Aluminum Titan Extruder from China

The original Titan extruder from E3D works pretty reliably, but has a few issues.

It's made of flexible plastic, the V6 hot-end fits a little bit loosely inside the extruder body, and the way it mounts on the printer is not very user friendly.

The flexibility of the plastic cover is a problem.  It is easy to over-tighten the screw that passes through the drive gear, which bends the cover and causes misalignment of the bearing.  The bearings used are very small and can't withstand much side-loading.  Unfortunately, that screw is one of the screws that mounts the whole assembly on the motor, and you really want it to be tight.

The V6 hot-end, also a reliable performer, is not optimal when paired with the Titan.  One of the design problems with the V6 hot end is that it has no anti-rotation features.  When you put it into a Titan extruder, it can rotate easily, even from the small force produced by the heater cartridge wires. More on the shortcomings of the V6 hot-end, here.

You can either use E3D's plastic mount, or print your own - flexible- or you can mount the extruder to a metal plate, as I have done in UMMD.  If you opt for the more secure mounting to a metal plate, when you remove the cover from the extruder, there is only one screw holding the entire extruder on the printer.  Three of the cover screws go all the way through the extruder body to the motor, so if you just want to take off the cover so you can take out the hot-end to clear a jam or to change the nozzle, you have to trust the one screw to keep the extruder in place.  That remaining screw is located behind the hot-end, so if you want to remove the extruder from the printer, you have to disassemble it completely.

The good things about the Titan include high pushing force on the filament due to the gear reduction and small diameter drive gear.

I saw an aluminum version of the Titan in a forum post and ordered one from a Chinese supplier.  It has a couple flaws that are obvious from the start, but I thought maybe those can be fixed.

Here's the aluminum Titan assembled with a V6 hot-end.  The unit I ordered came with a metal mounting bracket that should make it possible to swap extruders without taking it apart.  One nice feature that the original doesn't have is the small lock screw that grips the hot-end to keep it from rotating.

Just like the original, there's one screw located behind the hot-end that holds the extruder body onto the motor.  Three of the cover screws pass through the extruder body and into the motor.

Cover off, hot-end in place, and filament inserted.  Notice the large gap between the bottom of the drive gear and the top of the tube that guides the filament into the hot-end.  That's very bad.

This is what can happen when there's a gap between the drive gear and the filament guide tube. This is a BullDog XL extruder on SoM, and the filament is PLA or ABS.

This is that BullDog XL extruder with the front cover off.  The arrow points to the gap that allowed that mess to occur.  All they had to do to prevent the problem was make the brass tube a bit longer.  Doh! 

One more problem- the filament doesn't ride on the center of the drive gear concavity.  That means that it may tend to wander back and forth on the gear teeth, especially with the wide gap between the feed tube and the drive gear.  The result may be inconsistent extrusion because the diameter of the drive gear changes with the filament's position on it.

Extend the Filament Guide Tube

I found a piece of 1/8" OD aluminum tubing at the makerspace and used a belt sander to put a couple 45 degree chamfers on the end of the tube, then cut the tube with a jeweler's saw to about 15 mm long and deburred the ends with some jeweler's files.  Next, I drilled out the feed tube hole with a #30 drill (0.1285") and the aluminum tube fit loosely inside it.  I mixed some epoxy, put a drop on the aluminum tube, and inserted it into the feed tube on the extruder body.  I pushed it up to the drive gear and inserted a piece of filament to help hold the tube in position while the epoxy set.

Side view of the extruder with the aluminum tube installed (inside red square) and filament inserted to hold tube in position while epoxy set.  The ID of the tube is about 2 mm.

Extruder with cover off showing aluminum tube in place.

Pinch roller removed. 

The addition of the tube has made it easier to load filament, and should help control the position of the filament on the drive gear teeth.

Tests

I was curious to see if the E3D parts were compatible with the Chinese parts.  In particular I wanted to see if the Chinese Titan mount would work with the E3D Titan extruder, and if the E3D drive gear would work, too.  I am pleased to report yes to both!

I swapped the E3D drive gear into the Chinese extruder and it fit perfectly.  The aluminum extruder uses the same bearings for the drive gear, and careful measurement of the two gears finds them essentially identical except that the original drive gear diameter (the steel part that grips the filament), measured at the deepest concavity of the teeth is 7.78 mm and the Chinese drive gear is 7.39 mm in diameter.  That difference means that the steps/mm settings for the two should be slightly different.  I also noticed that there are fewer teeth in the filament drive part and they are cut deeper in the original E3D part compared to the Chinese part.  The best thing is that the filament path in the aluminum Titan seems to have been designed around the original E3D part - the concavity in the filament gripper teeth lines up perfectly with the holes that guide the filament in the aluminum extruder.

Here's the Chinese drive gear in the extruder body.  You can clearly see that the filament will be off center in the gripper teeth.

Here's an E3D drive gear mounted in the aluminum Titan.  Notice that the teeth of the filament gripper line up perfectly with the filament guide tube.

I had to take the E3D Titan off UMMD before I could mount the aluminum Titan, so I checked to see if the original E3D Titan will fit on the Chinese mount.  I am pleased to report that it fits perfectly.

Here's the E3D Titan mounted on the aluminum mount that I got with the aluminum Titan.  A perfect fit!

The other side of the E3D Titan mounted on the Chinese aluminum mount.  

Print Testing

I mounted the aluminum Titan on UMMD, rezeroed the Z axis, and ran a test print.  No problems were encountered.  After calibration I found that 443 step/mm was a good number for the extruder with the Chinese filament drive gear.

Chinese aluminum Titan extruder mounted on UMMD with an XCR3D hot end.

Aluminum Titan mounted on UMMD.

UMMD Printing With Aluminum Titan Extruder from Mark Rehorst on Vimeo.

The real test of anything like this is how it holds up with use.  I'll be using it a lot in the coming months and will do more blog posts if I encounter any problems.

UMMD Gets an XCR3D Hot-End

During some recent hunting for the source of a print quality problem with UMMD, someone posted something about a new hot-end on the Rep-Rap forums.  It looked interesting, and I've started seeing problems with the E3D V6 that was on UMMD, so I decided to check it out.

I ordered an XCR3D hot-end via Ali-express for a whopping $16 shipped and installed it in UMMD and found a few interesting things.

XCR3D Hot-End mounted on the Titan extruder in UMMD.  The heater block started out the same black color as the heatsink.

First, the Good:

It fits tightly into the Titan extruder, much tighter than the E3D V6 did, so it's very secure, no wobble, and no unwanted rotation caused by the heater cartridge wires pulling on it.  It doesn't feel over-sized - it feels like it fits properly.

The fan is absolutely silent- I put my ear within a few cm of it and couldn't hear it running.  We'll see if it lasts...

The fan bracket is metal and screws securely to the heatsink.  No more melted plastic, no more rotating fan.

The stainless steel heat-break is a bit more robust than the E3D part and the Teflon tubing doesn't go as deep into it.

The heatsink end of the heat-break is not threaded- it is held into the heatsink using set screws.  I like that!  I've had the heat-break come loose in the E3D V6 a few times.  Also, if you were setting up a multiple extruder machine, having the heat-breaks held in with set screws would allow you to set the nozzles at exactly the same height.  It also means you can take a jammed heat-break/nozzle assembly out without having to take apart the whole extruder- two thumbs way up!  It also means you can swap in a different heat-break/nozzle assembly without taking the extruder apart.

It comes with a 50 W heater cartridge that heats up quickly- it gets to 240°C in 60 seconds!

It has options for temperature sensors- I got the cartridge thermistor and it seems to be a direct and accurate replacement for the E3D part.

The heater block, heatsink, and fan bracket all have a black coating (anodized?) that looks nice.

You can order the kit with 1 m or 2 m long leads.  I just cut them off and put connectors on to fit UMMD's extruder carriage cable.

The brass 0.4 mm nozzle that comes on the unit appears to be well machined.

It comes with some little, stiff wire tools to clear a jammed nozzle.  I have not tried to use them.

There is a standard lock ring to hold the tubing into the hot-end for Bowden set-up, and inside the heatsink there's a phosphor-bronze (?) part with fingers that are angled downward.  You can slide in the Teflon tube and the fingers grab it and won't let it slide upward.

Now the Less Good:

The black coating on the heater block quickly burns and turns brown.  It doesn't seem to affect operation, just appearance.

The overall length is a few mm longer than the E3DV6 so you lose a little of your Z axis print capacity.  It is actually about the same length as a V6 with a volcano heater block.

The heater and temperature sensor cartridges are held into the heater block with set screws.  E3D's split block and clamp design holds the cartridges without crushing them.  You can always change the heater block.  One concern is that the set screws will fill up with plastic and I won't be able to get a wrench into them if I need to replace either of the cartridges.  We'll see...

Even though photos on the manufacturer's page at Ali-Express show Teflon tubing, none is supplied with the hot-end.  For direct extrusion you need 65-75 mm of tubing (I didn't measure it).  For Bowden you need whatever length your printer needs.

Installation:

It was pretty easy.

I took the heat-break and nozzle out of the heater block, applied anti-seize compound to their threads, and screwed them back into the heater block.

I put a little thermal compound on the heat-break and slid it into the heatsink and tightened the set screws.

Next I pried the black plastic Bowden tube lock ring out of the top of the heatsink,  pushed a piece of Teflon tubing into the heatsink until it stopped at the bottom of the heat-break, then cut it so there were 16 mm of tubing standing above the top of the heatsink.  That extra tubing fits up inside the Titan extruder's guide piece.

I applied anti-seize compound to the heater and thermistor cartridges and their set screws and mounted them in the heater block.

I cut the cables to appropriate lengths and installed connectors to mate with the extruder carriage cable.

I heated it up to print temperature and tightened the extruder nozzle against the heat-break with two wrenches, one on the heater block and one on the nozzle, then let it all cool back to room temperature.

Finally I ran a PID auto-tune on the hot-end and updated the firmware configuration with the constants returned by the controller.  When I heat it up to print it overshoots the set temperature by about 5°C then quickly settles to the set temperature and doesn't move after that.  It gets to 240°C in 60 seconds flat.

Printing:

I have printed both ABS and PLA with it and it seems to work fine.  At some point I may try the volcano hot-end again.