Spool Size Questions - What's your largest for a 1KG?  

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LewnWorx
(@lewnworx)
Active Member
Poll Question for ya'll:
What's the widest 1KG spool by a major manufacturer you've ran into?
Of all my spools the widest seems to be Overture's, which come in at 69.5mm.
What's the largest hub diameter you've encountered (and by hub I mean the larger outer surface the first wrap of filament sits on on the spool?
And finally, what's the largest flange size you've encountered?
There's a method to the madness..
I'm asking because I'm doing a complete rework of EA69's excellent Mutliple Mechanism Auto-Rewind Spool Holder
It works, and works well with the MMU, however the spool holder is overly wide and as a result the entire mechanism comes in at 150mm (just a hair under 6") wide and by the time you line 5 of these up side by side it's way wider than my enclosure (which is already a pretty healthy 29.5")
Granted this thing can accommodate pretty much any spool you'd ever want to throw at it, but I'm not going to be jumping to 3KG spools any time in the foreseeable future, and even if I did I could rewind them down to 1KG spools and use the MMU's join spool thing for insanely material intensive prints.
So that being the case I'd like to shave off the width, first to accommodate my enclosure width, but also to see if I can whittle this thing down enough to fit in one of those cereal dry storage containers as a secondary goal, which would be really spiffy for ABS/Nylon/TPU blah blah.
I've yet to see a non printed spring based auto rewinder that will fit in one of those. And while the printed spring rewinder is clever as hell, I just know eventually that printed spring will fail at the 49 hour point in some huge 50 hour print job. This is why I'm using the weighted vertical rack gear approach as there is no on it that will fail due to cycle counts.
Based of my sampling of all the spools I have I should be able to shave 24.6mm off the width as a bare minimum, probably more when I redo the flange with the gear on it, as it's overly wide. I get that he did that for the inner slope inside to be printable without supports but I think it's a tad overly conservative, and I should be able to pull at least another 1/8" if not 3/8" off the width as a result.
I'm also looking to address a few points I'm not super keen on about it:
The PC4-M10 hole on the base at the bottom is nice and all but a real miserable PITA to thread filaments through when the spool is mounted. I'd like to relocate that up to the top side of where a spool would unload to make spool changes easier.
I'm also thinking of revisiting his gearing, as it does 2 full revolutions which is a full 1/4 turn more than one actually needs based off a 100mm hub and a 17" required retract length using the Prusa supplied Festo PTFE from the MMU to the Extruder. I think that could be shortened a bit and get the height down somewhat for the rack gear, and a change up to gearing ratio would maybe let me take that down further.
It's also overly tall, granted it was set up to accommodate ridiculously sized spools, but nothing I have even comes close to touching bottom, so I'm thinking between dropping the spool holder shaft height and redoing the gearing I may be able to shave an inch or two off the height as well.
Another thing I'd like to address is the actual hanging mechanism for the spools when mounted. The bearing end pins go into receivers with a very short vertical inset and it's very easy for the spools to pop out, so I'm going to make that deeper to preclude that.
I've toyed with changing the gearing ratio even if I find out there's larger hub sizes than what I've seen thus far and I really do need the full 2 revs during retracts as a result for a couple reasons: He uses a 1:1 ratio on the two larger gears which accelerates wear on the gear surface, and if I change out the ratio I may be able to get by with less weight on the top of the rack gear. It works, but it's a pretty loud ker clunk on every ratchet out at maximum extension.
So...
IF ya'll don't mind and happen to know your spool sizes, I'd be really interested to know the largest:
Width
Hub Diameter
Flange Diameter
That you've run into (and if you wanna post the MFG as well just for reference, that'd be lovely.
Thanks in advance.
 

 

Posted : 09/01/2021 7:48 pm
Swiss_Cheese
(@swiss_cheese)
Reputable Member

Prusa PLA and Ninjatek straight up, huge unnecessarily large spools. no problems with overture spools at all

This post was modified 2 months ago by Swiss_Cheese
Posted : 10/01/2021 5:49 am
cwbullet
(@cwbullet)
Illustrious Member

@swiss_cheese

That I have to agree with.  

--------------------
Chuck H
3D Printer Review Blog...
Posted : 10/01/2021 11:44 pm
LewnWorx
(@lewnworx)
Active Member

@swiss_cheese @cwbullet:

 

Ok, but have you got any numbers?

Whatever’s your largest hub?

Flange?

Widgth?

 

Posted : 11/01/2021 5:04 am
Yveske
(@yveske)
Trusted Member

I respool everything to Prusament spools just for that reason.

Spool 200 mm diameter / 66 mm width
Filament 100 mm diameter
Axle 50 mm

Having problems with bed adhesion every morning......
Posted : 11/01/2021 6:40 am
LewnWorx
(@lewnworx)
Active Member

@yveske

Thanks.   Thus far my widest is 68mm (overture PLA), largest flange 200mm, and smallest hub was 70mm.   50mm hub is VERY small and will increase the revolutions needed for an 18” retract to 3 from just short of 2 for a 70mm hub.   What filament had that side hub (axle)?

Posted : 11/01/2021 2:15 pm
Swiss_Cheese
(@swiss_cheese)
Reputable Member

Ninjatek spools 202mm OD 75mm wide and 52 hub, I don't know that any of this matters because I re-spool all the time anyway

This post was modified 1 month ago 2 times by Swiss_Cheese
Posted : 11/01/2021 5:03 pm
egar
 egar
(@egar)
Trusted Member

@yveske

I've never respooled any filament, but I expect I'll need to one day.  Do you have an easy/automated method to do this reliably?  Seems it could be a really boring job without some type of automation.

Thanks

Posted : 11/01/2021 5:07 pm
LewnWorx
(@lewnworx)
Active Member

@swiss_cheese

Well that’s bigger on the flange and width size but not the smallest on the hub size (50mm).   Looks like I’ll need to add another 8mm to the width of the stand if I want to use ninja.

What do you use for respooling?   I line a couple of my auto rewinders minus the gravity weight back to back and go that route but it’s not ideal.  Would love to have something that does a good job of the back and forth weaving as part of that process as despite my best efforts to get a dead on spooling all it takes is a split second of losing tension on the filament and I have to unwind a lot of work and redo it, which takes a long time when I get a knot or something in a pretty much brand new spool (overture, matter hackers, I’ve given up on both of those outfits due to too many tangles).

Posted : 11/01/2021 7:43 pm
cwbullet
(@cwbullet)
Illustrious Member

I know NinjaFlex is large.  I do not have a 1KG spool at this time.  I have two on the way.  

--------------------
Chuck H
3D Printer Review Blog...
Posted : 11/01/2021 11:12 pm
Swiss_Cheese
(@swiss_cheese)
Reputable Member

@cwbullet

I currently have 8

and a couple Armadillo.

They're all the same size "huge" 

This post was modified 1 month ago by Swiss_Cheese
Posted : 12/01/2021 12:55 am
LewnWorx
(@lewnworx)
Active Member

@swiss_cheese

What’s armadillo?

To clarify: 

The spool width will drive the axle size and subsequently the width of the entire rewinder assembly.   I’m hoping to be able to fit this in a dry cereal box (starting to look less likely) but definitely want to keep all 5 side by side under 29”, ideally less to they’ll line up on the enclosure top to minimize the PTFE tubing length going down to the MMU.

Hub size (smaller is worse) drives how many revolutions the rewinder will require to do color changes at the end of a spool.   At 68-70 MM (most of what I have, which is Prusa, overture, Matter hackers and CC3D) it takes just two revolutions on a 70mm hub to retract the 17” needed for a color change using the stock feeder PTFE tube length from the MMU to the extractor (also includes the length INSIDE the MMU on the selector side of the pulley gears).   

If the hub drops to 50mm that goes up almost a full additional revolution which in turn drives the required height of the vertical rack gear that drives the rewinder.   I can do some clever stuff with the stacked gear ratios to offset this, but in doing so will change the torque exerted on the spool at the tail end of the travel, and I’m afraid if I get to radical with the gearing it’ll yank the filament right out of the feed into the MMU.  Then again, by the time it’d be doing a full 3 revolutions most of the mass of the filament will be gone, so maybe this isn’t as big of a concern.  

And finally, the flange size drives the height of the entire device.  If I can stay around 200mm for the spool flanges I can shave off some height from the existing mechanism I’m deriving this design from, which will make filament spool changes easier when the rewinders are on top of an enclosure.   Migrating the PC4-M50 connection to the top side of spool vs. the bottom of the frame should help this as well.

Posted : 12/01/2021 1:14 am
Swiss_Cheese
(@swiss_cheese)
Reputable Member

Armadillo is Ninjateks  hardest TPU with a durometer of 75D same size spools as the Ninjaflex and Cheetah.

Posted : 12/01/2021 2:26 am
jsw
 jsw
(@jsw)
Noble Member

One oddball I have is the RepRapper spool, which is about 58mm wide with a center hole of 72mm.

Posted : 12/01/2021 2:29 am
cwbullet
(@cwbullet)
Illustrious Member

@jsw

That is an oddball.  I am not sure what the spool is made of but it is flexible.  

--------------------
Chuck H
3D Printer Review Blog...
Posted : 12/01/2021 2:34 am
LewnWorx
(@lewnworx)
Active Member

@jsw

That is an oddball.   It’s narrower (most of mine run in the 65-70 range, hub size is decidedly larger, although I’ve got zero  problems with that from the rewinder design standpoint.   I had read someplace that some materials require larger hub diameters due to being more brittle and they’d break on smaller hubs.   

Posted : 12/01/2021 2:41 am
Yveske
(@yveske)
Trusted Member

@lewnworx

I think you misunderstood me.
The filament is wound onto a 100 mm diameter cardboard cylinder (use this measurement for your rewinder).
The plastic spool flanges have an axle of 50 mm.

Having problems with bed adhesion every morning......
Posted : 12/01/2021 6:54 am
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