# electric?



## klickitatsacket (May 16, 2007)

how many guys would run electric motors if there was an inexpensive option. We have been kicking around the idea of producing a chainsaw mill that uses an electric motor for a slabbing machine.


----------



## carvinmark (May 16, 2007)

Sounds interesting, I would like to see your ideas.


----------



## Husky137 (May 16, 2007)

Might defeat the main advantage of csm,portability in to the woods.


----------



## BobL (May 16, 2007)

The main reason I would be interested would for the reduced noise in an high density urban situation. 

I would be a bit concerned about using electric with an Alaskan unless it was fixed on a rig of some kind - too much sawdust and chances of not seeing and chopping through the power cord.

At the mobile end of the scale I would definitely not be interested in toting a 2kW+ geny through the bush.


----------



## wdchuck (May 16, 2007)

A neighbor of mine is trying to do just that, he has a broken chainsaw and wants to hook an electric motor to it for squaring off small spruce poles. The saw used to be a little puolon with 14"bar.

More info would be a good thing.


----------



## BlueRider (May 16, 2007)

I would be very interested. I have been thinking of building one myself. My biggest reason for wanting an electric chainsaw is not a decrease in noise but a decrease in sucking down exhaust fumes. 
As far as specs I am using an 075 on a 42" bar, I would want similar size and performance from an electric. the weight is a bit of an issue as I usually mill wood without a helper. cost is always a factor, but durability is more important than a low price. 

I have been milling wood for 14 years and would definately be interested in working with you on a design. I am also a patternmaker incase your design needs any castings.

Robin


----------



## woodshop (May 16, 2007)

I seem to remember that originally, you could buy the little Ripsaw bandsaw mill with an electric motor option instead of a chainsaw engine. Don't think they carry that any more although I suppose somebody handy could rig one up. I too would like to do without the exhaust fumes since with both a csm and the Ripsaw your face is right down there closer to the saw, and thus fumes. That's why I wear a respirator. I would worry about power though. You need to draw a LOT of amps to pull that chain or blade through logs. Example, I sometimes try and use my 2 1/4 HP 220V bandsaw as a mini sawmill, it has 12 inches between the blade guide and the table so theoretically could slice up a 12 inch log. But my experience has taught me that if we are talking wet wood, anything more than 8-9 inches is a chore. Not even close to the pulling power of even a 60cc chainsaw like on my Ripsaw bandmill.


----------



## clearance (May 16, 2007)

I don't see why not, three phase would help, if you don't have three phase you can get a phase convertor. Big sawmills use electric, works for them.


----------



## woodshop (May 16, 2007)

clearance said:


> I don't see why not, three phase would help, if you don't have three phase you can get a phase convertor. Big sawmills use electric, works for them.



Well sure... big sawmills use electric to power their huge bandmills. But I thought we were talking about something small enough to mount on a csm and push down a log, something you could plug into your house outlet or run from a generator. Those big electric motors mounted in sawmills weigh couple thousand pounds and use more current than is normally available out of a standard house electric service. Apples and oranges.


----------



## aggiewoodbutchr (May 17, 2007)

I have pondered this myself. What I'm hung up on is how electric motor power compares to chainsaw power in a real world application. How big of an electric motor would be needed to pull a 60+" bar and hang with a 088/084/3120? I dunno....


----------



## ShoerFast (May 17, 2007)

aggiewoodbutchr said:


> I have pondered this myself. What I'm hung up on is how electric motor power compares to chainsaw power in a real world application. How big of an electric motor would be needed to pull a 60+" bar and hang with a 088/084/3120? I dunno....



Down a 12Ga. extension cord, at 110V your only going to get about 3HP or 120V X 20A = 2400 Watts,,,, 2400 / 746 = 3.217 HP an MS-260 has 2.4K watts or 3.2HP (my 3500W truck-mounted generator has 20A breakers, but at that, a 12G cord dose get warm) Stihl only recommends 50' of 12G cord for there 1.7W 2.3HP electric chainsaw


220V moters would help, but your starting to limit you generators that could be used, and still dang heavy,,,, to get the same snort as even an MS-660 , your not going to cut far from the truck the generator is in. You would need a 5.5K 220V generator 7HP 220V motors are just plain heavy. 3-phase would help, but your pricing most out of the ball-game.

I'm thinking it will take awhile for an electric motor to make the power a CSM will give. 

Band-saw mills have a lot of frame compared to a Bar-chain , if a light BSB could be made to really sing, aluminum frame, maybe a rig could be designed?


----------



## klickitatsacket (May 17, 2007)

one thing to remember guys is that you need less electric HP then you do gas HP that is why train engines are deisel generators running electric motors. No transmission, no clutch and so on. The idea is to build a 220 outfit and I think a 3 hp motor for small mills and a 5 HP motor for larger mills.


----------



## klickitatsacket (May 17, 2007)

also this idea is because most guys run their mills in the back yard. The chainsaw mill is still for taking to onsite jobs.


----------



## BobL (May 18, 2007)

If you need 5kW (6.2Hp) to effectively drive a 60" bar you need a system that can deliver 5000kW/120V = 42 A . ie not likely through normal household circuits. To build in an added safety factor you would have to go to 3 phase.

Electric motor (current/HP) ratings are also neither constant nor accurate. For example, my 3HP rated table saw should then draw 2250 W which at 240 V = 9.4A. However, by really pushing it I can get it to draw up to 17A (4 kW) for about a minute before it trips its thermal cut out switch. The most I can get it to draw without tripping for an extended period is about 12A (2.9kW).

A comparative power to weight example can be obtained as follows. 
The biggest Makita electric CS is rated at 13A (120V) or 2.1 HP so ~3 of these will get you 6 HP. The Makita weighs 9 lbs so you'd be lugging about 3 of these (not quite because you don't have to duplicate everything when you go bigger) which is a similar power/weight ratio to CS. (But you'd really need 42 A ie 3 phase).

I understand that there are still significant improvements in the electric motor power to weight ratios that manufacturers have not released. Some of these may become relevant when electric cars become more common.


----------



## BlueRider (May 18, 2007)

*how about DC*

I had originaly thought about using a 3ph motor and runing it through a variable phase controler to control the speed. Prpblem there is that the the vpc eats up a bit of the hp output of the motor. 

My latest idea is to use a dc motor. Dc motors are really torqey and are the motors of choice for cars. just run the gererator through an inverter and then use a controller similar to a golf cartto control the speed. The thing about a dc motor is they have great low rpm torqe. Ive been looking at golf cart moters but they are a bit pricey and I can't find any info for how much they weigh.


----------



## BobL (May 18, 2007)

klickitatsacket said:


> one thing to remember guys is that you need less electric HP then you do gas HP that is why train engines are deisel generators running electric motors. No transmission, no clutch and so on. The idea is to build a 220 outfit and I think a 3 hp motor for small mills and a 5 HP motor for larger mills.



The reason for using a smaller power electric motor in vehicles is related to the stop-start action cycle of motor vehicles. You don't need high HP to maintain top speed but you need a lot of torque to get you there quickly. Trains especially and cars as well need a lot of torque to accelerate in a reasonable time so a "high torque - low HP" motor like electric is very useful for vehicles that stop and start. My understanding is that CS need raw power. Whether its electric or gas, if you need xHP to keep millin there is no difference between a gas or electric.


----------



## aggiewoodbutchr (May 18, 2007)

BlueRider said:


> I had originaly thought about using a 3ph motor and runing it through a variable phase controler to control the speed. Prpblem there is that the the vpc eats up a bit of the hp output of the motor.
> 
> My latest idea is to use a dc motor. Dc motors are really torqey and are the motors of choice for cars. just run the gererator through an inverter and then use a controller similar to a golf cartto control the speed. The thing about a dc motor is they have great low rpm torqe. Ive been looking at golf cart moters but they are a bit pricey and I can't find any info for how much they weigh.



This is interesting. There's a golf cart in my barn that was supposed to be a short term storage deal for a friend. It may be a candidate for cannibalizing...

What else can you tell me about this?


----------



## klickitatsacket (May 18, 2007)

I understand what you are trying to say. However one of the things I am trying get past is the power to weight ratio thing. It is not what i am looking at. I would not be trying to compete with the csm but rother add an option for others where it might fit there needs. These would be carriage mounted and semi portable. Meaning you would have to take it down to move it. I had a friend of mine who built a band saw using a 3 HP electric motor and built his entire house with it before he sold it. It worked great and was fairly cheap to build ($500). A lot of mills use electric chainsaws as deck and ripping saws and I was just looking at the idea for a back yard saw if others might be interested I might think about building others besides mine.


----------



## aquan8tor (May 18, 2007)

BlueRider said:


> I had originaly thought about using a 3ph motor and runing it through a variable phase controler to control the speed. Prpblem there is that the the vpc eats up a bit of the hp output of the motor.
> 
> My latest idea is to use a dc motor. Dc motors are really torqey and are the motors of choice for cars. just run the gererator through an inverter and then use a controller similar to a golf cartto control the speed. The thing about a dc motor is they have great low rpm torqe. Ive been looking at golf cart moters but they are a bit pricey and I can't find any info for how much they weigh.






This is true; the VPC, or static converter, as I've heard them called, eats up something on the order of 30% of the output, unless you get a rotary phase converter, which creates true three phase power. The difference between the two is simple......a few hundred dollars. I looked into them a bit when looking for a new motor for my woodworking bandsaw; I settled on a 1PH 220V 1.5HP model (its only a 14" bandsaw). 

The thing with a DC motor is that you have to have some MONSTROUS power cords to deal with the amperage, unless you're talking high voltage DC. You have to remember that the amperage goes up tremendously when you're talking about 12V or even 24V. This is why car battery cables are so thick, and why they heat up when you jump start a car. Better opt for the 2/0 or 4/0 ga. cable!! Not cheap. I remember that from my high school days when I wanted a big car stereo. For the record I did NOT listen to ghetto rap!!!!!

Logosol has some electric motor conversions available for their mills, and I'm thinking htat alll of them are three phase. They're quite large from what I remember from their video, around the size of a small watermelon! But, they also looked pretty darn fast, too. You just have to have 3PH power, or a big converter, which will cost you a good $500 or more for a 5HP rotary phase converter. I'll have to ask my cabinet making friend what brand he uses in his shop; he has a couple older tools that run off 3PH power, and he has a good converter.


----------



## Railomatic (May 18, 2007)

*electric*

I have tried electric motors before and its a non starter if you want portability but its ok for a static.
A motor which has the same power as one of the bigger chainsaws is a pretty heafty thing and costs more than two new saws unless you get second had, then there's the heavy duty cable needed and a power supply like 3 phase to run everything.
Single phase motors once you get near the 3-5hp range are very expensive items, you would be better off buying a 13hp 4 stroke Honda motor instead
which I'm still working on right now, should have some results later this year.


----------



## klickitatsacket (May 18, 2007)

3 phase motors are dirt cheap on the used market becasue few people want to deal with them. You can also build your own rotophase. My dad did when he was setting up a sgrag mill. I''l see if I can get some pictures of it. It has been sitting for quite a while but I will see if it is till hooked up.


----------



## woodshop (May 18, 2007)

...so bottom line so far as I see it boils down to, if you want serious milling power (forget portable, stationary only) using electric motors you either have to be handy enough with electrical components to be able to build your own 3 phase power converter OR you need a motor that weighs a ton OR you need a huge generator capable of putting out more amps than your house service OR you have deep pockets and can afford a big HP motor/phase converter along with expensive cable thicker than a garden hose to feed it OR you happen to have a used golf cart in your garage that you might be able to use the motor out of for this thing... did I forget anything?  

As much as I would love to saw with electricity, from a practical standpoint so far the numbers (both HP and $$) don''t seem to add up. If we're talking about a portable csm or small mill as the original post seemed to indicate, then it's a non starter as rail says.


----------



## aquan8tor (May 19, 2007)

woodshop said:


> ...so bottom line so far as I see it boils down to, if you want serious milling power (forget portable, stationary only) using electric motors you either have to be handy enough with electrical components to be able to build your own 3 phase power converter OR you need a motor that weighs a ton OR you need a huge generator capable of putting out more amps than your house service OR you have deep pockets and can afford a big HP motor/phase converter along with expensive cable thicker than a garden hose to feed it OR you happen to have a used golf cart in your garage that you might be able to use the motor out of for this thing... did I forget anything?
> 
> As much as I would love to saw with electricity, from a practical standpoint so far the numbers (both HP and $$) don''t seem to add up. If we're talking about a portable csm or small mill as the original post seemed to indicate, then it's a non starter as rail says.



You forgot that you could move into an industrial warehouse with 3 phase service.....big bakeries have 3phase powered equipment, machine shops sometimes do, and large scale buildings have 3 phase equipment for blowers & evaporative coolers...I've seen a couple things on the history channel on logging tech & the underwater log recovery out of the St. Lawrence that had giant electric motors on the mills, almost certainly 3 phase. 
A guy I built an aquarium filter for a few years back had a generator run of LP gas that had a supercharged 460cid V8 that produced something like 330amps of 220V, single phase power. He had a 5,000+ sq.ft reptile breeding facility that housed hundreds of rare exotics that had to be warm....


----------



## Al Smith (May 19, 2007)

Regarding true horse power rating on electric motors,the only true rating is 746 watts per horsepower.Often single phase motors are erroniously sold as "develpos" such and such power.Example,a 5 HP motor that develops this amount is really only about 2.8.It merely will with stand an overload for a period of time but not forever.

The conversion from gasoline to electric is about double,more or less.You can operate an electric motor for far less money than a gasoline engine,and less maintanence.

Static phase convertors only produce about 60 percent of the motors rated horse power.In other words about 6 HP from a ten horse.Rotary phase convertors are over 93 percent effcient,at least the ones I build are.I recently built a ten HP which I featured on another part of the internet I dare not mention.

A few facts.A three phase motor running at 240 volts is about 2.5 amps per horsepower.The Hp rating of a rotary convertor will start a like sized motor and run up to 3 times it's rating.In other words a ten will start a 10 and run up to about 30.

As far as efficiency regarding the use of convertors,a little example.I have a 5 HP convertor that runs itself,a 1/2 HP Brigeport mill,a 3 HP lathe and a 3HP drill press.Running all this draws less amperage than my single phase huge drill press.


----------



## TedChristiansen (May 19, 2007)

To get an idea of what kind of electric motor would be required, check out the Logosol website:

http://www.logosol.com

They make and sell both electric chainsaws and electric bandsaws for use on their M7 and WoodWorkers Mills.

The electric option would be nice in urban environments - but it is expensive.

Regards,

Ted


----------



## woodshop (May 19, 2007)

aquan8tor said:


> You forgot that you could move into an industrial warehouse with 3 phase service.....big bakeries have 3phase powered equipment, machine shops sometimes do, and large scale buildings have 3 phase equipment for blowers & evaporative coolers...I've seen a couple things on the history channel on logging tech & the underwater log recovery out of the St. Lawrence that had giant electric motors on the mills, almost certainly 3 phase.
> A guy I built an aquarium filter for a few years back had a generator run of LP gas that had a supercharged 460cid V8 that produced something like 330amps of 220V, single phase power. He had a 5,000+ sq.ft reptile breeding facility that housed hundreds of rare exotics that had to be warm....



whoa... slow down... sheeeesh... move into an industrial warehouse??? I'm fully aware that many large scale industrial electric services involve 3 phase power. Some have massive 440V motors... some have their own massive power generators like your example of a supercharged V8 putting out 330 amps. Not questioning that. Again, the original query was concerning whether if was feasible to use electric motors on a csm in place of a chainsaw!!! Logosol apparently found a way to do it using 3 phase, although kindof expensive and not without its own set of problems. It sure doesn't look too portable. You'd have a heck of a time trying to mount that on a csm you can carry back into the woods. 

btw, I watched that underwater log recovery History channel show too, what a cool concept digging up and salvaging old growth timber. As a woodworker, my mouth waters at some of the figure those huge maples have. They say there is still tons of it buried at the bottom of the lake up there.


----------



## Al Smith (May 19, 2007)

That sunken timber can be found with an internet search of either Superior lumber or Timeless Timber,both companys owned by the same person.As a note of interest,they had one "fiddleback" maple log that fetched 40 thousand dollars.Instrument grade wood,exactly like Stradivarius used.


----------



## poleframer (May 19, 2007)

There have been many discussions here regarding different mills. CSM vs band, and many types of each. In reality each fills a niche. I think Dean might be on to something. Like a carriage type mill of simple design (like mine, or Marks) for low to medium use, affordable, and with enough power to compare to a 100cc+ chainsaw. AND quiet to boot.
My only doubts have already been stated. Seems anything less than 8hp would be marginal at best. So could you include a phase converter and still be economical? How big of a 220 motor could be run? 
Maybe something like a kit deal, sell the hard to get, or fab. parts, (the carriage/motor/bar setup) along with plans for the rest (the rail system).


----------



## woodshop (May 20, 2007)

poleframer said:


> There have been many discussions here regarding different mills. CSM vs band, and many types of each. In reality each fills a niche. I think Dean might be on to something. Like a carriage type mill of simple design (like mine, or Marks) for low to medium use, affordable, and with enough power to compare to a 100cc+ chainsaw. AND quiet to boot.
> My only doubts have already been stated. Seems anything less than 8hp would be marginal at best. So could you include a phase converter and still be economical? How big of a 220 motor could be run?
> Maybe something like a kit deal, sell the hard to get, or fab. parts, (the carriage/motor/bar setup) along with plans for the rest (the rail system).



Definitely, for a stationary mill, maybe in a backyard of an urban or suburban environment like mine, an electric motor driven mill would be ideal. Again, looks like Logosol did the math and came up with something that fits the bill. Catch is it is pretty expensive, double or triple cost of a gas engine, so it would have to be an environment where you could ONLY use electric I guess. For some of us (not me) who are handy with industrial electric motors and phase converters, I suppose you could build your own from spare/used parts. I'd be interested in the design if somebody can come up with one that started with standard 220V house service, maybe sucking 30-50 amps, and went from there into a converter or some such. Anybody here that can do that for us?


----------



## aggiewoodbutchr (May 20, 2007)

I've had something like this on my wish list for a couple of years...


----------



## klickitatsacket (May 20, 2007)

poleframer said:


> There have been many discussions here regarding different mills. CSM vs band, and many types of each. In reality each fills a niche. I think Dean might be on to something. Like a carriage type mill of simple design (like mine, or Marks) for low to medium use, affordable, and with enough power to compare to a 100cc+ chainsaw. AND quiet to boot.
> My only doubts have already been stated. Seems anything less than 8hp would be marginal at best. So could you include a phase converter and still be economical? How big of a 220 motor could be run?
> Maybe something like a kit deal, sell the hard to get, or fab. parts, (the carriage/motor/bar setup) along with plans for the rest (the rail system).



thanks for the input. This is what I was looking for. I talked with my dad last night about this whole thing. he has quite a bit of experience with it. He not only built a rotophase for around $40 but he also designed much of the equipment that I built for him. Any how he was telling me that with electric you can go 1/3 - 1/2 of gas HP rating if you use electric motors to fill the need. A 5hp electric 220 motor will pull a 48" with no problems. the RPM is not as high but that can be fixed by gearing up the sprocket.


----------



## aquan8tor (May 20, 2007)

aggiewoodbutchr said:


> I've had something like this on my wish list for a couple of years...



Does that say "DOLMAR"???? WOW!!!! pretty incredible. Woodshop; I was only joshin' about the warehouse, but I do like the idea of how quiet it would be. The electric mill would be great if I were in a better position to move and load logs onto a trailer efficiently and without impact, but as it is, nothing can beat the versatility of your setup, which I'm trying to replicate. 

As far as these DIY rotary converters are concerned, I've seen ads for plans, but how good are they, and what size motors do you need in relation to the HP converter you're trying to make; in other words, do you need like a 1HP motor to make a 3HP converter, or what?? I understand the concept I think, but I'm not sure of the torque/HP needed to get the third phase out of the rotation; how much resistance that creates. I have a couple of small motors in the shed that might be of some use....


----------



## aggiewoodbutchr (May 20, 2007)

aquan8tor said:


> Does that say "DOLMAR"???? WOW!!!! pretty incredible. ...



Yep. Dolmar. I've searched all over for more info on these but no luck. Here's another angle.


----------



## aquan8tor (May 20, 2007)

Not to derail the thread, but do you know anything about the operation in the pics? What's the tree being slabbed? looks kinda like a maple from the bark, but the wood is pretty dark.


----------



## aggiewoodbutchr (May 20, 2007)

http://www.talaricohardwoods.com/index.html

This is one lucky [email protected]$#@rd.....


----------



## Al Smith (May 20, 2007)

*Phase converter*

This is the picture of the control panal of the last converter I built,a 10 HP.If you do an internet search using the words "phase converter "or rotary phase coverter you will find many instructional sites on the subject with an explanation of how they work.

I suppose I've built 20 or 30 of them,I lost count but the largest I think was 30 HP.
I would imagine if you bought the componets used you could most likely do the job for between 100 and 200 bucks.The motor itself doesn't have to be the best,could even have a broken shaft for that matter.I have total of nothing in this one,just 3 hours of my labor.

I use a large electrolytic capacitor for starting cap.,a couple thousand microfarad and figure about 7.5 microfarad per HP for the running caps which are oil filled type,pictured in the lower right in the control panal.I installed 4 but only used 3 for this one.By parrelling the running caps you can pretty much balance the 3rd or generated leg of the three phase.I think the one pictured was around 245 volts with the other two at 240.Too little capacatance will cause low voltage and too high will cause higher.Keep it below 300 volts on a 240 volt system.


----------



## woodshop (May 21, 2007)

Al Smith that looks like something I would try and build, and then when I threw the switch the street lights out front would dim and smoke would start pouring out of my little 100 amp service box in my cellar  If I do this, I want YOU here helping me. Believe it or not, I actually did do a google search, and sure enough there are plenty of places that have plans for phase converters. Simple enough that I think I could actually do this. Not sure I want to take the time to dig up the parts and then try it though. Point being if somebody was ambitious and had the time, this is feasible. Throw in a used 3 phase motor and maybe your "quietly" sawing wood?

As for that huge yellow Dolmar saw... now I'm curious too. So happens that mill is only about an hour west of me. I might just take a drive out there and ask them about it. If I do, I'll take pics (assuming they let me) and will post a thread. Won't be for at least 6 weeks though. Got wood down that needs milling, and I only have weekends to do that.


----------



## Al Smith (May 21, 2007)

100 amps would be just dandy,no problem at all.Even a 10 HP converter only draws about 13 amps,because it is not loaded.Couple that to another 10 and it would only be 38 amps,fully loaded.However I would recommend perhaps a 5 HP if you are on a fused main.You can do a lot with 5 HP 3 phase.


----------



## curdy (May 22, 2007)

Don't forget about Hearne Hardwoods Inc. in Oxford, PA. They also have a big mill. 67" bandsaw. About 1 hr from here.

http://www.specialtyhardwoods.com/exotic_wood/facilities_hardwoods.html


----------



## olyman (May 22, 2007)

ok----ive read the whole thread---ellis manufacturing--they make bandsaws--drill presses--and the like---i have one of their drill presses---guess what---its 220v single phase in----but the motor is dc---yup--dont know what they did--but tell you what---even at low rpms----itll break your fingers---maybe you can figure it out, al---i sure like it---- their out of wisconsin somewhere--not by the drill press right now--


----------



## Mr. Obvious (May 27, 2007)

An electric motor that puts out 5 hp will do the same amount of work as a gas engine that puts out 5 hp.


----------



## carvinmark (May 28, 2007)

Mr. Obvious said:


> An electric motor that puts out 5 hp will do the same amount of work as a gas engine that puts out 5 hp.



I find this to be untrue.


----------



## poleframer (May 28, 2007)

*gas vs electric*

I think it'd because a gas engine's hp is rated for its max output, in new condition. An electric motor will put out its rated hp continuously, and has the ability to surge to a higher output when loaded - until the blue smoke comes out.
I like the arch on the dolmar mill. Looks like the whole mill raises and lowers for each cut. I wonder if the posts are set in concrete. They would have to be pretty stable to keep a good cut.


----------



## Esbjug (May 28, 2007)

Mr. Obvious said:


> An electric motor that puts out 5 hp will do the same amount of work as a gas engine that puts out 5 hp.



I have the Logosol M7 with the E5000 powerhead. Rated power is 5 kW (6.8 hp). When comparing to a Stihl 660 on the same mill (about the same hp rating), with the same bar/chain, the electric drive gives almost twice the working speed.


----------



## Al Smith (May 28, 2007)

Electric to gasoline is a factor of 2 or 3 to 1 .In other words 1 hp electric equals at least two or possibly 3 of gasoline .I didn't write the laws of physics ,that's just the way it is,"google" it.


----------



## BobL (May 28, 2007)

Esbjug said:


> I have the Logosol M7 with the E5000 powerhead. Rated power is 5 kW (6.8 hp). When comparing to a Stihl 660 on the same mill (about the same hp rating), with the same bar/chain, the electric drive gives almost twice the working speed.



Poleframer is correct, Electric motor (current/HP) ratings are also neither constant nor accurate. For example, my table saw is rated at 3HP (2.25 kW, or 9.4A @ 240V) however, by really pushing it I can get it to draw up to 17A (4 kW) for about a minute before it trips its thermal cut out switch. The most I can get it to draw without tripping for an extended period is about 12A (2.88kW).

What's actually stamped on the side of an electric motor could be any of the above. Most motor manufacturers are conservative and the lower values are what's used.


----------



## Mr. Obvious (May 29, 2007)

If you read my post it says "puts out". I did not mention rated, max or some other words. 

If 2 different engines each put out 10 hp how much horsepower does each one put out?


----------



## aquan8tor (May 29, 2007)

So, which 10HP engine would you rather have on a mill? 

A 10HP gas engine, or a 10HP diesel engine?? Obviously the diesel engine. Torque comparisons are night and day. I don't know the actual specs, but I'm guessing the comparisons are similar....

Ever wonder why mill manufacturers that put electric motor options on their mills use motors with about 1/2 the rated power that the top gas offering produces?


----------



## Mr. Obvious (May 29, 2007)

> rated power



My job is going to be a little tougher than even I anticipated.


----------



## poleframer (Jun 1, 2007)

Gas, diesel, electric... whats best? Like I've said many a time- context is what matters. I use all of em. Diesels are torquey, gas revs better, electric has it's advantages- relatively cheap to run if yer close to a j-box -I'm off-grid and conservative in that regard (my own hydro-electric, love free power!)-but not nearly enough to play with big electric motors.
If I did'nt live so far out in the woods the 090 running for hours on end might cause adverse neighborly relations.


----------



## poleframer (Jun 1, 2007)

But I also would add that if you do yer engineering on the situation you'll want to keep the electric motors in spec. Otherwise you will be seeing the blue smoke, and replacing fried motors frequently.
Just remember- every electric device has blue smoke inside. YOU MUST KEEP THE BLUE SMOKE INSIDE OF IT! Thats why we have electrical engineers, and specs for such.


----------

