Recent content by frayedknot

More info: supply is single-phase and VFD converts to 3-phase. Underground lines so getting 3-phase supply would be $$$$. The VFDs are set at 3 seconds. When I referred to the "sweet spot" I meant that the techs would adjust the time based on performance, i.e. It clogged at 10s so they...

Thanks for the heads up on the VFDs. Rumor is that the area had power issues when the station was put in (2 other stations are nearby). The local water treatment facility owns the 2 other stations and installed VFDs in all 3 (ours by mistake). My background is in manufacturing and nuclear...

Since I have "engineer" after my name my local community HOA has volunteered me to head up the sewer committee to find a solution to our lift station problems. We own the lift station so we get to pay for all our problems - over $15k this year alone in pumps and emergency calls. 1) 80 homes 2)...

Try www.royalswitchgear.com if you haven't already. They have done custom designs in the past.

I was recently approved to sit for the Oct 08 PE exam in Alabama. You are required to have a PE verify your work experience. In my case, this was a combination of 3 different PE's that were familiar with my work history, but it is acceptable to have 1 PE. Separately from the work...

Thanks for the replies. I've figured it out to be Across Flats.

I've run across an abbreviation on a drawing that I've never seen before. The drawing is an older drawing of structural steel. A dimension followed by "A.F" is next to the face of a bracket that is welded to the structure leg. What does the "A.F." mean? I cannot find reference to it in any...

I'm looking to automate the process to cut copper tubing. The size ranges from 5/8" to 1-3/8" diameter with a wall thickness of 0.032" to 0.052". We cut about 12 - 15 thousand units a year of various sizes/lengths. I invision a piece of machinery that will pull and cut the copper tube however...

I am attempting to reduce our facility's power consumption/demand (monthly cost) by 20% this year. On the list of target items are the motors used to power our mechanical power presses manufactured in the 1950's and 1960's. These motors are 3-phase ranging from 5HP to 20HP. From what I can...

Thanks guys! Looks like the gibberish from a vibrations course I once took. I tried to model it as a 2-DOF system under simple harmonic motion (assume no damping) since I'm only interested in the maximum velocity. Where might I find this Blevins dude, i.e. is it a common book at a local...

I have a long rod that is coiled into a torsion spring at one end. I need to find the velocity at the tip when the rod is deflected X inches at the tip. I know I have a torsion spring and a flat spring. How do I model these together? Any help will be appreciated! I'm losing hair over this.

Where can I find info on the weather resistance of nylon hardware (Nylon 6/6)? Matweb and google aren't much help for my feeble mind. I need to put nylon hardware on an assembly that will be outside 100% of the time in all types of weather. Thanks in advance!

I'm looking for a replacement for our portable flame cutter (Victor DC 2400). Any ideas as to where to look? General search on the internet doesn't help much. Thanks in advance.

I need to evaluate/design a die to form 3/16" steel plate in the following design using one operation. _ _| |_ What resources (i.e. handbooks, standards, etc?) are avaible to assist me? Thanks in advance.

Anyone know of a decent source of info for setting up a lathe? I am turning/tapering beryllium copper rods (~3/8" OD); however, I am having problem setting the cutting tip so that it cuts cleanly. Any suggestions? Thanks...