Skimmy

May I ask, what type of pancake NEMA17 that is? ebay/aliexpress etc didn't show results...

thanks for the detail-pics! <3 how do you guide the belt? I see no flanges...

No resistors needed, as long as you don't put all 10 caps parallel to the fan Worst that could happen at this point: board resets/freezes cause of the voltage-drop. If you add caps, take the highest frequency possible. Rule of thumb is like "keep it above 100Hz". May I get a detail-shot of the mounting from one off your 2 Y-carriages? I'm not happy with my design to mount my linear rail, so maybe i can get a tipp from you?

Föhnsturm, if you want to "pwm" the fan, here is my advise: Just buy a pack of 10 Capacitors, each 10µF and start with one parallel to the fan. If it doesn't start at your desired Voltage, add another Cap parallel again. Rince and repeat till you are happy ;)Cost: less then 5€ with shipping, e.g. something like that: http://goo.gl/KrbvQ4 (ebay.de as I assume you are german as I am). I also don't know if your firmware is capable of PDM instead of PWM, PDM is a better signal for cleaning voltage out with capacitors and is just superior than PWM. Also, I can recommend you this fan: Lüfter, Titan, 50x50x15mm, TFD-B5015M12B, radial, kugelgelagert http://r.ebay.com/EAHXXU This fan works out of the box and down to 4V in my current printer. Furthermore, I am, as always, impressed by your designs! Keep up the work!

Video is private :/

Hello! I am a long time lurker on this thread and I am excited of the whole idea to change the hotends with magnetic holders! <3 I appreciate your work so much, that I want to share my knowledge on magnets with you and I only registered here in this forum because of this thread. So, the knowledge I want to share: First: You are absolutely right to use types of magnets, which withstand higher ambient temperature! I did measurements at another project of mine at the hotend-assembly after long prints and my hotend-carriage gets heated to around 65°C only from passive heating through the heated bed. Warmth is a really bad distortion factor for magnets. Second: You _really_ should use round magnets. There are only benefits when using round ones. Rectangular shape is only "for the eye". E.G.: They are magnetically stronger. They are tougher. They are up to 10% more long-lasting when being "permanently" hit (I am referring to the shock from snapping the carriage) and much more. Third: You should further use magnets with optimal measurements for maximum magnetic pull. As a rule of thumb for round magnets its: "diameter is twice the thickness" - e.g. a 10mm diameter magnet should be 5mm thick. Feel free to read some VERY good explained information at http://www.ibsmagnet.de/knowledge/index.php and also feel free to get numbers with an interactive web-calculator for magnetic flux density at http://www.ibsmagnet.de/knowledge/flussdichte_berechnung.php?f=rd With this calculator you can easily compare your rectangular magnets to round ones. I know about this, because I needed to to scale several really big and expensive magnets and therefor learned about it.