Bridgeport/pedersen mill. Suggestions on how to power it?

rnot · Jun 16, 2020

I just obtained a milling machine and was wondering about the best way(cost wise) to power it. The machine itself is a Vilh. Pedersen horizontal that has been modified to accept a Bridgeport style head on the overarm, giving it both a horizontal and vertical spindle. Vertical spindle is run by
a 5hp 3phase motor 220 volt 4 pole motor. It is controlled through a vfd and runs the spindle and power feed for the quill. Horizontal spindle and table feeds are run by a 4 hp 3 phase 1720 rpm 208 volt motor. This machine ran well on three phase power, which I do not have.The simple solution would be to get a 20 hp phase converter and be done with it, but $2500+ for a new one is a little pricey for me, and im not confident in building one myself.Can I just get another vfd for the 4 hp motor, or does anyone have other suggestions? thank you

thermite · Jun 16, 2020

rnot said:
I just obtained a milling machine and was wondering about the best way(cost wise) to power it. The machine itself is a Vilh. Pedersen horizontal that has been modified to accept a Bridgeport style head on the overarm, giving it both a horizontal and vertical spindle. Vertical spindle is run by
a 5hp 3phase motor 220 volt 4 pole motor. It is controlled through a vfd and runs the spindle and power feed for the quill. Horizontal spindle and table feeds are run by a 4 hp 3 phase 1720 rpm 208 volt motor. This machine ran well on three phase power, which I do not have.The simple solution would be to get a 20 hp phase converter and be done with it, but $2500+ for a new one is a little pricey for me, and im not confident in building one myself.Can I just get another vfd for the 4 hp motor, or does anyone have other suggestions? thank you

Building one is dead-easy if you buy a generic controller and find yer own idler.

You'll not be running both spindles at once. 10 HP should do yah to start and run a 5 HP and be easier to start than a single-idler 20 HP.

Should be under $1,000 with brand-new idler motor and freight, store-bought control box.

VFD needs circuit-breakers, disconnects, wire, boxes, and all that, too. RPC at least needs near-as--dammit "nada" altered or rewired ON the machine-tool.

VFD does need that but... since you have it already THERE, that one would need only an ugrade to a single-phase-input rated one, might otherwise use the same wiring and even controls.

How badly do you need the VFD for variable speed? RPC won't give you that part.

rnot · Jun 17, 2020

The sticky part of this problem is the lower motor. I need to run it in order for my table feeds to work, which is why I assumed I would need a 20 hp phase converter.If I am running the spindle and just using the lower motor for table feeding at the same time, do you think a 10 hp converter would get the job done?. I would like to post pics of the machine to make things a little clearer but I seem to be having trouble doing it.

thermite · Jun 17, 2020

rnot said:
The sticky part of this problem is the lower motor. I need to run it in order for my table feeds to work, which is why I assumed I would need a 20 hp phase converter.If I am running the spindle and just using the lower motor for table feeding at the same time, do you think a 10 hp converter would get the job done?. I would like to post pics of the machine to make things a little clearer but I seem to be having trouble doing it.

Ah, so... OK.

My "Quartet" combo mill, 5 HP H and sub 2 HP V are both served by a SEPARATE 3/4 HP motor for the knee. Add the juice pump, it was alway a no-brainer to use RPC, not "many VFD"

If your one's "lower" or H spindle is not in the cut, only spinning drivetrain for the knee, it is only partly a 3-Phase load, the other part acting as supplementary idler to the RPC.

A 10 HP idler should do yah, if not add a 5 HP as "supplementary" idler. 10 + 5 for 15. Or 5 or 10.

Or use two @ 7 1/2 HP each. or a 7 1/2 HP + a 5 HP. You can still have easier start-up and easier balancing that a single 15 HP or 20 HP and less waste when only lightly loaded.

rnot · Jun 18, 2020

Thanks for the replies. I think I will have to do a little more research on RPCs and how to install and wire them. Hopefully I will have this up and running soon.

thermite · Jun 18, 2020

rnot said:
Thanks for the replies. I think I will have to do a little more research on RPCs and how to install and wire them. Hopefully I will have this up and running soon.

The problem with RPC's is that they are too simple to believe they are ..simple.
Human nature as it is, we simply cannot accept that.

So we spend MONTHS, year after year, "right here, on PM", plotting, scheming, and arguing over the best ways to make them complicated enough we FEEL better about the time and money we have wasted at ... making them complicated.

You'd have to know human nature?

Not only "can't leave well enough alone", we insist on running up poor "well enough"'s lab work and medical bills!

DAMHIKT .. still working on topping all prior attempts at complification.

Simply because I can!

jim rozen · Jun 19, 2020

thermite said:
...arguing over the best ways to make them complicated enough ....

You guys are falling behind lately. No discussions about complications. Maybe you should all
figure out if putting an amp-clamp meter on every single wire in one of those things will make it
run better. You can buy 'em in bulk.

thermite · Jun 19, 2020

jim rozen said:
You guys are falling behind lately. No discussions about complications. Maybe you should all
figure out if putting an amp-clamp meter on every single wire in one of those things will make it
run better. You can buy 'em in bulk.

Heathen savage and yer "jury rigs!"

Current transformers, "James". Current transformers....

SomeoneSomewhere · Jun 19, 2020

jim rozen said:
You guys are falling behind lately. No discussions about complications. Maybe you should all
figure out if putting an amp-clamp meter on every single wire in one of those things will make it
run better. You can buy 'em in bulk.

Industrial large switchboards are increasingly being built with MCCBs with electronic trip units (instead of thermal-magnetic), all on MODBUS so you can get alarms easier.

So yes, a current sensor on every conductor is not uncommon.

jim rozen · Jun 20, 2020

SomeoneSomewhere said:
Industrial large switchboards are increasingly being built with MCCBs with electronic trip units (instead of thermal-magnetic), all on MODBUS so you can get alarms easier.
....

Ah, back on the profile! Just what every rotary installation needs.

SomeoneSomewhere · Jun 20, 2020

What, your shop air compressors aren't 50HP each? How do you survive?

Search

Largest Manufacturing Technology Community on the Web

Search

Bridgeport/pedersen mill. Suggestions on how to power it?

rnot

Plastic

thermite

Diamond

rnot

Plastic

thermite

Diamond

rnot

Plastic

thermite

Diamond

jim rozen

Diamond

thermite

Diamond

SomeoneSomewhere

Hot Rolled

jim rozen

Diamond

SomeoneSomewhere

Hot Rolled

Similar threads