I'd 3D print some low profile clips for the glass plate, or (my preference) use high temperature double sided adhesive to secure the glass plate to the print bed. I initially thought I'd be swapping glass beds between prints, but in practice, I prefer having the glass bed fixed to the printer. KISS. I'd need to wait for the glass bed to heat so I wouldn't save much time by avoiding the cool down phase, and handling a hot glass plate and swapping glass beds in general sounds goofy to me. I'd eliminate the clothes pins or binder clips ASAP. It's much better to have nothing sticking up where the nozzle can crash into it.
My 3D printers were fine with no retuning after I added some thick borosilicate glass, but my printers only move the bed vertically in .2mm steps when printing. The X and Y stages are suspended above, running on linear guide rods. If you were concerned about altered acceleration on your Ender 3 clone, I'd try printing two small test cubes, separated by 100mm in the Y direction, at 10% higher speed than you'd usually use. If the acceleration was too much for the stepper motors or the print quality was adversely impacted by the momentum of the added mass, only then would I try to reduce the acceleration. I'm too old to fix problems that don't exist or otherwise looking for dragons to slay. In practice, there is a high gear ratio so the 3D printer doesn't need much torque, and most of the torque requirements are when the motors are at low RPM where stepper motors have their most torque. I think these glass bed upgrades are usually done without changing the motor parameters. On 8/2/20 10:59 AM, Gene Heskett wrote: > Greetings all; > > Several question mark below. > > Those glass plates for my ender-3 Pro's build plate use have arrived, and > I'm somewhat taken aback by the mass of a 230x230mm by 4mm piece of > glass. This at least doubles, likely more, the weight the y motor has to > manhandle, in my mind affecting the ballistics of its movement. No glass > clips or instructions came with it although the glass was packed to > survive a tactical nuke, So I'll raid the laundry room for some spring > clothes pins. Plastic, lighter than the old wooden ones, but I stuck a > couple on the front of the bed and the heat isn't bothering them. > > The stock Merlin driver has some adjustments for both acceleration and > jerk. Accel is currently set at 500, sounds pretty instant to me and > jerk is set at 8 but thats a new term for me and I have no idea of how a > change to that effects the machine. > > Given the increased mass to move, is it even possible to keep the working > velocities at the currently set values, or is there a way to determine > what is optimum for this added mass it has to move? > > I'm assuming changes in the ballistics would have to be set in the x axis > at the same time to keep it from bending corners. > > Or, would I be better off spending the sheckles for one of the improved > 32 bit driver boards I see being offered? Power supply might come into > play too as its only 24 volts now, which will effect its accel and > ballistics envelope too. > > Discussion, educational/reference URL's all welcome. > > Thanks all. > > Cheers, Gene Heskett _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
