Taz 5 FR Control

I’m trying to print Emmett’s Geared Bearing -
http://www.thingiverse.com/thing:53451
My Taz is well calibrated, but I’ve mostly printed with ABS to this point.
I have a nice roll of Lulzbot PLA so I decided to give it a shot.
(I haven’t checked calibration with the PLA yet)
The Bearing (planetary gears) is printed all at once so close tolerances are very important.
The first try was fused solid (over-extrusion?).
I tried lowering the FR via the Taz control panel to 95% - still fused.
Again at 90% and I was able to free the parts fairly well (still a few rough spots) with judicious application of Maxwell’s Silver Hammer…
I still need to print this so that all of the parts are separate as they print.
My question is what does this FR control actually do?
It seems that reducing the Flow of Filament 10% is pretty drastic.
I have a feeling that I’m not understanding what this control does.
I am pretty sure I can lower the extrusion rate in Cura, but am curious about the FR control.
Any other suggestions would be welcome.



Best regards,
PCH

Hello PCH,

The FR setting for the printer is the feed rate setting. It should be at 100% unless you have issues with that feed rate.
The issue that you will be running into is that the part density of the part that you are printing will normally be 70%. This is what is used for all of the parts on the printer. If you choose to increase that density, please don’t go over 90%, as you will have issues with filament overlap.
If you adjust the feed rate to 100% and then set the fill density lower, you will probably have better results.

Please don’t use PLA, as the filament will become brittle, due to ambient conditions and the filament being a corn based filament.
ABS will work far better and is a much more resilient filament.
If you have any other issues with the model, then please contact support@lulzbot.com with photos and settings and they will get you running!

What the actual hell?

Thanks for the reply, but I think you mis-understand.
The part I linked is NOT a printer part.
It’s a set of planetary gears constructed like a bearing.
There is an outer race (large ring with gear teeth on the inside), an inner race (smaller ring with gear teeth on the outside), and 6 small planet gears that spin between the two races (orbit around).
The parts are all printed in the assembled configuration. It requires precise positioning and extrusion. The individual parts are printed very close to each other and when completed, lock each other onto the assembly.
It has little to do with the in-fill - again it’s not a part for the printer (I thought they were 85% infill ABS).
I want to try it again. First I’ll do a PLA calibration cube. I have previously checked my e-steps and they are good.
I will try again with an even lower FR setting (80% or 85%).
I guess I asking what this number means. Is it reducing the filament flow by 20%?
This somehow doesn’t seem right to me. Perhaps it’s just a qualitative reference…



PCH

Hello all,

Doing some forum training here is all :wink:

Feedrate changes all settings. Acceleration, speed, jerk, rate at which it is fed. Changing that will only change how quickly your printer moves, it won’t change one specific thing like flow percentage.

For the print fusing together on the lower layers: This is caused by first layer squish and can be changed by raising the nozzle just a tad, to allow the layers to print and stick to the bed without having them fuse together when you want movement.

I hope this clears things up a little,

Yeah that gear bearing is incredably difficult to print in ABS compared to PLA. I say this as someone with 3 of the ABS ones sitting on my desk here at work.

Feed rate is the rate at which the extruder pushes fillament into the hotend but also all the other motion axis. Increasing this number increases the speed the printer moves in all axis. In a perfectly calibrated machine, a feedrate of 100% on an extruder that is set to extrude 100mm of fillament would send 100mm worth of fillament into the hotend. In actual practice, the calibration of the extruder might be off, or the calibration is correct and the fillament diameter setting is off, so people tend to use feedrate to compensate for other issues. For example, if your extruder is calibrated perfectly but you are sending 3.2mm fillament down the extruder when it thinks you are sending 2.85mm fillament, you would be overextruding. Lowering the feedrate to 85% would appear to compensate for that, but it would be a workaround rather than the actual fix of measuring the fillament diameter and inserting the correct diameter value. Flow rate on the other hand just adjusts the amount of plastic extruded.

With PLA, cooling issues can also falsly show up as overextrusion sometimes, since overheated PLA tends to expand. A part without adequate fan, or a part printed with a failing barrel fan will show up as lumpy and slightly oversized even if the actual extrusion amount is fine.

If your extruder calibration is fine, check your fillament diameter setting against your actual fillament, increase your cooling, and verify the small barrel blower fan on a Taz 5 is still functional. They sometimes fail in partially working, but too low of flow mode.

edit: clarified things. NickP is correct.

Thanks Piercet and Nick.
I measured the Filament and it’s set correctly.
It’s not touching on the first layers, but somewhere in the middle.
I’ll look at the Extrusion Temp and cooling.
I did a 3 fan Extruder conversion and have 40mm Noctua fans on all three.
As I mentioned this is my first attempt at PLA so my defaults may be off.
Thanks for the advice, I really appreciate it.


Best regards,
PCH