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View Full Version : Mills and Drills Mill/Drill & VFD Questions



Trevor Remster
04-11-2011, 4:16 PM
I'm thinking about buying the G0519 Grizzly mill/drill/tapping machine. The machine is a gear head design. I only have three phase power thru a phase converter. The machine lists a top speed of 1970rpm. I really would like to have a higher top speed for woodworking tasks. Can a VFD accomplish this? If so, will the VFD impact the automatic tapping feature of this machine(when in tapping mode the machine will automatically reverse the tap back out when the preset depth is reached)?

Enco sells the very similar 325-5184 machine. The major difference being it is single phase and doesn't have the auto tapping feature. Would this single phase machine present better options to increase the highest speed.

One other option is the G9977 Woodworkers/Metalworkers mill. This machine is alot more money, and has the opposite speed range issue. 420RPM as the lowest speed. This machine is single phase and I'm not sure how to slow it down when needed.

Nothing really hits the sweet spot for me. Advice please.....:)

Regards,
Trevor

Dennis Ford
04-11-2011, 9:20 PM
That looks like a nice machine but I don't understand why they supply it with a 3 phase motor and don't include a VFD. A VFD could get you some additional speed, probably 50% increase for occasional use.
A potential problem with using a VFD would be the existing controls. VFDs do not work well with switches between them and the motor. When using a VFD, you want the controls wired into the VFD NOT breaking the circuit between the VFD and the motor.

Stephen Pereira
04-12-2011, 6:59 AM
I'd be wary of increasing the top speed of any machine..the bearings might not take it.

I think it would be difficult to find a machine with speed ranges suitable for both wood and metal working. You might consider a mill for metal working and mount a router on the spindle. If auto tapping is desired you can always buy a Tap Matic head.
BTW..planemakers Hotley and Marcou both use their metal working mill to machine wood. I use my BP to machine wood..works ok but makes a mess.

Steve

Trevor Remster
04-12-2011, 10:07 AM
A potential problem with using a VFD would be the existing controls. VFDs do not work well with switches between them and the motor. When using a VFD, you want the controls wired into the VFD NOT breaking the circuit between the VFD and the motor.

I really don't want to disable the existing controls due to the tapping feature. Thanks for confirming I would need to do this.

Trevor Remster
04-12-2011, 10:54 AM
I'd be wary of increasing the top speed of any machine..the bearings might not take it.

I think it would be difficult to find a machine with speed ranges suitable for both wood and metal working. You might consider a mill for metal working and mount a router on the spindle. If auto tapping is desired you can always buy a Tap Matic head.
BTW..planemakers Hotley and Marcou both use their metal working mill to machine wood. I use my BP to machine wood..works ok but makes a mess.

Steve

What exactly do you mean by mounting a router to the spindle? I was planning on using the spindle itself with a collet and mill bits as the router spindle. That is why I am concerned about the slow top speed of this Grizzly mill/drill. I am considering a used Bridgeport which has a top speed of 4200rpm, but moving around a 2400lb machine in my shop is not something I really want to do. Oh well, I think you are right about the difficultly in finding a machine that can do both real well. Two totally different materials really need two different machines. Maybe a mill & a cnc router......?

Stephen Pereira
04-12-2011, 9:49 PM
[QUOTE=Trevor Remster;1682573]What exactly do you mean by mounting a router to the spindle? I was planning on using the spindle itself with a collet and mill bits as the router spindle. QUOTE]

I've seen in magazines where you mount a router to the head of a mill. You use the mill's table for x-y axis control and the z axis could be the router's depth adjustment, quill downfeed or mill table adjustment. You would lose quite a bit of table width(y axis) and perhaps some room in the z axis depending on how you went about mounting the router. I believe there are some plans in Home Shop Machinist Magazine or Village Press' Working With Metal..I could check if you like.

Trevor Remster
04-13-2011, 9:36 AM
Thanks Stephen, I'll check that out.

Bob Akers
04-16-2011, 8:52 AM
I have a Bridgeport clone and mounted a PC router motor on the quill.
Works really well. I have the best of both worlds.
olf20 / Bob


191654http://www.sawmillcreek.org/images/misc/pencil.png

ray hampton
04-16-2011, 4:46 PM
what is the thickness of your clamp -plate ?

Stephen Pereira
04-17-2011, 5:27 AM
Thanks for the picture..what is that apparatus to the left..looks like a chuck coupled to a motor of some sort?

David Kumm
05-05-2011, 9:42 PM
What type of on off switch does the mill drill have? If it is a manual type or a drum switch for forward and reverse you can leave it alone and use the vfd. I do that with my Millrite. Just turn the switch on and leave it. Use the vfd for on off etc. The vfd doesn't know if there is a switch on the circuit. I wired the vfd with the same type plug so if I don't use the vfd I can just plug the mill into the 3 phase power directly. I don't use both the rpc and vfd together because the mfg leg voltage can screw it up. Dave