A word of caution for Ruby Olsson buyers
Hi all,
Yesterday I finished building my Prusa i3 MK3S kit, and the print results were spectacular, especially when comparing to the Velleman K8200 that I owned previously.
As I intend to print with carbon fiber filament I printed the Olsson nozzle torque wrench and changed out the standard nozzle for a Olsson Ruby nozzle, of course following all procedures with regards to heating up the hotend and adjusting the depth of the heatbreak in the hotend. As a first benchmark I printed the standard supplied 3DHubs Marvin on the Ruby nozzle with unmodified Gcode.
Results looked okay but I probably need to tweak the temperature as it looks a bit dull compared to prints on the standard nozzle. What concerned me however was the fact that a piece of brass was embedded in the print! The picture below shows this piece. It was bit more dull when I first saw it because it was slightly covered by PLA, I just saw a slight yellow hue under the surface and decided to scrape the top layer off, after which the shard of brass was revealed. It looks like the shard was already in the nozzle from the factory and came loose during the print. This part was visible on the surface, but who knows what else may be located in the print itself.
I guess It's a good thing that the nozzle was designed for abrasive materials, but heaven forbid the piece got lodged in the hole or worse things might have happened...
RE: A word of caution for Ruby Olsson buyers
For the price they charge for those Olsson nozzels they really should clean the metal shavings out of them. 😊
Wow, a Velleman K8200, I got one of those kits just for the parts because Microcenter had one left and was practically giving it away, I got it for what I would have to pay for just the stepper motors and some of the rods and bearings. What a terrible design to move the bed in X and Y, way too much mass to move around... I ended up using most of the stuff in the kit combined with the electronics from the early wood printrbot to build a large standard gantry design.
RE: A word of caution for Ruby Olsson buyers
I paid 600 euro's for the velleman about 7 years ago and never ever got a good print out of it, one of the worst investments I ever made. The Prusa has been wonderful so far, only had one print fail after installing the MMU2S, which I assume is because the filament got snagged somewhere. Otherwise very happy! And indeed it's very bad that the nozzle arrived with metal shavings inside. I performed a cold pull after that print just to make sure there wasn't anything else inside and the filament came out clean, so very happy now.
RE: A word of caution for Ruby Olsson buyers
Another update. If anyone of you decides to buy one of these nozzles, completely look it over and definitely keep an eye on it during use. I've had some prints fail in the past weeks due to irregular extrusion. Today, the printer failed to extrude even during the priming line. I prepared the steps to perform a cold pull, but after a while I could not push filament in even with the nozzle at 275 degrees.
I grabbed the acupuncture needle that was supplied with the printer, and pushed it into the nozzle from below with the pliers. Apparantly a lot of pressure had built up inside the nozzle because steam came out as soon as the blockage was pushed aside by the needle, and liquid PLA spewed out all over the needle and pliers (very glad I wasn't holding the needle with my fingers!). After which I could push in new PLA without issue.
After performing the cold pull I noticed that there was apparantly a brass shaving in the nozzle yet again, even though I performed a clean cold pull weeks ago. There's definitely some quality control issues at Olsson...
RE: A word of caution for Ruby Olsson buyers
I just realized something else as well. The clean cold pull that was performed a few weeks back had a small sink mark in it where I assumed the material shrunk a bit because I either pulled it out too fast or it cooled down.
But the embedded brass shaving is in exactly the same spot where the "sink mark" was previously. So instead of looking at a sink mark, I was actually looking at the imprint of the brass shaving that was still attached to the inside of the nozzle. In the last weeks it had apparantly bent a bit into the path of the filament and blocked the nozzle opening, and after pushing it back out of the way with the needle it had now snapped off and was able to be extracted with the cold pull.
(edit: if none of this makes sense, it's because the accompanying post is still awaiting moderation, and this one might appear before that one, just ignore this edit part as soon as the other one gets approved)