Zero warping mod

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madprinter
Posts: 17
Joined: Wed Oct 17, 2012 6:03 pm

Zero warping mod

Post by madprinter » Sun Oct 25, 2015 12:12 am

Hey,
If anyone is interested, I have modded UP mini to print with zero warping with ABS.
You have to build a heated chamber to heat air inside of the mini to 70C and increase the heated bed temperature to 100C.

The heated bed needs to be at around 100C, this is necessary to prevent the perf board being curled up by the force of the cooled ABS, as ABS shrinks considerably when it starts to cool. But at 100C ABS is still soft and the force is almost zero, so the perfboard will stay flat, and your printed part too. That was a constant problem with my previous prints, the print would adhere to the perfboard, but as it shrunk, it would deform the perfoboard causing all other layers to be warped.

Heated chamber - I use two low profile cpu fans with copper heatsink for laptops with one 0.47Ohm 50W resistor mounted on each of them and connected in series. Powered by ATX 12V, consumes around 12A with 144W of heating power. You of course need a temperature controller with the probe inside the mini to monitor the tempreature. The whole mini also needs to be wrapped in some foam insulation (3-5mm thick is enough) from outside to prevent heat escaping. Also seal all gaps. The mini is great for this as it is already a closed design.

I have measured the temperatures of all steppers when using 70C build chamber and the only problematic stepper is the one on the extruder, which would get too hot and start slipping. Other steppers are less than 90C hot, which is I think acceptable. I have designed a fan mount to put 40x40 fan on the extruder stepper. It keeps the temperature of the stepper under 85C which is about the highest it can go before it starts slipping.

Before every print, you have to wait around 10-15mins for the whole thing to heat up to its temperature. But it is WELL worth it. Getting prints with perfect geometry is very satisfying

I'll post photos if anyone is interested and some print samples.

caesar
Posts: 64
Joined: Sat Feb 22, 2014 1:32 am
Location: Romania

Re: Zero warping mod

Post by caesar » Sun Oct 25, 2015 10:22 pm

Well done!

Very interested to see some prints from your beast.

madprinter
Posts: 17
Joined: Wed Oct 17, 2012 6:03 pm

Re: Zero warping mod

Post by madprinter » Tue Oct 27, 2015 2:47 pm

Here's the difference between unheated chamber (top) and heated chamber (bottom):
10x5x136mm long bar printed diagonally on the platform

There's only very slight warping on the bottom part, but I think with raised bed temperature or chamber it could go away completely. Smaller parts are entirely flat.
Attachments
diff.jpg
diff.jpg (121.43 KiB) Viewed 12441 times

brainzilla
Posts: 141
Joined: Sat Nov 29, 2014 5:41 pm

Re: Zero warping mod

Post by brainzilla » Wed Nov 25, 2015 9:01 pm

I have pretty much given up on ABS.
High quality PLA prints pretty flawless on my mini and has only marginal warping.
Of cause ABS and PLA have different properties, but for most uses PLA is cool.

I have tried ASA lately - nice material, less warping than ABS, has a feel between ABS and PLA I would say…

mrgibbon
Posts: 30
Joined: Mon Aug 31, 2015 12:28 am

Re: Zero warping mod

Post by mrgibbon » Thu Nov 26, 2015 12:43 am

Photos? pls :)

madprinter
Posts: 17
Joined: Wed Oct 17, 2012 6:03 pm

Re: Zero warping mod

Post by madprinter » Thu Nov 26, 2015 11:08 pm

Here's some photos. I am now very happy with this machine. Stock is unusable. Being able to print large parts with flat under side and zero warping is great. entirely different machine.
Attachments
heated_chamber_3.jpg
inside insulation and heater heatsinks with fans from laptop, the other one is on the left side (click on the image to show full size)
heated_chamber_3.jpg (177.06 KiB) Viewed 12258 times
heated_chamber_2.jpg
outside insulation
heated_chamber_2.jpg (107.9 KiB) Viewed 12258 times
heated_chamber_1.jpg
the extruder stepper cooling fan
heated_chamber_1.jpg (96.95 KiB) Viewed 12258 times

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DrewPetitclerc
Posts: 581
Joined: Sat Feb 12, 2011 7:39 am
Location: Silicon Valley California
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Re: Zero warping mod

Post by DrewPetitclerc » Fri Nov 27, 2015 7:37 am

You should keep a steel brush handy to give the hot-end and nozzle a quick cleaning before each print after everything has heated up before printing, it works wonders to keep all those brown spots from appearing in your prints after the oxidized plastics flakes off your extruder.

They can be found in auto parts stores for cleaning machine parts and I recommend the steel but they also come in brass, usually with wooden handles and slightly larger than a tooth brush.

Regards
Drew
Drew Petitclerc
Petitclerc Designs
Owner/Senior Principal Designer, prototype, tooling and test equipment design and 3D printing
http://flash-graphics.deviantart.com/
http://www.thingiverse.com/DrewPetitclerc

madprinter
Posts: 17
Joined: Wed Oct 17, 2012 6:03 pm

Re: Zero warping mod

Post by madprinter » Fri Nov 27, 2015 4:09 pm

I know it's dirty, but it always reappears because of stupid initialization procedure - right before it starts printing, it extrudes a rather long strand of plastic which then when sticks to the printing head when platform is raised. Dumb idea.
Here's some pictures of the largest part I have printed so far - 3.5h print of 10cm tall 7cm diameter tube I needed for something. Nice flat bottom, no warping.
Attachments
heated_chamber_6.jpg
heated_chamber_6.jpg (142.49 KiB) Viewed 12225 times
heated_chamber_5.jpg
heated_chamber_5.jpg (43.92 KiB) Viewed 12238 times
Last edited by madprinter on Fri Nov 27, 2015 7:10 pm, edited 1 time in total.

Tiertime-Joseph
Posts: 155
Joined: Mon Aug 27, 2012 3:45 am

Re: Zero warping mod

Post by Tiertime-Joseph » Fri Nov 27, 2015 4:19 pm

Wait for the new UP Flex Print Board, guys. No Warping, and easy peeling as well.

Happy Thanksgiving everybody!

Joseph

madprinter
Posts: 17
Joined: Wed Oct 17, 2012 6:03 pm

Re: Zero warping mod

Post by madprinter » Fri Nov 27, 2015 7:11 pm

Tiertime-Joseph wrote:Wait for the new UP Flex Print Board, guys. No Warping, and easy peeling as well.

Happy Thanksgiving everybody!

Joseph
That will never work. There's a reason the professional FDM printers have heated chambers.

Tiertime-Joseph
Posts: 155
Joined: Mon Aug 27, 2012 3:45 am

Re: Zero warping mod

Post by Tiertime-Joseph » Sat Nov 28, 2015 3:02 am

It does help a lot, and removing the parts from the print board will be much eaiser than working with PCB board.

Joseph

Mike
Posts: 1
Joined: Mon Oct 16, 2017 10:08 pm

Re: Zero warping mod

Post by Mike » Mon Oct 16, 2017 10:33 pm

I know its a couple of years since this discussion was last addressed, but if u see this post I have a question. Can u remember what model of laptop CPU fan (with copper sink) u used ? I have been scouring eBay for such but not found anything suitable. Most do not have a good copper sink with it.

Regards
Mike

antibyte
Posts: 1
Joined: Wed Jan 17, 2018 10:16 pm

Re: Zero warping mod

Post by antibyte » Wed Jan 17, 2018 10:21 pm

Just solder a bit of wire between the legs of the thermoswith below the printbed.
It is a 60 degree celsius thermoswitch. This way the heatbed is always on and goes up to 80-90 degree.
Much better results and only a few minutes of work.

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