Question about the G0766 lathe.

[Randy Red Bemont]

When I need to stop the lathe to check on the piece being turned, how do YOU do it? Do you turn the variable speed knob to zero or do you switch the F/O/R switch to “O” check the piece then switch it back to “F” without touching the variable speed knob? I don’t want to hurt anything.


Also, how long can the lathe be "on" with the speed set to zero? Will anything happen if it sits there too long? I’m thinking as if I turned the speed to zero and then walked into my storage room to get something and come back. That kind of time. These may be simple questions but I want to do things correctly.


Thanks.


Red

316190

[Matt Schrum]

If I want to pause my work, I turn mine off by flipping the Forward/Off/Reverse switch to "O" and I leave the speed setting unchanged. If I'm done for the night, I use the master switch on the left to completely shut it down.

I'm not sure about the "leaving it set at 0" question.

[Roger Chandler]

Randy.......the proper way to do it is to turn the speed dial all the way down till it stops. The safety system built in to the electronics is that if you push the big red button [emergency stop] then you will have to take the foward/reverse button back to 0 [neutral] after pushing the green on button.......then, put it back in the foward or reverse position. It is designed that way to prevent somone turning the lathe on with a big piece of wood mounted, and the speed dial being on high rpm's......:eek:........a disaster waiting to happen, especially if it is unbalanced!

Follow this proceedure I am outlining here and you will be doing the right thing and operating correctly.

[Roger Chandler]

If I want to pause my work, I turn mine off by flipping the Forward/Off/Reverse switch to "O" and I leave the speed setting unchanged. If I'm done for the night, I use the master switch on the left to completely shut it down.

I'm not sure about the "leaving it set at 0" question.

Matt......please see my reply to Randy above! If you just want to pause and check on your work, all that is necessary is to turn the speed dial down............this will prolong the life if that foward/reverse switch!

If you want to shut down for the night, then use the big red button, and switch to 0, then next session, push the green button, and the switch to foward, and turn up your speed dial.

[Matt Schrum]

Matt......please see my reply to Randy above! If you just want to pause and check on your work, all that is necessary is to turn the speed dial down............this will prolong the life if that foward/reverse switch!

If you want to shut down for the night, then use the big red button, and switch to 0, then next session, push the green button, and the switch to foward, and turn up your speed dial.

Is the main reason for turning the speed knob to 0 is to prolong the life of the F/O/R switch? If that's it, then I'm not too worried about the switch, I imagine it should last for more actuations than I'll ever put it through. If I want to quickly inspect a piece, I find it more convenient to use the F/O/R switch so I don't have to adjust the knob back up to the same speed when I fire it back up again.

If there is some other reason that I am not thinking of, then I can adjust my habits-- but most of the switches I've used in the past are rated for tens of thousands of actuations when treated correctly.

[Roger Chandler]

Is the main reason for turning the speed knob to 0 is to prolong the life of the F/O/R switch? If that's it, then I'm not too worried about the switch, I imagine it should last for more actuations than I'll ever put it through. If I want to quickly inspect a piece, I find it more convenient to use the F/O/R switch so I don't have to adjust the knob back up to the same speed when I fire it back up again.

If there is some other reason that I am not thinking of, then I can adjust my habits-- but most of the switches I've used in the past are rated for tens of thousands of actuations when treated correctly.

I think the proper sequence is the speed dial for pausing..........I don't find getting back up to my previous speed setting at all tedious. You may choose to do it another way, but with my previous 5 + years of experience with this headstock design with my former 0698, and having zero issues with swtches, etc, I am going to continue what I believe is the best way.........

I have no specific knowledge on the design of the forward/reverse switch, but did read through the manual, and the manual on my 0698........I cannot recall specifics, but somewhere I got the impression that the sequence I use is the correct way to use the controls..........your mileage may vary.

[Matt Schrum]

.... but with my previous 5 + years of experience with this headstock design with my former 0698, and having zero issues with swtches, etc, I am going to continue what I believe is the best way.........

Fair enough-- I'll try stopping it via the knob next time I get it going and see if it's much of a hassle to bring it back up to the same RPM after. Thanks!

[Randy Red Bemont]

Thanks for the responses. I do turn the speed dial down until it stops.

Red

[Roger Chandler]

Thanks for the responses. I do turn the speed dial down until it stops.

Red

Randy.......just going back and reading your original post, I see I forgot to answer one of your questions. When I had my 0698, there were a couple of times I left the lathe on for a couple of days in my shop.....the rpm indicator was at 0000, and I had just not turned it off, so if you go away with just the speed dial turned to 0000, then that should not be a problem!

I don't think I would leave it that way on purpose, but it never affected my 0698 at all, but I do always try to remember to hit the red stop button and unplug the lathe when not in use.........that just to keep power surges that happen when thunderstorms mess with the power grid, to keep any damage from happening to the inverter........sensitive electronics should be guarded when possible.

[Jeffrey J Smith]

Just a question - does this lathe include a braking resistor as part of the VFD? I'd think that would influence the best method of stopping/starting from operating speeds.

[Roger Chandler]

Just a question - does this lathe include a braking resistor as part of the VFD? I'd think that would influence the best method of stopping/starting from operating speeds.

Jeff, from information given by David Roseman, the inverter does have a place for a braking resistor, but does not come with one included..........he added one to his G0733 18/47 lathe.

[Jeffrey J Smith]

Jeff, from information given by David Roseman, the inverter does have a place for a braking resistor, but does not come with one included..........he added one to his G0733 18/47 lathe.
If I had one of these, I'd certainly consider adding one. For those who are coming to a large diameter swing from smaller lathes, a braking resistor really helps when slowing or stopping a heavy, large diameter blank traveling at any speed. There is a difference between a 12 or 16" blank and a 22" blank. Also, just a friendly reminder, those grub screws in your chuck adapter are there for a reason, too.
Turn safely.

[Roger Chandler]

If I had one of these, I'd certainly consider adding one. For those who are coming to a large diameter swing from smaller lathes, a braking resistor really helps when slowing or stopping a heavy, large diameter blank traveling at any speed. There is a difference between a 12 or 16" blank and a 22" blank. Also, just a friendly reminder, those grub screws in your chuck adapter are there for a reason, too.
Turn safely.

We might just have to get David to post part numbers and a how to tutorial on what he did to add a braking resistor to his unit. He has the same inverter, but we have a 3 hp motor and the 0733 has a 2 hp motor........not sure if that makes any difference or not.

David........you got a copy? ;)

[Dennis Collier]

Ive yet to turn anything large but my lathe seems to stop pretty fast. I assumed it had a brake built into it. It stops a whole lot quicker than the mini lathe I upgraded from.

Oh and I stop the spindle with the speed control knob like Roger outlined. I got the same impression from the manual that he did. That's the way it was designed to work.

[Randy Red Bemont]

I left the lathe on for a couple of days in my shop.....the rpm indicator was at 0000, and I had just not turned it off, so if you go away with just the speed dial turned to 0000, then that should not be a problem!


I won't be doing that!! Just a couple of minutes at most. I didn't know if I would cook something. Thanks for letting me know all will be fine.

Red

[David C. Roseman]

I'll second Roger's comments on the start-stop procedure as a matter of best practices, but more from a safety standpoint than anything else. Electronically, I don't think the lathe cares much whether you dial the pot to zero or flip the F/O/R switch to center position. But from personal experience, let me say that it can be quite exciting to flip the F/O/R switch to F or R after forgetting that the speed is already dialed to 3200 rpm. :eek:

On the braking resistor issue, a BR is nice to have, but not at all necessary, IMO. It allows you to adjust the parameters of the VHD to increase the rate of deceleration. So a heavy workpiece can be brought to a stop quicker, allowing faster work. But if the rate is tweaked much, the overrun inertia can spin the piece right off the spindle if you aren’t careful. Happened to me while I was experienting with different settings. Fortunately the tool rest stopped the blank just before launch. Jeff's comment on using grub screws (set screws) is well taken. But that's if you have them and they seat in the right place on your spindle (e.g., not on the threads). But not all good chucks have inserts that are pre-drilled and tapped for set screws, and those that do may have the set screws in the wrong place for a particular lathe. E.g., the set-screws in the 1-1/4” x 8 tpi inserts of the Oneway Stronghold and Talon chucks seat partially on the threads of the G0733 rather than in the dedicated groove of the spindle. Tightening them down would gall the threads, so brass-tipped set screws should probably be substituted. Last I knew, the inserts of the well-regarded Hurricane HTC125 and HTC100 chucks do not come pre-drilled for set screws at all, precisely because of the variation in spindles from lathe to lathe, this from Steve Fulgoni at The Woodturning Store.

In any event, the G0733 does not come with a braking resistor installed, and from a quick look at the manual and parts list, neither does the G0766. As Roger says, the Delta Electronics VFD-M drive has terminals for one (visible by removing the black metal dust cover), and they are only around $20 or $30 online. Installing one is simply a matter of attaching to the outside of the dust cover and hooking it up to terminals. However, to make it functional you must adjust some of the default parameter settings on the VFD. The VFD-M manual calls for a 300w 100 ohm BR for a 230v 2 HP motor (what I used on my G0733), and a 300w 70 ohm BR for a 230v 3 HP motor. In particular, Pr. 25 (over-voltage stall prevention) must be switched to "disabled", otherwise it will prevent the braking resistor from working. Changing the VFD-M parameters is a bit of a challenge because Grizzly locks out that capability on the VFD keypad, I’m assuming to prevent tampering. So to make the changes, you need to go into the drive through its computer interface using a special cable and adjust the settings from a laptop using the VFDSoft software (downloaded from the Delta Electronics website). This is not particularly hard, but probably not something everyone would want to bother with for the relatively small benefit from having a braking resistor. Also don’t know whether Grizzly might view this as a material modification that would jeopardize the Grizzly warranty if made within the first year.