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Video Review Request - Running a 3 Phase Machine with Single Phase Power Using a VFD

TimWilborne

Plastic
Joined
Oct 14, 2015
Location
Roanoke, VA
Hi everyone. I'm working on a series about VFDs and phase converters and I was wondering if you could review the following video. I get lots of inquiries about how to run 3 phase equipment off of signal phase power and I'm trying to make sure I'm covering all the details. In this video I go through the basics of installing a VFD to a 3 phase motor, next week I'll go over how my phase converter works, then I've made a miniature model of a phase converter where I can really go into the details of how it creates 3 phase power, how it gets started rotating, and some basics on phase balancing. What have I missed or what else should I include? Also you should at least check out this 1800s shaper running at the end of the video. She's a real beauty.
YouTube

Thanks in advance. I enjoy reading the post hear near daily but as an automation guy whose more of an amateur machinist I try not to chime in.
 
You shaper looks to be running backwards because the belt is slipping on the back stroke, It's not the world's smallest shaper, there are bench top size available. You dad is not running a shaper! It's a Planer, Difference is shapper the cutting to moves, planer the work attached to the table moves. The shaper to take more material off the table with work attached is moved and Planer the cutting tool is moved. They are opposite in operation. The machine you dad is operating is known as an open-side planer. A while ago shapers were considered boat anchors and were sold at auction for scrap. But now they a being used again. Lots of things that shaper can do your mill can't like cut an internal keyway unless you have the shaper attachment. But it only has a short stroke.
 
Haha yes I figured that out later. It took me some studying to understand how the vary the stroke on it. It's a fascinating machine. Thanks for watching!
 
Interesting the difference between a shaper and a planer. Maybe they did call it a planer, it's been many years ago and I was about 12.

At full stroke the connecting rod was rubbing the back of the casting which was why it was slowing down. Still it was backwards, mainly the feed numbers were running the wrong way. Once we got it lubed up really good it ran smooth.

I've still got to find an antique box to but the drive in for the guy but it was one of my more interesting recent projects.
 
Looking at 18 minutes and 7 seconds, I can't understand how the stroke is faster on the return. I can physically see it, I just can't follow why
18 minutes 7 seconds of the video

The speed of rotation is constant and the distant moved is constant but the time spent on return is less therefor the velocity must be higher.
 

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If you do much work on engines, you'll find that SOME, especially high-performance 'experiments', you'll find that they're designed with the centerline of the cylinder bore offset from the crankshaft. They have several reasons for doing this, but the geometric result is that the offset changes trigonometry such that piston speed in ONE direction, is naturally higher than the other. While the mechanical drive of your shaper is different, some use offset crankpin, regardless the result is the same... the velocity is higher, and force lower, on the return stroke than on the working stroke.

If you're a mathematician/physicist/engineer, you'll see the relationship of geometry, but from a METALWORKING standpoing, why would this matter?

Simple... the velocity of the cutter THROUGH the workpiece is important. Having a faster return speed isn't substantially important, but having the cutter make a consistent pass, with consistent force, and consistent chips, is everything.
 
It is amazing the engineering that went into these machines. When you first glance at it, it looks crude but every little piece has been carefully designed.

I put out a video today laying out the equipment I'm going to use to go through how VFDs and Rotary Phase Converters work. Rotary Phase Converter and VFD Workbench Preview - What Topics Should We Cover?

I really enjoyed your video on the shaper. They are fascinating machines, I've heard it said that you can make anything using them in the shop except money! :)

Dan
 








 
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