I am using a sekomak blower I got on ebay for about 150 I had to replace the motor to get the volume and pressure up to the limits of the blower. The motor is a 5 hp at 3450 rpm with a three to one belt overdrive to the blower. I am using a vfd to drive the motor up 90 hz The transformer is a step up from 240 to 480 volt. The high volt vfd are in lower demand on ebay so better prices about 150 I am using a dadaq 194 4 channel dac for my pressure transducers to pc interface. and 4-20 ma transducers. and windaqxl to export the data to fpxl for read out. The bench became operational this last weekend and I am now learning how to calibrate it. I cant get over 20"wc on my 400cfm scale with limitd 240 volt input at 15 amp with out tripping the circuit breaker. I have no problem with the 300 cfm at 28"wc. This is a single direction bench but reversing will be done on top of the bench with a movable head fixture. I made the step gauge for valve positioning the steps are .050 increments up to .600 I start at the .6 mark set up the pressures and pull the gauge one click at a time for each measurement. I am going to try a watlow pid controller to automatically keep the pressure set at 28" and controlling the vfd.
