[bobkeyes]

Blades,

Nice job on the lathe. I'm really interested in converting mine in a similar way.

One question! Did you use the Delrin nut and the lead screw instead of a ball screw because of cost? Also, have there been any problems with using it so far?

Thanks a lot.

Bob Keyes

[blades]

Thank you Bob!
I opted for the delrin nut & ACME leadscrew for both cost and simplicity. Although running has only been limited to jogging and bench-testing, I really don't forsee any issues to arise from it. I also picked up a couple extra delrin nuts in case wear becomes an issue, but delrin is tough as nails and generally wears great.

The cost of small ballscrews was more than I cared to spend, although it wouldn't be out of the question to upgrade to them at some future point, I really don't forsee the need. There is extremely little backlash in this setup, and is capable of taking a much higher load than you would typically see on this size machine.

[levelzero]

Amazing conversion, one of the best I have seen.

If it was mentioned I'm sorry, but what did you do for spindle control?

[blades]

Amazing conversion, one of the best I have seen.

If it was mentioned I'm sorry, but what did you do for spindle control?

Thank you very much levelzero, I appreciate your appreciation! :rainfro:

No, spindle control has not been addressed too much, but it is still high on my hit-list of things to complete. Main issue is, I am utterly clueless as to how to integrate spindle control.

I am utilizing the C3 index pulse card and optical gate shown here:
http://www.cnc4pc.com/Store/osc/prod...roducts_id=129 and a slotted disc. I verified operation of it, but the output wire is just an orphan at the moment. I am using a G540 for control, but have no clue as to what else I'm lacking (other than smarts) to fully integrate the spindle control. I've only got the OEM speed control, so obviously I have to interface with that somehow.

Any input would be greatly appreciated, as I'm currently at a brick wall. With other stuff going on, this project has been neglected for awhile.

[dustin1706]

I've been following your build as I have the same lathe. Have you made anything with it yet?

[blades]

Not yet Dustin, just playing with Mach and trying to figure out the spindle control.

[heilcnc]

i would like to say one thing about mach3 turn spindle speed control if you
want good threads i found manual pot control gives you better rpm control
when threading 1 to 2 rpms var i have been using the software on mills and
lathes for years and i would like to ask is + - .003 good enough for these
machines we BUILD?

[blades]

Good info on the software vs. manual pot control. I'm surprised to hear that, actually.

With regards to +/- .003, I guess it really depends on what you're doing with it and what the tolerance applies to. When getting down to the nitty-gritty tight tolerance stuff, it has as much or more to do with the machinist as it does the machine. A highly experienced machinist knows how to deal with machine play.

[heilcnc]

by the way i have been machinist for 28 years and yes on manual lathe i can
hold better than +- .003 i was talking about many parts over 2" long steel
off my 7x12 cnc lathe yours? most of the time they come +-.001 just takes
constant upkeep

[blades]

I was a machinist (mostly Bridgeport) for almost 20 years, then tool design for the next 10 years, but machining whenever I could get my hands on one
I haven't really machined anything since doing the CNC conversion, but I would expect decent results from it.

[blades]

Wow, time to shake the dust off this thread and update!
After lots of thinking, looking, and playing around regarding a control box to house the G540, power supply, and other misc. wiring I decided to do something different (those who know me know that I'm all about doing something different ) I decided to make the lathe self-contained (with the exception of the computer, of course) and built everything into the lathe. I was on a roll yesterday, and it just started going together. It's not completely done, but maybe 90%. I still have to wire the cooling fan and the spindle encoder. If for some reason this turns out to be a stupid idea, or I change my mind, I'm only out a $15 change-gear cover after hacking mine up.
Here's some pics. The bottom pic what it looks like from the inside. There will be only 2 cables coming from the lathe: the power cord and the printer port cable.

[RotarySMP]

Nice!!!

I have my drivers in a separate 19 rack cabinet, and have about six cables between the lathe, the vfd, the power board and the rack. Your set up is much better.

[kd5ahl]

That's a really nice idee for the controller!

Cheers!

[justin bowser]

Blades, SLICK! I can't wait for you to get your spindle encoder/control sorted so I can "steal" your design!

[blades]

Thanks guys, glad you like it!
Mark, I sure don't know about it being "better" than your setup, as it's pitfalls are yet to be discovered. But it is different. I was looking at it last week, trying to decide what to do and where to mount the controller. At first I was looking at a way to mount it below the power supply on the back, but then discovered it would fit nicely in the change gear cover. Soon after I was hacking away

Justin, steal it at your own risk, as its unproven
I need to install a switch so I can switch between manual spindle control or programmed spindle control. I found a thread on here that details how to do it.

[knudsen]

Slick! Now you need a cover for it

[blades]

Jon, long time! Yeah, I look at the cover idea fairly regularly, but the design just hasn't clicked yet.

I've been on vacation for the last 12 days, but back to work tomorrow. Would have got more done on the lathe but was distracted by a couple new toys (new Tacoma and new Ruger MK III)

BTW, I was in WL this past weekend for a few hours, had to bring Nick home so he could go to a wedding in Louisville. Was extremely glad to find Dog-n-Suds opened again.

[blades]

Got a bit more done the past couple of days. Everything is wired up with the exception of the output signal wire to the G540. Still trying to get an answer on how the CNC4PC Pulse Index Board is supposed to tie into the G540. Anyway, I've got a toggle switch wired in to switch between manual speed control or G540 spindle control. You can see the switch on the side of the control box on the front of the lathe.

In all honesty, I'm not so sure I really like this setup as compared to a single, dedicated enclosure for the power supply & G540. Yeah, it's different, but it it really better?? I'm not entirely sold on it. The thought originally was to keep things neat, with only a power cable and parallel cable being the only external connections to the lathe. But I've still got cables exposed from the side & back of the lathe, so it's not as neat as I originally thought. I dunno... as I said before, I'm really only out a $15 change-gear cover if I decide to do something different.

[RotarySMP]

Hi Blades. I see what you mean. But I have six cables out of my lathe (X motor, Z Motor, VFD Control, VFD to motor, mains power, indexer (which should also have the home switches, but I didn't bother reinstalling them after the last maintenance - This cable needs to be redone properly). I still think your set up is much cleaner.

[LeeWay]

Looks great.
Now you can remove that HF label and design your own to put in it's place.