Printing Radius and Chamfers

[12th-man 0]

I am new to 3D printing so please bear with me. I have printed several items either from the web or from files that have been drawn in SolidWorks. One of the issues that I have not been able to solve is how to print a radius or chamfer that starts out at the build plate that is being printed outwards. That print portion turns out like garbage. Once the print gets ot a verticle portion and starts to print inward the job turns out great. I have adjsuted a few settings like quality settings down to .06mm and had the fan turn on full at 1.0mm. I also turned up the print speed and turn it down with no effect. I am prinitng parts that I need so they need to be done correctly. One file that is an example of my problem is http://www.thingiverse.com/thing:93798 . The bottom turned out like garbage but the remaining portion turned out great.

Any help would be much appreciated.

 

[gr5 1,345]

Overhangs are difficult. Fan is your friend here. You really need the fan at 100% right from the start which is not normally recommended. This will help somewhat but it still won't look so good. Have the nozzle start out hotter than normal as the fan will cool it and the PID controller will need half a minute or so to adjust. Then slowly lower the temp to the desired final temp. Or just print the first layer at 240, then lower to 225 for second layer, then 220 for third.

I'm really hoping UM comes out with a recommended dissolvable support structure for dual extruders. Soon!

Is there any way you can cut the part in half and glue it together after printing or flip it onto another side?

You can wet sand the part to remove all the bumps at the chamfer. You need to keep the plastic cool (if it's PLA). Then to make it look nice you can put some baby oil on it afterwards. Or you can use a vapor solvent to smooth it out after sanding. Or paint it with automotive primer.

 

[eldrick 63]

Or use a deburring tool to remove the flange left by the first layer:

http://www.amazon.com/gp/product/B003JY7MDW/

 

[12th-man 0]

Thanks gr5. I put the fan on full at 1.1mm and adjusted the temp on the nozel up. This did help, but it still isn't perfect.