Sunflower - K280 large 2020 delta

EasyTarget

This is Sunflower; I guess she's just a hobby printer but I've had a lot of fun getting her to this state. She prints art and big brackets with a big nozzle really well.

Highlights:

280mm x 630mm (at centre; more like 520mm at full radius), magnetically attached PEI bed but can quick swap to glass.
Built from a HE3D K280 Chinese kit; The hardware is just fine, functional aliexpress stuff. Good bed heater and PSU but the rest of the electronics less impressive. I ordered a DuetWiFi the same day I ordered the kit.
My own E3dv6 mount and modular easy access (click together) fan system.
My own simple adjustable slider brackets and clamps.
Spot the endstop switch? - it's done by encapsulated reedswitches and bar magnets in the slider brackets. No visible wiring and is very repeatable! Once calibrated I can reliably home, even when paused.
PrintEye status panel; temperature, status, info. Also mine.
DC42 IR sensor (she's also had a PPiezo unit at times)
Quite a bit of 'fluff' to finish her; 9mm belts, 0.9 steppers, lights. The (supplied) 16A 24v PSU is under the bed with additional fan ducting, the Duet has a mcu fan + duct underneath the board.
Purple. Lots of Purple. I like purple.

Everything useful I that designed, and the other designs I use, are collected here: https://www.thingiverse.com/Nanocube/collections/sunflower-a-k280

Phaedrux

@EasyTarget said in Sunflower - K280 large 2020 delta:

magnetically attached PEI bed

What is the PEI mounted on to make it detachable?

EasyTarget

It's on a spring steel plate, with a 'Whole Bunch' (tm) of high-temp supermagnets under the aluminium heatbed. Works very well and I can pop things off it almost trivially.

However, very large footprint objects can warp the spring steel off the bed and end up with the model rocking or dancing about. So I have a system to use the original glass bed instead when needed.

the clamps you see are part of that (edge grip) and also hold the heatbed down against some springs (which in turn allow the bed to give a bit ifwhen the head crashes
I like this arrangement, it gives good results. But lacks enough surface hardness to let me use a PPiezo Orion with the PEI bed (though it worked OK on glass.)
Magnetic flux over the printbed is awesome! I can feel it dragging my watch down sometimes. Most people have a 'warning HOT!' sticker, but I also need to follow Prusa's example and put a 'Warning, high flux' one there.

EasyTarget

PS: I got the spring plate+pei, some bar magnets and spare PEI for this and my RF100 from this store:
https://energetic3d.aliexpress.com/
I freely recommend them, not the cheapest but fast well packed delivery, and good products.

Phaedrux

The magnets seem quite thick to leave air gap between the bed and plate. Are the magnets also the points for thermal conduction?

EasyTarget

@Phaedrux
In that picture the bed is upside down.. Aluminum is non-ferrous, it does affect the field strength but not very much, those magnets project through 3mm of aluminum with enough force that I have to be careful not to pinch my fingertips when I'm taking the plate on/off.

Danal

FANTASTIC! Always happy to see a big delta! I like the name too... Sunflower.

I called mine BFD, Big Fast Delta. And if you think that middle word is actually "Fast"...

EasyTarget

@Danal said in Sunflower - K280 large 2020 delta:

if you think that middle word is actually "Fast"...

Fanatics ?
Big Fanatic's Printer... yep, that's it.

My goal was fast printing too; rather than go for a beefy solid frame I have soft rubber feet, as little moving mass as I can manage, and all the weight under the bed. She sways quite a lot, but this doesn't seem to translate into print artefacts.
The best speed modification turned out to be a 60W heater cartridge, lots of niggling layer inconsistencies at high-speed simply disappeared when I fitted and tuned that.