Calibrating your 3D printer’s extrusion rate is a great way to really dial in the quality of your prints. I find that when using the same brand filament I can get away with calculating the extrusion once, and checking it now and again to make sure I’m fairly close. When introducing a new filament or type (like switching from PLA to PETG for example) you probably want to run this quick check again and make sure you are within a few percent for the new stuff. Calibrating is easy, and if you use Octoprint or Repetier Host or Simplify 3D and can send terminal commands, it’s just this simple:
- Set your extruder to relative mode by issuing a M83; command
- Next mark your filament 120 mm from the entrance to the extruder with a Sharpie
- Then tell the printer to extrude 100mm of filament using the G1 E100 F100; command
- Now measure the amount of filament yet to enter the extruder. I had 30mm left over. That means that 10mm is not extruded, though the machine settings think it has. So lets fix that now. (If you have 20mm yet to enter the extruder, congrats. You are done and can go get a tasty beverage.)
- Lets find out what the current steps/mm setting is on the printer. Enter the command M503;
- You will get a bunch of settings returned, and we are looking for the M92 output, mine was:
M92 X80.00 Y80.00 Z400.00 E93.00
- So lets calculate what we need here instead. I had 30mm left over. So 120mm-30mm= 90mm. My printer is pushing 90mm through, thinking it is 100. That is a 10% difference, and pretty significant. The original output above shows that my extruder steps value was 93 (see E93.00 above.) Lets calculate the correct value. A quick formula for this is (original step value x 100) / actual distance. In my case, this is (93×100)/90=103.333
- Lets set this value as the new extruder step value with the command M92 E103.333;
- And save those settings to the board with a M500;
- Now your extruder should be set, so lets test! Run through the instructions again by measuring another 120mm and running the
G1 E100 F100; command one more time and you should be pretty darn close.
Happy printing! Leave a comment below if this helped your or you have feedback on your results.
Printing beyond PLA on an Ender 3 can be tricky. Here are a few tips to get you started with printing PETG, a filament that is stronger and has some qualities like better heat resistance than PLA. If you head into a print with PETG using your stock tried and true PLA settings, you may be up for a surprise – it just isn’t that easy. After some testing, here are some tips that will help you get started:
- SLOW it DOWN – Running PETG through your Ender 3 is going to be troublesome on many prints running it through at the stock 60mm/s. You need to slow it down. 40mm/s may work, but 30mm/s is probably the sweet spot for this machine and filament. This one is going to be the key to your success. You might get lucky on some prints, like cubes or anything that is pretty continuous in laying down a layer, but for anything with even a bit of complexity, just slow it down.
- GET the TEMP RIGHT – This one is going to vary. You can choose a nice test cube and start at the low end of the temp range for the PETG you buy, let it print for a while, and up the temp by 5-10 degrees. Keep track of what you are doing, and when you are done give the layers some pressure with your thumb and find out where the strength and layers are really holding tight. If you head too high, you will get a solid print, but you will end up with stringy prints that take a lot of cleanup or just plain fail. Also, you will note that when you start getting to that sweet spot, the color will start to change from a milky white to clear. This is when you are getting the temp right. I find that most PETG likes it HOT! Try 250C – this may just be your Ender 3 sweet spot too.
- FAN all DAY LONG – Sure, let the first layer or two go down without a fan to get a nice adhesion, then blow on! Let the fan run on high, add better cooling by printing a better cooling duct for your machine (I like the PetsFang on Thingiverse – even went with the dual blower version).
- BED HEAT – PETG does not require a heated bed, and you may not need any heat there if you have a nice sticky magnetic mat or tape or the like but on glass and some other surfaces you may find that getting the surface up to 70C will help a bunch with keeping the print down, without warping or just plain coming loose.
- CLEAN the NOZZLE – Going from PLA to PETG or any other high temp filament is a huge bump up over what you have been using for PLA. Heat up your hot end to 250 degrees and let it sit for 15 minutes and clean it very thoroughly – pulling off everything you can find, even wire brushing around before you get started. You will not be happy if you skip this step and find an overnight print that has lumps of that awesome orange PLA that has dripped into your new PETG piece of trash.
- FLOW – Increase the flow (OK maybe decrease – but usually increase). PETG needs it hot, and if your hot end doesn’t keep up (slowing it down as I said in #1 helps a BUNCH) it will lay down layers that don’t have enough material. Use your slicer to increase the flow to 105% or more and see if the layers go down happier. This one you will need to test yourself. If you are doing a bunch of PETG prints, you may even want to calibrate the machine to the filament and your extruder to get it just right.
- THINK SUPPORT – Here you may want to just rethink some of the support that you are planning on printing for your model. I have found that the support blocking in Cura is useful for PETG sometimes – eliminating support that is unnecessary and causing you stringing issues that bleed into the quality of the finished product. Mess around here and find out which supports are going to work, and which are failing you. Another great thing to look into (in addition to standard brims potentially) is the ability to support your support with support brims – lol. Check it out in Cura 4.x, you can add brims to your supports while keeping skirts as your starting layer.
- BABYSIT those first few layers – and give them a a helping hand if need be. The first few layers are key to a great print. Babysit them for a while and use tweezers and clippers to remove anything that you can easily remove without stopping the print. Often a bunch of stringing or pulled over support issues can be solved by removing the offending clumps early on, making new layers take over and saving your print. This goes for any type of filament, but taking the time with your PETG will pay off even more in my experience.
- Lastly, use a profile for your slicing software that has some great extrusion and speed settings for retraction. This one should get you going for PETG if you are using Cura:
Have a Ender 3 Printer, or getting one soon and want to know which upgrades you might want to take a look at? Well here is my list of the best of the bunch, in the order that, in hindsight, make the best upgrades. Some are better at making your prints turn out, some are for ease of use, some are just plain fun – let’s take a look:
- Upgraded extruder arm mechanism – this is the first thing you should do if you plan to print more than just now and then. Even then, you will want to do this in the long run. The plastic arm included in the stock Ender will wear and does not have the strength that an aluminum upgrade will give you. Upgraded extruder arm mechanism – this is the first thing you should do if you plan to print more than just now and then. Even then, you will want to do this in the long run. The plastic arm included in the stock Ender will wear and does not have the strength that an aluminum upgrade will give you.
- Glass Bed – A glass bed is just the best surface you can get (followed closely by #3 below). Get a glass bed and a can of Aqua Net Extra Super Hold hairspray and never look back. Perfectly smooth bottoms, no more dents in your stock build surface from improper leveling, and a great all around performer when it comes to adhesion.
- Removable Magnetic Build Surfaces – OK, the truth is, some days I think this is better than glass. I have 2 Enders, so I don’t have to choose. The removable magnetic build surface gives you a super easy way to remove prints, rarely needs cleaning because it sticks so darn well, and you will never drive a spatula into your arm trying to get a stuck on print to come loose.
- PetFang Cooling – This is a 3D print you can do yourself, for a nice improvement on finished products. The instructions take a bit to figure out which ones you need to print (and it depends on if you do #5 below) but it’s so worth the time.
- Dual Fans on the PetFang – While you are on #4, go ahead and add 2 fans to the Fang. If you get into PETG or just want great results on overhangs and no stringing, boost the airflow and rejoice.
- OctoPrint – Get a Raspberry Pi, an SD card, and install OctoPrint. Best thing you can do. Drag and drop files, monitor your progress on a PC, install some plugins to make everything more better, add a web cam and record that 3 day print. Just so much value here. Get this one done soon.
- Upgraded Rollers – Print these rollers out, and grab a few bearings for other fun projects while you are at it. This upgrade reduces drag and lets your filament be free to roll on! This Thingiverse link has a great wall mounted version, which I added to my space where 16 rollers now live to feed the printers. Awesome look, and they work really well. Print them at 50% infill or up for a nice solid roller and mount.
- Filament Guide – Get a guide to keep that filament away from your Z axis screw and the rollers on the motor. I like this one (
https://www.thingiverse.com/thing:3275225 ) because you can stick it in when you forget (every time for me) and it stays nice and secure – also bonus is screwless install. Print an extra for the day when you break it off wresting with your printer or something nearby.
- Firmware Upgrade – Grab an Arduino and upgrade your firmware to the latest Marlin code for advanced features and the most important runaway thermal protection. If you leave your printer alone a lot to do it’s thing, move this one up on the list.
- Main Board Gen L Upgrade – Pretty thrifty way to upgrade your printer to take cool upgrades (see steppers and auto bed leveling). The Gen L won’t really make your prints any better, but you can add more to the firmware and upgrade the steppers.
- Upgraded Steppers – You can do this with add-on chips for the stock Ender board, but I have heard that you don’t get much with that route. Adding the Gen-L above and upgrading your steppers will give you super quiet motors (your existing ones become very quiet). I used the TMC2130’s – on the X and Y only. You can replace all 4, but I went with 2x 2130’s and 2x A4988’s (direct replacements of the stock ones that come on the original). This gives you a pretty quiet machine, and leaves the Z axis a little noisier – which you only notice on homing, and makes for a great audio cue when a print starts to take a look and make sure those crucial first layers go down right.
- BL or 3D Touch – Here is one that you can print a mount from the Fang kit above and add auto leveling to your machine, and after doing so you may wonder why this is so far down on the list. I added this to both of the Enders, and really it is one of the best upgrades you can do but learning about leveling first really is handy – manually. You will learn a bunch of stuff about your printer and 3D printing in general that will help you troubleshoot a pesky print, and pays off if you don’t have that knowledge already. After you have that figured out, do this one.
- Color Touch Screen – I did this one on one of the 2 Enders I have and I love it. It is a nice upgrade that does absolutely nothing other than makes you smile. It’s a fun weekend project, has some wow factor, and if you do OctoPrint above, you will rarely if ever touch it. But it’s cool.
There it is, the complete getting started list. Leave comments below if you have a must have upgrade, or want to share your experience. Check out the Teaching Tech channel on YouTube for many guides on how to install this stuff, his content is superb. Happy Printing!