Friday, 31 March 2017

Upgrades and changes to the BCN3D Sigma 3D Printer including Bondtech extruders

SIGMA v2016 3D Printer upgrades, changes and tweaks

In this blog post I'm collecting up all the modifications, changes, upgrades and general improvements I have done to the Sigma (2016 version) over the last ~18 months.

This blog post and video is for the Sigma 2015/16 versions, and may not be the same for the new Sigma R17 (2017 model).

A lot of the information here is also relevant for any 3D printer, things to check, changes to make and improvements.

The main goals were to improve complex print performance - especially dual colour or dual material 3D Printing on Sigma, and also to reduce the noise.

Thank you to the team at BCN3D for the allowing me to test out some of the upgrade boards in this machine, and also to Emvio Engineering and Bondtech for the dual drive Extruder upgrade kit.

All the info is in the video below, and feel free to use the quick jump point index if there is something you specifically want to know about -

Quick jump index -
00:10 - Intro to Sigma 2016 changes
02:20 - Auto Fan control for hot-ends
04:30 - Hot-end Thermistor changes (PTFE removal)
07:50 - Adding heatsink compound to Hot-ends
12:10 - Fitting Bondtech Extruders to Sigma
16:00 - Updating Firmware eSteps/mm for Extruders
17:10 - Printing with Sigma and Bondtech extruders
18:00 - Further thoughts on testing and upgrades
19:00 - Compare print results
Final thoughts and wrap-up.

Video is also over on YouTube if you wish to watch in HD and also subscribe to my channel for more videos, help and advice.

I'll post a few images below as they are easier to see than in the video. My thoughts and advice are in the video so I'll keep the post short and look forward to any comments or questions - feel free to post here or in the YouTube comments. Thanks.

In the video I look at a number of significant changes Including -

Automatic fan speed control for both hot-ends -

Hot end improvements -

I replace the original hot-end thermistor sleeves (PTFE Max temperature 250 Deg C) with Fibreglass (300+ Deg C)

Still using the grub-screw to clamp for now, but I comment on why this is not really a good idea.

 I show you how to remove the Hot-ends and improve their thermal performance by adding thermal heatsink compound.

I then fit Bondtech dual drive Extruders into Sigma and compare print results.

In all comparison testing I used exactly the same Gcode for both system configurations of extruders (just the eStep/mm setting was changed in firmware for the new Bondtech gear rate).

The Hollow Draudi printed small with standard 0.4mm nozzles is a very tricky small print for FFF 3D printers - Designed by BCN3D

You can get the file here from Youmagine.

"The Hollow Draudi is designed to be created on resin 3D printers mainly due to their empty geometry. In addition, all orifices, modeled with Rhinoceros and Grasshopper, give it a unique personality and a plus of difficulty that will challenge any 3D printer FFF."

This is a tricky print - the extruders need some tweaking, but even with exactly the same Gcode used we can see less stringing and better formed structures between the holes.

Smoother extrusion on the feet - easier to see on the Brim rings - less indications of the individual extruder stepping points on the Bondtech print.

Low-Poly Bulbasaur - Multi and Dual Extrusion version - by- Agustin Flowalistik

Get this great 3D model from Youmagine here

Smoother extrusion and less problems with filament control here using the Bondtech extruders.

And yes, I know you can get better results out of the Sigma, by slowing down the print speed and being slightly less aggressive with the extruder settings, but I wanted to do a like-for-like comparison of exactly the same Gcode here to show the difference a gearbox and dual drive teeth make to a 3D printers extrusion system.

Sigma 2017 -

I also now have the new Sigma R17 machine now, so do keep an eye out for another comparison of the above tests along with the new Sigma R17 version.

If you have a Sigma 3D printer and need any help or advice, please catch me on twitter and I'll do my best to help out. I have been printing with Sigma for a few years now and have (I think) mastered using it for single and dual colour/material printing. It's my go-to printer for all dual 3Dprinting.

I'm really excited for the new Sigma 2017 and can't wait to show you what it can do.

Thank you for reading & watching, see you next time.


Please join me on Twitter @RichRap3D   -

Files and designs shared on YouMagine -

Files and designs shared on GitHub –

Files and designs shared on Repables -

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