Spool finishing, how to attach new one mid print

[teoman]

As the title says. My spool is coming closer to the end, and i am not sure if it will suffice.

So 2 questions,

1- If the filament were to be depleted mid print, how do i attach another roll? Just pause the print and thread the new filament in?
Or wile i still have slack, use a soldering iron to attach the filament and then carefully sand off the bulge?

2- Do we have an effective means of determining how much filament is left?
- Use the display to calculate, and then reset the filament printed when changing rolls?
- just be sensible and dont start a long print when you think you dont have enought left.


Thanks in advance. Print still has 5 hours to go...

[Mac The Knife]

I pause the print while it's doing infill, pull the filament, feed in a new one. hit start.

[teoman]

I suppose you need to have the computer connected to the unit. (Max V2)

Thanks for the input though. Good to know it should be while it is doing the infill. I would have done it randomly on my first try before realizing i was a moron.

[Mac The Knife]

Hmmm, how about adjusting the speed multiplier to 25% while doing infill,,, assuming your quick about it.

[nitewatchman]

I will splice mine on the fly during printing using a butane torch if I pay attention and catch it. Also if I have pieces of spools if will splice the pieces up while sitting at my desk and respool the smaller onto the larger.

To splice I heat the ends of the filament by holding close to the base of the flame and then push together the ends to develop an upset flange. You can judge if the two ends are aligned by looking at the flange. If it is square to the filament all the way around the two filaments centerlines are aligned, if angled the centerlines are off. After cooling, I clip the flange off using a small pair of flush cut end nippers and sand smooth.

I also weight every spool when I receive it and record the tare weight on the spool. I something big is going to be printed I will weight the spool, calculate the remaining material, add a generous fudge and decide if there is enough on the spool.

nitewatchman

[Brian]

Is it possible to just feed a new roll behind the one that is ending and just let the new one push the old one down the Bowden tube? The retracts would not work, but once what was in the line was cleared it would be ok, right?

[teoman]

Thanks for that nitewatchman

mind sharing your grams to meters numbers?

[teoman]

That is theoretically possible in my inexperienced opinion, but your interface zone is very very small. Remember, the filament does not get pulled in the tube, it is pushed from the top. So you have to be waiting there when the final little bit is getting sucked in the EZstruder with your other spool in hand.

And if there are retracts, then it will kick your filament out.

[nitewatchman]

Thanks for that nitewatchman

mind sharing your grams to meters numbers?

For PLA about 3gr/m.

[artexmg]

Is it possible to just feed a new roll behind the one that is ending and just let the new one push the old one down the Bowden tube? The retracts would not work, but once what was in the line was cleared it would be ok, right?

No, not possible. I had tried and cannot make it work. once the filament is in the middle it lose traction.

Try yourself, maybe you have better luck

[artexmg]

I pause the print while it's doing infill, pull the filament, feed in a new one. hit start.

Yup .... or, if printing from the computer:

1- Slow the speed
2- Aim to infill
3- Hit Pause
4- INMEDIATLY, raise the hot end 50mm (or any more, just to avoid the heat in the piece) - just hit the +10mm button (depending on your software, of course)
5- Change the spool, eat dinner, take a bath, watch a movie
6- Set down the hot end -50mm (or the "other" distance of your choice)
7- INMEDIATLY, resume print.

Tada!

[artexmg]

I pause the print while it's doing infill, pull the filament, feed in a new one. hit start.

If PRINTING from SD (repetier firmware) is even easier:


1- Hit "Pause" command in LCD (SD Card Menu --> Pause).
2- The nozzle will be moved to the perimeter of the print bed, avoiding damage to the piece
3- Change the filament
4- Hit resume command, it will move the nozzle back to the same point it was printing.

TaDa!

[artexmg]

I had tried both methods with success ... as a matter of fact, I just tried (the one from the PC) just some minutes ago.

They work!

word of caution! before trying the LCD command, test it. The place were the nozzle will be moved is given by (I think!) the dimensions entered in the firmware. I am not sure where these coordinates are coming from, but if they are not set correctly, then your nozzle could end out of the bed, causing a hard hit and lost of the position (and the print).

Does anybody knows where the X and Y values are taken from the PAUSE command in the LCD? I think it is just looking for it, but I am lazy!

[artexmg]

As the title says. My spool is coming closer to the end, and i am not sure if it will suffice.

So 2 questions,

1- If the filament were to be depleted mid print, how do i attach another roll? Just pause the print and thread the new filament in?
Or wile i still have slack, use a soldering iron to attach the filament and then carefully sand off the bulge?

2- Do we have an effective means of determining how much filament is left?
- Use the display to calculate, and then reset the filament printed when changing rolls?
- just be sensible and dont start a long print when you think you dont have enought left.


Thanks in advance. Print still has 5 hours to go...

What I do for the 2nd question: I measure the length of the circumference of the spool. I know it will be less in the center and more at the end ... but you can average it


I see how many loops I have per "layer" in the spool. Then, I just multiply the number of loops per layer, per the average length per loop. This will give me the lenght per layer.

Then, I can know how many layers are left in the spool just by measuring the distance from the core of the spool to the first (or last?) layer of the filament. divide by 1.75mm.

TaDa!

Sure, you could make an equation that gets you the length of the loop, as a function of the distance of the layer from the center of the filament, then integrate it, times the diferencial of such a distance ... but, I get very good results with my empirical method

For example, the SeemeCNC spool has a inner circumference of 30.5mm and 37 in the middle. I had count 37 - 40 loops per layer. So, being conservative and taking 35 loops per layer, and using the inner circumference, it means 35x30.5mm = 37 cm per layer. I use this value as a constant

So, every time I want to know how much filament is left, I just measure the thickness of the spool, divide it by 1.75 and multiply it by 37cm. This had been my method and had worked fine so far, not running out of filament (well, I had, but always when I had not measure, just guessed ).

I hope it works for you as well!

[artexmg]

I will splice mine on the fly during printing using a butane torch if I pay attention and catch it. Also if I have pieces of spools if will splice the pieces up while sitting at my desk and respool the smaller onto the larger.

To splice I heat the ends of the filament by holding close to the base of the flame and then push together the ends to develop an upset flange. You can judge if the two ends are aligned by looking at the flange. If it is square to the filament all the way around the two filaments centerlines are aligned, if angled the centerlines are off. After cooling, I clip the flange off using a small pair of flush cut end nippers and sand smooth.

I also weight every spool when I receive it and record the tare weight on the spool. I something big is going to be printed I will weight the spool, calculate the remaining material, add a generous fudge and decide if there is enough on the spool.

nitewatchman

Thanks for giving me another reason to buy a torch!

[artexmg]

Thanks for that nitewatchman

mind sharing your grams to meters numbers?

For PLA about 3gr/m.

This sounds easier and more practical than the differential equation method