Flexystruder and swapping extruders

So, I gave mine a try today. It worked well, and was about as easy as something like that could be to swap out.

The downside I discovered, and should have anticipated, is that every change throws off the Z-offset. This is particularly irritating on the mini with 10 minutes of heat/cool/wipe/level per test, and a cool down for the bed. It can easily take me an hour to dial in to the new value.

There has to be a better way. I was thinking of a program that could take a gcode for something like a slow spiral and allow me to tune the Z-offset as it prints. That way, I take the hit once for the test. Maybe a way to use feeler gauges to test and calculate a good value?

I found one option for this, once I get a z-offset that is close enough that the prints stick down without damaging the PEI. Use Simplify3D’s multi-process feature. I print the same test part 3 times with 3 different settings. Just adjusting one setting a little for each part. In the case I did last it was to test the extrusion rate as I was getting a lot of over-extrusion. It works with just about any setting, so it’s handy for attempting to dial in the final details. I could do more parts, but I suspect I’d have a hard time remembering what I did for each one. :smiley:

Even after calibrating the e-steps, and double checking that I did it right, I find I need the extrusion rate around 0.70 to prevent ugly print artifacts from over-extrusion.

Does the auto level not work right? Isn’t that gonna measure the Z offset after the extrusion change?

Or are you trying to change the extruder mid print or something?

The auto-level process runs, but when I set up the same filament and extruder I was using before, the offset I tuned for no longer worked. Perhaps it was an auto-level failure. I do watch to make sure it doesn’t deflect the bed during the process, but I did start cleaning the nozzle better, perhaps that made a difference.

So I’m not convinced it’s caused by swapping now. After more checking I found that when I printed a single layer at 0.4mm, that’s what I got on a caliper. So what I ran into could have been a one time thing. I did swap again and it seemed to adjust properly, which makes me think I messed up something the first time I did it.

Even with that, it’s nice to be able to test multiple variations on the process to help get the best print quality. Test parts tend to be small and print quickly, so the time needed to do the pre and post scripts adds up fast. Doing many tests per run gets the average down and lowers the time I have to sit watching it per test.

I bought some ninjaflex thinking I could use it with my mini but then found out i should buy the Flexystruder to use it. If I buy one and swap, is it only good for flexible filaments? I suppose so if you are swapping yours back and forth. Wish they could have come up with an extruder that handles flexible and non flexible together.

Sadly, not currently. The flexystruder PTFE tube gets worn out quickly by harder filaments. I haven’t found any testing to determine how much faster it wears out. You also can’t adjust the tension on the filament. It would be nice if there were a single unit that worked well for both types.

Apparently the Flexystruder can handle ABS and PLA just fine and won’t wear out any faster according to Jebba: https://www.reddit.com/r/3Dprinting/comments/41ksci/my_first_attempt_at_ninjaflex_on_taz_5/cz4mwfo?context=3

The only reason I’d use the flexystruder for ABS or PLA is in the hopes it can handle all the spare 1.75mm filament I have laying around. It gets all jammed up in my mini using the normal extruder.