The output constrains are used to filter the results in Step 2 - User Section tables. Whilst a large array values can be calculated for a given windings angle/radius combination, the user is likely to only require values within a certain range. The inputs shown on this tab enable the filtration of values in Step 2 to better identify useful variables.
Number of Pivot Points
The number of pivot points controls the fibre density, and therefore the pore size of a scaffold. For a greater array of pivot points listed in the Length table increase the maximum number of pivot points variable.
Effective Velocity
The effective velocity is the resultant velocity of the translational and tangential velocities.
The effective velocity minimum and maximum inputs constrain the table values shown in Step 2 - User Selection, velocity table.
For controlled MEW printing it is critical that the effective velocity is greater than the mass flow rate of the polymer, this is often termed the critical translation speed (CTS). The faster the effective velocity is above this CTS value the greater the polymer lag will be. It is advised that the minimum effective velocity be set approximately to the CTS value to ensure only velocity parameters which will achieve printing are displayed. However, determining the CTS and an appropriate effective velocity range is at user discretion and will require trial and error on the given machine with the chosen printing parameters e.g. temperature, pressure, voltage, printing distance, spinneret diameter.
Number of Displayed Lengths
The Number of Displayed Lengths input controls the maximum number of lengths which can be listed for a single pivot point entry (or row entry) in the the Length Table shown in Step 2. The minimum number of entries depends on the mathematical results, if no lengths are listed, none exist for this combination.
