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Star/Delta start applies to 3 phase motors, you mentioned this is a 1 phase? IIRC the code states that all heavy load starting motors, the protection can be increased but should not exceed 225% of the FLA. Al.

Yes Krazatchu I would love to avoid the DIY . That is why I am here to pick the brians of the more knowledgeable . So in converting the AC to DC will I lose amperage or will I gain like on the voltage side . Also what does SMPS mean . I would like to keep the 20 - 30 amps that I will be inputing as well but keep the converter as small as possible .

Originally Posted by keebler303 Kreutz I was not looking for an "apples to apples" comparison. I was more giving you the opportunity to show why yours was a better value over similar commercial offerings. For the tuning I was thinking of something like a plot of the temperature response. So you could qualitatively say you need to increase damping if you have excessive overshoot, etc. Just something more than...

Allrighty... According to the PM you sent me, you want to convert 120VAC to 120VDC... Rectified 120VAC will not give you 120VDC, it will give you 120VAC * 1.414 = 170VDC... Rectified AC without the use of an isolation transformer is incredibly dangerous... It has the potential to kill... I would suggest a transformer to step down the 120 AC to roughly 85 volts AC ... And then rectify and smooth... The resulting no load dc voltage would be...

hey bill, call me i am in team with a very good machinist who is making a retrofit of a lagun mill (1,5 tons) using home made roller screw but unfortunately he do not speak english also your machine despite his price is suffering of insufficient rigidity so making a team might be interisting we have tig ac/dc plasma mill lathe oscillo servo and due to the ecomomic slowdown time me i work only sat/sunday

Kreutz I was not looking for an "apples to apples" comparison. I was more giving you the opportunity to show why yours was a better value over similar commercial offerings. For the tuning I was thinking of something like a plot of the temperature response. So you could qualitatively say you need to increase damping if you have excessive overshoot, etc. Just something more than "feel" to make it easier for...

The fluid coupler is out due to space issues. Also, I can probably find another motor for what that coupler will cost me. I cannot remember how to determine if a motor is able to start under load. Idea? I think my first mistake was settling for an open drip motor instead of TEFC but this motor in a 1ph is HARD to find. a dime a dozen in the 3ph variety. I am looking at VFDs now. If I have to change this motor, I am strongly considering just...

Cool, Thanks Al. Now I know which direction I need to head to get this thing together.

Any one here build a motor speed controller that will run off 120V ac house power to run 90V dc motors using triacs? If yes, will you share your experiance and schematic. Today I tried one of the Chinese router speed controllers for AC/DC motors with a fullware bridge rectifier and it runs a DC motor very nicely. Thanks

First, I want to thank everyone who has responded to my post. All the information was very appreciated. Second, I would like to answer Lee's question in post #24. This project actually began in our local library when I found a book entitled "CNC Robotics Build Your Own Workshop Bot", it can be found at www.books.mcgraw-hill.com . It goes into detail on how to build a cnc router, everything from printing the circuit...