MakerBot Support Forum/MakerBot Community/Community Meeting Place
Prevent folding of plastic on platform
Marc Edwards
posted this on May 14, 2012 10:13
I'm building a pencil case for my 6 yr old niece. The structure is about 6cm x 6cm x 10cm, ABS plastic (Blue).
The print method is the default platform temperature: 100 degrees C, extruder temp 220 degrees C. The problem I have noticed is that the mesh base has partly become unstuck from the platform and the base of the pencil case has curved up slightly from the platform.
Could this be a calibration problem (distance of nozzle from the platform) or should I raise the temperature of the platform?
Fantastic product and I'm learning a lot from this.
Marc (from Bangor, Wales, UK)
Comments
Hi Marc
Have got similar issue, have changed my plate temp to 110 deg C, it is generally better, but I think I'm going to do some test runs at 1 deg C increments because there is a temp drop across the build plate in both x and y directions, as a result might not be hot enough away from middle of plate. The temp is easy to set, just find the line that reads M109 S100, the S100 is the plate temp edit to S110 say and save the file, then build via usb or SD as normal
I agree the beast is awesome!
Brian (Keighley, West Yorks, UK)
Thanks Brian,
Yes, you're right. I recently Increased the nozzle temp to 220degrees and the platform to 110degrees which increases the temperature of the peripheral parts of the platform. In addition, I got better results by slowing the print rates too. I also found that putting some covers (plastic foam or fabric) around the 'windows' of the device helps against wind chill and creates a more even distrubution of heat around the platform. This has helped me produce good quality cogwheels with good resolution (by tweeking other stuff too e.g print rate).
Your reply if much appreciated and best wishes with your prints.
Hi Marc
Glad to help, I would be interested in your print rate values to compare with mine, I noticed the 'window' effect also looking a some cheap acrylic cut up to make a set with magnetic or velcro tape of ease of removal etc.
Brian
I'm having the same problem. I have a cool office environment and have sheets of lexan and cardboard (whatever I could find today) around my firmware version 5.5 Replicator. I modified the calibration dual gcode files on the SD card and set the temp all the way up to 120. I grabbed an IR thermometer and am only reading about 80-90 deg C at best (even close to the center where the thermistor is located). I tried tightening the screws on the aluminum platform in hopes that the heating pad would more evenly distribute the heat. I am tempted to keep pushing the platform temp up but am not sure if that is ok since I am already at the limit (even though I am not reading a true value of 120 on the surface of the platform. Moving the temp up helped, and the kapton tape is clean. However I fear that adding acrylic or lexan or whatever on the sides to lessen draft will eventually damage the drive motors?
Hi,
When I changed the GCode to ramp up the platform to 110 deg C and the nozzle temp to 220 degC, as well as insulating the side 'windows' of the printer on its sides (not teh top window), then the folding stopped as the plastic would stick better to the platform.
Are you sure that your IR thermometer is calibrated correctly? Also if you reduce the printing speed (rate of plastic extrusion) that could also help.
Regards, Marc
Yeah the IR thermometer is calibrated. Even if it was off by +/- 5 degrees I'm not getting anywhere near the temps needed. I sure could reduce the speed of the toolhead movement - that sort of defeats one of the main benefits of the machine. Per your comment Marc - are you saying the extrusion speed and the toolhead movement speed are fixed at a specific value? With the motors feeding the plastic and the toolhead movements being separate - I would think you could set different extrusion speeds and toolhead speeds.
In addition - it might make the oozing filament problem (I have a dual extruder) worse. I haven't looked into what exactly "acceleration" is yet. Right now it is off. In CNC terms - I'm wondering if it is equivalent to "High Speed Toolpaths". If that is the case, the extruder would accelerate and decelerate appropriately - where "appropriately" means it would slow down for a sharp turn so that it doesn't shake the machine so much... I'll try that too. Right now I have my Replicator on a sturdy table, so most of the shaking of the machine translates to the build platform...
Does the heat pad under the aluminum build platform supposed to be tightly held together? Did anyone else's Replicator come shipped with most of the screws/nuts loose?
Do the MakerBot folks not recommend panels on the sides of the box to keep heat in? I'm concerned about overheating motors and other items inside the chamber...
Lastly - has anyone had problems with keeping their ABS dry? All other machines I've use have kept their ABS in a sealed container such that humidity in the air isn't absorbed by the filament.