As we come up on the holidays and down times for many plants and customers, we are addressing those last minute lists on how to best do shutdowns, maintenance, materials orders to be ready for a upwing in orders just after everyone returns, and assessment of machine “what if.” Earlier this month we did a quick webinar on machine shutdowns and getting ready for having your machines down for a week or so, and that webinar presentation is available on video. It is a quick 20 minutes that goes over shutdown on the Fortus 450mc, the Fortus 250mc, and the Objet desktop machines and answers many of the questions on when to consider doing a shutdown versus allowing the machine to sit idle but on in the office.
I am always a bit surprised by how many users leave their machine in idle or power save mode for months at a time and then expect the machine to run as if nothing was amiss on demand when they need a part quickly. In general, on PolyJet machines, if the machine is sitting idle for more than 3 days, on the fourth day you should consider running a small part in order to keep the lines clear and the nozzles cleaned out. This will extend your print head life and keep any semi-cured materials from settling in your lines and the nozzles. The small part we suggest would be a small piece or sample part where the file and volume used is minimal – you can get STL files from online sources such as GrabCAD. We use these pieces as trade show giveaways, awards and sales samples. One firm even paints the small hand they print with gold paint and awards it to the employee that “shook things up” that week and announces it in the employee newsletter.
In Engatech, we are a bit more conservative with tango, Durus and Rigur materials, and typically like the materials to not sit idle for more than 2 days. We will transition out the material within 48 hours if the parts requiring the material are in the machine. We treat the digital materials like the Vero materials, and will run a small part every 3 days to keep lines clear.
In the FDM printer, if the machine is going to sit idle for 4 days, a small part should also be printed to keep the head clean and the tips from having material that has sat in the area (and possibly degraded) that a new print with material flow will have to clear. Same aspect of keeping the machine running means that the lines, and the hardware, has fresh materials and no problems for when the machine is needed and parts have to out the door.
In general, 3D printers like to be run continuously and put out parts on a consistent and persistent basis. Running the machines hard and constantly gives you the best ROI on the print head and hardware and often prevents problems with print heads and tips. Check your waste containers daily, emptying them out on a regular basis keeps you from being surprised in the build chamber.