Replace the tubing on your Cube 3 cartridge

[MegaloDon]

The tubing that goes from the cartridge to the print head is a pain. If the filament breaks (and it often does) because of the sharp turns it has to make, it jams up or I have even had it poke through and feed into mid-air.

I have developed an alternative that works very well and decided to share it.

You will need to buy some PTFE (Teflon) tubing that is 2mm ID and 3mm OD. You need about 560 mm (22 inches) for each cartridge. The tubing that is inside the cartridge is not long enough. In my first attempt, I spliced a couple pieces together. It works but not worth the hassle.

You will also need to drill a hole in the top of the print head plastic casing. We’ll get to that later.

First heat up the print head and remove the filament from the print head and drive mechanism. (The picture I took still has the filament in it, but it is just to show the print head.)

Then disassemble the print head (it just pops apart if you pry it from the end where the tubing is) and cut the tubing off. Now you can remove the lower half.

PrintHead_Disasembled.JPG

Drilling the print head


I made a jig for the print head to make sure the hole gets drilled perfectly straight.
Also, I do not have a drill press, so I made a guide to fit my Dremel 3000.


If you have a drill press, you just need to print “DP_Fixture_Left.stl” and “DP_Fixture_Right.stl”.
If you don’t have a drill press and you want to use my guide, you need to print “DG_Fixture_Left.stl” and “DG_Fixture_Right.stl”.

Drill_Jig.JPG

They go together with screws that are about 3 mm around and about 70 mm long and nuts to match. The little rings in the middle of the nut holes are just supports. You can easily remove them with needle-nose pliers.

If you have a drill press, you can skip the next part.

The "DrillGuide_Outer.stl" has a window so you can see what you are doing. The little bars in there are supports. Remove them.

DG_Closeup.JPG

Put the outer in place before you tighten the screws on the fixtures. This will clamp the outer in place.

The "DrillGuide_Inner.stl" is threaded on one end to fit my Dremel 3000. You may have to modify that to fit whatever drill you have.

Dremel.JPG

The "Do_Not_Print.stl" is just for reference on how to put it all together.

Drill_Guide.JPG


Putting it all together

It might take a little effort but you should be able to just pull the print head tip off the tubing.

The little lug next to where the tip was just screws off. Save it. You will need it later. It’s what holds the tubing in place. Save the piece of tubing for later reference.

Disassemble the drive mechanism and remove the tubing. There will be another lug on the end of the tube. Unscrew and save it.

Drive.JPGLug.JPG

It turns out that the outside diameter of the original tubing is around 2.7 mm. Whereas the new stuff I bought is 3 mm. That's why it was so difficult to attach the lugs and print head. The new tubing is stiffer so it works out better that way anyways.

You will need to find a metal coat hanger that is just the right size to fit inside the new tubing you purchased. Straighten out the coat hanger as straight as you can get it. I used super fine sand paper to remove any paint or varnish from it and it polished it up nice. You will need this to put the lugs onto the tubing. If you try without it, the inside diameter of the tubing will be too small for the filament. The reason I used a coat hanger is that it needs to be a little longer than the tubing. You’ll see later.

Make sure you put the tubing through the hole you drilled in the print head before continuing.

Insert the coat hanger into the tubing and screw one of the lugs onto one end. You may need to get it started without the hanger, but make sure it is fully in when you screw it on. You can use 2 pairs of pliers to make it easier. As long as the coat hanger is in there, you can use pliers to hold the tubing, but be careful not to damage it. This one only needs to go on the very end (the same way it was on the end for the drive mechanism).

Now for the hard part. Do the same as above, except the lug needs to go on a lot farther. Use the old piece of tubing as reference for how far.

Make sure the hanger is still all the way in. I found that I needed to drill some of the old filament out of the print head tip. Use a 3mm or 1/8” drill bit if necessary. Put the spring in place before installing the tip. Since the tubing now has ridges from where it was threaded, if you try to push the tip on, it will scrunch up the tubing and get bigger around. I had to screw mine on. The further you go the harder it gets. I had to use pliers towards the end. Now you can see why you need the length of a hanger. You have to be able to pull it out after you get the tip on.

If for some reason the tubing goes in easy, don’t worry if it seems a little loose. It doesn’t have to be a tight fit. The washer looking thingy and spring are what holds it firmly in place. And the lug holds the tubing firmly in place.

Top.JPGSide.JPG



Download the pack HERE!

[bolsoncerrado]

Wow! Awesome hack! Thanks a lot!

I own a dremel official workstation, so may be you could adapt the design to it too

[MegaloDon]

What needs to be adapted? I'm certainly willing to try.

[bolsoncerrado]

Well, since the Dremel Workstation already allows you a "precise" straight drilling, I guess its just a matter on how to keep the red part from moving on the workstation "table"?


Perhaps a set of this would be enough? https://www.thingiverse.com/thing:624589

Also, given you have knowledge on this, I've always thought of raising the printer with raisers below it and add some sort of spooler there, so we can forward the filament towards one of the sides "the cleanest" way and keep asthetics of the printer at its max

[MegaloDon]

Well, since the Dremel Workstation already allows you a "precise" straight drilling, I guess its just a matter on how to keep the red part from moving on the workstation "table"?


Perhaps a set of this would be enough? https://www.thingiverse.com/thing:624589

I would think that would be more than enough. If I had a drill press, I would even venture to hold it with my hand. Although I wouldn't recommend it to others for safety reasons.

Also, given you have knowledge on this, I've always thought of raising the printer with raisers below it and add some sort of spooler there, so we can forward the filament towards one of the sides "the cleanest" way and keep asthetics of the printer at its max

Certainly seems possible. Personally, I don't care about the appearance, as long as it works well. I would think that putting the filament under the printer would make it more difficult to change the spool. Perhaps if there were a tray that can be easily slid out the front to change spools, it wouldn't be so bad.

You would need something similar to this: http://www.thingiverse.com/thing:508896

[TommyDee]

Love all the printed tools

I ordered some of the 4/2 tubing from McMaster to fill out my order. PFA rated to 500F. I'll give machining the ends for the keepers a try.

[TommyDee]

Another tool idea; evening up two nozzles for dual filament prints. In over a dozen cartridges, once did I have a coincidence that both extruders had the same gap.

You can press off the push-nut backwards. Then you can reset the depth. If you regularly maintain your cartridges anyway, this might be a useful step to get all your cartridges compatible with each other. One less hassle when you need dual printing. Thoughts?

[MegaloDon]

I'm not sure what you mean by "evening up two nozzles" or "compatible with each other". Please explain. Perhaps some pictures?

[bolsoncerrado]

Yeah Im curious too?

BTW when extruding some filament of a latter clogged white cart, I measured it and its between 0.33 and 0.35

Was it supposed to be 0.4?

[TommyDee]

When you gap the nozzle to the plate, you only gap the left one according to the instructions. The right one "is what it is". Yes, for good prints, both the nozzles should be exactly the same gap so they don't redo each other's prints. Or say you have a right side that is just a hair longer than the left. And you print with the left, and the right is constantly knocking the print around.

If your entire inventory of cartridges were to be consistent about the clearance as installed, you can mix and match cartridges at will, and not worry about constantly setting the build plate gap. With only 2 nozzles and this mod, the effort is even easier.

- - - Updated - - -

Yeah Im curious too?

BTW when extruding some filament of a latter clogged white cart, I measured it and its between 0.33 and 0.35

Was it supposed to be 0.4?

I measured the provided gauge to be 0.23mm at the label.