electronic lead screw

ttabbal said:
The thing I like about the Clough42 system is that it is relatively simple. It tracks the spindle and moves the leadscrew to match. It is an electronic gearbox and doesn't try to be much more. You can add some things, but if you go much further you get into CNC land. This is a a manual machine that I don't have to fuss with change gears on. I didn't mind so much for threading, but I was already thinking of adding a variable speed drive for feed rates. He beat me to it and included threading in the mix.

I would like to see custom speeds and such, as well as using the power button to disable the driver. There is a patch out there for that, I just haven't taken the time to integrate it. Right now I go old school and flip the switch on a surge protector strip.
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So if I understand @ttabbal you HAVE clough42's ELS? Can I hit you up for help? I ordered his board today, but looking through the 3 pages of many files....I have no idea WTH to do with them. o_O
 
GunsOfNavarone said:
So if I understand @ttabbal you HAVE clough42's ELS? Can I hit you up for help? I ordered his board today, but looking through the 3 pages of many files....I have no idea WTH to do with them. o_O
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Yup. I built one. A few of us here have.

The files are the code for the launchpad board. He has a step by step video showing how to set up the build tool and load the code into the board. It looks complex, but it's not too bad overall. If you get stuck at a spot, I'm sure one of us can get you going. My build is documented on the forum here..

www.hobby-machinist.com

Electronic Lead Screw

I'm going to attempt to adapt clough42's ELS to my PM1127. I figure I might as well do it publicly in case it ends up being useful for someone else. I have most of the parts now, and have the electronics and servo running on the bench. The first thing I decided to mess with is the rotary...
www.hobby-machinist.com www.hobby-machinist.com
 
Thank you @RJSakowski and @ttabbal I know I'll get stuck more than once. What parts did you have to machine vs what did clough42 make available on his website? What about the box/control buttons he has in his video? As far as bypassing the ELS, could you build a power switch into the unit somewhere?
 
I machined the motor mount and the encoder mount. My motor is a NEMA 24 hybrid stepper and with a little work, it fit under the headstock. The encoder is mounted forward from the spindle and slightly above. Some details of the build are in post # 233 in this thread.

My display box has separate power switching for the ELS Launchpad and the stepper driver so I can switch off the stepper and still leave the ELS display active. I made my own SolidWorks model and machined the cover plate to fit an existing box. Not having a 3D printer, I made Delrin push button extensions. I also installed new LED's with longer leads so the came up through the cover plate.I also engraved the lettering on my box with my CNC. Clough is offering face plates made from printed circuit board soon.
 
GunsOfNavarone said:
What I need (or at least, really WANT to understand) is design software creates G-code, what does that go to, then what does that go to, and so on. It SEEMS like, depending how you want to do this, the hardware can vary.
I'd like to know WHAT I'm shopping for and why.
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Here's the thing, not all arduino type CNC platforms support threading cycles or constant surface speed. You want to check that the platforms supports G96 and G76. Threading is not as simple as simple gcode motions and the motion planner needs to be able to do some sort of synchronization for the spindle position. As far as I know there are forks of grbl that support threading but they are all fairly fringe and not super well tested. There are a couple grbl mega forks that supports it as well as grblHAL ( only MSP432 supported for spindle sync). There may be others but it seems CNC lathe is much less popular than mill type CNC.

Regarding Centroid Acorn, expect to pay an extra $140 for the CNC 12 lathe pro software. This is tied to the hardware so you can't use it for more than one machine. Also expect to spend ~100 on a differential signal encoder which is required by the hardware. you may be able to pickup a used one on ebay.

Finally, Clough's system still requires a ton of manual effort. You will be cranking handles quite a lot without the X motion. If you add a motor to your X you are 90% of the way towards full CNC hardware setup. All you need to add is end stops. That is not to say you will have a machine which will work well for CNC lathe work. The backlash is typically so bad on a small lathe you may have a hard time with it.

If you still want to look at the arduino path take a look at this thread where some very simple encoders are hand made and the folks are working out the kinks for threading: https://github.com/gnea/grbl-Mega/issues/26.

The nice thing about the arduino/grbl mega path is that you can do it very cheap. You can pick up a mega for $6-10, stepper drivers are ~$7 each, $30 for a decent power supply, $12 for a 2400 CPR encoder. 3NM motors are ~$70 for 2. So for around $120 you have a fun project to fool with. The Centroid Acorn would run you $650 to start assuming you used the same motors/drivers. The Acorn will work out of the box but I would highly recommend you read the manual before you pulled the trigger. I find their software very clunky.
 
Don't forget the gears and belts; I bought US-made parts and it was around $100 as I recall.
 
I am going to just copy to the finest detail, Clough42's ELS as @ttabbal and @RJSakowski did. Sounds like it was fairly straight forward and works well.
The money aspect has no bearing to me...within reason. Looks like its sub $500, I get that for allowance jst for taking out the trash and mowing the yard. ;)
 
ttabbal said:
Good luck! Sometimes taking a break is the best way to clear your mind. I've even thought up solutions while away from the computer.
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I hope you guys weren't thinking I was ignoring your input, I just had to walk away from this for a while. I was thiiiis close to dragging the project out to a remote field and giving the whole mess an Office Space-style geek beatdown. Also, waiting on a new display board, which arrived today.

I opened an issue on Github and a couple guys suggested maybe S9 was in the wrong position. I was aware of the S9 default position. Knowing the meaning of the word "default," I simply left it alone, never even touched the tape. Maybe TI doesn't know what a default is; they were right, the switch was in CAN bus position. So, now the encoder is driving the servo!

Unfortunately, the display is still out other than the small LED to the left of the digits. That light had been intermittent, which I traced to a short between the CLK and GND pins in one of my connectors. That's fixed now so the LED is on steady, but that's it. I checked continuity from the display board header pins all the way to the first components on the booster board (C5, C4, C3, C6, and +5v). The first display and the replacement respond the same, or rather they don't.

Next? New booster board?
 

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Wow @luxige even though I have already ordered 4 or 5 parts for this mod....your remarks are the thing that puts the fear of God in me....and I didn't even understand half of what you said. In the end, would you do if you had the chance to go back? No harm no foul, 0 dollars spent?
 
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