electronic lead screw

The easiest way to get a handle on that is probably to watch some YouTube videos showing really basic start to finish CNC stuff. It doesn't matter what kind of CNC. The basic process is the same, though the details vary..

You start with design software like Fusion360. Make a thing. It can be simple, think a wood coaster. Circle, extrude. Then you switch to the CAM process, take the thing and stock, determine zero points, and it figures out the movements. The output from all that is gcode.

Feed that gcode to the motion control system. And set the machine zero to the same spot as in the design. People usually use the top of the stock in a corner or the center. Much like setting your zero when machining. There are fancy probes and such. Can be helpful, but not required.

Hit go and hope you didn't mess up.
 
Ok, well this is what I think I'm looking at...the kind of direction I'm looking for.
Arduino UNO or clone (board)
G-shield (board)
DC power supply
Stepper motor (one for each axis) Nema 34?
4 wire (14 or 16 gauge?)

GRBL software download and install on Arduino board
G code sender (software for PC)
In theory, I think this is a working model...g-code to g code sender to Arduino to steppers.
 
@GunsOfNavarone You got it. You need something to interpret the G-code into motion commands for each axis, and that's GRBL. Then you need something to use those motion commands to drive the steppers for each axis, which I guess is the G-shield and the power supply. Then you need the actual steppers (depends on the machine).

You might want to look at the Centroid Acorn - it looks pretty CNC friendly.
 
GunsOfNavarone said:
@ttabbal I wanted to avoid the ELS as there is more involved...timing one type of motion with another. 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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Disclaimer: I'm no expert on g code but here goes

The function of CNC is to move the three axes of a machine in a coordinated fashion such that the path follows a defined pattern. In addition to coordinating the position, the rate of travel of each of the axes is controlled. A simple example would be to make a diagonal cut .05" deep from the origin to a point 1" to the right and 1" to the front, i.e. a 45º angle. The spindle would be turned on at a specified speed, say 1000 rpm by the command S1000 M3 and the cutter would be lowered to the .05" depth at 10"/min. feed rate with the command G01 F10 Z-.05. Next the command X1 Y1 F 20 will move the cutter to the coordinate1,1 at 20"/min., cutting the diagonal line. It isn't necessary to resubmit the G01 command as it remains in effect until it is overridden with another command such as G00, G02, or G03. G00 is called a rapid and moves at a maximum rate. G02 and G03 move form point A to point B in arcs rather than in a straight line.

G code is a standardized command language which is then sent to a controller which translates the code into a series of commands for the individual stepper or servo motors in terms of stepper rate and direction and number of steps. In addition the controller synchronizes the movement of the thre axes. The controller can be one of many, Mach, LinuxCNC, and PathPilot being common for hobbyists. The aforementioned controllers use a PC as the computer engine. CNC controllers can be written for Arduino, Raspberry Pi, or similar microcontrollers as well.

In the case of the ELS, then motion is rather simplified. Only two axes are being used, the z axis and the spindle. The primary difference is that the spindle motion is an independent variable which controls the motion of the z axis as opposed to a CNC machine where all axes are dependent on the control program. Note that a CNC lathe has feedback coming from an encoder which controls the x and z axis, permuting the necessary synchronization required to successfully cut threads.

It is possible to write complete machining programs manually and for many years that is what was done. However, when machining complex curves in two or three dimensions, this process is tedious and error prone. This is where CAM comes in. Software like Fusion 360 contains a sophisticated mathematics engine that is able to analyzes a three dimensional model and , with some guidance from the operator, create an effective g code program to create the three dimensional part.

One g code program that I had contained over 200,000 lines of code. (https://www.hobby-machinist.com/thr...in-your-shop-today.14637/page-115#post-298744 post#3444)
 
Thanks @RJSakowski I actually run CNC machines all day long, but I want to build a working single controller on my kitchen table. I am slowly now learning what that would take. This is why I said forget X,Y,Z.... I just want to be able to have a laptop on the table, send a command to turn the motor and watch a stepper move. I assume then, I would have a working axis nearly ready to go. I don't fully understand all the hardware needed to accomplish this (servos?) and, depending if I use an ACORN board or an ARDUINO...what will it take to get my PC to get the G code to the stepper. I've been reading a lot, but that is no replacement for someone here that has actually gone from start to finish with it.
On the ELS, I don't know that I would be able to give up manual use of my lathe, If you went this route and removed gearbox, could you still use it manually? I know you can add stepper to ELS rather than remove the gear box, seems like getting rid of that would be a win as long as manual us is unaffected. I know Clough42 has a video on this, I'll have to watch, he was the basis for my VFD mod on my G0602.
 
GunsOfNavarone said:
Thanks @RJSakowski I actually run CNC machines all day long, but I want to build a working single controller on my kitchen table. I am slowly now learning what that would take. This is why I said forget X,Y,Z.... I just want to be able to have a laptop on the table, send a command to turn the motor and watch a stepper move. I assume then, I would have a working axis nearly ready to go. I don't fully understand all the hardware needed to accomplish this (servos?) and, depending if I use an ACORN board or an ARDUINO...what will it take to get my PC to get the G code to the stepper. I've been reading a lot, but that is no replacement for someone here that has actually gone from start to finish with it.
On the ELS, I don't know that I would be able to give up manual use of my lathe, If you went this route and removed gearbox, could you still use it manually? I know you can add stepper to ELS rather than remove the gear box, seems like getting rid of that would be a win as long as manual us is unaffected. I know Clough42 has a video on this, I'll have to watch, he was the basis for my VFD mod on my G0602.
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I'm sorry for overstating the obvious to you. It is difficult to know what a person's knowledge level is. I cherish my ability to run the lathe manually as well which us why I didn't consider converting to CNC. I must confess, that should a need for a CNC lathe arise, I can revert to using my Tormach as a vertical CNC lathe. The ELS doesn't preclude using your lathe manually. You still control carriage movement with the half nuts. You will engage the half nuts for power feed but this is no different than the OEM setup in principle with the exception that it is more convenient.

On the subject of an ELS, I believe the issue is how to synchronize the X and Z axis movements to the spindle orientation. Clough does this by tracking the spindle position from the start of the operation with the rotary encoder and some heavy math computation but it seems to me that this is unnecessarily complicated What is necessary is that, at a particular spindle orientation, the carriage will be at one of a number of points defined by the thread pitch. I envision this as operating something like the thread dial,

In threading, an initial carriage start and end position would be set by the operator as well as a spindle orientation. The correct ratio of encoder pulses to stepper pulses would also be set. To start the threading pass, the stepper driver to would be enabled and the spindle encoder would trigger the stepper driver to begin spending step pulses. At the end of the run, stepper pulses would stop and the threading tool backed out. After a pause which could be automatically set or ended by an operator carriage would be returned to the starting point and stopped. The operator would make necessary cutter adjustment and arm the stepper driver for another pass and the process would repeat.

Since there is no need to keep track of total encoder counts. the spindle wouldn't need to be reversed which is a plus for lathes with thread on chucks. Also, because the end point of the threading pass is precisely defined, threading to a shoulder is now practical. Cutting left hand threads simply involves swapping the start and end points and changing the stepper motor direction.

Because spindle speed isn't precisely controlled, you would probably want to track it and make real time adjustments to the stepper rate to keep in sync.
 
And all that’s sounds terribly complicated. I don’t want to throw a lot of money and stress at something that I would have to ditch as it doesn’t work right. This is the attraction to a plug and play system, but the one or two I can find are not as appealing and quite pricey. I would be happy to share costs and elbow grease to anyone capable who wants to go down this path with me. It’s really not money concerns directly as much as it is wasted money... been there, done that.
 
GunsOfNavarone said:
And all that’s sounds terribly complicated. I don’t want to throw a lot of money and stress at something that I would have to ditch as it doesn’t work right. This is the attraction to a plug and play system, but the one or two I can find are not as appealing and quite pricey. I would be happy to share costs and elbow grease to anyone capable who wants to go down this path with me. It’s really not money concerns directly as much as it is wasted money... been there, done that.
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Going down a new development path, you will still have the cost of a stepper/servo and driver, gear belts, and pulleys, and power supplies. A less expensive encoder is possible but that wasn't a huge expense. The remaining cost in the Clough ELS are Clough's board, the display, and the Launchpad which amounts to around $65. My cost was a little over $200 in total , using an existing power supply and repurposing an old mains load center.

My suggestion above was based largely on what I saw as an unnecessarily complicated scheme requiring additional computing horsepower. On the whole, I am happy with the performance of the Clough ELS. What I see as shortcomings are the lack of ability to dial in a user defined feed rate and not being able to effectively use the enable feature of the driver. To a large extent, this is due to a limitation in the display board. With a little creative programming, this could probably be worked around.

The German Rocketronics ELS looks like a very nice unit and actually closer to a true CNC in function but is lacking the ability for the user to enter in custom programs, relying on preprogrammed routines. Adding the x axis stepper drive, one is almost at a fully functional CNC lathe. At that point, I would be inclined to go full CNC.
 
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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