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    Default Help w/ new lathe motor - home shop

    I have a 12" Logan lathe that came with a 3ph, 1hp, 66 frame motor. It burned up, and I am attempting to replace it. Baldor makes a pre-1952 NEMA 66 frame motor, $600-700. Before I commit, I have a couple questions.

    The old motor was wired through a phase converter, which I never liked. I am thinking of using a 3ph with VFD instead. Any reason not to? If I replaced it with a single phase motor, I could continue to use the Logan system to change rpm...I think. Realize most probably aren't familiar - it's a mechanical system of changing rpm infinitely from low to high (think it goes from around 600 to 2500rpm) by tensioning a system of belts with the crank on the front...VFD would be electronic. Lathe has back gears for slower speeds. Does the motor produce 1hp at any VFD-selected rpm? Will it bog down at lower rpm settings on VFD, and should I consider higher HP?

    I assume all VFDs are not equal, and am leery of buying a bad one. Suggestions on where to go or brand, assuming it's even a good idea?

    The 66 frame is the only motor with a .75" shaft...don't laugh, but does shaft size matter? Old motor was foot mounted to a height-adjustable plate which I can easily adjust for a different motor mount. If I used a 56c with 5/8" shaft, any consideration as far as turning metal on a medium size machine? I would have to make a sleeve for it to fit the original pulley...or a new pulley, etc.

    End of day, just want to know if any particular setup is better or to be avoided. Machine is great, want to do it justice. Thanks very much,

    Coty

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    Quote Originally Posted by wild_musk View Post
    I have a 12" Logan lathe that came with a 3ph, 1hp, 66 frame motor. It burned up, and I am attempting to replace it. Baldor makes a pre-1952 NEMA 66 frame motor, $600-700. Before I commit, I have a couple questions.

    The old motor was wired through a phase converter, which I never liked. I am thinking of using a 3ph with VFD instead. Any reason not to? If I replaced it with a single phase motor, I could continue to use the Logan system to change rpm...I think. Realize most probably aren't familiar - it's a mechanical system of changing rpm infinitely from low to high (think it goes from around 600 to 2500rpm) by tensioning a system of belts with the crank on the front...VFD would be electronic. Lathe has back gears for slower speeds. Does the motor produce 1hp at any VFD-selected rpm? Will it bog down at lower rpm settings on VFD, and should I consider higher HP?

    I assume all VFDs are not equal, and am leery of buying a bad one. Suggestions on where to go or brand, assuming it's even a good idea?

    The 66 frame is the only motor with a .75" shaft...don't laugh, but does shaft size matter? Old motor was foot mounted to a height-adjustable plate which I can easily adjust for a different motor mount. If I used a 56c with 5/8" shaft, any consideration as far as turning metal on a medium size machine? I would have to make a sleeve for it to fit the original pulley...or a new pulley, etc.

    End of day, just want to know if any particular setup is better or to be avoided. Machine is great, want to do it justice. Thanks very much,

    Coty
    "In great condition", perhaps.

    "Great", not so much. It's a light-weight vocational/hobby/garage or maintenance department repair shop lathe.

    "Justice"... is an industrial-sized box of rubber-bands.

    A single-phase motor from Grainger/Zoro .. or even Harbour Freight .. will run it well-enough if you don't feel like winding-up the gumbands with a hand-crank.

    Shaft adaptor split-bushings are cheap and common - often ship with new motors, no extra charge.

    Shaft size usually relates to torque more closely than to HP. Note that same HP @ lower RPM may have a larger diameter shaft. See 2, 4, 6, and 8 pole AC motors or a 5 HP DC motor with the same shaft size as a 10 HP AC motor.

    Most anything 3-Phase in a single-phase environment is going to add more money-out than grins-in, plus waste 150% of the time available implementing it.

    The modest Logan already has plenty of ratios. They are all it can effectively use.
    Last edited by thermite; 06-21-2019 at 07:56 PM.

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    FYI- metric(IEC) frame 80 motors are 19mm shaft(.748") and if you want 3ph are typically inverter rated for use with VFDs....can be had comparably cheap too.

    Not to mention the snazzy removable/position changeable feet and junction box.

    RANDOM example(unfamiliar with brand)

    https://dealerselectric.com/20MFM-3-1-18P.asp

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    There is a somewhat predictable relationship between the motor's speed, the torque, and the HP. Here is a short paper that describes this:

    http://pumped101.com/hp%20torque%20vfd.pdf

    What I get out of this is that the sweet point for a motor is at it's rated speed, from the nameplate or manufacturer's specs. Big surprise there, as if the manufacturers did not know what they were doing.

    So, as you move away from that 60 Hz operating point (50 Hz in some countries or regions), you are going to sacrifice either torque or HP. At slower speeds the torque remains at 100% but the HP is reduced. At faster speeds the HP remains at 100% but the torque drops. You can't have it all.

    To my mind, a system that would be close to ideal would combine both the VFD and mechanical speed control (gears or belts). The gears or belts would allow a range to be selected and the VFD would allow you to select any speed within that range. The more mechanical range selections you have in the gears or belts, the closer you can stay to that sweet, 60 Hz operating point and the better you can preserve the full torque and HP of the machine.

    If I were to convert any of my machines to VFD, I would keep the gear or belt drive systems and calculate a chart that would allow me to select the mechanical range that I need to use for any desired RPM. I don't know if they exist, but I would look for a VFD that would display the actual RPM for any mechanical range that I have set the gears or belts for. Actually I would want that automated with switches or sensors on the gear or pulley train that input that data to the VFD so I did not have to worry about setting it manually. Just set the belts or gears and then crank the VFD to the RPM desired. This would be my "near ideal" system.

    This would be difficult to implement with those mechanical systems that employ an infinitely adjustable speed - variable diameter pulleys or wheels/belts that ride on conical surfaces. In those systems you might pick a number of standard mechanical RPM settings and make your VFD work with those individual settings. Or you could work with displays of the motor and spindle RPM, keeping the motor RPM as close to the nameplate value as possible. Digital RPM meters are inexpensive.

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    Quote Originally Posted by wild_musk View Post
    I have a 12" Logan lathe that came with a 3ph, 1hp, 66 frame motor. It burned up, and I am attempting to replace it. Baldor makes a pre-1952 NEMA 66 frame motor, $600-700. Before I commit, I have a couple questions.

    The old motor was wired through a phase converter, which I never liked. I am thinking of using a 3ph with VFD instead. Any reason not to? If I replaced it with a single phase motor, I could continue to use the Logan system to change rpm...I think. Realize most probably aren't familiar - it's a mechanical system of changing rpm infinitely from low to high (think it goes from around 600 to 2500rpm) by tensioning a system of belts with the crank on the front...VFD would be electronic. Lathe has back gears for slower speeds. Does the motor produce 1hp at any VFD-selected rpm? Will it bog down at lower rpm settings on VFD, and should I consider higher HP?

    I assume all VFDs are not equal, and am leery of buying a bad one. Suggestions on where to go or brand, assuming it's even a good idea?

    The 66 frame is the only motor with a .75" shaft...don't laugh, but does shaft size matter? Old motor was foot mounted to a height-adjustable plate which I can easily adjust for a different motor mount. If I used a 56c with 5/8" shaft, any consideration as far as turning metal on a medium size machine? I would have to make a sleeve for it to fit the original pulley...or a new pulley, etc.

    End of day, just want to know if any particular setup is better or to be avoided. Machine is great, want to do it justice. Thanks very much,

    Coty

    Nothing wrong with a Logan, especially the 12" size. Will serve you well. Logan is not "hobby" it is "nearly industrial".... not built as heavily, but has all the goodies normally found, and works well. Could be used industrially perfectly well within its limits, same as any machine. No. it ain't a "Monarch", and does not pretend to be.

    A VFD will be fine, you will get HP proportional to speed below 60Hz, so, no, it is not very good as your only speed control. It is best viewed as a 3 phase converter, with the ability to change speeds a bit. You really do not need speed changes by VFD when you have the Logan drive, but it would be there,.

    Keep the Logan drive. Use the VFD for smaller adjustments.

    A single phase motor would not be fun.... single phase really drives "chatter" and 3 phase is far nicer. RPCs are fine, fairly bullet-proof, but VFDs are good also, I will leave others to suggest VFD brands, I use an RPC, although I am very familiar with VFDs (have designed several).

    You can get more HP at lower speeds only by more current input (torque). That gets you into oversized motors and all sorts of trouble. But there is no need for large VFD speed adjustments when you have back gears and a variable speed mechanical setup that is for all intents and purposes constant HP.

    Shaft size to fit your input pulley... if you cannot find the size on a motor, modify the motor shaft or the pulley to suit. Shaft size goes with frame size, and frame size tends to go with HP (and design type). I'd choose to make the pulley fir the common shaft size for the frame size you can get, that way you can change motors if you want to without a fuss.

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    "Sacrifice HP..."

    What is "HP" though? HP is just a shorthand way of expressing the formula for torque at a given speed. If you reduce the speed and keep the torque the same, yes, it technically means the HP is lower, but does that really matter? The work done at the shaft of a machine is done by the torque. The HP is consequential.

    Where most people get into trouble in changing from a mechanical speed change system to a VFD is in the concept of "mechanical advantage", wherein you lower the speed mechanically and at the same time, you are INCREASING the torque at the work shaft. Sometimes that it also consequential, but sometimes it is necessary and in those cases, if you change to a VFD, you can end up with not having enough torque at the lower speed.

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    I should have said a bit more on that HP / torque matter. HP is necessary, but it is not the factor that directly determines how heavy of a cut you can make. A heavier cut requires more force and torque is force X distance (radius). The fact that, with the same mechanical gear or belt ratio, the torque remains constant for all slower speeds selected with the VFD, prevents you from getting more torque for a heavier cut.

    If you want more torque, for a heavier cut, you can only get that by changing the mechanical gear or belt ratio.

    The available HP determines how much torque you CAN get. But it is not what you consider when you need to make a heavier cut; torque is. And no setting on a VFD will give you more torque than what you have at the 60Hz, nameplate rated speed.

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    Quote Originally Posted by EPAIII View Post
    I should have said a bit more on that HP / torque matter. HP is necessary, but it is not the factor that directly determines how heavy of a cut you can make. A heavier cut requires more force and torque is force X distance (radius). The fact that, with the same mechanical gear or belt ratio, the torque remains constant for all slower speeds selected with the VFD, prevents you from getting more torque for a heavier cut.

    If you want more torque, for a heavier cut, you can only get that by changing the mechanical gear or belt ratio.

    The available HP determines how much torque you CAN get. But it is not what you consider when you need to make a heavier cut; torque is. And no setting on a VFD will give you more torque than what you have at the 60Hz, nameplate rated speed.
    You cannot effectively utilize more than 3/4 to 1 HP of input power for "heavier cuts" on a Logan.

    It will only over-stress the other bits as were not designed to transmit greater forces to the spindle, and/or increase deflection and chatter from cutting forces at the tool-tip.

    Recognize that "almost industrial" is like "half pregnant".

    It won't remove as much metal as fast as a medium or heavy lathe.

    Get used to using it within its modest design envelope. It's probably all you need.

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    Most single phase motors can not be reversed until they slow down to almost a stop. A 3 phase motor can be reversed at full speed. Makes a difference for turning or threading to a stop. In truth a lathe can not be stopped in a instant or gear teeth will be broken. Many set a vfd to 2-3 seconds until full stop after the stop button is pressed. Do it too fast and a screwed on chuck can unscrew itself and run around the shop.
    Bill D.

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    Quote Originally Posted by Bill D View Post
    Most single phase motors can not be reversed until they slow down to almost a stop. A 3 phase motor can be reversed at full speed. Makes a difference for turning or threading to a stop. In truth a lathe can not be stopped in a instant or gear teeth will be broken. Many set a vfd to 2-3 seconds until full stop after the stop button is pressed. Do it too fast and a screwed on chuck can unscrew itself and run around the shop.
    Bill D.
    Not really a show-stopper for a light lathe.

    Unwise to try to reverse those "at speed" in any case. Even an emergency is better served with a good motor/drive independent brake.

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    Thanks so much for your responses, the experience here is overwhelming. The Logan is a modest machine, and I enjoy using it.

    Torque vs HP....I have a KMG belt sander with a 3hp w/VFD. At low rpm, I can press steel into it and stop the belt..hard to do when it's wide open. But that's not the goal with low rpm in that operation, so not an issue. Not quite the same as removing steel on a lathe. Thanks for all the insights into that relationship...and the one about 60hz being the sweet spot. Yep, printed right on the motor label, duh.

    I understand the detriment to running 3ph on single, but was not dissatisfied with my vfd machines like I was the ph converter that was on the lathe. Felt like I was limping it along and there was a better solution.

    I would consider the metric frame if we go to war with Iran and the Ruso-Sino alliance invades Texas. I feel like that would be ok "in extremis"...just kidding, never thought about it, so I might as well look into it.

    Seriously, thank you all for your time and help.

    C

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    Quote Originally Posted by wild_musk View Post
    ....
    I understand the detriment to running 3ph on single, but was not dissatisfied with my vfd machines like I was the ph converter that was on the lathe. Felt like I was limping it along and there was a better solution.

    .....

    C
    If the phase converter felt like it was "limping along", then either it had a serious problem, or it was not what we are thinking of when you mention "phase converter"... maybe a "static phase converter", which does not really "convert" anything of importance. When you also mention that the old motor "burned out", that seems even more likely/

    I use a rotary phase converter, or 'RPC", and it is just like power company three phase, not a hint of "limping along".

    Now, if you try to use a VFD to do large speed changes, you may indeed be "limping along". it will probably feel like there is "no power" at the low RPM end, and it may just stall out in the cut. Power is the capability to remoove a certain amount of metal per minute. If you slow the machine down by 10x by means of the VFD, to 1/10 speed, your "power" will also be 1/10.

    Since the general reason for slowing the machine is to work on larger diameter material, to keep the speed of the material past the cutter the same (the speed is known as the "SFM", surface feet per minute), you see that you may need more torque to do the same cut. Material 4x larger diameter needs 4x more torque for the same cut, due to the diameter increase. If your torque is the same, you have to reduce the cut or you may just stall..You may end up unable to remove more than a tiny thread-like amount of material without stalling.

    But the mechanical speed change is constant HP, not constant torque. So a 4x reduction in rpm means a 4x increase in torque. You can take the same cut at the larger diameter as you could at the smaller diameter, at the same SFM. That makes a large difference.

    Don;t be fooled by people comparing the Logan unfavorably to big Monarch machines. It is a perfectly good machine for its size, and "nearly industrial" is not anything like "half pregnant".... it means a machine that has the same facilities, but us not overbuilt to the same degree , It will do the work that larger machines will do on any work that fits within its limits. It may not, due to being lower power, take as large a cut, and it is not built for the same heavy service over many years,

    But there is no reason whatever to assume that it will be limited to the same sort of low performance as the truly "hobby" machines which we do not discuss here. And no reason to make changes that artificially limit performance just because "it is only a Logan".

    Keep the Logan VS drive, Your choice as to using a VFD or an RPC as your "phase converter". Either can work equally well with a machine having the variable speed setup that has,. Just remember the VFD is not a sarisfactory substitute for the mechanical variable speed.

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    Quote Originally Posted by JST View Post
    If the phase converter felt like it was "limping along", then either it had a serious problem, or it was not what we are thinking of when you mention "phase converter"... maybe a "static phase converter", which does not really "convert" anything of importance. When you also mention that the old motor "burned out", that seems even more likely/

    I use a rotary phase converter, or 'RPC", and it is just like power company three phase, not a hint of "limping along".

    Now, if you try to use a VFD to do large speed changes, you may indeed be "limping along". it will probably feel like there is "no power" at the low RPM end, and it may just stall out in the cut. Power is the capability to remoove a certain amount of metal per minute. If you slow the machine down by 10x by means of the VFD, to 1/10 speed, your "power" will also be 1/10.

    Since the general reason for slowing the machine is to work on larger diameter material, to keep the speed of the material past the cutter the same (the speed is known as the "SFM", surface feet per minute), you see that you may need more torque to do the same cut. Material 4x larger diameter needs 4x more torque for the same cut, due to the diameter increase. If your torque is the same, you have to reduce the cut or you may just stall..You may end up unable to remove more than a tiny thread-like amount of material without stalling.

    But the mechanical speed change is constant HP, not constant torque. So a 4x reduction in rpm means a 4x increase in torque. You can take the same cut at the larger diameter as you could at the smaller diameter, at the same SFM. That makes a large difference.

    Don;t be fooled by people comparing the Logan unfavorably to big Monarch machines. It is a perfectly good machine for its size, and "nearly industrial" is not anything like "half pregnant".... it means a machine that has the same facilities, but us not overbuilt to the same degree , It will do the work that larger machines will do on any work that fits within its limits. It may not, due to being lower power, take as large a cut, and it is not built for the same heavy service over many years,

    But there is no reason whatever to assume that it will be limited to the same sort of low performance as the truly "hobby" machines which we do not discuss here. And no reason to make changes that artificially limit performance just because "it is only a Logan".

    Keep the Logan VS drive, Your choice as to using a VFD or an RPC as your "phase converter". Either can work equally well with a machine having the variable speed setup that has,. Just remember the VFD is not a sarisfactory substitute for the mechanical variable speed.
    Yes, it used a static phase converter...I thought a VFD would improve it, and thanks for the further explanation on limitations of cutting power at slower speeds using the VFD. That's what I needed to know, thanks very much for your post.

    I'm not worried about the comments, just
    part of asking for help. I've been using this machine for 5-6 years, and I was attempting to impress that it is worth it to me to set it up appropriately, not that I was overly proud of it.

    While I see I can use a VFD, I guess it's really more appropriate to look at a RPC. Thanks very much for all the help.

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    Quote Originally Posted by wild_musk View Post
    Yes, it used a static phase converter...I thought a VFD would improve it, and thanks for the further explanation on limitations of cutting power at slower speeds using the VFD. That's what I needed to know, thanks very much for your post.

    I'm not worried about the comments, just
    part of asking for help. I've been using this machine for 5-6 years, and I was attempting to impress that it is worth it to me to set it up appropriately, not that I was overly proud of it.

    While I see I can use a VFD, I guess it's really more appropriate to look at a RPC. Thanks very much for all the help.
    Pragmatism, rather than pride. I actually preferred a 10" Logan over a 10" "toolroom" SB (both with 3/4 HP and mains 3-P), back in school, and was grateful for its bigger-brother (1-P) for repairs on a Day Job a score of years later.

    Not as if they were junk, but.... from having run BOTH, there is scant reason to spend extra coin on a "smoother" 3-P motor when the powertrain pretty well smooths-out any of the so-called vibration of a 1-P.

    Which isn't really noticed ANYWAY until it it close to overload.

    Variable speed within the already sufficient ratio ranges is also not a really necessary benefit. "Now and then.." one might find it useful to move a situation away from a resonance so as to avoid chatter. Before stepless variable power, one got adequate results by changing the speeds, feeds, or cutter, so how much spend is it worth to gild that particular lily when you might rather buy other stuff?

    One thing there is NO argument over: Static alleged-converters don't really. Convert.

    They just trick a 3-P motor into running crippled rather than locking-up as their own good sense would prefer!



    Any RPC will see you much better served, but... ONE decent 1-P motor should be waaay less cost than a decent 3-P motor, PLUS the RPC (or VFD or Phase-Perfect..) to run it.

    So it's really about your budget. Time as well as money, more than whether the lathe weighs under 1,000 lbs Avoir ... or over 3,000.

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    I own and use a 10" Logan. When I changed over to 3phase andan RPC, I saw a HUGE improvement in performance. Now part of that was because the 10" is a flat belt machine.... the 3P got more power through the flat belt than single phase did, due to the pulsating nature of single phase..

    But the rest of the improvement was in cutting down "chatter". While any lathe can chatter, the lighter wight ones, and Logan is lighter weight, have a bigger issue with chatter. I found that I got much less chatter, and that the chatter I DID get was far more easily controlled, using 3P vs 1P. The usual solutions of changing speed etc, worked, where they did not work with 1P.

    It was worth it to me. Your mileage may vary, but I expect you would see some of the same improvements.

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    Quote Originally Posted by JST View Post
    I own and use a 10" Logan. When I changed over to 3phase andan RPC, I saw a HUGE improvement in performance. Now part of that was because the 10" is a flat belt machine.... the 3P got more power through the flat belt than single phase did, due to the pulsating nature of single phase..

    But the rest of the improvement was in cutting down "chatter". While any lathe can chatter, the lighter wight ones, and Logan is lighter weight, have a bigger issue with chatter. I found that I got much less chatter, and that the chatter I DID get was far more easily controlled, using 3P vs 1P. The usual solutions of changing speed etc, worked, where they did not work with 1P.

    It was worth it to me. Your mileage may vary, but I expect you would see some of the same improvements.
    Apples & kumquats, J:

    I could continue to use the Logan system to change rpm...I think. Realize most probably aren't familiar - it's a mechanical system of changing rpm infinitely from low to high (think it goes from around 600 to 2500rpm) by tensioning a system of belts with the crank on the front.
    Shades of a Reeves drive or clone. Sheldon-esque, even. The so-called 1-P vibration is soon lost in such a rig's inertia, friction, and belt-flex hysteresis.

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    Quote Originally Posted by thermite View Post
    Apples & kumquats, J:


    Shades of a Reeves drive or clone. Sheldon-esque, even. The so-called 1-P vibration is soon lost in such a rig's inertia, friction, and belt-flex hysteresis.

    A good theory. What actually happens in practice is that it is "different types of apples but they are still apples". It just goes with the lighter machines. it may be "reduced" by the drive system, but it is not eliminated.

    maybe the OP would not care or notice....
    A

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    Quote Originally Posted by JST View Post
    A good theory. What actually happens in practice is that it is "different types of apples but they are still apples". It just goes with the lighter machines. it may be "reduced" by the drive system, but it is not eliminated.

    maybe the OP would not care or notice....
    A
    There's theory. And there's practical USE:

    Reeves drive on my shaper - 'bout 1 3/4 HP, 3-P.

    Reeves-licensed clone on one mill - 5 HP, 3-P.

    Different patent, same principle on my HBX-360-BC 7 HP, 3-P

    PIV-Werner Reimers on my drillpress - 7 P, 3-P

    Similar drive, Powermatic drillpress, ?? HP 3-P (old day-job)

    "Many, many" of them operated and repaired on letter-size sheet-offset printing presses - generally 1 HP and under, all single-phase (another old day-job).

    Don't expect to be able to even detect the 3-P // 1-P difference on a 1 HP Logan lathe after passing it through a Reeves or any other vari-drive with a stiff belt in it. (PIV drives sort of "grumble")

    Mind.. you'll lose anywhere from 5% (as-new condition) to 30% (not-uncommon degraded condition) of the power. Ratios aren't the only "variable" to a Reeves drive.



    Otherwise, damned-near everything else will vibrate FIRST.. but only if you push it beyond its very modest limits.

    Which he probably does not do after five hours (or even five minutes..) of running it, let alone five years.


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    Very helpful thread. I recently acquired and am refurbishing a South Bend 9 lathe. It has a 0.5 hp 3-phase motor that I have been expecting to swap out for a 3/4 or 1 hp single phase motor, but I was recently advised to consider a vfd drive with the existing motor. I am not so impressed by what I have read on vfd for my situation: the cost relative to a used single-phase motor, and I gather that a matched (low hp) vfd would not be compatible with the existing master and reversing switches both of which I want to use. This is a home-garage-hobby machine. Any further thoughts on the merits of motor swap v/s vfd would be appreciated.

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    Quote Originally Posted by ZeroGravid View Post
    Very helpful thread. I recently acquired and am refurbishing a South Bend 9 lathe. It has a 0.5 hp 3-phase motor that I have been expecting to swap out for a 3/4 or 1 hp single phase motor, but I was recently advised to consider a vfd drive with the existing motor. I am not so impressed by what I have read on vfd for my situation: the cost relative to a used single-phase motor, and I gather that a matched (low hp) vfd would not be compatible with the existing master and reversing switches both of which I want to use. This is a home-garage-hobby machine. Any further thoughts on the merits of motor swap v/s vfd would be appreciated.
    HALF horse 3-P, VFD'ed? Marginal. Whenever variable-speed is wanted - AC or DC - it is useful to upsize the motor. They tend to drop off in power at one end or the other of the variable range.

    3/4 to 1 1/2 HP if you want to use the VFD for more useful range of speed changes than mostly resonance-elimination by minor tweaking of RPM within physical ratio changes.

    That said, seek a 1 1/2- 2 HP-capable (off 1-P input..) VFD and try it WITH the half-hoss motor first..

    If, then you need to up-motor, later, no need of a new VFD, too. Right around 2 HP is a common VFD size. Might even be cheaper than a 1/2 HP-3/4 or 1 HP one anyway.

    All that said, for a light SB9? It can only use 3/4 HP.

    I'd go with a 1 HP single-phase and just not push it into the belt-slip zone. The reserve to insure it never gets pushed off its smoothest behaviour.

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