Should I scrap this reel of filament?

[Nick Clarke 3Participant @nickclarke3]

Fitted a new reel of Filament to the 3D printer (Ender 3) and it was quite springy. The feed to the head was a bit jerky but I didn't notice until a duff print was produced.

I realised the spool was not keeping in step with the needs of the printer but sometimes over ran allowing the filament to go slack – not only between the reel and the head but on the reel itself.

I think I have fixed the original problem with a couple of elastic bands (thoughtfully left on the drive by the postman) wound round the tube it sits on providing a minimal amount of friction and preventing the over running but due to having been loosened the filament now jams in the loose winding on the reel when the feed reaches the cheeks of the spool.

What to do? Carefully unwind the filament until a tightly wound section is reached and dumping the excess, the same but try to carefully rewind it tightly or saying 'to hell with this its only £20' and dumping the whole reel to obtain reliable printing?

[Nick Clarke 3Participant @nickclarke3]

[BazyleParticipant @bazyle]

Do lyou expect the filament to be tight between the spool and the feeder? I always stand by the machine pulling it off to avoid this and leaving a suitable amount loose. Means I can't leave it for more than a coupe of minutes though. Rather than adding friction I keep meanig to make a ball bearing spool holder.
If it is jaming itself up perhaps rewind it onto an old spool using some model engineering ingenuity to make a motorised gizmo to assist that.
my most worrying failure to date has been a short section of about a foot where it had gone brittle and perhaps hard so the feeder wouldn't grip it to feed. I think perhaps it was where there was a join during production. Lucky it was only a few minutes into the job and I was there to see it stall (and hear the feeder juddering )

[Nick Clarke 3Participant @nickclarke3]

Bazyle –

I didn't seem to be the looseness that caused the problem but rather the top layer in the spool becoming loose and then trapping the outgoing filament so it jerked before carrying on.

[Dave HalfordParticipant @davehalford22513]

Posted by Nick Clarke 3 on 07/03/2021 10:28:50:

Fitted a new reel of Filament to the 3D printer (Ender 3) and it was quite springy. The feed to the head was a bit jerky but I didn't notice until a duff print was produced.

I realised the spool was not keeping in step with the needs of the printer but sometimes over ran allowing the filament to go slack – not only between the reel and the head but on the reel itself.

I think I have fixed the original problem with a couple of elastic bands (thoughtfully left on the drive by the postman) wound round the tube it sits on providing a minimal amount of friction and preventing the over running but due to having been loosened the filament now jams in the loose winding on the reel when the feed reaches the cheeks of the spool.

What to do? Carefully unwind the filament until a tightly wound section is reached and dumping the excess, the same but try to carefully rewind it tightly or saying 'to hell with this its only £20' and dumping the whole reel to obtain reliable printing?

I would have thought that any filament 'spring' would always cause the outer layer to uncoil the first chance it gets given a bit of slack. You might have success with making a soft foam 'grommet' to fit between reel and drive to run the the filament through.

That said it's a shame to waste a whole reel and Creality talks about a tight filament pathway, which you don't seem to have so perhaps the spool is not to spec.

[JourneymanParticipant @journeyman]

Don't ditch it, the reel can probably be saved. Firstly rewind the reel to get rid of serious overlaps and more importantly make sure the filament is not trying to tie itself in a 'clove hitch' where the end has managed to get under one or more previous turns. Then make sure the filament is dry, put it in a bag with some fresh silica-gel for a couple of days. Also worth checking that the entry and exit points to the bowden tube are nice and smooth, no sharp corners. Restrict the reel from swinging too much, as you have with the elastic bands.

It helps to buy quality filament have a look at the following images the first is from Prusa (Prusament) note the even wind. The second is an unknown brand but note how uneven the wind is. The difference is fairly obvious as is the outcome. Always try to keep the filament under control when loading. Even a smoothly wound roll can end up in a mess if the turns become too loose.

The second image also shows some useful ball-bearing spool holders (search TUSH on Thingiverse). I have recently made myself a dry filament feeder box using these ** Journeyman's Workshop ** and they work well.

John

Edited By Journeyman on 07/03/2021 13:02:57

[Alan Wood 4Participant @alanwood4]

I would echo the comment that despite being a new reel the filament might have a high moisture content and needs drying out. I always soak heat a new reel before using. 36 to 38 degrees for PLA/ABS /PETG for 5 hours.

[nigel jones 5Participant @nigeljones5]

I have this problem – I have a stick leaning against the spool, in contact with the filament to act as a restricter, works perfect

[Neil WyattModerator @neilwyatt]

It's amazing how filament bvaries in its vulnerability to humidity. I recently had a reel of PLA where the unwound length filament would spontaneously snap after about 24 hours. Because of the move another PLA reel spent weeks with an unused section when moving the printer I had to cut it because I couldn't get it to snap, even bent double!

Clearly there is PLA, PLA and PLA!

Neil

[Henry BrownParticipant @henrybrown95529]

I've had similar issues with PLA, even though the printer is in the living room and apparently the more exotic filament can be worse! I have some silk silver PLA that seems to be very susceptible to moisture and some Aldi black PLA that has gone brittle as its got towards the centre of the roll.

I started off by putting them in the oven for a few hours at 50 degrees C but found that the enemy wanted to use it for cooking so invested in a cheap second hand food dehydrator that has a timer and temperature control that seems to do the trick just as well. There are several blogs/videos on the web showing how to do this.

[BazyleParticipant @bazyle]

Those spool holders immediately made me think of rolling roads. Got the ruler out and yes, my spool is gauge 3.

Is brittleness the sign of damp? I hear people mention it and thought the problem was the danger of steam generation during melting.

[JourneymanParticipant @journeyman]

Yes, unfortunately moisture can have many unforeseen effect on filament. Plenty on the web about it, try for example, this article from the Product Automation Corporation or this from MatterHackers.

John

[Henry BrownParticipant @henrybrown95529]

This is what moisture does, the little pits are just about visible:

It can be heard popping while printing and if it happens on the outer layer is quite visible and it is supposed to weaken the print if excessive. This is the silver silk PLA I mentioned in my earlier post, after drying I have almost removed the moisture and it has printed quite well this afternoon.

I made a spool holder from some 50 x 50 box with some POM wheels that the spool mounts on, I mounted it on a large block of oak as the spool has to be parallel to my printer due to space limitations.

Edited By Henry Brown on 08/03/2021 18:57:27

[not done it yetParticipant @notdoneityet]

Nylon is the worst for a steam problem – it can absorb loads of moisture.. PLA will be brittle and break easily if it picks up moisture.

[The Novice EngineerParticipant @thenoviceengineer]

I've had some good results reviving an old reel of PLA that had gone brittle by using a dedicated filament dryer that can also be used to feed the filament [it has a set of rollers in it]

Though some reels can be a bit tight

 

 

 

 

I know this thread is a bit old …but I felt this relevant to anyone printing with PLA

Edited By The Novice Engineer on 03/02/2022 20:33:11

[not done it yetParticipant @notdoneityet]

Keeping the filament dry obviates the need for this? Careful drying over a period of time at low heat (and humidity) readily returns PLA to its former non-breaking condition.

Maybe 3-d printing a suitable reel container/feeder might be a good idea? Likely there is a program on one of the sites that provide plans/programs (like thingiverse).

[BazyleParticipant @bazyle]

I think printing any kind of container is wasteful when there are so many plastic packaging boxes around from buying other things.There are food dryers for making eg dried apple slices that are only used for a short period of the year, or metal containers like stock pots and marmalade pans which can be used if warmed up by a suitable heat source, eg light bulb underneath, soldering iron etc.
But does anyone have a recommendation for the temperature to aim for. – I'm thinking just above 100C for PLA.

[Engine BuilderParticipant @enginebuilder]

Posted by Bazyle on 03/02/2022 21:11:18:

But does anyone have a recommendation for the temperature to aim for. – I'm thinking just above 100C for PLA.

I have the Sunlu dryer shown above. Max teperature is 55C.

[Neil LickfoldParticipant @neillickfold44316]

Having the filament in a box with desiccant is very important. Especially with Nylons to a degree PLA. The worse days is when the humidity is very high in the shop, and you change the filament on that day. Ours is a perspex box with the crystals in the bottom of the box. The crystals can be dried out in the oven over time, or just replace it. We have Bowden tube covering most of the filament as possible. Some printers it is not possible to have a tube covering over the filament all the way to the print head or extruder.

[JourneymanParticipant @journeyman]

PLA should probably not be kept above 50C for any length of time as it will start to 'change' above that temperature. The glass transition (Tg) of PLA is in the region of 65C (PETG around 75C) This is not the melting point but a temperature at which the material begins to move from solid to liquid (change of state). Safer to use an unheated box with silica gel to remove moisture, will take longer but may prevent some permanent changes mainly shrinkage. Of course if you kept a reel of PLA at 100C for a long time it would likely become a solid block.

The glass transition temperature is useful to know as it is used when annealing prints to improve strength. Maintained at a suitable temperature a printed item will increase in strength as the layers gradually bond together. Of course if overheated the print will become a blob!

Useful article on annealing at Prusa's website. – *** How to improve your 3D prints with annealing ***

John

Edited By Journeyman on 04/02/2022 08:57:54

[Colin HeseltineParticipant @colinheseltine48622]

I have had my Prusa I3 Mk 3 for around 3 years. It has not been very heavily used at all. It even has the original spool of filament. I have had no issues printing using this spool. I did 4 8.5hr prints around 2 weeks ago and they came out with no issues, no breaking filament or anything. I am using the originally supplied Prusa filament. The reel is still wound beautifully and has not unwound itself. The printer is located in my 1st floor office at home which is possibly the warmest room in the house (according to my wife).

Colin

[BazyleParticipant @bazyle]

Thanks for the temperature advice. Will stick to like warm and crystals then.

[Henry BrownParticipant @henrybrown95529]

Since commenting earlier I have found that the buckets with lids on that fat balls, for the birds, com in make great storage containers, depending on the spool size you can get at least two if not three in them. I also keep mine in their original bags wit a silica gel sachet in for good measure.

[JourneymanParticipant @journeyman]

Be aware that silica gel does not last particularly long before it has adsorbed all the moisture it can. It is possible to buy silica gel with an indicator that changes from yellow when dry to purple when wet. Silica gel can be revived easily in the microwave a few minutes at full power or more slowly in an ordinary oven. *** Silica Gel with Indicator ***

John

[not done it yetParticipant @notdoneityet]

Posted by Journeyman on 04/02/2022 16:00:52:

Be aware that silica gel does not last particularly long before it has adsorbed all the moisture it can. It is possible to buy silica gel with an indicator that changes from yellow when dry to purple when wet. Silica gel can be revived easily in the microwave a few minutes at full power or more slowly in an ordinary oven. *** Silica Gel with Indicator ***

John

Do remember that the magnetron in a microwave oven can be damaged by running the with nothing to absorb the microwaves within the oven.

That link says rejuvenate at defrost for several minutes, not full power.

When the silica gel is dried, it may well not absorb microwaves, or will heat up very much more quickly. The tell-tale colouring chemical (a cobalt salt?) will be decomposed if over-heated and then be of no further use.

Of course, as always, it depends on how much desiccant you are rejuvenating at the time….

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