Large format 3d fdm printer

Ok, so this is a large format 3d delta printer,  that uses the extrusion method in order to build 3d models, it has a 3d print volume of approximately 255mm diameter and 700mm high, not that big nowadays but back in 2016 it seemed enormous,  the design brief  was that it had to fit in the garage.  The base of the printer was designed to use powder coated steel in order to provide enough mass to absorb a lot of the vibration components from the motion.  The machine weighs in at about 25Kg and this is mostly in the base, which is actually quite full,  besides the drive components there is also an embedded PC that runs 'Repetier' as a manager that stores the build models in a database and the whole system is capable of been managed remotely via ethernet.

One of the biggest issues I have had with this printer is good adhesion to the heated bed,  which is an insulated 250w 230v heated bed, constructed from 15mm thick 'Tuffnel' with a borosilicate glass disk held with stainless steel clips,  the whole bed has three adjustable spring loaded anchor points to the base. This is the second glass disk I have used as the first one distorted as it came up to the working temperature of about 85degC, I did plan on having a fan blower mechanism to vent cool air directly under the glass disk for forced cooling ( but not done that yet ).  The heater element is attached to an earthed copper disk 3mm thick the same diameter as the glass as a heat spreader so that the bed is always at a uniform temperature across the surface.

I have tried multiple coatings for the glass in order to promote good adhesion to the bed,  pva slurry worked reasonably well but could get quite messy over time with build up,  I currently use a Polyetherimide PEI coating that is absolutely brilliant, but you can't get PLA off it until the bed has cooled to about 30degC,  just a wipe with Isopropanol on a clean tissue between prints is all it seems to need.

Here's a short video of the printer in operation,  Ideally it still needs covers to stop extraneous drafts from entering the build area, this would make it more user friendly as there could be interlocks to prevent opening whilst the machine is in operation.

Here are some examples of components made on this printer,