A horizontal flat rectangular tube
As the subject describes I want to print a flat hollow rectangular tube. I find if I print with internal support it is a devil to remove and without there are looping strings inside the tube which are harder to remove. I though about creating a separate solid block inside which gets knocked out. the size is about 20mm wide 15mm deep and 4mm high.
Any thoughts and techniques would be appreciated, especially probable required separation to allow an internal block to be removed or better bridging settings.
BTW it isn't practical to re orient
i3 Mk3 [aug 2018] upgrade>>> i3MK3/S+[Dec 2023]
RE: A horizontal flat rectangular tube
- Start with making sure that the bridge layer that closes your tube is perfectly perpendicular to the tube and thus spans the shortest distance over the unsupported space.
- Watch this video on optimizing bridging performance. You don't need a solid bridge layer, it's enough when it's straight and not droopy and you can lay the next layer on top.
- Profit!
RE: A horizontal flat rectangular tube
If you can, put the short face (~4mm) on the bed. You noted its not practical to re-orient, but a bit more context would be helpful there. You also don't note what material you are using to print. I've successfully printed ~45mm bridges with PLA. Slow speed, maximum cooling. When you slice, look at the results to make sure the slicer is applying bridge settings to the bridge layer. In Slic3R, you have to export the gcode before the preview will show the path types.
RE: A horizontal flat rectangular tube
Thanks for your replies. Clearly I need to get on top of this but I have always been perplexed why my earliest prints of this were OK. The main difference being the earlier tests used 2 perimeters and in an attempt to bolster the strength of the part the recent prints used 8 perimeters.
In both instances, to help the leading edge of the openings, I slightly over-hanged the roof of the tube compared to the base to force supports direct off the plate (which are really easy to remove).
I have now noticed the supports don't get wider with more perimeters and the inner perimeters were not directly supported. This appear to be why it was failing - doing a test print now. BTW using PLA.
I'll play with speeds to see if it makes a difference. I note the video reference by Wojtech suggests high speed and low flow rates but William has success with slow speeds - go figure.
i3 Mk3 [aug 2018] upgrade>>> i3MK3/S+[Dec 2023]
RE: A horizontal flat rectangular tube
I'll play with speeds to see if it makes a difference. I note the video reference by Wojtech suggests high speed and low flow rates but William has success with slow speeds - go figure.
The reason might be that the Mk3/Mk3S cooling is not strong enough to allow those fast speeds.