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  1. #21
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    I left out the 3600 alternative because many lathe users told me that more low and medium end torque should be a goal of any motor swap. Some even suggested going to a 1200 rpm motor. I saw 1800 as a compromise that could deliver on both ends yet keep the motor cooler on the low end. I suppose a 5 hp 3600 rpm motor should be a consideration though. In a lathe application, is there any difference in how smooth a two vs four pole motor runs? My woodworking machines tend to be 3600 but they are direct drive.

    Maybe those with toolroom lathe experience can tell me the rpm range most useful so I can work with that in my choices. Dave

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    Quote Originally Posted by Jraef View Post
    OK, NOW we are at the meat of it...

    You are correct on your choices, but you left one out; use a 3HP 2 pole (3600RPM) motor to begin with. You seem hell bent on using a 4 pole 1800 RPM motor and artificially boosting the speed. Just start off with a 3600RPM motor and turn it DOWN with the VFD.
    I thought 2 pole motors were not a good choice for lathes.

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    Generally 2-pole motors are much lower inertia and do not produce as nice a finish due to velocity perturbations . . . that is why I suggested having a motor that was at least equal to the reflected inertia of the lathe drivetrain when in its highest speed gear setpoint.

    HP for HP . . . an inverter duty TENV motor from Baldor will win in the freight train level of inertia contest compared to a Black Max from Marathon

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    I can get a Baldor IDM 3665 to the door for under $400, NOS. That motor is TEBC. Is that a reasonable choice vs IDNM 3665 ? Dave

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    Wouldn't use a 2 pole motor on a lathe, you are correct that a 4 pole is more ideal for a most manual lathes that top out at 2500 RPM. You also have smoother pulses and less visible surface issues. A 2 pole motor you would not be able to belt down sufficiently. The Baldor IDM3665T is a beast of a motor, I think you would have a problem with it being too long (22") with the blower, but it would be a pretty ideal motor otherwise. You will have no shortage of turning power, unless you have a massive lathe. These vector motors have pretty much full torque down to a few RPM, I installed two Baldor IDNM 2 HP TENV motors on 1340 lathes, absolutely solid RPM control running them sensoreless vector and quiet. If you go with a TEBC motor, I put the blower on a timer so it doesn't run continuously. The blower cannot be run off of the VFD, but one could use the VFD relay output to trigger the blower.

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    Both are 184TC NEMA Frames so they have similar rotational inertia. The IDNM-3665 has 0.37 lb-ft2 of inertia . . . the IDM-3665 has 0.38 lb-ft2 of inertia.

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    Quote Originally Posted by motion guru View Post
    Generally 2-pole motors are much lower inertia and do not produce as nice a finish due to velocity perturbations . . . that is why I suggested having a motor that was at least equal to the reflected inertia of the lathe drivetrain when in its highest speed gear setpoint.

    HP for HP . . . an inverter duty TENV motor from Baldor will win in the freight train level of inertia contest compared to a Black Max from Marathon
    I never thought about the mass of the rotor. That makes sense. I always thought that 4 poles are smoother running because they have twice as many poles. 2 cylinder vs 4 cylinder.

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    If you are running a 1340 or 1440 lathe and can fit a smaller motor pulley, then I would also consider a 3 Hp vector motor and run it to 120 Hz with a 240VAC VFD. I just worked with another person who purchased one of these motors and is installing it on an older mill. It will be going from a 4 speed to a 2 speed and will probably run the motor to 180Hz.
    Allen Bradley Bulletin CM202-FC00318AXZCC Vector Duty 3 HP AC Motor NEW NIB | eBay

    If you want the 5HP in a Baldor/IDNM style then you might check this one out. Interestingly I find it easier to source NOS 5Hp vector motors than those in the 2-3HP range if I am looking at auctions as a source.
    Allen Bradley CM202 NV00518AXZCC AC Motor 5HP 184TC 1750RPM - New | eBay

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    Dave sort of cryptically mentioned what lathe he owns in one post. Nice lathe.

    Smart & Brown Model 1024 lathe

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    Thanks for that link. Now I will add AB ( I think they own Baldor ) to my list. I can get a Baldor IDNM 3661 3 hp for about the same $400. Now I see an AB cm202 for $300. More decisions but more fun learning. Any differences betwee the AB and Baldor ?

    Pulley is crowned and runs a flat belt to a Matrix clutch gearbox which in turn runs a flat belt to the head. Plenty of meat to enlarge the bore but hard to change the size. At 3600 rpm the spindle rpm is 3000 so shouldn't need to go over that. The pulleys were originally sized for a 50 hz motor. Dave

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    We have a 5HP IDNM based motor in a Tree J425 milling machine - wired on the 230V leads with a 10HP 460V drive, installed in 2008.The motor itself is our design and proprietary to our company. It has 0.46 lb-ft2 of inertia and is a 213TC frame motor that we developed and use in the Glass Container industry.

    In our milling machine it gets run at upwards of 7500 RPM on a regular basis without complaint and it has a 4096 count encoder and is being run by an SP UniDrive. The max rated nameplate speed is 6000 RPM . . . not sure if this was intended to be a mechanical or electrical limit.

    It can be operated in velocity or position mode - here we are using it to develop a means of automating installation of a wire clip on an aerospace fastener. Just a plain old 4 pole induction motor controlled in closed loop vector mode with a CNC on top of it.

    Shared album - Ken Brown - Google Photos

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    For those familiar with the S and B 1024, the original set up generates a torque in the range of 4.5 from low to high. A three hp vector duty run off a 230 vfd would have a range of 9 low to 4.5 high assuming 120hz on the top end, a 5 hp range would be 15-8. The 460 vfd would give the 3 hp a high end torque of 9 so it would double the existing motor across the range. Motor costs for the 3 and 5 IDNM are about the same if you assume the AB and Baldor are equal. I'm trying to find out the torque limits of the Matrix and the rest of the machine is pretty stout. Dave ( bean counter in real life )

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    As far as I am aware the Baldor/ABB and Allen Bradley vector motors are equivalent spec wise. The 5Hp listed has Blador name on the cover. There can be some difference in a particular build spec. like shaft size. The shipping cost can be significant, so factor that into your cost. I have a TEBC on my mill and a TENV on the my lathe, the latter is much quieter.

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    Baldor and Reliance were at one point independent companies. Rockwell bought them then ABB purchased them together from Rockwell. Shaft size is defined by the NEMA designated frame size and generally only specials deviate from that standard.

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    I see that in the vector listings, the AB NV is TENV and AB FC is TEFC. For a motor running from 30-120 hz, is the TENV a better choice and how are the fan cooled blades designed to operate over such a wide speed variation? The original motor is ODP. It sits under the Matrix which is under the head. Surprising how much crud was under there when I cleaned it out. The longer TEBC is a very tight fit so that won't work.

    Thanks to all for the motor information. I was headed in the EM and ECF duty lines and didn't know the terms to get to the IDNM and AB sources. That has helped a lot. Dave

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    All of these motors should have thermal click switches embedded in the windings. These switches should be wired to the drive to cause a fault when they open up.

    TENV motors can operate at full torque at zero speed indefinitely. Motors with fans affixed to the shaft lose cooling efficiency at lower speeds and can explode at higher speeds (I have inadvertently shattered a cooling fan on a 50hp reliance motor at some speed above 10,000 rpm) a dumb mistake that I have never repeated.

    3600 rpm will be noisy but not likely to be a problem.

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    The TEFC I usually run from 15-120 Hz, below 15 Hz you could run into some cooling issues in theory, but you are not running the motor anywhere near full load for any length of time. Since the CM202-FC00318AXZCC Vector Duty 3 HP is rated to 5400 RPM which is 180Hz, so pretty much a non-issue. The TENV CM202 NV00518AXZCC AC Motor 5HP is rated to 6000 RPM. The TENV motors I installed on lathes never got past luke warm, I did incorporate the thermal switches, but it is pretty light duty for this type of motor. Looking at the specs on your lathe, the choice of motor probably distills down to the number of mechanical gears you have available and the ultimate speed range. I assume you have at least 2 mechanical gears, otherwise you would be looking at a larger motor. Also the type of work you plan to do with the lathe. At the end of the day, if you have the room, I probably would go with the 5 HP vector motor if you have a minimum of 2 mechanical speed ranges. If you can belt the motor speed up a bit, it will give you wider usable speed range. You can use electronic braking with an external braking resistor and get pretty quick stops. The 5 Hp motor is a bit less if you buy it direct from the surplus store:
    https://www.idealsurplus.com/allen-b...00518axzcc-new

    So a few things to also consider, bigger motor is more rotating mass, stopping that mass will take longer in particular if you are doing high speed work and are using a heavier chuck. Braking will occur quicker for the same spindle speed if a motor is running in the 30-60 Hz range vs. 90-120 Hz for the same spindle speed (assuming you have multiple head stock gear ratios) due to higher rotating momentum. So for things like threading I get better repetitive stopping positions using an electronic trigger circuit at lower Hz, but there are multiple factors. A smaller motor will have less rotating mass, that being said I have done lathe installs with vector 3 and 5 Hp motors and we are talking a stopping time of something like 1 vs. 1.5 seconds before you risk tripping out the VFD. Different VFDs handle a buss over voltage differently and have different programming parameters to prevent this from occurring. So the VFD and properly designed controls are also part of the equation.

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    The S and B 1024 has a two speed Matrix clutch with 1-1 and 3.6-1 ratios and a back gear to further slow things down. I think at 1200 rpm the bottom speed was 50 and top at 3600 rpm is 3000. I'm not exact because the speeds listed on the lathe assume a 50 hz motor. Once i get a motor, I will contact someone who sells drives for advice on vfds and braking resistors needed to handle the load. The set up now are two solenoids that trip a mechanical brake shoe on the back side motor shaft. It doesn't work very well and the original system is AWOL. I don't know if the shift on the fly Matrix needs to vfd to momentarily go to neutral or coast or if it can stay engaged with the motor. That will be a next question. Dave

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    I made a deal on the 5 hp CM202 NV motor so now have to figure out the vfd, braking resistor, and a tachometer for it. Opinions are welcome. Dave

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    Last two lathe installs with vector motors, they were setup to run on either single phase or 3 phase input, so installed 3 phase input Yaskawa V1000's. I used their CIMR-VU2A0020FAA for 3 Hp and the CIMR-VU2A0040FAA for the 5 Hp that drew more amps then the motor you purchased. It is a good mid priced VFD, has been very reliable, straight forward to setup and worked well in the application. I use all 7 programmed inputs, the only other native single phase 5 Hp VFD that I am aware of (other than the generic Chines ones) would be the Invertek, which I would not use for this application. If you want to go with a 3 phase input VFD and derate for single phase there are quite a few VFD's to choose from.

    If just using single phase input then Yaskawa CIMR-VUBA0018FAA can be used without the need of a DC buss choke.
    Yaskawa CIMR-VUBA0018FAA, 5 HP, 200-240V, VFD
    Buy CIMR-VUBA0018FAA - 5 HP Yaskawa V1000 Series VFD

    Their three phase input Yaskawa CIMR-VU2A0030FAA has a 3 phase output of 25A in HD, the motor you purchased is 13.2A. You can run single phase input with a DC buss choke on this model and have sufficient derating factor. I have also used quite a few Hitachi WJ200's which have worked well, there are newer more expensive VFD models by both of these manufactures but they do not offer anything more for this type of application.

    If you have a mechanical brake (other than the motor one that I assume you will remove) and possible when shifting under power you can program an input to base block so the motor will coast and VFD braking will not be applied. With a foot brake the VFD base block must be maintained until the system is cycled through a stop command (to prevent restart if the brake is released). You mentioned some some form of clutching system with the lathe, it could be tied into the VFD system/relay output if it currently uses and elector-mechanical interface. At the end of the day it may be easier to not shift under power, as there is no need. You will most likely end up using two speed ranges of back gear and 1:1. If you change the motor pulley size to something like .83 its current diameter at 60 Hz you would match the previous 50Hz motor speeds running the new motor to 125Hz (~3600 RPM). You probably will want to look at the machines current controls and see how they would be interfaced with the VFD programmed inputs. If you need a tachometer, they sell inexpensive ones that I use routinely for lathe installs. The alternative is you can use the VFD analogue speed output and scale the a digital volt meter for two speed ranges (back gear and 1:1). You select the tach. input/range with a small micro switch on the back gear. If you want SFM you can use something like the Tachulator, I have used these with a hall sensor that I purchased separately. You can get more complicated if you want to.

    Braking resistors are specific to the VFD purchased, you can get factory braking resistors/DC buss chokes or purchase alternatives. Depends on the application and if you need a integrated temperature monitor. On manual lathes in this range, I have been using the Ohmite ARF500, ARF600, HS500 or HS 600 in the appropriate ohms.


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