exxos's Atari, Amiga & retro forum

rubber_jonnie wrote: 01 Jun 2020 23:27 Out of curiosity, what was wrong with the old one? Not pink enough?

https://www.exxosforum.co.uk/forum/viewt ... 820#p39672

exxos wrote: 01 Jun 2020 23:37

rubber_jonnie wrote: 01 Jun 2020 23:27 Out of curiosity, what was wrong with the old one? Not pink enough?

https://www.exxosforum.co.uk/forum/viewt ... 820#p39672

Ahh, I see.

looks like these are the suspect blown MOSFETs..

https://www.nexperia.com/products/mosfe ... 30YLC.html

Edit:
Typical farnell no longer sell them .. But this one will do..

https://uk.farnell.com/nexperia/psmn6r0 ... dp/2067550

Pretty much same spec really.. CBA to look at the data sheet, but only one I can get anyway. Still, 70+ amps overkill for a fan :lol:

Hopefully I've not killed the chip driving the gate to it.. Well at least the printer still works. Plus considering I shorted out the PSU enough for the printer to go dark, its probably fair to say the MOSFET has shorted out. It doesn't look blown.. I guess I could meter it out tomorrow...

:sigh: :headbang: :mad:

So whoever designed was an idiot :roll: I specifically went for this particular model, Because it was designed to miss the motor at the back and be used on the right-hand extruder. But the mounting bracket needs to be like a inch further forward to miss the motor, this spool does actually fit in the printer bottom, but I cannot straighten it up because the motor is in the way..

So if you want something doing.. Do-it-yourself basically :roll:

I seem to be limited to about 60mm/sec print speed. But the annoying thing is, it can actually print at 160mm/sec or higher, BUT there are some annoying issues which actually stop that from happening :cry:

Take for example this object base...


There inside and outside parts can print out 160mm/sec, BUT the inside circle cannot... I think the problem is that it has no apparent de-acceleration on changing direction :roll: So it does a arc in the middle, then there is a half hole and then another arc etc.. So the head does the arc, and then has to move at a angle all of a sudden we should then causes the whole printer to "thump" and the whole thing shakes, any prints the next part of the arc, it's the next bump, and start shaking even more :roll:

Take a leaf out of the large format printers we have a work. Their bases are designed to move as the head is accelerated so as to dampen the apparent acceleration. Try putting the printer on springs or some other bases which will allow it to move around. In that way the energy is absorbed elsewhere and the frame isn't distorted as much (so it won't shake so much relative to the print).

stephen_usher wrote: 02 Jun 2020 19:47 Take a leaf out of the large format printers we have a work. Their bases are designed to move as the head is accelerated so as to dampen the apparent acceleration. Try putting the printer on springs or some other bases which will allow it to move around. In that way the energy is absorbed elsewhere and the frame isn't distorted as much (so it won't shake so much relative to the print).

I did wonder about putting it on springs to dampen the thumping on my desk, can you suggest any large feet which may work or supplies of them or something? Or is it just roll your own?

The trolley/mount that the large format printer is supplied with is designed to flex, allowing the printer to swing from side to side.

For your set-up a four or five inch thick foam rubber blocks at each corner may work, though they may be a bit too stiff.

ube wrote: 20 May 2020 14:53 I’ll knock something together.

From idea to product in two weeks. Added optional pull up/downs (connect solder pads) for outputs, the three unsoldered pins on the left.

Firmware makes it possible to reconfigure reset time; power on with reset pressed, release reset, push reset 1 to 8 times to configure reset time multiplier: X * 250ms.

Usage: press reset 1+N times to switch polarity of pin N, numbered from lower right side of PCB.

Ping @exxos.