VMC vs CNC Knee Mills

[memphisjed]

Really? Have you used a Roll-In? Not trying to start an argument, just curious.

Two shops I worked in. Honestly, the worst bang for buck in saws and versatility.

 

[Bakerprecision]

Really? Have you used a Roll-In? Not trying to start an argument, just curious.

To the OP- does the TM-1 have a tool changer? It should be a good introductory drug. And definitely don't spend $15k on a manual lathe, you could spend a tenth of that and get a good machine out of a tech college.

The TM-1 does have a tool changer. I definitely didn't want to spend $15k on a lathe. I just picked one up today. It's a used, clean, GMC 1440HD ($9k). It's a 6hp 3 phase. I'm now researching the phase perfect vs rotary phase debates...

 

[Bakerprecision]

Alright guys, so I'm needing help deciding between a phase perfect and american rotary. It's for my lathe (6hp), so a 15hp rotary or 7.5hp phase perfect will do the job. Question is which one to go with? Price seems to be negligible between the ADX line and Enterprise line. Both will run $2500ish to my door.

Or I found some used 20hp and 30hp units locally, but these are overkill for just my lathe.

 

[Garwood]

Alright guys, so I'm needing help deciding between a phase perfect and american rotary. It's for my lathe (6hp), so a 15hp rotary or 7.5hp phase perfect will do the job. Question is which one to go with? Price seems to be negligible between the ADX line and Enterprise line. Both will run $2500ish to my door.

Or I found some used 20hp and 30hp units locally, but these are overkill for just my lathe.

This is a manual lathe? Replace the start contactor with a quality VFD for about $600. Invertek works good.

$9k for a 1440 Chinese lathe? Yikes. I need to sell my shop off and retire.

 

[Nmbmxer]

I have a 25hp rotary in my garage, I’d get the larger rotary over a PP. I don’t really care for a VFD on a lathe compared to a mill where it is a lot more useful.

Once you have 3p power you can get nicer(cheaper) air compressors, saws, manual mills, grinders, etc that will all need 3p power. You can then buy all the cheap stuff at auction that Harry Homeowner can’t since he doesn’t have 3p.

 

[Bakerprecision]

This is a manual lathe? Replace the start contactor with a quality VFD for about $600. Invertek works good.

$9k for a 1440 Chinese lathe? Yikes. I need to sell my shop off and retire.

Can't afford "new American" and I certainly didn't want to spend a lot of time fixing an "old American" machine.

 

[Garwood]

didn't want to spend a lot of time fixing an "old American" machine.

Like what would need fixing??? It's GD manual lathe? Simplest thing there is.

You're going full speed ahead into this with a monster budget for what you're trying to accomplish. Ten grand will get a nice used VMC and a good manual lathe, a phase converter and tooling.

I just can't fathom spending what you have on the machines you've purchased. There's no possibility of a return. Not a chance.

 

[LOTT]

Alright guys, so I'm needing help deciding between a phase perfect and american rotary. It's for my lathe (6hp), so a 15hp rotary or 7.5hp phase perfect will do the job. Question is which one to go with? Price seems to be negligible between the ADX line and Enterprise line. Both will run $2500ish to my door.

Or I found some used 20hp and 30hp units locally, but these are overkill for just my lathe.

Well, I started with a $110 capacitor kit off ebay wired to a 15HP 3P motor that was a $30 junk yard find. It's still powering the wood shop, ten years later. So you can save about $2300 of that if so inclined.

But if money isn't an issue PP are nicer to have around, and don't burn as much power when idling.

 

[moonlight machine]

Well, I started with a $110 capacitor kit off ebay wired to a 15HP 3P motor that was a $30 junk yard find. It's still powering the wood shop, ten years later. So you can save about $2300 of that if so inclined.

But if money isn't an issue PP are nicer to have around, and don't burn as much power when idling.

Before you buy a PP read about wheelie kings experience with his PP as posted here. No chance I will ever get one after reading that post. I have had an American Rotary RPC for about 10 years and it is flawless. I have recommended A R to 3 friends and they have had no trouble either.

 

[LOTT]

Before you buy a PP read about wheelie kings experience with his PP as posted here. No chance I will ever get one after reading that post. I have had an American Rotary RPC for about 10 years and it is flawless. I have recommended A R to 3 friends and they have had no trouble either.

In fairness to Phase Perfect, over the course of that thread WheelieKing has also had trouble with Haas, Brother, Orange Vise, Pierson Workholding, a couple banks and several employees....

 

[moonlight machine]

In fairness to Phase Perfect, over the course of that thread WheelieKing has also had trouble with Haas, Brother, Orange Vise, Pierson Workholding, a couple banks and several employees....

Over how many YEARS?

 

[LOTT]

Over how many YEARS?

Nine, give or take. We all love Bill, but he lets everyone know if there's an issue. And he'll talk about the issues being fixed too, but it might not be till later.

 

[Bakerprecision]

I'm intrigued by the VFD idea for my lathe, especially if I don't have to run a bunch of boxes for a rotary or PP, but I still don't understand what is involved in getting it wired up. Is there a good article or "how to guide"?

Is there a HP limitation with VFD's? The lathe I have is 6hp.

 

[memphisjed]

6 hp on single phase might be outside Vfd range. If they exist they will be expensive. 5 hp is generally the cut off in single phase.

 

[Bakerprecision]

6 hp on single phase might be outside Vfd range. If they exist they will be expensive. 5 hp is generally the cut off in single phase.

That's my worry. I'm leaning towards an American Rotary 30hp unit to run both my lathe and TM1. I know the TM1 will run single phase, but if I'm doing a phase converter, then why not.

 

[Garwood]

6 hp on single phase might be outside Vfd range. If they exist they will be expensive. 5 hp is generally the cut off in single phase.

I wonder if the universe would explode if you ran a 6HP motor on a 5HP VFD and current limited it in the settings to think it was a 5HP motor?

 

[Bakerprecision]

I wonder if the universe would explode if you ran a 6HP motor on a 5HP VFD and current limited it in the settings to think it was a 5HP motor?

I'm certainly sure this is possible. Problem is, I'm not educated enough to figure the ins and outs of wiring a VFD properly. It seems like options and wiring configurations are endless. And the fwd reverse is gear driven on my machine (not sure if that matters)

 

[LOTT]

That's my worry. I'm leaning towards an American Rotary 30hp unit to run both my lathe and TM1. I know the TM1 will run single phase, but if I'm doing a phase converter, then why not.

I would consider a RPC, but not for the reasons you mention.

There's plenty of 6 HP VFD available for $200-$250. And wiring them isn't a big deal, I forget and have to relearn every time. It doesn't matter that FWD/REV is gear driven, just don't reverse the VFD.

DON'T set up your TM-1 to run three phase off a rotary. There's no point in having a rotary spinning away sucking up juice and making noise when you mill finishes the program and you walked away. Unless you can run it faster on 3P there's just no reason.

The reason TO get a big RPC (or PP, whichever) is that it's easier to get other 3P machines. Band saws, surface grinder, cold saws, all the other stuff you'll want.

 

[memphisjed]

I'm certainly sure this is possible. Problem is, I'm not educated enough to figure the ins and outs of wiring a VFD properly. It seems like options and wiring configurations are endless. And the fwd reverse is gear driven on my machine (not sure if that matters)

They are not voodoo to wire or program for on/off. Wall wires in, motor wires out. You want them to respond to inputs and boost torque and tell you what time it is- that gets a little more in depth.

As long as motor doesn’t need all amps then the universe will not implode. The drive is just outputting chopped and screwed dc voltage- it does not know what brand or even if a motor is on the other side. Current limiting device on motor side is outside my pay grade.

 

[Garwood]

As long as motor doesn’t need all amps then the universe will not implode. The drive is just outputting chopped and screwed dc voltage- it does not know what brand or even if a motor is on the other side. Current limiting device on motor side is outside my pay grade.

My point was just that the motor and drive do not have to match. If you power a 6HP motor with a 5HP drive you can't do 6HP of work with it, only 5.

If you overload a nice VFD it just shuts down.

I have had terrible experiences/luck with low cost VFD's. I would only buy one from a reputable brand. I highly recommend Invertek optidrives.

I wouldn't avoid the rpc route, but the VFD option is very simple for small 3 phase equipment.