3d Printing tips

When the corona crisis hit Denmark around a year ago and there was a shortage of protective equipment for the health sector, it was obvious to see if it we could help with the 3d printer. It was actually very easy in Denmark;

‘Makers against corona DK’ (makersmodcorona.dk) had found a visor that was very easy to print and used clear foil A4 sheets from presentation binders or similar. The visor was tested and approved by the authorities and a temporary dispensation was made to the CE marking rules for producing protective equipment for the health sector. That dispensation is no longer in place.

The Danish group only communicated via FaceBook. I’m not on FaceBook but I just printed away anyway and there where no problems finding local takers for the visors; nurses, dentists and school-dentists. Visors where also given to chronically ill, cancer and KOL patients.

A lot of visors were printed and I’m very surprised how well my budget printer handled it. The model I have is the bog standard Ender3 printer, priced at around €150 today. It did however get the motherboard(€50) upgraded to the ‘silent’ version when we started printing visors. Before the upgrade the printer could be heard all over the house. We would all have gone stark raving mad within days if it hadn’t been upgraded.

The printer has been printing morning to evening, week after week, and not a single visor print failed.

The daily routine was simple:

  • Wash the build plate using washing up liquid
  • Rotate the build plate 90 deg compared to the previous day
  • Level the bed manually
    Now it’s ready to print all day
  • Never touch the build plate
  • Remove build plate from printer before removing print
  • Use gloves when removing print
  • Plate back and it’s ready to print again… and again…

If the printer is properly adjusted and calibrated, that’s it. My best tip for good adhesion of the first layer is to wash the build plate using washing-up liquid and never touch it.

If you want more details here below is a longer version. It’s not a tutorial, there are loads of other people doing them better than me, but more of a collection of tips and what too look out for.

Assembling the printer and firmware

On the box it says 10 minutes to assemble an Ender3 – forget that, use as much time as you need to do it as good and precise as you can. I found a video with a few extra steps to make sure the frame was as straight as possible.
Do not trust the parts that comes pre assembled to be done correctly. On mine everything under the build plate was WAY too tight; the belt was tighter than I thought possible and the wheels so tight that they had gotten a flat side. Luckily the flat side disappeared after a few weeks. Extra time spend while assembling is easily saved later.
It is very important to check that the firmware is safe! Creality have had problems with runaway protection not working or completely missing, in the worse case that might cause a fire. I recommend a vanilla installation of Marlin instead of Crealitys firmware.

Calibration

It’s easy to find good tutorials about test prints and calibration. It’s not hard but will take some time, but again, it’s time well spent.

DIY upgrades

When the printer is ready, printing a few upgrades is the perfect way to test it. My must-have upgrades are;

  • Cover to prevent filament falling in to the fan
  • Finger wheel for the filament motor
  • Anti snag for the cable going to the hot bed
  • Filament guide

At first I skipped the last upgrade, in the beginning it seemed fine but I noticed a lot of tension in the filament when the spools are almost empty.

Apart from those upgrades I printed some clips for cable management and a cover for the power supply fan to dampen the noise. It’s easy to find upgrades on thingiverse.com.

Filament

I only print in PLA. There can be huge differences from brand to brand. Pay attention to the temperature on both hot end and bed when switching to another brand, consider a testprint or two. I have tried a fair few different brands in the last year and price and quality don’t necessarily go together, you just have to see what works best for you.

When I get a new PLA colour the first print is always a colour sample, here is 4x white on a lightbox.

Wash the build plate and avoid touching it

When the printer is new there is rarely problems getting the first layer to stick. After a while it might start to give a little trouble and there is many creative solutions on the internet; Hairspray, glue stick, painters tape etc. They all work, but I found a much simpler solution that works for me; Just wash the build plate in washing-up liquid and do not touch it, ever! Grease from the fingers will make it less tacky. I use gloves when I remove prints from the plate. A pair of cheap cotton gloves with rubber dots does the job perfectly.

Washing-up liquid and gloves are probably my best tip. It quickly becomes a habit and it dosen’t take any longer.

Level the bed every day

Once you get the hang of it, it only takes a few minutes. If you don’t turn the build plate everyday you can easily print for days or weeks without having to level the bed. It’s easily done so my strategy is to do it often instead of waiting until a problem occurs.

Remove the build plate before removing prints

When you spend time on adjusting someting where fractions of millimetres can be the difference between succes and failure, it always surprises me seeing youtube videos where people totally manhandle the printer trying to get a stubborn print off the plate – even using a hammer on a spatula to try to chisel it off. The plate is held in place by 4 clips so it only takes a few seconds to remove it. Removing the plate also makes it easier to get prints off the plate.

If you print the same over and over again

If you print the same over and over the wear will quickly start to show on the build surface. The plate is square so it’s easy to just rotate it 90 deg every day, simple but efficient. Every now and then I also make new print files changing where the prints are placed on the plate.

Spool holder upgrade

By the time the spools where almost empty, the friction between spool and holder had made a fine white powder. I could see that the friction was higher and sometimes it made a really annoying sound when the spool was turning. I found a spool holder with ballbearings on thingiverse.com. The 3 ballbearings came from a €3 fidget spinner where they functioned as weights in the arms. Works perfectly, no friction and no annoying sounds anymore.
I haven’t heard about this problem before. I only think it was a problem because I was using full spools and kept printing until they were empty.

Luxury upgrade; OctoPrint

In the beginning I just had the bed level and print files on a SD card in the printer and it worked flawlessly. After I moved the printer in to the garage I sometimes forgot to keep an eye on the time to empty/restart the prints. I had a Raspberry Pi with camera leftover from another project. I installed OctoPrint and mounted the Pi and camera directly on the printer. It is a bit of overkill for my needs but it does work really well! The only thing I do directly on the printer is leveling the bed everything else I can do in a browser or on my phone, including monitoring the print with a livestream directly from the build plate. When a print is done the printer plays a small tune and I get a notification on my phone. It has definitely help me to get even more visor prints through the printer. I can even see the livestream via AppleTV if can’t be bothered to leave the couch – My wife was not overly impressed by this feature…

It’s not great film art, but perfect for checking up on the printer.

Time for service

It’s been around 2 years since the printer was top-tuned and calibrated. Many spools have passed through it since then and it’s starting to show.
When I change colour it takes a while for the new colour to come through ‘clean’. The print quality is not as perfect as it used to be either. It’s time for service.
I already got a bowden tube and other parts in and I think the service can be done in an afternoon. I got a glas bed in long ago because I didn’t expect the stock build plate to last very long. I was wrong, it’s still going strong, but I might still upgrade to the glass bed while I’m at it.

Happy printing

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