I just recently bought a Series I with a Centriod control system on it. I want to upgrade the motor and ad a VFD to it in order to be able to use single phase power and have programmable spindle speed.

Does anyone sell a "kit" for a series one that is a pretty straight foward install? Does the motor need to be changed?

Does the motor just need a pulley that matches the spindle pulley in order to get the 1:1 and let the VFD take over?

You can do pretty much everything you are looking to do by the simple addition of a VFD. No need to change the motor.

Check www.driveswarehouse.com. There are many other places - maybe others will chime in and help locate some killer deals on VFDs.

****edit***** I just realized that you are likely asking for details of how to integrate into the original machine control system. I can't help you there. Sorry.

Scott

Scott,

The way I understand it, the machine is already capable of interfacing with the VFD. I was not sure on whether or not I needd a new motor or anything else.

I should still need a replacement pully though, correct?

If it already has a 3 phase motor, see what the name plate rpm is, if it is ~1700 then it is a 4 pole motor and can usually be run up to 120hz effectively doubling the rpm. If ~ 3500 then it is a 2 pole motor and normally not recommended to go over this unless a vector rated motor is fitted.
For the control, ideally you will need analogue spindle output from the controller the level of which is controlled by the S value, this also means you must have a way, either in the controller (parameter) or VFD for scaling this signal to correspond with the S value.
Al.l

Al -

Are there concerns of overheating?

Sorry for the minor hijack but this seems relevant to the thread....

Scott

You mean at low rpm? Possibly, but You would have to run at prolonged low speed at high current I would think.
The knee mills I have that I converted I use in this manner, although they are fortunately fitted with a two speed gear box, I removed the Vari-drive belt in favour of 1:1,
For the low speeds, I use the 6:1 gear ratio.
Al.

If it already has a 3 phase motor, see what the name plate rpm is, if it is ~1700 then it is a 4 pole motor and can usually be run up to 120hz effectively doubling the rpm. If ~ 3500 then it is a 2 pole motor and normally not recommended to go over this unless a vector rated motor is fitted.
For the control, ideally you will need analogue spindle output from the controller the level of which is controlled by the S value, this also means you must have a way, either in the controller (parameter) or VFD for scaling this signal to correspond with the S value.
Al.l

It's definately a 3 phase motor. I am also pretty sure it's a 1700 RPM as well.
The controller supposedly already has the correct outputs inplace to work with a VFD. As for setting it up, I am not totally sure how that will work. It would be nice to not have to get a phase converter or the likes.

You mean at low rpm? Possibly, but You would have to run at prolonged low speed at high current I would think.
The knee mills I have that I converted I use in this manner, although they are fortunately fitted with a two speed gear box, I removed the Vari-drive belt in favour of 1:1,
For the low speeds, I use the 6:1 gear ratio.
Al.

It has the 2 speed head and the vari-drive setup now.

How hard of a job is installing the VFD and getting it setup?

You wire two phase in - three phase out to the motor, 2 wire ±10v Analogue from controller to the VFD, Ideally you also need two output signals from the VFD for Zero speed and Up-to-speed to the controller.
Some rudimentary electrical/electronics knowledge is a help.
For tuning the VFD, it helps if you get one with the self tuning option.
I have not done one on a bridgeport, the ones I have are Excello, but the principle is the same.
Al.

You wire two phase in - three phase out to the motor, 2 wire ±10v Analogue from controller to the VFD, Ideally you also need two output signals from the VFD for Zero speed and Up-to-speed to the controller.
Some rudimentary electrical/electronics knowledge is a help.
For tuning the VFD, it helps if you get one with the self tuning option.
I have not done one on a bridgeport, the ones I have are Excello, but the principle is the same.
Al.

There isn't any need to run a bigger VFD than what the motor rating is, is there? (like to be able to handle the starting load of the motor)

Some manufacturers will suggest a de-rating factor, I have used the Mitsubishi 1.5kw for 2hp motors for some time and not had a problem, the VFD also controls the accel/decel so the the inrush is different than starting a motor across the line, the VFD parameters limit things like maximum current etc, DC braking etc.
Al.

Thanks Al!

I am stuck on wheter or not I need to get the VFD now or get a 3 phase rotory converter - if I do the later, I can get a "bigger" converter and use it for my lathe if it's a 3 phase. If I don't get a rotory phase converter now, I'll have to limit my lathe search to 220V single phase, or heaven forbid 110V.

turbostang,

You might want to consider a VFD over a rotory phase converter. Reason is most VFD's can run off single phase. The plus is what ever 3ph motor you want to control will also have variable speed. That way you won't need to change belts or gears as often when serching for that perfect cutting speed.

Trevor

turbostang,

You might want to consider a VFD over a rotory phase converter. Reason is most VFD's can run off single phase. The plus is what ever 3ph motor you want to control will also have variable speed. That way you won't need to change belts or gears as often when serching for that perfect cutting speed.

Trevor


Trevor, I mention it above - but the VFD would wind up being more work for me at this point - even though I'd sure love to have programmable spindle speed.
If I get a slightly bigger RPC, I can use it for my upcoming lathe without having to specifically search for a lathe with 220V single phase.
Right now, my mill has variable speed and a hi-lo geared head, so changing speeds is pretty easy - just not as cool as having it automatically change with programming.

Hello I have a series I with a VFD control installed on an AJAX (Centroid) system there are two things to consider make sure you get a VFD with good programmable facilities as, the first one I had worked fine but I could not set the main frequency to match the motor and the unloaded spindle not cutting the motor was drawing 6.0 amps and after a reasonable time of machining started tripping out, after replacing it I am now able to get the motor to run at 3.7amps unloaded which is fine and has been no bother. Again like has been said get one that is tune-able. The second item to check on is although you have the facility to control the spindle speed on the Centroid system have you got the option that is normally an extra with the AJAX system and I would think it is with the Centroid It is a small printed circuit board that plugs int the nine pin RS232 socket on the computer and linked with the wiring to the main control unit but you have to get and pay for the code to switch it on (one of the drawbacks with the system just like it used to be with the Fanuc controls RIP OFF ). I don't know if the Ajax components work directly with the Centroid But they are normally cheaper to buy. All in all it does work well and is very accurate on speed control, I put spacers in between the variable speed disc's on the pulleys to fix and set the max speed to about 3000 RPM which is O K as long as your spindle runs fairly quiet one Day I will get round to changing them to fixed ratio with timing belts or Polly Vee belts. Has anyone done this if so I would bee interested to hear which type of belts and pulleys they used, hope this has helped Cheers Colin.

Hello I have a series I with a VFD control installed on an AJAX (Centroid) system there are two things to consider make sure you get a VFD with good programmable facilities as, the first one I had worked fine but I could not set the main frequency to match the motor and the unloaded spindle not cutting the motor was drawing 6.0 amps and after a reasonable time of machining started tripping out, after replacing it I am now able to get the motor to run at 3.7amps unloaded which is fine and has been no bother. Again like has been said get one that is tune-able. The second item to check on is although you have the facility to control the spindle speed on the Centroid system have you got the option that is normally an extra with the AJAX system and I would think it is with the Centroid It is a small printed circuit board that plugs int the nine pin RS232 socket on the computer and linked with the wiring to the main control unit but you have to get and pay for the code to switch it on (one of the drawbacks with the system just like it used to be with the Fanuc controls RIP OFF ). I don't know if the Ajax components work directly with the Centroid But they are normally cheaper to buy. All in all it does work well and is very accurate on speed control, I put spacers in between the variable speed disc's on the pulleys to fix and set the max speed to about 3000 RPM which is O K as long as your spindle runs fairly quiet one Day I will get round to changing them to fixed ratio with timing belts or Polly Vee belts. Has anyone done this if so I would bee interested to hear which type of belts and pulleys they used, hope this has helped Cheers Colin.


Hey Collin, Thanks for the input! I've talked to Centroid a number of times and they haven't mentioned needing any sort of unlock code - but that doesn't mean anything.
Not sure on if the spindle runs quietly or not, but I'll soon find out. :) Do you have any pictures of the spindle spacers where you shimmed the discs?

BTW - which brand of VFD did you end up with?

Al -

Are there concerns of overheating?

Sorry for the minor hijack but this seems relevant to the thread....

Scott

In an industrial motor controls class I took I was told operating a standard 3 phase motor (not inverter rated) at low rpms could cause premature failure. Problem is, these motors are cooled by a centrifugal fan, at low rpm the motor could be pulling a lot of amps ( a massive roughing endmill maybe?) but the fan isent moving much air and it overheats. some extreme duty inverter motors have a fan on top run by a separate motor.

That said I have a vfd On my step pulley series 1 and plan on belligerently abusing(nuts) the 1960's 1hp motor till it gives up the ghost then replacing it with a larger inverter motor.

Trevor, I mention it above - but the VFD would wind up being more work for me at this point - even though I'd sure love to have programmable spindle speed.
If I get a slightly bigger RPC, I can use it for my upcoming lathe without having to specifically search for a lathe with 220V single phase.
Right now, my mill has variable speed and a hi-lo geared head, so changing speeds is pretty easy - just not as cool as having it automatically change with programming.

Turbostang,

Ideally you would not want a single phase lathe. The reason is you would have to change the motor and add a VFD to get programable speed control, where as a lathe that alredy runs off of 3ph power just requires a VFD. Also depending on the size of the RPC, it maybe more cost effective to purchase a VFD for the mill and another for the lathe.

Turbostang,

Ideally you would not want a single phase lathe. The reason is you would have to change the motor and add a VFD to get programable speed control, where as a lathe that alredy runs off of 3ph power just requires a VFD. Also depending on the size of the RPC, it maybe more cost effective to purchase a VFD for the mill and another for the lathe.


I get what you are saying for sure, but for those of us who are electrically challenged (me) it's not quite so easy to wire up something like that. :(

I like my Centriod controls a lot (haven't actually got to use them, but I live the demos ;) ) so I'll most likely look for a lathe that is compatable with their stuff (which is single phase-able) - I'll just have to pay one of their techs to hook it up (maybe.)

There sure is a VFD you can buy! It's cool as all get out!!! But you'll have to dump or strip the veri-disk drive (which is easy) and go to a direct drive configuration running a haring bone belt made by Goodyear & a Hitachi sensorless vector drive or facsimile and also dump the Bridgeport motor, I know it’s hard to do but its a necessary evil in order to go to a newer motor with a better insulation rating. A company called EMI in Pennsylvania can help you out putting a turn-key package together for you. There are some HUGE advantages by going to this setup which makes it well worth any hassle you might have to ender. Trust me,,, I’ve all ready done this! IT’S OWESOME!!!! Better finishes, auto torg in cuts plus much more. My product coming off that machine looks like it came off a $100,000.00 CNC. It's been worth every penny. EMI (Electro Mechanical Integrators at www.emiinc.com ) Big Daddy

Hi Big Daddy,

I tried you link to EMI and it seemed to be incorrect.

Is this the correct link for EMI?

http://emi-inc.net/

P.S. Thanks for the information.

Sweet, I'll have to check that out!

Sorry about that John, yep your right! It is www.emi-inc.net . Also one more thing,,, if your gonna go through all the trouble to do this hop-up I might suggest a spindle bearing grade hop-up as well. I went to a class 7 sealed bearing. Thats a CNC rated bearing they run about $400.00 a set for anything decent.

Approximately how much money are we talking about when replacing the vari drive and the motor and adding the VFD? sounds like at least $1500-2000 without any labor.
Curious,

Ben

One other question. Should the VFD for a milling machine be a "variable torque" or "constant torque" model?

I talked to EMI, it's about 1600$ for the VFD, motor, hardware etc. This was so I could get programmable spindle speed and not have to use 3 phase.

Not sure on the vari-torque or constant torque, but EMI told me that I'd lose quite a bit of power using a 3 phase converter. NOt sure about that part though.

You will only lose horsepower if you use a "Static" phase converter. I'm pretty sure if you use a rotary 3 phase converter, your HP loss will be extremely minor if any. Before I had a three phase drop from the power
pole to the shop, I used a 5 hp rotary converter to power my 2hp bridgeport
manual mill, 5hp manual engine lathe and 5hp milltronics CNC mill. I ran two machines at a time, all the time.

I'm interested in the VFD drives because my Bridgport is a step pulley.
I installed a TECO/Westinghouse VFD on it but it never has worked as well
as a liked. It does manipulate RPM settings like I wanted but it faults out
all the time. The unit does not have auto tuning toward the motor, so it's
been a 3+ year headache. Many setting changes and advice from others
have been futile. Worst thing is, when you blow its fuse, the whole unit has to be disassembled to get at it for replacement.
The Teco FM100 VFD is now a "legacy" product, so I'm looking for a replacememt and possibly a vari-disc kit replacement for an Alliant mill I
also own.
The $1600 isn't that bad for a vari-disc replacement kit. Sharp wants close
to that much to replace my motor and vari-discs just on the rear (motor end)
of my vari-drive.
Not sure which way I'm going to go, but I'm in need of something reliable with
accel/decel performance and breaking.

regards,
Ben

Some questions to anyone.
Should the VFD have a larger Horsepower rating than the motor it's going to
run?
What about a breaking resistor or dynamic breaking? for 2-3 HP manual milling
machine.

Ben

You will only lose horsepower if you use a "Static" phase converter. I'm pretty sure if you use a rotary 3 phase converter, your HP loss will be extremely minor if any. Before I had a three phase drop from the power
pole to the shop, I used a 5 hp rotary converter to power my 2hp bridgeport
manual mill, 5hp manual engine lathe and 5hp milltronics CNC mill. I ran two machines at a time, all the time.

I'm interested in the VFD drives because my Bridgport is a step pulley.
I installed a TECO/Westinghouse VFD on it but it never has worked as well
as a liked. It does manipulate RPM settings like I wanted but it faults out
all the time. The unit does not have auto tuning toward the motor, so it's
been a 3+ year headache. Many setting changes and advice from others
have been futile. Worst thing is, when you blow its fuse, the whole unit has to be disassembled to get at it for replacement.
The Teco FM100 VFD is now a "legacy" product, so I'm looking for a replacememt and possibly a vari-disc kit replacement for an Alliant mill I
also own.
The $1600 isn't that bad for a vari-disc replacement kit. Sharp wants close
to that much to replace my motor and vari-discs just on the rear (motor end)
of my vari-drive.
Not sure which way I'm going to go, but I'm in need of something reliable with
accel/decel performance and breaking.

regards,
Ben


That's encouraging to hear your RPC worked that good. I just cant decide on how I want to attack my project. I can get the RPC and end my problems and be operational immediately OR, I can get the kit from EMI and run single phase. The cost is close to the same but the EMI upgrade will give me the programmable spindle speed, which I don't have now. This will also give me some parts to put on ebay and get some money back off of.

What amperage breaker did you have driving that RPC?

I believe it was a 30 amp breaker on the RPC, but it might have been a 20 amp. The RPC was a Phase-A-Matic brand, and I went with the breaker size that they recommended. When I added more machinery ( 3hp manual mill and
a Brother CNC drill/tapping center ~4hp) I added an additional 5 HP RPC and ran the two RPC's in parallel to a 3-phase panel that ran all the machines.
Two 5HP RPC's in parallel ran 2 handmills, 2 CNC mills and a 5hp geared head
engine lathe. There are only two of us working in the shop, so not all of the machines ran at the same, but we did run both CNC's and handmills all together.
I would have stayed with this setup, but I added a Mazak CNC lathe to the mix. This forced me to add a 3-phase drop from the power company that
cost around $4000.00. Obviously, this option isn't available everywhere.

good luck,
Ben

www.automationdirect.com sells a nice series of drives that can do single phase input and 3 phase output up to 3hp.

http://web6.automationdirect.com/adc/Shopping/Catalog/AC_Drives/GS2_(115_-z-_230_-z-_460_-z-_575_VAC_V-z-Hz_Control)

These go for less than $300.

Also servos and steppers, drives and motors.