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Prusa i3 Adjustable Spool Holder

by Aero3D, published

Prusa i3 Adjustable Spool Holder by Aero3D Jun 3, 2017
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This is a remix of two great designs which I very much like.The Hex Design Toolless Mounting Spool Holder and the adjustable Filament Spool Holder. I really wanted a spool holder that could be easily adjusted while sitting atop the Prusa frame. So I have created a remix of these two designs to give an adjustable holder which clips to the top frame, uses bearings with sleeve rollers to ensure your filament spools stays in place and glides in a straight line.

This new design is easy to print as it is printed in separate parts, with minimal supports required. You will need the following hardware to fix the parts.

4x M3 12 - 14mm socket head bolts
4 x M3 hex nuts
4 x 608zz bearings

Simply Push the vertical arms into the base connecting the lugs with the appropriate holes. Next, place the nuts into the slots on each arm (x2 per arm) , Prusa style :), and bolt through the base. Then simply slide the end part onto the base, screw in the screw thread with thumbwheel and attach the rollers with 608ZZ bearings inserted. That's it.

Now, when you need to adjust the width of the bearing rollers for different width spools simply turn the thumbwheel until the rollers are at the requied width. The slot cutout on the front edge of the base is so you can add a filament guide. It has been specifically designed to accept this filament guide, https://www.thingiverse.com/thing:2341182, but many other will fit. When preparing for print please ensure you add required supports for the under base holes and accomodating lugs on the arms. This will ensure they print with the correct shape to engage. You should find that the liugs engage with a push and, whilst this will likely be enough to attach and hold the arms to the base, you still need to use the nuts and bolts.

And if you decide not to use on the frame then simple remove the side bracket arms and place on the desk, using the bolt holes to screw to the surface or simply use sticky tape.

I hope you enjoy it and please let me have any comments. Thanks.

03/06: it appears the screw threaded part was somehow incorrect rotation (mirrored). The corrected STL has now been uploaded.

22/06: I have added 3 additional parts which allow you to join multiple spool holders together when using on a flat surface (not connected to the Prusa frame). For example:

If you want to create a dual spool holder print 2 end connectors and 1 mid connector.
If you want to print a quad spool holder print 2 end connectors and 3 mid connectors.

The connectors simply push fit into the holes in the flat base of the spool holder. If you wish to physically connect the joined parts to your flat surface use the end connectors with fix holes and screw to the surface using 2 suitable screws at each end.

UPDATE: I have just added a new pair of brackets to enable mounting this holder on a 3030 extrusion frame. These brackets only use the rear bolts to hold the main part to the brackets.

UPDATE: I have added v2 versions of base, slider and rollers which include spigots for better grip on the rollers.

UPDATE: I have added a v3 of the base which includes a wider filament guide cutout to assist when using narrow spools.

UPDATE: Added a custom version of the filament guide for Haribo users.

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Just wanted to say thank you for the post. I have printed all parts but there is no proper file for the regular filament guide (meant for the prusa frame and not 3030). :( could you upload the file for it please.

I believe I provide a link in the description for the filament guide.

Prusa_Adjustable_Spool_Holder-rollers_v2. What is the design intent for the center posts on the inside of the roller? If I push the bearings in all the way, the post impedes the bearing from going all the way to the mating shoulder on the Prusa_Adjustable_Spool_Holder-slider_v2? Again, thanks for sharing your design.

The centre posts are specifically intended to prevent the bearing from touching the "mating shoulder", as you write it. If the bearing touched it would not turn freely.

Really cool design. I've got a great start on this and can't wait to finish it. Just wanted to say thanks!

Thank you. Appreciate you taking the time to comment and thanks for choosing to print it :)

Can't find the file for the v3 base with the wider slot. Did it get uploaded?

It is now. No idea what happened to it. Apologies.

Any tips to keep the bearings/wheels on the frame? It's a pretty loose connection so might glue the bearings onto the shafts somehow?

Unfortunately all bearings are ever so slightly different. 3 of mine are push fit and one is slightly loose. Also different print materials will have ever so slightly different shrinkage etc. A careful dab of superglue should work.

Hello mate very nice work, just wondering I have another printer do you think i can have the raw files possibly fusion 360 or Step file, to modify this spool holder to fit it?

I got a 2.6 filament spool that is too big for this holder .... of course I didn't measure it before and only found out after ;)

Could someone be so nice and enlenghten the parts that need to be longer to work? I uploaded an image of the roll on the too-small-of-a holder.

Prusa i3 Adjustable Spool Holder
by ForAiur

Why not just print a second one (you’d have to print a new one anyway), join them together usin the joining pieces then you can use spools up to 200mm wide

Did you design the filament guide too on this one?

No, the filament guide shown in the pics is this one https://www.thingiverse.com/thing:2341182

Filament Guide
by wrodz

it will be nice if you can combine the thumbwheel with the screw as 1 part.

If they were one part you would not be able to assemble it

I've been using the holder for a couple of months now. It worked great for the most part, but there's one design flaw and from what I can gather, it affects every bearings-based spool holder.

When the extruder is pulling on the filament and then stops, the momentum of the entire spool roll spins it a bit further than needed, because the bearings aren't providing any resistance/friction. Within an hour of this, all of my spools get unwind/loose. I then have to manually wind the filament back on to the holder. I don't know why, but this seems to affect some spools more than others.

The solution seems to be to introduce some kind of friction/spin resistance, so that when the extruder stops pulling, the spool holder stops as well, instead of turning for another mm or two.

Put some grease in the bearings so they dont spin so freely. Easy fix.

Yeah, I'll do that and it will hopefully solve the issue. I wanted to mention it here as well though, I'm probably not the only one who's encountered this.

Thanks. I've printed hundreds of hours on 2 Mk2s with these holders and never had an issue so think it depends very much on the bearings used and how free running they are. Also, I guess the different tolerances on filaments will also play a part as to how free or stiff the bearings are when inserted. Too stiff and it will affect print quality. Make sure also you are using a filament guide as this will also add some additional friction on the filament path and also prevent the filament from jumping off the spool.

I have the Mk2S as well. I've never used bearings before, but mine appear to be super smooth. I just ordered the cheapest ones I could find on eBay.

This does occur with a particular brand a lot more often, so it's probably a combination of how they spin the filament and having bearings with zero resistance.

Worked great, threaded rod tested my first layer calibration, had to make sure it was perfect or it toppled over 3/4 through the print.

One thing I noticed is the bearings can really rattle and make noise. They will be hard to pull off but soon I think I'll do so and really cram in a thick layer of grease. This should stop rattling and they should still roll plenty easily, they almost roll too easily now.

Great to hear. Re the bearings, depends where you purchase as they can have different tolerances and with the different filament shrinkage rates etc. Bearings on mine (fairly cheapo 608zz from Amazon) they are smooth as silk. I usually wash all the grease out with a bath of WD40 :)

Do you print the base flat with supports or rotate 90 degrees with the base pointing up?
I tried printing without supports and it wasn't real pretty

Print with the banana shaped side piece on the print bed. You may want to add a few small supports in the holes to make them cleaner on the vertical printed part (which is the base)

Comments deleted.

What's the widest spool this can hold? My Prusa PLA spool is much wider than "normal", about 9cm

Just aboiut 92mm when measured between the centre of the spool walls (hence sitting on the centre of the rollers). Will easily accommodate a Prusa spool with thread to spare. A Prusa spool is about 85mm centre to centre. It will accept the widest spools I have from Prusa, PrimaValue, Rigid.ink etc.

Hey nice design. however the adjustable arm the free sliding one. where the bearings connects to, is 11.89 mm, needs a wee tweak . As well the knob is seriously messed up as well, Mine jumped up a cm with 3.6 mm left to print. Drop me a message when it's ready, if You'd be so kind?

Nothing wrong with the design. I'd check your slicer.

Can I swap the 608ZZ bears for 608-2RS? They're the same size but the ZZ has the metal seal whereas the 2RS has the rubber seal (I think).

I got the metal ones they fit fine spins ok, but I have an issue with the adjustable arm needing a tweak and how well did the knob print for U?

Printed good with out support


Did you need to print the thread rood with supports?

I printed it no supports, Prussa group on FB

No support required

Question: if I don't install the two parts that attach the spool holder to the Prusa, can I set this down on the table behind the Prusa? I ask because my Multi-Material Upgrade shipped and I would rather use three more of these than the spool holder Prusa ships.Is there some way I can connect four together to make a quad?

I'm getting a piece of lexan cut to fit my top of my enclosure, getting it pre drilled to hold 1 for now.

Yes, you can simply use on any flat surface if you do not attach the vertical connecting arms.

I have also just uploaded some connecting pieces (mid connector and end connector) which will allow you to join multiple spool holders together.

Enjoy :)

Good stuff! Now I need to order a dozen bearings.

Great design! How are the rollers held on to the arms? And why 14mm? M3 screws are a bit of a chore to find in the USA and oddball lengths doesn't make it any easier.

Wow! That place is a total Maker-gasm!

I am very spoiled having will call 20 minutes away, order and then able to pick it all up in about two hours. I refer to it as CrackMaster-Carr.

Push a 608zz bearing inside each roller and then the bearing with roller is poushed on to the arm spigots. There is a flange that prevents them touching the side arms ensuring they spin freely. You should be able to get away with bolts between 12mm and 15mm. Metric because I'm based in UK. Affraid I cant help it if parts are not easy to obtain in your region.

I have 10mm and 16mm M3 bolts in the set I purchased a few weeks ago.

10mm will be too short and 16mm too long.

Amazon to the rescue. Downloading files now.

When I loaded the Thumbwheel to Slic3r PE, it was reported to have over 1300 errors.

No such issues in S3D or Cura, so must be a Slic3r thing. However, I have just run it through Meshmixer and rey-loaded so should be good in Slic3r now also

Super good looking!

Thank you. I hope it proves useful for you.