I have a Hurco KMB1m 3 axis CNC that has a manual speed adjustment via
an adjustable sheave pulley system. It's similar to the one on my
Bridgeport, and likewise has a High/Low range. I'm planning to
install a 1ph to 3ph VFD to eliminate the static phase converter in
use now. The spindle start up is kinda slow on the static, as is
reversing. Questions: Once the VFD is installed what kind of max RPM
above base should I allow? I'm thinking of ditching the variable belt
drive and putting in a 1:1 gear belt from the motor to a new spindle
pulley, (I would keep the How/Low gear reduction unit in place).
Anyone do this on a BP or the Hurco? I happen to have a set of solid
bore gear belt pulleys about the correct size...

Keep the static converter and use it to start the idler motor of a rotary phase converter. I
wouldn't anticipate any CNC problems from a rotary if you obtain an idler motor of at least 2 x the
HP rating of the Hurco. See rotary phase converter in metalwebnews.com.

Bob Swinney
"oldjag" wrote in message
...
I have a Hurco KMB1m 3 axis CNC that has a manual speed adjustment via
an adjustable sheave pulley system. It's similar to the one on my
Bridgeport, and likewise has a High/Low range. I'm planning to
install a 1ph to 3ph VFD to eliminate the static phase converter in
use now. The spindle start up is kinda slow on the static, as is
reversing. Questions: Once the VFD is installed what kind of max RPM
above base should I allow? I'm thinking of ditching the variable belt
drive and putting in a 1:1 gear belt from the motor to a new spindle
pulley, (I would keep the How/Low gear reduction unit in place).
Anyone do this on a BP or the Hurco? I happen to have a set of solid
bore gear belt pulleys about the correct size...

On Jan 28, 2:08*pm, "Robert Swinney" wrote:
Keep the static converter and use it to start the idler motor of a rotary phase converter. *I
wouldn't anticipate any CNC problems from a rotary if you obtain an idler motor of at least 2 x the
HP rating of the Hurco. *See rotary phase converter in metalwebnews.com..

Bob Swinney"oldjag" wrote in message

...
I have a Hurco KMB1m 3 axis CNC that has a manual speed adjustment via
an adjustable sheave pulley system. *It's similar to the one on my
Bridgeport, and likewise has a High/Low range. *I'm planning to
install a 1ph to 3ph VFD to eliminate the static phase converter in
use now. *The spindle start up is kinda slow on the static, as is
reversing. *Questions: Once the VFD is installed what kind of max RPM
above base should I allow? *I'm thinking of ditching the variable belt
drive and putting in a 1:1 gear belt from the motor to a new spindle
pulley, (I would keep the How/Low gear reduction unit in place).
Anyone do this on a BP or the Hurco? *I happen to have a set of solid
bore gear belt pulleys about the correct size...

I already have a 10hp capacity rotary phase converter, but I don't
really want to run 3 phase service and a control circuit for the phase
converter over to where the mill is located, in any case I won a 5hp
1phase in to 3 phase out ABB VFD on Ebay which is en route. So the
the VFD will get used, it's just a question of if I pull off the
variable speed belt drive from the mill. Mainly would do this to get
auto speed control via the ABB's A/D input from the Hurco's Servo
board.

oldjag wrote:

On Jan 28, 2:08 pm, "Robert Swinney" wrote:
Keep the static converter and use it to start the idler motor of a rotary phase converter. I
wouldn't anticipate any CNC problems from a rotary if you obtain an idler motor of at least 2 x the
HP rating of the Hurco. See rotary phase converter in metalwebnews.com.

Bob Swinney"oldjag" wrote in message

...
I have a Hurco KMB1m 3 axis CNC that has a manual speed adjustment via
an adjustable sheave pulley system. It's similar to the one on my
Bridgeport, and likewise has a High/Low range. I'm planning to
install a 1ph to 3ph VFD to eliminate the static phase converter in
use now. The spindle start up is kinda slow on the static, as is
reversing. Questions: Once the VFD is installed what kind of max RPM
above base should I allow? I'm thinking of ditching the variable belt
drive and putting in a 1:1 gear belt from the motor to a new spindle
pulley, (I would keep the How/Low gear reduction unit in place).
Anyone do this on a BP or the Hurco? I happen to have a set of solid
bore gear belt pulleys about the correct size...

I already have a 10hp capacity rotary phase converter, but I don't
really want to run 3 phase service and a control circuit for the phase
converter over to where the mill is located, in any case I won a 5hp
1phase in to 3 phase out ABB VFD on Ebay which is en route. So the
the VFD will get used, it's just a question of if I pull off the
variable speed belt drive from the mill. Mainly would do this to get
auto speed control via the ABB's A/D input from the Hurco's Servo
board.


Install the VFD and leave the variable speed sheaves in place - at least
until the drive belt wears out and you have to replace it anyway. If
your mill is anything like our Wells-Index, the job of replacing the
belt is quite a challenge.

You'll probably never use the reduction gears again since the VFD will
give torque controlled speeds down to a crawl.

The ramp-up and ramp-down speeds and dwell times on reversing are
adjustable from the VFD. If this is your first VFD conversion, you'll be
amazed...

Carla
"The English language doesn't just borrow words from other languages.
It follows them down dark alleys, hits them over the head with old beer
bottles and rummages through their pockets for loose grammar."

oldjag sez:

"I already have a 10hp capacity rotary phase converter, but I don't
really want to run 3 phase service and a control circuit for the phase
converter over to where the mill is located . . . ."

I have no direct experience with VFDs but I do feel entitled to an opinion re. RPCs. If you have a
10 HP idler RPC, appropriately "voltage balanced" and use it to run a 3 HP Hurco, then you should
have no problems with voltage sag, or etc. Didn't you say it presenly runs ok from a static phase
converter? Remember, you can run more than 1 machine from a RPC, but only 1 at a time from a VFD.

Bob Swinney




wrote in message
...
On Jan 28, 2:08 pm, "Robert Swinney" wrote:
Keep the static converter and use it to start the idler motor of a rotary phase converter. I
wouldn't anticipate any CNC problems from a rotary if you obtain an idler motor of at least 2 x
the
HP rating of the Hurco. See rotary phase converter in metalwebnews.com.

Bob Swinney"oldjag" wrote in message

...
I have a Hurco KMB1m 3 axis CNC that has a manual speed adjustment via
an adjustable sheave pulley system. It's similar to the one on my
Bridgeport, and likewise has a High/Low range. I'm planning to
install a 1ph to 3ph VFD to eliminate the static phase converter in
use now. The spindle start up is kinda slow on the static, as is
reversing. Questions: Once the VFD is installed what kind of max RPM
above base should I allow? I'm thinking of ditching the variable belt
drive and putting in a 1:1 gear belt from the motor to a new spindle
pulley, (I would keep the How/Low gear reduction unit in place).
Anyone do this on a BP or the Hurco? I happen to have a set of solid
bore gear belt pulleys about the correct size...

in any case I won a 5hp
1phase in to 3 phase out ABB VFD on Ebay which is en route. So the
the VFD will get used, it's just a question of if I pull off the
variable speed belt drive from the mill. Mainly would do this to get
auto speed control via the ABB's A/D input from the Hurco's Servo
board.

On Jan 29, 3:55*pm, "Robert Swinney" wrote:
oldjagsez:

"I already have a 10hp capacity rotary phase converter, but I don't
really want to run 3 phase service and a control circuit for the phase
converter over to where the mill is located . . . ."

I have no direct experience with VFDs but I do feel entitled to an opinion re. RPCs. *If you have a
10 HP idler RPC, appropriately "voltage balanced" and use it to run a 3 HP Hurco, then you should
have no problems with voltage sag, or etc. * Didn't you say it presenly runs ok from a static phase
converter? * Remember, you can run more than 1 machine from a RPC, but only 1 at a time from a VFD.

Bob Swinney

wrote in message

...
On Jan 28, 2:08 pm, "Robert Swinney" wrote:



Keep the static converter and use it to start the idler motor of a rotary phase converter. I
wouldn't anticipate any CNC problems from a rotary if you obtain an idler motor of at least 2 x
the
HP rating of the Hurco. See rotary phase converter in metalwebnews.com.

Bob Swinney"oldjag" wrote in message

...
I have a Hurco KMB1m 3 axis CNC that has a manual speed adjustment via
an adjustable sheave pulley system. It's similar to the one on my
Bridgeport, and likewise has a High/Low range. I'm planning to
install a 1ph to 3ph VFD to eliminate the static phase converter in
use now. The spindle start up is kinda slow on the static, as is
reversing. Questions: Once the VFD is installed what kind of max RPM
above base should I allow? I'm thinking of ditching the variable belt
drive and putting in a 1:1 gear belt from the motor to a new spindle
pulley, (I would keep the How/Low gear reduction unit in place).
Anyone do this on a BP or the Hurco? I happen to have a set of solid
bore gear belt pulleys about the correct size...

*in any case I won a 5hp
1phase in to 3 phase out ABB VFD on Ebay which is en route. *So the
the VFD will get used, it's just a question of if I pull off the
variable speed belt drive from the mill. *Mainly would do this to get
auto speed control via the ABB's A/D input from the Hurco's Servo
board.

The 10 hp phase converter runs a Leblond Lathe, a Bridgeport, a
bandsaw and a delt/disc sander so it's pretty well utilized now. The
static phase converter in the Hurco I'll probably get rid of or may
use it with a 13" Clausing late, but I'm not sure it will work with
the Clausings 2 speed motor.