Starting a new shop and 3-phase. Good machines cheaper?

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Forum topic by Planeman40 posted 07-04-2012 02:18 PM 1143 views 0 times favorited 4 replies Add to Favorites Watch
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792 posts in 2185 days

07-04-2012 02:18 PM

Topic tags/keywords: shop 3-phase machines

For those of you who are in the beginning stages of building a really nice home shop with top end industrial quality machines, you might want to pay attention to this.

I have considered 3-phase in my home shop in the past but never did it as my machines were collected over a long period of time and it didn’t occur to me there might be some advantages if I had started with it in the beginning.

I keep up with the used woodworking machine prices and auctions and it become obvious that there are some fantastic used machines available at VERY low prices as they are 3-phase. I also read that some of our Lumberjocks have installed 3-phase converters in a 220 V single phase home shop and swear it works well.

So I am starting this discussion and asking those of you who have 3-phase converters in your home shop to tell us your thought about cost, reliability, the best type of converter, and anything else that might be of interest.


-- Always remember: It is a mathematical certainty that half the people in this country are below average in intelligence!

4 replies so far

View AHuxley's profile


425 posts in 2746 days

#1 posted 07-04-2012 11:08 PM

First, it has been clear over the past few months the used market for industrial/production machines is begining to tighten back up most of the stuff that is going to be dumped has been. So the best buys may be gone but the prices are still nice, some mashines are better than others, jointers and big sliders are still good buys, shapers never seemed to go off the cliff… In any event if you want scrap prices with wide selection you probably want to move quickly.

The best 3ph power come from the digital phase converters ie Phase Perfect, if you have the money it is a no brainer, on the opposite end is the SPC (static phase converter) it starts a 3ph motor but then it runs on single pahse, used more in the past since there were few other economical means but now they are becoming extinct. They do not allow the 3ph motor to produce full power derating to 2/3-3/4 full power. RPC, rotary phase converters are essentially a SPC with a 3ph idelr motor that works as a generator to produce the 3ph. These are the way to go in most cases for a shop with multiple 3ph machines especially if any or over 3hp. They can be bought trun key relatively cheaply BUT you can build one for not a lot of coin if you source a used or surplus 3hp motor cheap to use as the idler. VFD (variable frequency drives) have come down in price to the point they are very viable alternatives for 3hp and under machines (much less so for larger motors). Without getting into how they actually work (unless someone wants to know) they take in 1ph power and (most) send out 3ph power. They have the benefit of being able to control speed and direction of the 3ph motor as well as add options like motor braking, soft start etc etc. These are serious motor control for cheap (under 200 for a basic drive for a 3hp motor). The extra features are very useful on lathes, drill presses, shapers, bandsaws etc. If you only have 1 or two 3ph machines these can be an excellent way to go or if you would like to add speed control to a lathe or braking to a bandsaw they are very useful.

I have an RPC but also use VFDs on some machines for the added options they give. In the end the cost of these are far outweighed by the deals out there. I just bought a 12” jointer at auction that is 3ph with direct drive (so no switching the motor to 1ph) a new one sells for $14,000 or so, I paid a little under $1,000 and it was in great plug and play shape. I decided to get a VFD to run it so I could speed the motor up to equal the fater speed of the belt driven version, now I have the best of both world (better finish, lower vibration) and I have less than $1,200 in it, about what a new 8” Chinese jointer costs…

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8178 posts in 3072 days

#2 posted 07-04-2012 11:25 PM

You do want to be aware that some machines with 3 phase motors
have been used very hard and poorly maintained. Also, some
high-tech machines such as planers with digital controls,
edgebanders and so forth may be prone to electrical problems
that are very costly to repair…. and sometimes when a machine
becomes a hassle to fuss with the shop writes it off and buys
a new one.

Still lots of great deals out there.

View Planeman40's profile


792 posts in 2185 days

#3 posted 07-04-2012 11:47 PM

Thanks AHuxley! That was a great help! And thanks also to Loren. Yes, there are a number of poorly maintained used machines out there, but this is true of any used market. You just have to be careful and be informed about what you are buying and be prepared to do some refurbishing if necessary. I am thinking about the home shop so the machines with digital controls would most likely be too large. And things like edgebanders wouldn’t be of much interest to a home shop user.

What I would have in mind if I were to do this is set up a special 3-phase electrical circuit for these 3-phase machines in the shop in addition to standard 115 V single phase. As I would be the only user I would only be using one machine at a time so overload shouldn’t be a problem. I would want to prepare this special 3-phase circuit when I built out the shop. This would allow me to keep an eye out for real bargains on good pieces of equipment. I might also install a 220V single phase circuit at the outset also.

Keep the thoughts and ideas coming!


-- Always remember: It is a mathematical certainty that half the people in this country are below average in intelligence!

View AHuxley's profile


425 posts in 2746 days

#4 posted 07-05-2012 12:41 AM

While a lot of what Loren said is true the majority of the machines sold in the last 4-5 years have been for two other reasons besides being worn out thats what we saw for years before that. One reason is the changing way wood is processed in production shops, the move to Euro machines has left a lot of old US iron out in the cold, still prefectly servicable for 100 years in a hobby shop, and even more so the move to CNC based cutting, lots of sliders are on the market for that reason. The second factor is the number of wood processing businesses that have gone under or moved production offshore or outsourced parts of the production, one outsourcing example is cabinet doors, not many “cabinet” shops do much more than making boxes now, they buy their doors from door vendors on and off shore. Many of the machines sold for these reasons are plug and play, I am much more likely to go to a liquidation auction than any other type.

On the shop electrical, building a shop from scratch without 240v 1ph is a mistake. Fully wire for 240V and 120V. I am planning my new shop and will have a full ring around the shop and down the center ceiling of 10 gauge wire for 3ph from the RPC. I will leave extra wire in the boxes but only add the outlets if/when needed. The only negative is without knowing what machines and what power requirements you need you can’t develop a perfect plan, just overbuild and you are likely fine. My choice is to have a circuit that can be used for 3ph distribution from an RPC and 240v 1ph outlets throughout (for 1ph machines or 3ph via VFD) gives one a very flexible starting point.

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