35-50 hp Electric bandsaw logmill

[paul case]

I don't have VFD just because they are more expensive.

They offered a 15 hp electric option back in 1994 when my old LT40hd was new.

It works well for me.

I did have to upgrade to the 97 or newer head lift motor as the little one just wasnt enough. I also put on a Pineywoods helper spring too.
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[fishfighter]

I saw only for myself. To have a 3 phase line dropped, that would cost an arm and a leg. :( Any idea of getting a electric motor strong enough that would run on 240V's?

[killamplanes]

Mines 240v single phase 10hp. That runs saw only hydros are another electric motor. It's not a power house but it gets the job done and I saw by myself and while it's running I'm slinging lumber of the deck as fast as I can move. It's really a perfect match for what I do. I use to make ties, now just pallet stock for my business.. I have 3 phase at my farm up the road so if I every get a resaw or somethin 3 phase I'll probly station it up there.

[killamplanes]

Mine can run hot if your pushing hard in the heat of the summer, mainly long logs where your in the wood without a break.. but I usually trip a breaker before it does :D

[fishfighter]

Mines 240v single phase 10hp. That runs saw only hydros are another electric motor. It's not a power house but it gets the job done and I saw by myself and while it's running I'm slinging lumber of the deck as fast as I can move. It's really a perfect match for what I do. I use to make ties, now just pallet stock for my business.. I have 3 phase at my farm up the road so if I every get a resaw or somethin 3 phase I'll probly station it up there.

Any pictures? Are you using a overhead cable tracking system for the power feed?

[paul case]

If you have 230volt and a big enough service to run a 100 amp breaker you can buy a rotary phase converter. It uses a 3 phase motor as a generator for the 3rd leg of 230volt.  You need one a little more hp than the motor you plan to run. Like on my old mill I run a 15hp and my RPC is a 20hp. Now that converter will run 2x as many motors as its own hp rating but the biggest it would start is a 20hp under no load.

There are a few ''rules'' on RPC use. They need to have less than 100 feet of lead from your transformer to them. There are a few others but none come to mind right now.

I purchased the 20 hp that I have and the 15hp motor for about the same as what a 25hp kohler conversion kit from woodmizer. However they need no gas and almost always start. IT may be a pain getting them fixed up to start but after that no oil changes and no hauling fuel to them an quiet.

10 hp single phase motors actually cost more than a 15 hp 3phase and the 3 phase motor will generally last longer. I have been told that the 3 phase motors actually cost less to run too.

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[redprospector]

I saw only for myself. To have a 3 phase line dropped, that would cost an arm and a leg. :( Any idea of getting a electric motor strong enough that would run on 240V's?

A few notes of interest, since some of you seem to be interested in this subject. I run a part time motor shop. I have been building phase converters for around 30 years. I have built an electric motor dyno. In my experience motors run off of a phase converter do not put out full HP. But, the larger the phase converter is to the driven motor the closer you get to full HP. I tell people to double the size of the converter to the driven motor, sometimes 3 times. I also build large single phase motors [ over 10 HP] that will put out full HP. No phase converter needed for these. Also do not neglect wire size. I did an experiment with a 3 HP single phase motor, run on 240 V it put out a full 3 Hp. Run on 120 V It put out 2.3 Hp. The only difference was voltage drop. If you want to see a single phase motor that I built in action, go to the members web pages and check it out.    Muggs 8)

I think muggs is making an option.

[woodworker9]

3 phase motors are indeed more efficient than single phase.  They are also more powerful, hp for hp.  What I mean to say is that an older 3 phase 10 hp motor is much more powerful than a new single phase 10 hp motor, and it runs smoother, quieter, and with less power consumption. 

I've done the "pepsi challenge" in my shop, and have swapped out machines that have single phase motors for 3 phase.  I usually can pay $100 or less for a 3 phase motor.  I built one of my rotary phase converters using a kit from American Rotary and my own 10 hp, 3 phase Baldor motor.  I bought it off of craigslist for $100 because it was "noisy."  All it needed was new bearings, which were $17 apiece.  Once you've done one, motors are extremely easy to open up, clean up, and change bearings.  Typically, all they need to run 100 years or so.  I've got a couple of 3 phase motors in my shop that are nearing their 100th birthdays, and with new bearings, they run smooth as silk.  One is an 800 lb. monster 15 hp motor that runs my 30" Whitney planer.  What a beast.

[woodworker9]

Another thing that I forgot to mention is that RPC's can be balanced with capacitors, and the more balanced they are, the better they operate.  As stated, I have 2 RPC's in the shop.

The bigger one, which is a 20 hp completely built and CNC balance rated by American Rotary, will start that monster 15 hp motor.  Some machines are harder to start than others.  For instance, compressor motors are notoriously difficult to start, so you would want at least a 2 to 1 ratio for running a 3 phase compressor.  Also, big 36" bandsaws are also harder to start, because your initial startup must get that big, heavy cast iron 36" wheel spinning. 

Before I got a bigger RPC, I used to start my 36" Tannewitz bandsaw by opening up the upper wheel, and giving it a hand spin to get it moving before hitting the "Start" button.  This eliminated alot of the initial startup problems, and I could run that 5 hp bandsaw with a 7.5 hp RPC.  Without the helping hand, it would just trip the breaker.

[pineywoods]

I've seen several home-made rpc's that use a small single phase motor belted to the rpc to get it started. Turn on the "pony" motor to get things started moving, then switch on the rpc. I bought a large lathe and a big old table saw, both with 3 phase motors. Happen to have a couple of 5 hp 3 phase motor handy and started to build an rpc. Backed off and replaced with single phase motors due to re-sale value. Just about can't give away 3 phase tools here..

[muggs]

I saw only for myself. To have a 3 phase line dropped, that would cost an arm and a leg. :( Any idea of getting a electric motor strong enough that would run on 240V's?

After looking at my website, I see the video is gone. [ I will have to fix that]. The video is of a 5 HP motor on a 16 inch Powermatic Planer. In the beginning it was a 3 phase motor run off of a 7.5 HP phase converter. When run off the converter, it brought the planer up to speed in 2.5 seconds. The same motor after being modified into a single phase motor, It brought the planer up to speed in 1.5 seconds. The motor on the dyno shows it putting out 5.9 HP I have 5 years time into developing these motors I have a 15 HP and a 20 HP sitting here, but nothing to put them on. If your mill is stationary and you have the electric service, Why use an internal combustion engine? Just do the arithmetic.    Muggs

[bandmiller2]

Muggs, I have messed around with motors single and three phase for many years and built rotary converters. I have never heard of converting three phase motors to single. If its a proprietary thing I understand but please tell more. It must be done with capacitors and or lead switching. Thanks Frank C.

[carykong]

Goin to see Tmbrcruiser's Baker 3650 later this month

[killamplanes]

There's my 10hp single phase. Very easy to replace gas motor on my tk. And yes it runs on an overhead pulley system with hydraulic lines to the up/down for head. I also agree 3 phas is better/quite etc. BUT around farm country here 10hp 240v 1 phase motors are as common as corn fields :D

[killamplanes]

Another view

[paul case]

I always like to see other peoples Ideas at work and mods that give me Ideas what to do and how to fix or get around certain issues.

What is the 1 gallon plastic jug hanging on the front of the mast?

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[killamplanes]

Well there's a story. Tk originally uses 12volts up/down for head. Never liked it. You would touuch the up down button and it would jump 1/2 inch on you thickness. It was hard to tune in board thickness. So put a hydraulic motor on it from I think a combine. Absolutely love it, and had to because no longer 12v without gas motors. BUT the 1 gallon jug catches a ever so small drip of hydraulic oil that the hydro motor has a 3rd line coming out of it. It should (in its original application ) returned to hydraulic tank. Believe me when I say this mill is highly MODIFIED, that's using a nice word..

[paul case]

 

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[redprospector]

Goin to see Tmbrcruiser's Baker 3650 later this month

Good deal! Let us know what you think.
I'm still weighing out the options. I grew up in a production wood shop and know the benefits of electric. But I've got a lot of other things to spend money on right now.
I've never ran a sawmill that wasn't gas powered. Electric sure sounds like a nice option.
Sorry we kinda took over your thread, but it's made for an educational conversation. 

[muggs]

Muggs, I have messed around with motors single and three phase for many years and built rotary converters. I have never heard of converting three phase motors to single. If its a proprietary thing I understand but please tell more. It must be done with capacitors and or lead switching. Thanks Frank C.

Hi Bandmiller Yes the info. is proprietary, but I can tell you this much. These are modified 3phase motors. When I am done with them. They are capacitor start and capacitor run 2 phase motors with soft start built into them, and you had better be able to rewind motors.     Muggs