Important calibration when loading new 3D printer filament

Note to self: The most important calibration to do when loading new 3D printer filament (even if it's the same brand and type, because the formulation may have changed) is to calibrate the extruder steps/mm (also called E-steps/mm).

Details of this calibration is given here.

The (simplified) steps I take are:

Power up the 3D printer and hook it up to the laptop via a USB cable.

Install and run a program that is able to talk to the 3D printer via the virtual serial port (eg. Prointerface).

Mark 10cm of filament, starting from the hole where the filament enters the extruder stepper mechanism and work backwards. An extra piece of filament that is measured to exactly 10cm helps here.

Use the following G-Code to find out your current E-step value.

M503

The current E-step value is the last value (96.5) on this line:

Steps per unit:
    M92 X80.00 Y80.00 Z400.00 E96.5

Issue the following G-Code:

// Set nozzle temp to 190c. Set to temperature you'd be printing the filament at.
M104 S190

// Relative positioning
M83

// Extrude 100mm at 50mm/s rate
G1 E100 F50 

// Reset extruder's origin
G92 E0

Visually inspect how much over or under extrusion there is. If there is over-extrusion, it helps to make a 11-cm marking to estimate how much over-extrusion there is.

The new E-step value is calculated simply as:

10 / actual-extruded-length * current-e-step

The new E-step value can be saved to firmware using:

M92 E100.9 // 100.9 is the new E-step value
M500 // Persist to firmware

Try again and make sure approximately 10cm of filament is extruded. Some filament requires a higher temperature than the typical 190c for this to happen.

Another important calibration to do is to adjust the retraction distance until there is no stringing for the target temperature and filament using one of the models designed for this purpose on Thingiverse.

Comments

Adding "Stereo Mixer" to Windows 7 with Conexant sound card

This procedure worked for my laptop (Thinkpad E530) with a Conexant 20671 sound card, but I suspect it will work for other sound cards in the Conexant family. I was playing with CamStudio to do a video capture of a Flash-based cartoon so that I can put it on the WDTV media player and play it on the big screen in the living room for my kids. The video capture worked brilliantly, but to do a sound capture, I needed to do some hacking. Apparently, there was this recording device called "Stereo Mixer" that was pretty standard in the Windows XP days. This allowed you to capture whatever was played to the speaker in all its digital glory. Then under pressure from various organizations on the dark side of the force, Microsoft and soundcard makers starting disabling this wonderful feature from Windows Vista onwards. So after much Googling around, I found out that for most sound cards, the hardware feature is still there, just not enabled on the software side. Unfortunately, to

Hacking a USB-C to slim tip adapter cable to charge the Thinkpad T450s

This hack is inspired by this post . A year ago, I bought an adapter cable for my wife's Thinkpad X1 Carbon (2nd Gen) that allows her to power her laptop with a 60W-capable portable battery (20V x 3A). A USB-C cable goes from the battery into the adapter, which converts it to the slim tip output required by the laptop. Everything works out of the box, so I didn't give much thought about it. Recently, I decided to buy a similar cable for my Thinkpad T450s. I know technically it should work because the T450s can go as low as 45W (20V x 2.25A) in terms of charging (though I have the 65W charger - 20V x 3.25A). I went with another adapter cable because it was cheaper and also I prefer the single cable design. So imagine my surprise when the cable came and I plugged it into my laptop and it didn't work! The power manager just cycle in and out of charging mode before giving up with an error message saying there is not enough power. After much research and reading the Thinkwiki

Using Google Dashboard to manage your Android device backup

I used to use AppBrain/Fast Web Install to keep track of which apps I have installed on my phone, and to make it easier to reinstall those apps when the phone gets wiped or replaced. But AppBrain had been going down the tubes, and Fast Web Install had always been a hit-and-miss affair. Android's own "backup to the cloud" system had previously been even more unusable. There isn't a place where you can see what has been backed up. And when you setup a new phone with your Google account, you just have to wait and pray that your favorite apps will be restored to the phone. Typically all the stars have to be aligned just right for this to happen. More often than not, after waiting for an hour or so and nothing happens, you just curse under your breath and proceed to install your favorites apps manually via the Play Store. But I just looked again recently and was pleasantly surprised that things are much more civilized now. Firstly there is a place now where you can loo

Random Sequence

Search This Blog