scrap box.

[redgatemodels]

It's possible I suppose but as a dedicated Alphacom user, one who thinks the Sinclair printers are pile of junk I'm not best qualified to answer any deeper into their workings which would need a gurus touch and the half dozen I have had the misfortune to own did about a dozen listings between them before going tits up and are currently in my scrap box.

Having had mine apart I am amazed it makes any kind of mark on the paper at all LOL. Maybe I am expecting too much from it. I'll try to tweak the staple pins in a bit to see it it helps unless someone else has a better idea

It's a bit like typing in an old program listing though, very satisfying when it works!

[XavSnap]

Hi,
Your printer seem to had an attic needle.
The paper side needle profile need to be band to ovoid to scratch the paper !

This kind of problem can be explained because of the nature of the steel used.
The sparks overheat the needle by partially melting steel, and goes warm at the end of the printed line.

At the start of the new line, the needle taken the time to cool down during the needle left return.
Try to change the needle by a new one, or build it with a proper steel alloy (carbon steel), with a spring made steel.

torsional_spring.jpeg (7.56 KiB) Viewed 4111 times

Have fun.