Index Model 40 mill, with 2 speed motor
Thanks Bruce, doing due diligence I have searched Jraef's posts, he is an excellent and prolific source, but with more than 500 posts just on three phase, converters, VFDs. I just have not found (yet) an answer to my wiring dilemma
Originally Posted by toolnut
I think you are right, doing this in a new thread would probably be beneficial to others.
Actually I wish I had come here before purchasing the VFD. I never guessed that this would be so complicated. So many questions, the subject has hundreds of pages and tens of thousands of views. If I had reviewed 1% of these I might have made a different decision.
Reviewing current data:
The machine is a 1943 Index vertical mill with a three-phase 220 volt, 1/2hp, two speed motor. (see below for more motor information) This is controlled by a rather amazing gang switch that takes in L1,L2 & L3 (or X, Y & Z, if you prefer) and sends it off to two bundles of three wires at the motor marked 1, 2 & 3, and 1 1, 1 2 & 1 3. The switch (yes I know now that there can be no switch in the line) is five position low-forward, low-reverse, off, high-forward and high-reverse. There is so much going on inside this gang switch that it will give the investigator a headache trying to figure out the internal jumpers.
The reason I mention the switch, is that I have no wiring information on the machine or the motor, so I am thinking, the switch and how it was setup, might help me to understand the design wiring of the motor.
I understand that two speed motors are not (sometimes) a case where you connect power to three wires for one speed and then connect to a different set of three for the other speed.
In this requirement of NO SWITCHES: (while I am asking more than one question it might be good to quote and answer each separately so that someone with the same question might be able to locate an answer) This mill comes with two motors, the spindle motor which is two speed 1/2hp and a 1/4 hp X-axis powerfeed motor. They are powered by the same input.
Meaning that in my ignorance, I did what a hundred others have done, I wired the VFD to an outlet, plugged in the machine and thought I was done. Obviously not so. I can only credit the quality of the VFD, the size (5hp) output, the fact that the main motor for the mill is only 1/2hp, and God, for the fact, that I didn't smoke the VFD on the first day. (This would have been tragic, this ain't no $100 ebay unit, but a $600 SpeedStar, Polyspeed, single phase, into three phase, rated 5hp device with a manual of about a hundred pages, and yes I have read through it dozens of times, not that it has helped much)
The result was a spindle motor that would run on high speed, but not on low. On low speed, the start up was slow and I could stop the spindle by hand.
On high speed, the motor would run, with good torque, but would get hot, 180° in about ten minutes. (measured with an IR thermometer, and hot only in a couple of spots on the motor case) Obviously this was not right.
While I never worked the mill on pole power I did run it a few times before moving to its current location, and there seemed to be NO problem with pole power and the function of the mill. It had been working in its previous location for a long time.
Motor wires: You can see, the two tie wrapped bundles of black wires.
The gang switch, this really is ten pounds of stuff, stuffed into a five pound bag. I have dealt with lots of gang switches over the years, they used to be the norm, before contactors. But usually they are generic and all the jumpering is external. Not with this amazing contraption, there are lots of internal jumpering going on, but I am not going to bore you with my enthusiasm trying to figure this out.
A basic schematic of the machine wiring. This is not complete, there is a on-off switch, three pole, single throw between the outside feed and the gang switch. It is at this point the 1/4hp, 3ph powerfeed motor is connected which has its own 3PDT with center off switch.
Taking the philosophical perspective, that a switch is not a switch, unless it is switched. The physical connection, we are trying to work with, can be considered, hard wired direct, the electrons should not know or care if they happen to be traveling a path which contains an UN-switched switch. I am trying to figure this out electrically, then I will go back and change this temporary setup, into a permanent one with NO switches.
The gang switch set in high-forward position seems to connect W, X, Y to wires 3, 1, 2 of the motor. There might be more going on, I can’t tell for sure.
I have gone back and disconnected the 1 1, 1 2 & 1 3 connections at the motor. Result has been that the motor now runs pretty much the same as it did before, except that the over heating problem has diminished. Not gone away, now it take more than thirty minutes for the motor to reach 180° instead of ten minutes. Another interesting bit of information?
There is some confusion, at least to me, as to exactly what this motor is, which might be an important piece of information. I have been reading up on three phase motors and it seems that there are a number of possibilities.
Constant HP 2 speed, constant torque 2 speed, 2 WYE, or 1 Delta, or 2 Delta or 1 WYE, these all having to do with leaving open or shorting some of the wires of secondary set of coils?
My experience is large on DC circuits, extensive on AC single phase, but very limited on 3 phase.
I have been confused before with the design of three phase control circuits, especially where there are both three phase and single phase relays, and single phase taps. But that is another story.
The motor is made by Howell Electric Motor Company, Induction Red Band Motor.
Yes I know this is unreadable, so let me translate.
I hope to someone out there, that this "Wiring diagram 3278" is a magic piece of information?
Back for a moment on the power feed. So we have this circuit, which I will eventually get right for the spindle motor, but the VFD is being asked to power two motors at the same time. By its very nature the feed motor is being switch on and off all the time and being reversed. This is the way most mills are set up. Some have more than two motors or electrical draws, with the addition of a power Y axis or a power knee or power drawbar.
How is this handled within the confines of a single, no auxiliary switch, VFD environment?
Let me say right off, THANK YOU for considering all this. I am out of my depth with this setup and trying to work the best I can, with the limited information I have. I have only been on the forum for a little while, and have enjoyed the reading. What a valuable resource.
Last edited by machmat; 11-12-2009 at 12:58 PM.
Table feed motors are mostly fractional hp, and a small-cheap VFD will do a nice job for the table. Then buy a nice vector drive for the main motor. This will greatly simplify what you're trying to do.
the VFD is being asked to power two motors at the same time.
Index 40 power
I too have the same mill only a later model. Same motor and Xfeed set-up. Currently cleaning and repainting the machine, plan to wire next spring. So, your thread is of great interest to me. I was also planning to use a VFD and remove all the conduit, junction boxes, switches, etc. After reading your thread, maybe I'll just go with a rotary phase converter. Does the VFD manufacturer offer any technical support? Please keep your efforts going, you are not alone.
Index Model 40
Good..... I think the power of any forum is to get out as much information, to as many souls as possible, and those of interest sharing what they have. This thread is a parcel of another that might also interest you, it is more general interest in vintage the Model 40s:
Originally Posted by Black & Chrome
When the subject was getting more focused on the electrical element, it was suggested that I start a new thread.
Update, I still do not have an answer to the motor wiring, been tied up with some other projects lately but, I plan to measure the coil resistance between every wire and publish this. I am thinking that there is a problem in the motor, not at all sure about this. But now with powering just the supposed high side field it is still over heating.
Here is what I would suggest, keep watching this thread. More information is forth coming that might make a difference in your decision.
If you are desiring to power more than one piece of equipment maybe an RPC might be the way to go. I wanted the capability of variable speed and it is nice to have, but all the associated difficulties, I am not sure yet if it is the right choice.
I purchased a 5hp VFD, because I wanted it to power more than one piece of equipment, I think this was a mistake. I could have invested one fifth the price in a much smaller unit and would have been fine for just the mill.
The powerfeed motor....... still thinking about it but I am leaning and have been leaning to replacing the motor with a DC motor, variable speed independent from the main power. I have experience with DC motors in this capacity.
I would love to see your machine and hear about it, but I would suggest that this be posted in the other thread, keeping this one just about solving the electrical problem.
So you have this same gang switch, two speed motor?
What model do you have?
Once I do the coil resistance measuring, would you be up to do the same? That would be a good way to see if there is something wrong with the motor.
Yes, my index 40 is a 1954 model year and has the same switch with a different knob. Everything else is the same. I assume yours is a Cutler-Hammer as all the electrical components are with the exception of the motors. My motor is obviously a newer model but is still a Howell 2 speed 1/2 HP 3 phase 220/440v.
You really had me thinking about this today, and it occured to me that the diagram that you seek may simply be for high & low voltage motor wiring. It is shown on my motor ID plate (see pic). From my very limited knowledge of motors, I believe this is pretty standard motor wiring for 220/440v. I tried to get a good photo of the plate but the conduit is in the way. This is the best I could do for now.
I'd be happy to discuss our machines in another thread. I've only had mine for about 3 weeks now and am in the process of cleaning and getting familiar with it.
Index model 40 1954 wiring & switch
I am not sure what the manufacture is of the electrical components for mine, maybe this bit of information may help in my particular search, and certainly for others, as there seems to be little information about the wiring from Wells-Index.
Originally Posted by Black & Chrome
First; my motor is not the same, it has but six wires, yours has nine, and mine is 220volt only, not dual voltage. So the wiring is different. I have no motor wiring plate, so this is also a piece of information, maybe not for me but for others.
Second; the switch while a gang switch, mine seems to have a lot more segments, seven as opposed to what looks like three for yours.
When I spoke with Wells-Index I was told that some units had two switches one for fwd-off-rev and a second one for low-high. Is this how yours is setup?
Even though these are not like mine I would like to have whatever pictures at higher resolution you can provide, you can send them directly to me at firstname.lastname@example.org.
1954, I never realized that the Model 40 was around for so long.
I stand corrected. My switch has only 3 segments. It is obvious by comparing the photos that they're not the same. At first I would look at the screen, then run out to the barn and look at the machine.
I believe that the switch shown is for low/high. There's also an identical switch on the opposite side that I believe is fwd/reverse for the Xfeed motor. Does that make sense to you? Or would spindle fwd/rev make more sense?There is a main box containing fuses and a knife switch, a small junction box, a thermal breaker box, and two pushbutton on/off switch boxes (I assume one for the mill motor and one for the Xfeed motor). Pretty intimidating at first-at least for me, but I think I've almost got it all figured out. Just thankful that it's all intact & in decent shape.
ID decals are inside the covers of all the boxes and I'll try to get some photos of them this weekend. The lighting is bad for photos in the evenings. I'll also sketch the wiring layout. Probably won't be too much help to you, but at least I'll have some documentation for discussion over the winter without having to freeze to death trying to trace wires in January.
Model 40 Index wiring
I have been remiss actually, there is a lot more than this switch in the mix. There is a push-button switch, a tap for single phase 110, a three pole, single throw switch that turns everything off and on and there is a another fwd-off-rev switch for the 1/4hp feed motor. I know what you mean about daunting bunch of wires. I will eventually eliminate all this extraneous connections. Right now you’re on rung one looking up at rung two of the ladder necessary to climb to get all this working. I am maybe on rung four.
So what kind of condition is your Model 40 in?
She's not too bad considering it's 55 years old. Just dirty from sitting in storage for a dozen years. It looks 100% better after scrubbing all the grime off. It definately was not abused. Only missing the X axis vernior scale, otherwise complete. The usual conduit spaghetti. It sure would look nice with all that gone.
Fine looking machine, much better than mine. Have you trammed the head, curious to hear how close it is?
Thanks, I'm very pleased with it. Should serve my needs well.
No, I haven't yet trammed it. All I have currently is the jacobs chuck. Which I could use but I think a collet with an indicator would be more accurate than the chuck, don't you?
May I ask you why you don't persue the RPC route instead of the VFD?
Yes you may.
Originally Posted by Black & Chrome
My first hindsight answer is; ignorance.
Second answer before hindsight: I had the money and wanted to have all the advantages that technology could offer. VFDs are light and have amazing abilities.
I am not convinced......... YET, that a VFD isn't the right answer. But I would say that for this particular machine DO NOT go out and purchase a 5hp very fancy unit for $600. What I wanted was a single power solution for three, maybe four machines. If I had read more, especially on this forum, I would have reconsidered. I did not realize that I couldn't use the control switches built into each machine. I did not realize that I could not power more than one at a time, actually I had no plan on powering more than one at a time and currently the VFD goes to a three phase outlet, which I plug one of two machines into, one at a time.
I think, that by some opinions, a VFD is a singular power and CONTROL source and should be assigned to a single application. So in hindsight I probably should have purchase a less than 1hp VFD for the mill spindle motor and then maybe another smaller unit for the X powerfeed motor. This would allow control of each motor separately, including the ability to vary speed.
Another hindsight, the manual for my VFD is about sixty pages, of which only about ten seem applicable to me. There are SO many parameters that can be set, maybe at some time in the future, I will avail myself of all this technological advantage. At the moment it seems like varying the frequency and off, on and reverse is about it.
Why not an RPC, well do I want a seven horsepower three phase motor running all the time, seems like a serious waste. And it isn't really 120° phase spread three phase. It is kind of like pseudo three phase, it works but it isn't perfect.
At the same time I have three phase close, and for the cost of the VFD I could have pulled in three phase to a separate box, most individuals in a home shop do not have this option. So for me it wasn't a decision between RPC and VFD, it was a decision between VFD and pole power. I chose the VFD because of the technology, and portability, if ever I had to move, and ended up somewhere where there was no three phase option my investment would still be good.
Now I wish that I had purchase two 1 hp VFDs, and if I ever do need 30 amp service I would think about an RPC or pulling in pole power.
The three units to power is a 5hp Monarch lathe, the VFD would allow me more RPM options, including maybe getting up to about 1000 spindle RPM, only a VFD would give me this ability.
A surface grinder, I have used the VFD to lower the RPM to get a different final surface finish. This isn't a best use practice so having the ability to change frequency isn't really much of an advantage.
Third machine is the Index Mill, this was a primary reason to go with the VFD.
Fourth is a smaller lathe that is currently single phase, and I have thought about changing it over to DC just to get the ability to adjust spindle speed, with the VFD, I could instead change over to three phase.
Now let me add one more note. A couple of years ago we could purchase new old stock, or very good condition three phase motors dirt cheap. I mean a three horsepower motor for less than $50. You could barely give these motors away. There was this paradigm where people who used three phase motors, industrial-commercial applications, would not waste the time, money or energy on anything but a brand new motor. And the non-commercial applications did not exist.
Now with the advent of VFDs in the lower price range, these cheap motors have been sucked up. Now cheap for a 3ph motor is hundreds of dollars, not so cheap.
[QUOTE=Black & Chrome;1243313]
Thanks, I'm very pleased with it. Should serve my needs well. No, I haven't yet trammed it. All I have currently is the jacobs chuck. Which I could use but I think a collet with an indicator would be more accurate than the chuck, don't you? [QUOTE/]
Yes, there are a bunch of messages, some by me in another thread that speaks to the issue.
Since there is no easy way to adjust the tilt of the spindle front to back, I ended up having to shim the head, not the best idea I think but it worked. Right to left the head tilts, but it is touchy, and I bet I loosened, adjusted and retightened those head bolts at least a couple of dozen times. I don't think I will ever tilt the head, but if I needed to then at least I am mentally prepared for half a day trying to get it straight again.
I think this will make you a great tool.
Ok, I didn't slog through every post. probably repeating some stuff
The prime reason for not switching the VFD output is NOT really the transients, because internal catch diodes will suppress those, and they are in every VFD ever made. Only with really long wires might you start having problems.
I have what amounts to a big VFD, a battery-to-AC inverter. I run all sorts of shop equipment from it, as well as yard tools etc. I happily turn them on and off with their switches, and have done so for 10 years. I'd be sirprised if there WAS a problem.
The prime issue is because the turn-on surge for the motor will typically exceed the current limit of the VFD, and cause shut downs. if the VFD is big enough to deal with it, it's too big for the motor, probably, and will have to have the limits set down, bringing back the troubles.
2) multi-speed motors.
They change speed by changing the number of poles in the motor. That explains the switch complexity, 3 phases of pole splitting. That one seems to go from 4 to 6 poles.
3) possible usage idea
You could set the thing up for high speed, and take off the switch handle. That would beat heck out of trying to figure out how to bypass it.
You really need to see if it overheats on 3 phase mains power. if so, the motor may have a problem, try it again with no belt, so it is idling no load. if it overheats again, you have a motor problem of some sort, wrong voltage or coil short.
Check line current with a clamp-on meter on mains current against the 2 amp indicated on the plate. Should be less idling, maybe 40% of 2 amps.
Could also be it does not work well with PWM pulsing, due to lossy iron, etc. Seems like too much rise for that though.
5) aux motor
No good solution for that, aside from a static converter for the feed motor. Or using an RPC for the whole unit.
Do you think that the battery to AC inverter would be the same?
Originally Posted by JST
Have you ever heard of Helionetics? (Not sure of the spelling.) We had these onboard vessels, they basically took any power and turned it into DC and then converted it to any power back into the vessel’s electrical panel. So you could theoretically run a single phase 200 volt 60 cycle yacht panel, using anything from 440 three phase 50 cycle to a handful of D cells batteries. They were very popular and expensive units but were really great when you were traveling to foreign ports and never knew what to expect from shore power. Some vessels just ran on generator power the whole time they were away from their home dock, but that puts a lot of wear some very expensive equipment.
Back to the VFD, if you read a lot of the posts on the forum about VFDs there seems to be universal philosophy about transients and switching, that you will kill your expensive VFD and the only difference between a big fancy one and a cheap little one, is how long it will take to smoke the unit.
I have dealt with a lot of electrical equipment, especially some microprocessor controlled commercial equipment, power supplies and control circuits. And what I have found, in my experience, is that there is usually a lot of built-in design safe guards to protect the equipment. These are, at times, more a source of trouble, than the actual failing of the equipment. I am surprised, if indeed this is the case, that VFDs are so delicate, that they can not tolerate some minor abuse without being damaged.
I would be very depressed if I did blow up a very expensive VFD because I used the machine's on-off switch. (which before anyone jumps in, I am NOT using)
There is some question how this motor actually operates and how the wiring is suppose to work. I am short on knowledge on three phase but have read that there are lots of wiring options if the motor is Delta or Star or?
Originally Posted by JST
As part of the process trying to understand, I am to disconnect the six wires from the motor completely and check the resistance between all the wires to one another and to ground, write all this down and post it. There seems to be a consensus that this information will help to determine what kind of wiring it has and also if there might be an internal problem with the motor.
Right now, the current situation, I have disconnected the low speed wires, or what I think are the low speed wires and are powering, what I think is, the three high speed wires.
Right now, like I said, the current situation, I have disconnected the low speed wires, or what I think are the low speed wires and are powering what I think are the three high speed motor leads.
Originally Posted by JST
Before I did this motor would get hot, 190°, in about ten minutes at 60 cycles with or without a load.
Once I changed to just powering the three high speed leads, and the three low speed wires disconnected, the motor still gets hot, but takes about thirty minutes of running, load or no load, belt or no belt.
I MIGHT be able to get pole power to the machine, but this is not going to be easy.
Another piece of information: Neither the auxiliary, single speed, three phase, X power feed motor, nor the 1/2hp three phase motor on the surface grinder gets hot while being run on the VFD. So what ever the problem, I am thinking, has to be unique to this two speed spindle motor on the mill. Whether this is due to a wiring problem or setup or internal failure or something I did, or something I haven’t done, is the looming question.
Amperage; 1/2hp single phase motor would draw about 4 amps. According to the tag this motor should draw only 2 amps. The VFD has a setting that will show current on its panel and this runs 3.4 to 4 amps.
That increase in current may very well be why the motor is getting hot?
But why the increase. I attempted to use a clamp-on device to read current on each lead while the motor was running, but it would never settle down enough for me to feel confident in what it was reading. I am thinking some of this might have to do with the way the VFD supplies pulsing power. I am reading using a Fluke model 27 VOM with hold and averaging, and max recording.
I am thinking of doing again, this time with a Fluke 190 Scopemeter so that I can see the graph, current over time, maybe this will be more accurate and educational than trying to use a VOM.
I have been warned that nothing can be gained by trying to measure the output of a VFD, but this seems counterintuitive, it is power output, and it seems with the right equipment, like an o-scope, one should be able to make some evaluation?
Going back to WHY CHOOSE A VFD....... this inability to understand the output and evaluate what is going on, when what is going on isn't working, is one reasons to NOT choose a VFD, over pole power or a RPC.
I am sure this is going to work out eventually, and sharing, I hope, will offer some insight to others ignorant in the ways of setting up a VFD to power a Model 40 Index mill with a two speed motor.
What is "good"?
With multiple 3 phase motors, operated together, an RPC is a good option. The VFD bigots typically say "no", but really the machine will work as well on an RPC as if you get 3 phase AC mains in the shop. And the advantage is of course that all the motors get 3 phase at a usable speed. You'd need multiple VFDs, or a static for the pump, etc, otherwise.
If you NEED the features of a VFD, and don't mind the switch conversions etc that may be needed, fine. Go right ahead, and more power to you.
At work, we SELL VFDs, I can get them cheap. I don't have one in the shop, because I already have an RPC and it does what I need.
The biggest difference is going from single phase to 3 phase. After that it is all icing on the cake, you get nice bells and whistles, but the basic plan of good three-phase power is still there.
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