There are a lot of options for bowden couplers and while I haven’t tried them all, here are the ones I’ve tried and my experiences with them. They were all used with 1.75mm filament, 4mm teflon tubes, a BondTech extruder, and an E3D v6.
The plastics used in 3D printing behave differently under a constant tension, some are elastic and return to the original shape when that tension is removed, some creep, and take on a new shape as a result of that strain. Then there’s crazing and cracking which you can see in the print above.
Sometime a part detaches from the build plate, especially when using higher warp filaments or an unheated build plate. There are several things that can happen at this point with a filament hairball being one of the best results.
Almost all of the filament suppliers vacuum seal their filament with a desiccant packet pack to ensure your filament arrives dry and ready to use. That’s the theory, but I’ve noticed a few filaments arrive wet, with the moisture perfectly sealed in to ensure you have a poor first experience with the filament.
I’ve been wanting to try metal casting in printed molds for years, but never had a use for the heavy, low melt alloys that would work in a printed mold. When I saw this mod for anti-backlash weights by Pratyeka in the Tiko 3D forums, I figured I’d finally give it a try and ordered a block of metal.
I’m always surprised when a 3D printer designed around printing PLA comes without a part cooling fan. Though less so in the case of the Tiko, given the pricepoint. If you’ve seen some of my extruder designs, I prefer printing with a lot of airflow, the more the better (as long as you have control over it). So here’s one way to add part cooling to the Tiko.
I’ve heard many times over that to test backlash in a printer you can grab it by the nozzle and wiggle it around (with the nozzle cold of course, but with the motors powered up). Ideally nothing moves, but when I tried that with my Tiko there was a disconcerting amount of motion. The motion came primarily from two sources, the motor mounts and the flexible delta rods. The movement from the rods at least offered up a bit of resistance so I expect those to be only an issue at higher speeds, but the movement in the motor mounts offered almost no resistance.
I assume this is the source of many of the unexpected motion I sometimes see from my Tiko, the jumping to the side when moving the nozzle up and down, the shifting when trying to print a straight line. You can see some of the shifts in the raft print above, the nozzle will be printing a straight line and it will shift to the side. Interestingly you can also see some craters in the filament, that’s what happens when you don’t store your filament properly and it absorbs moisture (I’ve mostly been testing unspooled leftover filament that wasn’t stored properly). I store all of my open filament spools in watertight bins and with rechargeable desiccant, but you can read more about that here,
I added some epoxy tubing to reinforce the the delta arms on my Tiko. The tubes are approximately 200mm long and have an inside diameter of 0.219 inches (5.56mm). You can get them from Tap Plastics, but you will need to cut them yourself (one 32.5″ rod can be cut down to 4 – 201mm rods for the Tiko, you’ll need 6).
My first prints with the Tiko was terrible (not unusual for a 3D printer), I used the default settings including the default temperature of 210°C and it was clearly too hot, making the test print come out a melted mess. No problem, I know how to fix that. So next I tried 190°C and it came out very underextruded. The clicking sounds made it clear that the something in the extruder system wasn’t keeping up.
Along with some 16 thousand other people, I joined the Tiko Kickstarter in the spring of 2015, and it recently arrived in the last days of 2016. The Tiko is an interesting printer, a mini delta, costs less than $200, includes built in WiFi, is fully enclosed, is fanless, comes with a built in slicer, is compatible with other slicers and filaments, and is easy to setup. And although it doesn’t come with a heated bed, it’s also compatible with the heated bed of my Eustathios (pictured above). As of early 2017, here’s a few of my first impressions (I expect things will be changing quickly).
This post describes my initial build of a Eustathios Spider v2 (github link) in 2015. It isn’t a detailed build log, just a list of changes I made from the standard build process and the rationale behind them. I have made other modifications since then, but I will have to save that for a future post.