The stem of the insert gives greater rigidity of the length of pipe within the fitting, reducing the chance of leaks if a side load is applied. Retractions try to counter this by “pre-pumping” at the start of extrusion and relieving pressure at the end of extrusion. The more nuanced pressure advance algorithms do a conceptually similar thing, but are continuously compensating during acceleration and deceleration. Whatever control method you use, it is not possible to gain control authority over a system that is inherently less responsive. You can compensate for the errors to an extent, but you can’t eliminate them. Your extruder has a finite amount of speed and acceleration which it can use for compensating. The spool weight myth is countered because you get the same no-drag effect with a direct extruder by running a guide tube from the spool holder to the extruder in the normal way, thus keeping a constant filament length between extruder and spool independent of carriage position. Collet covers for use with standard Speedfit fittings, are available in white or in red or blue to allow colour coding of pipes. Other things you can do to improve performance include having the shortest bowden tube possible, while keeping bend radius no less than around 150mm.

Don’t forget that bowden tubes can and do wear over time. Abrasive filament will gradually eat away at the inside of the tubing, and just the passage of filament with drive-wheel toothmarks on it will have an impact. Additionally, the ends where the couplings grip can get chewed up over time, but this is much reduced if you use our new collet clips. By diving a little deeper into the physics of where the downsides to a bowden system really come from, we can begin to understand how to improve these systems by minimising the negative effects. What needs fixing? In the 1980s the first ever fibre optic push-fit fitting was developed by John Guest in collaboration with BT. Such fittings are now commonplace, with over 2.5 million being produced every year for delivering high speed internet to millions of homes and offices.

Details

In the original incarnations of 3D printer extrusion systems the motor, gearing, filament drive and HotEnd were all built together in a single assembly. The extruder (motor, gearing, and filament drive) thus fed filament directly into the HotEnd. More lag/lash/hystersis/slop/whatever you want to call it. The extrusion system is simply not going to be as responsive as a direct extrusion system Push the pipe into the fitting, up to the pipe stop. If the Speedfit Pipe has been cut correctly the insertion mark on the pipe will be level with the collet head. The ‘O’ ring on the Superseal Pipe Insert provides a secondary seal against the bore of the fitting. A good connection has been made.

Those of you who've seen our new Gold V6 will have seen the swanky new Capricorn PTFE tubing and collet clips that it comes with. This blog post goes into more detail on the need for these upgrades, and how they work. TL;DR:An ‘O’ ring at the head of the insert and the shape of the stem, provide a secondary seal against the bore of the fitting. A combination of this and the main ‘O’ ring ensure a good connection. You just need to increase retraction and your bowden system will be as precise as a direct extruder" Speedfit Fittings have a unique grip then seal construction made up of a collet with stainless steel teeth to grip the pipe and an ‘O’ ring to provide a permanent leak proof seal. Use of the Superseal Pipe Insert ensures a double ‘O’ ring seal.