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Shroomslip
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Increasing the power of an electric motor?
#23649510 - 09/16/16 04:01 AM (7 years, 4 months ago) |
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I understand the basics of what determines the amount of power an electric motor has, but it's a pretty rudimentary understanding so this is probably a stupid question with an obvious answer..
Is there a way you can take say, a 1/5 HP motor and tweak it up to 1/3 or 1/2? What determines how many amps a motor can or does use? Is there a way to increase that amount? Not talking about a motor on a speed control or anything. Something connected directly to it's power source and free to draw whatever power it can and will.
I'm going to guess this is probably one of those things a lot of people say aren't worth the time or effort but I have a good motor I want to use but it's pretty well underpowered for my needs. The simple answer is find or buy a bigger motor but that's proving troublesome (don't really want to spend as much as I need to on one, the only ones in my price range look like they're 10 minutes from failure) so if there's a way I can make what I have work, then it's worth the effort to me.
Unfortunately I can't just address this with pulleys and sacrifice a lot of RPM for torque. I need most of the RPM it has.
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With my face against the floor I can’t see who knocked me out of the way. I don’t want to get back up but I have to so it might as well be today. Nothing appeals to me no one feels like me, I’m too busy being calm to disappear. I’m in no shape to be alone contrary to the shit that you might hear. You can't wake up, this is not a dream. You're part of a machine, you are not a human being With your face all made up, living on a screen. Low on self esteem, so you run on gasoline
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40oz



Registered: 01/18/01
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Loc: Sandy Eggo. Ca.
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Re: Increasing the power of an electric motor? [Re: Shroomslip]
#23651254 - 09/16/16 06:56 PM (7 years, 4 months ago) |
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the coils/windings on a motor are limited to take a certain amount of load. if you put a load stronger than it can handle it will burn up.
Quote:
the only ones in my price range look like they're 10 minutes from failure)
don't let the exterior of an induction motor fool you, they last a very long time, and if they don't they are easy to fix by either cleaning the centrifugal switch contacts or replacing the power cord, power switch, bearings, the start and/or run capacitor. all of these can be done very inexpensively (ebay). there are plenty of restoration/repair tutorials on youtube.
the least expensive route to getting a tefc 1 to 1-1/2 HP induction motor is to buy a used craftsman table saw on CL. they have shit-resale value and the owner just wants it gone.
what kind of machine are you building?
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Shroomslip
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Re: Increasing the power of an electric motor? [Re: 40oz]
#23651298 - 09/16/16 07:12 PM (7 years, 4 months ago) |
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Gonna build a lathe but don't want one under powered and don't want a "small" one. Not going for anything gigantic but I'm looking to do more than just pens and stuff. Ideally something that could at least handle 10-12 inch stock with a diameter of no less than 2-3 inches. I don't mind taking my time to get it done but I'm pretty sure the motor I have just isn't gonna cut it, even with me taking my time.
So the only way to increase it's power would be to add to it's wingdings then? I know you can rewind them... There's no way you can just add to that is there?
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With my face against the floor I can’t see who knocked me out of the way. I don’t want to get back up but I have to so it might as well be today. Nothing appeals to me no one feels like me, I’m too busy being calm to disappear. I’m in no shape to be alone contrary to the shit that you might hear. You can't wake up, this is not a dream. You're part of a machine, you are not a human being With your face all made up, living on a screen. Low on self esteem, so you run on gasoline
Edited by Shroomslip (09/16/16 07:13 PM)
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40oz



Registered: 01/18/01
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Loc: Sandy Eggo. Ca.
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Re: Increasing the power of an electric motor? [Re: Shroomslip]
#23651395 - 09/16/16 07:51 PM (7 years, 4 months ago) |
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not unless you want an electrical fire as there is a definitive science to it all.
i think you're probably better off scrapping the idea of using the motor you have for other options. Ryan Nodwell built a lathe by upcycling a small drill press here and Mathias Wandell built a lathe with what looks like a clothes dryer motor here
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Shroomslip
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Re: Increasing the power of an electric motor? [Re: 40oz]
#23651448 - 09/16/16 08:12 PM (7 years, 4 months ago) |
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Yeah I was originally looking for a washing machine motor (I figure if it can handle all that water and wet laundry it could handle some decent sized wood) but no one has one they're tossing right now. I might get my hands on one in the near future, a friend's started acting up a while back and it's some issue with the controller board so the motor is still good. I'm just hoping it dies .
I think to get enough torque out of the motor I have now to work I'd have to lose way too many RPMs for it to be viable for a lathe. I hadn't sat down to do the math I'm just taking a stab in the dark and using common sense to guess that.
I figured I'd just ask to make sure of my options, I tried looking it up myself but wasn't getting anywhere with it. All the technical talk just kinda goes in one ear and out the other. I only understand the basics when it comes to motors. Until recently I didn't even know the difference between single phase and 3 phase. I thought it had something to do with the power cord. 
Amps and current I really only understand because of ecigs. Until that I had never bothered to really research it and understand it.
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With my face against the floor I can’t see who knocked me out of the way. I don’t want to get back up but I have to so it might as well be today. Nothing appeals to me no one feels like me, I’m too busy being calm to disappear. I’m in no shape to be alone contrary to the shit that you might hear. You can't wake up, this is not a dream. You're part of a machine, you are not a human being With your face all made up, living on a screen. Low on self esteem, so you run on gasoline
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Mojo
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Re: Increasing the power of an electric motor? [Re: Shroomslip]
#23651684 - 09/16/16 10:07 PM (7 years, 4 months ago) |
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Motor windings may or may not be able to be modified. Some windings are dipped in an epoxy resin to extend motor life making them nearly impossible to modify.
I will mirror what 40oz said, don't judge a motor by its cover.. The motor powering my metal lathe is date stamped 1955 and is completely covered in oil dirt and grime, but it is 100% dependable, despite daily operation in an industrial setting for over 50 yrs... Yea..
I am assuming that you are building a wood lathe. A 1/2 HP motor would probably be more than enough for such a small diameter work-piece. I would hit craigslist to see what you can dig up, check out the free section, a lot of times people are giving away furnace blower fans. The motor from a Jacuzzi pump may work as well, which are also fairly common on the free section. You could also use a treadmill motor and have variable speed on the fly available, these are typically high voltage DC motors and will need the treadmill control panel and power supply to operate.
As I am sure you have now researched, non-brushed electric motors are powered by an alternating magnetic flux generated by the field winding, the stronger the magnetic flux, the stronger the motor is, and the more power it consumes. The magnetic flux cycles on and off at a frequency expressed in Hz. A 2-Phase motor has two alternating magnetic fluxes, while a 3-phase motor has three. 3-phase motors are industrial grade and made to be run hard, non-stop, for years and years, but you cant run them without 3-phase power, which you don't have coming out of your outlet. For your purposes, stay away from 3-phase, it wont work..
When you are looking for a motor just make sure it can be operated on 110 or 120v. You don't need to worry about the amperage all that much if you are staying around 1/2 HP.
It's a long shot, but if you happen to live in Colo, I can give you an old 1/2hp motor for free. I am slowly converting all of my equipment to 3-phase. If you find a motor and need help interpreting the name-plate just shoot me a PM.
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Shroomslip
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Re: Increasing the power of an electric motor? [Re: Mojo]
#23651717 - 09/16/16 10:27 PM (7 years, 4 months ago) |
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Nah I'm in Texas and yeah I already know I need 110/120v single phase. Never heard of 2 phase before (google says it's the same thing as single phase?). I know how to read the labels on the motors and how to figure out HP (when it's not listed). Hadn't really looked up what the Hz actually meant so good to know I guess.
And yeah, wood lathe. I haven't started drawing up the plans yet so I'm not sure how big I'll end up making it but I'm probably gonna be aiming around 12 inches or so (work area not total length). I won't be building anything fancy and I'm not sure how I'll deal with RPM yet. I did some initial reading up on it and what I read is that using just voltage to reduce RPMs isn't how you want to go about it because at lower voltages and speeds you'll lose torque which is when you want the torque the most. If true I'll probably end up doing some kind of slidable/adjustable motor mount and have different sized pulleys to achieve it. I don't want to try and over complicate things.
In the mean time I think I may turn this other motor into a table top band saw so I can stop trying to jigsaw everything. I plan to build a full size one capable of resawing up to 8-12 inch thick boards sometime in the near future. I'm gonna need a really good motor for that though.
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With my face against the floor I can’t see who knocked me out of the way. I don’t want to get back up but I have to so it might as well be today. Nothing appeals to me no one feels like me, I’m too busy being calm to disappear. I’m in no shape to be alone contrary to the shit that you might hear. You can't wake up, this is not a dream. You're part of a machine, you are not a human being With your face all made up, living on a screen. Low on self esteem, so you run on gasoline
Edited by Shroomslip (09/16/16 10:31 PM)
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Mojo
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Re: Increasing the power of an electric motor? [Re: Shroomslip]
#23651871 - 09/16/16 11:59 PM (7 years, 4 months ago) |
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Oh yea, I meant to say a single phase motor has two alternating magnetic fluxes.
Sounds like a fun project. I have had similar hurdles when I converted a large drill-press to variable speed... I think step pulleys will be the easiest and cheapest way to achieve variable speed, unless you fall into something like a treadmill DC motor which is capable of constant torque throughout a broad RPM range.
3-phase motors are also capable of maintaining constant torque at variable speeds, but need special controllers called variable frequency drives, which is what I have. They vary the frequency (Hz) at a constant voltage to control the speed of the motor.
Anyway good luck... Have you ever heard of a YouTube channel by Matthias Wandel? If not, you should check him out.
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Shroomslip
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Re: Increasing the power of an electric motor? [Re: Mojo]
#23651886 - 09/17/16 12:11 AM (7 years, 4 months ago) |
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Yeah, I'm gonna be using his design for the bandsaw more or less. The actual frame may very a bit but I'm following his lead for the guide bearings and arm adjustment and the rest pretty much exactly. He was the first person I came across when I was looking into how difficult it would be to build a bandsaw myself (instead of paying like 800+). I kinda prefer the idea of making my own tools when I can. Not just for the cost factor but I don't have to sacrifice one feature here to get 3 there. I can just custom tailor it to my own exact needs from the ground up.
Obviously there are certain tools I can't really build myself. There's no way I'd ever try to build a thickness planer . I don't really do metal working so that would be pretty far out of my grasp. Maybe a drum sander. Hey, I need one of those too!
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With my face against the floor I can’t see who knocked me out of the way. I don’t want to get back up but I have to so it might as well be today. Nothing appeals to me no one feels like me, I’m too busy being calm to disappear. I’m in no shape to be alone contrary to the shit that you might hear. You can't wake up, this is not a dream. You're part of a machine, you are not a human being With your face all made up, living on a screen. Low on self esteem, so you run on gasoline
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40oz



Registered: 01/18/01
Posts: 30,119
Loc: Sandy Eggo. Ca.
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Re: Increasing the power of an electric motor? [Re: Shroomslip]
#23653353 - 09/17/16 03:02 PM (7 years, 4 months ago) |
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good luck on your builds! if it were me i would probably stick to buying Mathias's plans. long dedicated builds are hard to keep your attention. i'm sure it's even longer and harder when you have to solve the guesswork yourself with a high probability of you eventually losing interest and abandoning the project all together.
i am a woodworker, my passion is with woodworking. and then, i developed a romance with restoring vintage woodworking machines. now i have a huge collection of old rusty machines (i picked up off CL) that need my attention, taking up all of my time, keeping me from woodworking.
you really question your lifes' worth when you spend 30 minutes getting the rust and funk off a 25 cent washer/bolt/etc
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Shroomslip
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Re: Increasing the power of an electric motor? [Re: 40oz]
#23653971 - 09/17/16 07:10 PM (7 years, 4 months ago) |
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Eh, designing it is half the fun. I use 3D modeling before doing anything though. There's always some minor thing that needs to be tweaked or doesn't work as I intended but for the most part I can work out all the bugs and make sure it's going to work as intended before I ever even make my first cut into a piece of wood. The more I draw up my models the better I get at them. I just recently taught myself to work rendering software so I can get a better idea of how appearance pieces will look after staining/finishing.
Besides, at any given point I have several projects I'm working on, so if I get bored with one I don't really have down time or anything. I just go work on something else for awhile. At this moment I'm about to be finishing some dog stairs so I can stack our dog's crates up and save some space, I have some tweaking to do to the frame of my home made drill press (one of those little bugs that 3D modeling couldn't show me before hand, the rails it slides on are not sturdy enough and they slightly bow under pressure throwing off the angle of my bit by a degree or two) I have a half finished oak slab bench I've been working on that I made from logs I cut up myself on my chainsaw mill (another of my home made things). Once I'm done with the stairs I'll be starting on this:

It's just a very simple computer desk for my wife to replace her crappy Wal-mart one that is too small and wobbly. (This was also the model I taught myself the rendering software on)
Plus it feels so much better and more of an accomplishment to design something myself and build it than to just copy someone else's plans. To me that makes all the difference. Just cutting pieces and forming them isn't really all that hard. Drawing up your own idea from a blank slate is more of a challenge.
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With my face against the floor I can’t see who knocked me out of the way. I don’t want to get back up but I have to so it might as well be today. Nothing appeals to me no one feels like me, I’m too busy being calm to disappear. I’m in no shape to be alone contrary to the shit that you might hear. You can't wake up, this is not a dream. You're part of a machine, you are not a human being With your face all made up, living on a screen. Low on self esteem, so you run on gasoline
Edited by Shroomslip (09/17/16 07:15 PM)
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idiotek


Registered: 02/06/04
Posts: 40,728
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Re: Increasing the power of an electric motor? [Re: 40oz]
#23657935 - 09/19/16 06:35 AM (7 years, 4 months ago) |
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There are some crazy videos of people on Youtube making 3 phase power to run those old machines using a belt driven motor attached to a 120v motor. Gives you really inefficient but adequate 3 phase to run old equipment. Might be cheaper than trying to build your own shit and I know the three phase stuff goes for a good deal less than the household rated stuff.
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Shroomslip
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Re: Increasing the power of an electric motor? [Re: Shroomslip]
#23659909 - 09/19/16 08:02 PM (7 years, 4 months ago) |
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Finally went and yanked the motor out of the old furnace we have up there (didn't know that's what it was til a few days ago).


Kinda disappointed. Was hoping for at least 1/4 or 1/3 HP. Turns out it's only 1/6. Have no idea why that furnace was trashed and a new one installed. Hoping that it was something other than the motor. Haven't started messing with it yet (obviously) so no idea if it even works. I guess it's not all bad. If it at least works maybe I can sell it and "trade up" to the motor I want/need for my project. Could also just keep it and find a use for it elsewhere.
We have a second furnace up there and the motor still works. We never use the furnace. Might see about opening it up and seeing what it's power is. If it's worth it I might just unhook that furnace as well and take it.
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With my face against the floor I can’t see who knocked me out of the way. I don’t want to get back up but I have to so it might as well be today. Nothing appeals to me no one feels like me, I’m too busy being calm to disappear. I’m in no shape to be alone contrary to the shit that you might hear. You can't wake up, this is not a dream. You're part of a machine, you are not a human being With your face all made up, living on a screen. Low on self esteem, so you run on gasoline
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40oz



Registered: 01/18/01
Posts: 30,119
Loc: Sandy Eggo. Ca.
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Re: Increasing the power of an electric motor? [Re: Shroomslip]
#23661635 - 09/20/16 12:40 PM (7 years, 4 months ago) |
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Quote:
Shroomslip said: Eh, designing it is half the fun. I use 3D modeling before doing anything though. There's always some minor thing that needs to be tweaked or doesn't work as I intended but for the most part I can work out all the bugs and make sure it's going to work as intended before I ever even make my first cut into a piece of wood. The more I draw up my models the better I get at them. I just recently taught myself to work rendering software so I can get a better idea of how appearance pieces will look after staining/finishing.
Besides, at any given point I have several projects I'm working on, so if I get bored with one I don't really have down time or anything. I just go work on something else for awhile. At this moment I'm about to be finishing some dog stairs so I can stack our dog's crates up and save some space, I have some tweaking to do to the frame of my home made drill press (one of those little bugs that 3D modeling couldn't show me before hand, the rails it slides on are not sturdy enough and they slightly bow under pressure throwing off the angle of my bit by a degree or two) I have a half finished oak slab bench I've been working on that I made from logs I cut up myself on my chainsaw mill (another of my home made things). Once I'm done with the stairs I'll be starting on this:

It's just a very simple computer desk for my wife to replace her crappy Wal-mart one that is too small and wobbly. (This was also the model I taught myself the rendering software on)
Plus it feels so much better and more of an accomplishment to design something myself and build it than to just copy someone else's plans. To me that makes all the difference. Just cutting pieces and forming them isn't really all that hard. Drawing up your own idea from a blank slate is more of a challenge.
if machine making is your forte' then so be it. i'm not so much into machine building but i am fascinated by the process so i watch a lot of videos on youtube. Mathias Wandell, Izzy Swan, & Ryan Nodwell are great channels. Matt Cremona is currently building a massive band saw mill that i'm keeping up with. check those out if you want!
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40oz



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Loc: Sandy Eggo. Ca.
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Re: Increasing the power of an electric motor? [Re: idiotek]
#23661687 - 09/20/16 01:02 PM (7 years, 4 months ago) |
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Quote:
idiotek said: There are some crazy videos of people on Youtube making 3 phase power to run those old machines using a belt driven motor attached to a 120v motor. Gives you really inefficient but adequate 3 phase to run old equipment. Might be cheaper than trying to build your own shit and I know the three phase stuff goes for a good deal less than the household rated stuff.
yeah if you have a heap of motors laying around it's pretty much free to build a static converter, and yeah you can get 3 phase equipment for cheap cuz mostly no one has 3 phase power, but like mojo said all you need is a vfd, that can be had fairly cheap on ebay.
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Mojo
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Re: Increasing the power of an electric motor? [Re: 40oz] 1
#23663460 - 09/20/16 10:24 PM (7 years, 4 months ago) |
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There are a ton of advantages to 3-phase, the primary one being how inexpensive 3-phase motors are on the used market. This is because industry would largely rather buy a new motor from a contractor that comes with a warranty.. Industry consumes a lot of 3-phase motors for a multitude of equipment, and when it eventually gets scrapped there are no buyers for these 3-phase motors which has caused them to sell for just above scrap value.. The least I have paid for a 3-phase motor is nothing, but anymore I find it worth my time to hop on ebay and spend $30-50 for a motor that meets my parameters for mounting, shaft-size, power, rpm ect... Out of pure convenience.
Additionally, consumer grade 3-phase equipment doesn't exist, so a 3-PH marking on a motor is basically a stamp that says this motor will outlive whatever tool you are going to put it on.. This is doubly true for hobbyists who don't intend to run the motor all day every day.
With that said, I don't recommend you do it and this is why:
You can use an old 3-phase motor as a rotary-phase converter for your shop, but you need to read up on it and be very comfortable with electrical work, this shit can kill you. Additionally, using a 3-phase motor alone can fall victim to fluctuations in power as the load increases. So lets take a lathe for example, the last thing you want when making a deep cut is for the rpm of the work-piece to fluctuate, this could cause a bad finish or a host of other problems. This is why proper phase converters utilize a capacitor bank to act as a reservoir for load fluctuations. So as you can see this seemingly simple and inexpensive project just got less simple and more expensive. For your purposes, with an appropriately oversize motor acting as the rotary-phase converter, you probably wouldn't run into this problem, but it is hard to say for sure considering all of the variables in equipment you could end up with when scrounging up free crap on CL
The above method is probably the least expensive, and some people manage to build them for basically nothing... Therefor I assume it would be the only method you would be interested in.. In my opinion, to build one "right" is no longer cheap, and its way more hassle than it's worth considering you end up with a constrained system, the hazards of building it, and the fact that you can simply find a single phase motor for cheap or free that will suit your needs.
The other affordable ways to get three phase power into your shop would be a static phase converter ($$$) or a phase-converter/variable frequency drive ($$$). The latter is the less reliable but more bad-ass option because its basically like hooking a computer up to your motor making it possible to vary the speed, change rotational direction on the fly, vary the spin-up and spin-down time of the motor, and more... Expect to invest $150 minimum for a mediocre unit.
A lot of people hear about VFDs and immediately want them, but they are plenty of a pain in the ass on their own.. First of all, don't be fooled in the idea that varying the speed of a motor can immediately replace a step-pulley drive system. Your motor may have constant torque down to low RPM, but step-pulleys MULTIPLY torque down to low RPM, which may or may not be significant to an application.
Another VFD mistake that a lot of people make is the idea that you can buy 1 VFD and power all of your various 3-phase equipment with it.. While this can be true (sorta) its a bad idea at worst, and a total pain in the ass at best. Because your VFD is going to be programmed to specific motor parameters, so unless you have the exact same motors in all of your equipment, and the load on all of the equipment can be characterized with similar programming, you would have to reprogram the VFD before switching it between each machine... Otherwise your going to run into a host of issues.
Sorry for the long post, I just wanted you to know some of the downsides in case you were getting the 3-phase itch.. Ultimately it makes the most sense for people that have multiple pieces of industrial 3ph equipment, who would incur a significant expense in retrofitting to single-phase.. Given that 3-phase is superior, people in this position tend to keep 3-phase equipment original, and go the phase-converter rout.
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Kenetic
Nam Sayin



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Re: Increasing the power of an electric motor? [Re: 40oz]
#23677503 - 09/25/16 05:54 PM (7 years, 4 months ago) |
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Quote:
40oz said: the coils/windings on a motor are limited to take a certain amount of load. if you put a load stronger than it can handle it will burn up.

Source: I'm an electrician
-------------------- Todo Cambia    DMT said: Everyone know's me, they just don't know it yet
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Kenetic
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Re: Increasing the power of an electric motor? [Re: Kenetic]
#23677518 - 09/25/16 05:59 PM (7 years, 4 months ago) |
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And by the way you cannot run a three-phase motor directly on a single phase (which is what you get in houses). This will also burn it up.
I do commercial work so 3-phase power is always available, however I don't know what you'd have to do to get three phase power in your home. It sounds like you need to just buy a stronger single-phase motor.
-------------------- Todo Cambia    DMT said: Everyone know's me, they just don't know it yet
Edited by Kenetic (09/25/16 06:02 PM)
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