I shared my initial findings with one of my favorite online 3D printing communities, /r/3Dprinting, last weekend. Thanks to input from Sanjay Mortimer, as well as other Titan users, I had clear objectives in mind for my second go-around with the Titan extruder.
First came disassembling the darn thing. I was wondering how I'd take the hot end out, since it was so difficult to insert to begin with, but all it took was a bit of twisting and shimmying around and it was out in no time.
As an illustration, I reinserted the same problematic hot end into the extruder body as far as it could go before the fit became very tight. You can see that there was indeed a clear issue.
Thankfully, I had a few spare E3D heatsinks lying around (honestly, I didn't know I had this many until I looked for them). I tested each one inside the Titan and to my astonishment, all of them fit into the groove without any issues!
So basically, even though my Titan has some visual defects (Sanjay referred to this as crazing, though it could have been some other cosmetic artifact of the manufacturing process), 3 of my 4 E3D v6 heatsinks had no problem at all mounting in the extruder body. What gives? Obviously, this was the perfect time to break out the calipers. I started off by measuring the thickness of the upper flange on the heatsink's groovemount--turns out I didn't need to look any further than that (see below).
It's now apparent that my original heatsink was out of spec. I took a look at the drawings available on the E3D site, and it seems like the dimension for this is meant to be 3.7mm. I could not find a tolerance marked for any of the dimensions on that sheet, however, so it's hard to say just how out of spec my part was.
That aside, it was easy enough replacing the heatsink I had been using with one of the good ones (I'm very glad in this case to have been hoarding all these extra parts).
Based on Sanjay's tips from the Reddit thread, I was also able to press the PTFE tube into the idler arm with again some twisting and shimmying (lack of twisting and shimmying seems to be a recurring problem for me). A simple change I would suggest in the assembly process would be to insert this part before installing it onto the motor shaft, as it's easier to maneuver everything that way (I was also a bit limited since my motor was already mounted and I didn't want to bother removing it).
Here's it all put back together! Happy to say that the front cover plate seated just fine, with no clamps at all necessary. Phew! I was ready to fire it up once again.
As you can see, it breezed through this PETG print. The cover picture for this post also shows a print I did in PLA of the low-poly T-Rex skull. When everything goes together correctly, I find this extruder very easy to interface with, and the small number of individual parts (namely really small parts) makes it pretty easy to service. Thanks, E3D!
Hot-swapping hot ends
But wait, there's more! You saw that I already own a 3mm E3D v6. As soon as I get my hands on some 3mm filament, I intend to test out the interchangeability between filament sizes. I currently have quick connects wired up for the heater cartridge and thermistor going to the board, which makes this process especially easy :) Just need to wire the same thing up for the 3mm hot end and I'll be hot-swap ready.
You may have seen Tom Sanladerer's newest review on the E3D Titan. He displays its (awesome) use as a very light extruder assembly by using the smaller form-factor NEMA 17 "pancake" steppers. As soon as I can source some of these, I plan to try this out as well. Perhaps on the newest iteration of Scrappybot?! Dun dun dunnn...