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5050frames / core-frame-system

50/50's Core Frame System development kit
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Print skrinkage/warpage #5

Open hunterstabler opened 3 years ago

hunterstabler commented 3 years ago

Hi, Just finished my first test print of a frame design for the Core system. I have a fair amount of experience printing with stereolithography resin, which is quite mathematically accurate down to 100th of mm, but much less experience with FDM printing. I am wondering if overall dimensions need to be scaled up, hole diameters scaled up etc to account for shrinkage. My print seemed to shrink a fair amount at the ends and pulled up. It was 20% infill and PLA+ for the test. I am using a Creality CR10 S pro and Cura. I am also modeling in Rhino3D, so there is a small chance I am getting some discrepancies converting Fusion files to STL to 3DM geometry, but I kind of doubt it because my file measurements match my caliper measurements of the 50/50 Core frame and hardware within 10ths of mm. Any breakdown of bed temperature, layer height/resolution, print speed, brim, supports, etc would be very helpful. Also, if you are scaling up your holes for frame spacers, what diameter are you using?

HeXiBLiTz commented 3 years ago

I have been using a +0.2mm on the holes and internal width with 0.5mm around the core or using the CDK files the outer offset line of the core sketch. I hope this helps. shrinkage will happen I recently calibrated my machine to print more accurately also (Previously I was printing at 271 and 251mm axle holes and the core fitting fine but that meant my machine was technically printing innacuratly)

vnznconcepts commented 2 years ago

My suggestion is to adjust the 3D model to account for shrinkage. Also consider the line width, if not a perfect multiple of the dimension of the feature, Cura will compensate by rounding down to the nearest multiple of that features width. Holes printed on a vertical plane will never be perfectly round. Even with support material (although soluble support gets you closer). I plan to make drill jigs to ream axel/bolt holes to final size.

Test by using smaller cross section chunks (rather than full frame walls), printed in the same orientation as the full print. Test fit/measure, then adjust until you are happy, then do a full print. Saves time, material and $$$.