"(uscs units) fused deposition modeling is used to fabricate a part which is a model of the step pyramid at sakkara in egypt (built circa 2670 bce). the model has six levels or steps, each with a thickness of 0.17 in. the bottom layer = 2.20 in on a side, and successive levels are 1.85, 1.50, 1.15, 0.80, and 0.45 in on a side, respectively. height of the pyramid = 1.02 in. in the fdm process, layer thickness = 0.010 in and the width of the extrudate deposited on the surface = 0.025 in. the extruder head moves in the x-y plane at a speed of 10 in/sec. a delay of 12 sec is experienced between each layer to reposition the worktable.
compute an estimate for the time required to build the part. setup time = 35 min. ignore post-processing time.
using the time estimated to build the part, determine the part cost (in $) if the abs polymer used in the process costs $9.50/lb and its density = 0.038 lb/in^3, machine hourly rate = $8.00/hr, and labor rate = $30.00/hr but labor will be used only 40% of the build time, mostly for setup
answer & explanation:
"the force on a cutting tool are 2600n vertically downward" sounds a little unusual, since most of the time, the tool is above the object to be cut in such a way that the force acting "on the tool" is upwards. we will accept the statement as it is (downwards).
since the two forces are acting at right angles to each other, the resultant can be found using pythagoras theorem, namely
resultant = sqrt(2600^2+2100^2) = 3342 n (approx.)
the angle can be found using the arctangent function, or
angle = arctangent(2600/2100) = 51.07 degrees below the horizontal, since the 2600 n force is acting downwards.
the drive force for diffusion is 7 fick's first law can be used to solve the non-steady state diffusion.
efficiency of reversible power cycles operating between a hot re
heat transfer through conduction is a slow process and both conduction and convection require material medium