Filament continuation
I am about to run a large print, but I know there will not be enough filament on the reel, how do I get my XL Original (2 heads) to automatically swap heads when the first reel has run out?
https://help.prusa3d.com/article/tools-mapping-and-filament-mapping-xl-mmu3_732461
One problem to look out for: The inner end of the filament on some spools was bent sharply into a hole when starting the fill - so in some cases this hooked end catches the spool and tugs the filament tight causing underextrusion and if it does come free the bent end can resist entering the PTFE delivery tube with the same result.
If possible, cut off this bent end, ok, it's tricky when the spool is full so at least try to attend the printer when the filament is low enough to do so.
Cheerio,
RE: Filament continuation
Word of warning: test spool joining on a small print first, using a short leftover piece of filament for the first tool used.
I have not been able to get a decent print using spool joining: there seems to be a problem with the tool heights, and the layers do not stick together when the tool changes wich results in a part that splits and is unuseable, every time. Always fun when that happens near the end of a >20 hours print.
So, I just leave the filament run out and load the new on the same tool.
Spooljoin works well as long as you do as I suggest and the machine is properly calibrated. At worst you will see a couple of centimetres of slight under-extrusion and if the second filament has been waiting a long time it may show some of the defects typical of damp filament - consider printing the second filament from a dry box.
Cheerio,
RE: Filament continuation
Sure. The reason why a layer is printed too high when using the spool join function is because of bent or damp filament. The same exact filaments that print properly when reloading the same tool, and somehow the spool end bend doesn't cause any problem then.
That's plausible.
We understand you're some kind of Prusa employee or contractor who's just intervening everywhere to defend the company, but you could at least use some believable material.
RE: Filament continuation
No, just another user trying to help people.
Cheerio,
RE: Filament continuation
Hi Diem and Bryan,
Thank you for your comments, I had already had failed go.
Before you posted, Prusa had emailed me a 'how to', which got me going.
But I was watching the print and spotted the hooked end coming and so cut it off, but I can easily see that being a stopper.
However, having set the printer to use head 1 then head 2, I watched the filament pass right into head 1, and the machine just kept going, it is very difficult to see if it has stopped printing. Eventually I decided it had not realised it had run out of filament, so I did a manual change, but I think it had printed a layer without any filament, so when it re-started it failed.
Why did it not realise it had run out???
I looked at the filament sensor screen and the top 'switch' (Filament Sensing) appeared to be on and all the others off. (see image)
After I had played with the switches a bit I realised the switches were actually the other way round.
Can I suggest the the top switch be changed to dark grey when it is off and even some text adjacent to stating it is 'OFF'.
I hope that helps someone else.