Big ol’ printer

by Darren Poulson RepRap, Uncategorized

A few years back I purchased a large form 3d printer, the Creality CR10-S5. This has a bed size of 500x500mm, and can print over 500mm high. Just about right for a single print R2 dome!

However, since getting it I’ve managed to get one half decent print off it. The problem is that this size bed is pretty much the limit of the standard Prusa design. That means that bed levelling is a real pain, and therefore first layer adhesion is a problem. Doesn’t help when the supplied glass can be bowed quite badly.

Oh, and did I mention loud? Even on a couple of inches of foam to cushion it off the floor it could be heard all over the house. Not good when you are wanting to do prints that may take over a week of constant printing.

Upgrades

So all that being said, it has been sat idle for well over a year. I just couldn’t be bothered with the faff of getting a print working on it, and then not being able to sleep because of the constant whine. Thing is, its a big piece of kit to sit idle, not to mention fairly expensive, so I decided to research a few upgrades.

So far, I have done the following:

  • Added stepper dampers
  • Added a PEI metal sheet for the bed
  • Added a BLTouch sensor
  • Replaced the motherboard

DamperS

The dampers are just some shock absorber addons to try and reduce any vibration from the actual motors. This was the first upgrade I did on the X and Y axis, tho it didn’t have that much effect.

PEI Sheet

The PEI sheet I got seeing as my official Prusa Mk3S has one, and it is very useful. Just needs a clean after every print with IPA and the next print will stick with no issues. Tho it does need to be heated to work properly I’ve found

BLTouch

The BLTouch probe allows for automatic bed levelling. It doesn’t actually level the bed, but it probes a number of spots and the firmware then compensates as you are printing. The bed still needs to be reasonably level, but it does mean you don’t have to level after every single print.

Motherboard

Now this last one. Replacing the motherboard is a bit of an understatement. I basically threw away all the electronics that came with the printer and put new ones in. From the power supply, to the motherboard, to the stepper drivers. The drivers you use can have a lot of effect on the noise of the steppers, so I wanted to go with Trinamic based ones as they can run the steppers really quietly. To get these to work, I got a BigTreeTech SKR 1.3 motherboard, and five drivers. For power I got a 12V 30A power supply, it needs the high current for the heated bed.

The added benefit to this is that it is now a 32bit based machine, with much fewer memory restrictions, and can run Marlin 2.0 firmware. I’ve actually forked the Marlin firmware repo to keep track of the changes I make to the config files:

https://github.com/dpoulson/Marlin

Results

So far, I am very pleased with how the printer is now running. Bed levelling is a lot easier/non existant, first layer adhesion seems reliable, and we can hardly hear it running in the house, just a dull whine when its doing certain operations.

I’ve also been using PrusaSlicer, rather than the more usual Cura, so I’ve had to do my own profile for the printer. It still needs a few tweaks, but the results are good.

Future Work

Its still not perfect. There are a few things I still want to do to make printing more reliable and to speed it up.

  • Braces – The top part of the printer can move quite a bit, so I want to brace this. Might also stop some of the resonance.
  • Heated bed cable cover – The cable to the heated bed can get caught or frey, causing many issues and possibly a fire. I want to strengthen that up.
  • Tweaks to Marlin – The BLTouch is still a bit temperamental so some more tweaks are needed on that front
  • Tweaks to print profile – Still a fair bit of stringing, so the retraction needs increasing. Its also very slow on some operations so I need to find the balance between speed and quality.
  • Tidy up – Well, its taken a lot of messing to get it working, and the area around the printer is a state, as well as cables coming out everywhere and the MOSFET for the motherboard hanging loose. Everything (including the Raspberry Pi running Octoprint) needs to be tidied up somewhat.

I’m glad I finally got round to doing all this work, I was seriously at the stage where I thought I was going to get rid of it. But whilst its not up to official Prusa standards, its actually not too bad.