Limit switches?

I am reading electronics guide and it mentions limit switches "If using endstops", which I understand basically what they are. Also mentions a "emergency stop switch" but same questions.

Are they necessary / how important are they? Trying to figure out where they would go on the machine if so.

In the initial phase where the FLEX was being designed to be a cheap, simple, and accessible as possible we had left both out. Neither is strictly necessary to getting a CNC machine running, but they are generally nice safety features to have.

A lot of folks coming from 3DP technology are alarmed by the fact that the homing switches were left off, because with additive manufacturing tech the mechanical home positions (determined by those switches) are used to set the position of the print/build and resume that build in case of interruptions, printhead/filament swaps, etc.
In CNC fabrication on the other hand, a material probe and location is significantly more important than the machine's home; basically, being able to tell where the toolhead is relative to the workpiece that you're removing material from is much more important than knowing where in the workspace it is in absolute terms.
A FLEX build without endstop uses either probing or proximal placement (the endmill moving to a known position and then the workpiece being adjusted to touch the endmill) to locate workpieces and then proceeds from there. Since most of the .dd projects are single process with at most 1 or 2 toolchanges, no re-homing or additional probing is necessary in normal circumstances.
Since .dd files have homing procedures in their gcode (which would cause the axes to crash if they don't have endstops), those calls either need to be removed, the firmware altered to disable homing, or a mechanical jumper installed in place of the switches to trick the firmware.

The E-stop is even more optional; feature support for them is recommended by the GRBL project for any affiliated hardware developers though, so I thought it would be good to highlight that option.
Also, any commercially produced machines that ever make it on the market would need the E-stop included as a liability and safety measure (though their effect on the overall safety of the FLEX is negligible).

Quote :

The Uno should be powered directly by the USB cable attached to the PC - just a redundancy that cuts power to the controller if the host is disconnected.

Not sure what you meant, but sounds like the USB drive only powers the UNO, and I could add a second power supply to have redunancy in case usb is disconnect from PC. Then there must also be a separate power supply that powers the shield/motors.

Quote :

material probe and location is significantly more important than the machine's home

Probe: Okay, I will try to add a probe--just ordered one. Any tips/guides you know of might be helpful. As mentioned in another post, I still feel like I could be missing parts since electronics are not part of BoM

Quote :

since .dd files have homing procedures in their gcode (which would cause the axes to crash if they don't have endstops

If I do sell this as a complete machine, then I think it makes sense to add endstops rather than assume all end-users will need to edit ever DD files, right?
Therefore, if adding endstops (4 in total I am guessing) then only way to attach seems like some epoxy since there are no screw holes, unless I can figure out how to reprint parts with screwholes.

On the other hand, if it runs fine without the endstops, why bother (then I would prob edit all the DD files and host a separate repository of my own)?

Code:

any commercially produced machines that ever make it on the market would need the E-stop included as a liability

FYI GG2 manual states has no E-stop, they say to simply to pull the power plug.

where do the 3dp limit switch mounts attach to?

https://www.thingiverse.com/thing:3691917
I used this for both ends of my y axis.

dmbe11 wrote:

mrcastle92 wrote:

where do the 3dp limit switch mounts attach to?#

EEM-LLC Do you have 3d printer files for the end-stop brackets? I purchased end-stops but don't have a good way to mount them. I have looked for one I could adapt with no luck so if you happen to have some I would like to get a copy.

2.2 releasing shortly (waiting on updated PDF's and some parts edits from some other folks involved in testing) will contain three different types of modular, backwards-compatible endstops, as well as an official release for updated printed parts that include the mounts for MK3 types built in. As with the factory GG2, these mount to the right rear of the Y-carriage (containing both the Y and Z endstops) and right X-motor (for X).

Modular endstop mounts are mostly unchanged from the current 2.1 version if you just want the quick version ( https://github.com/EEMLLC/GGFlex/tree/master/QOL-package-2.1 contents)

Could you tell me where on the design these Endstops attach? Are they designed for a specific type of Endstop?

thx

EEM-LLC wrote:

dmbe11 wrote:

mrcastle92 wrote:

where do the 3dp limit switch mounts attach to?#

EEM-LLC Do you have 3d printer files for the end-stop brackets? I purchased end-stops but don't have a good way to mount them. I have looked for one I could adapt with no luck so if you happen to have some I would like to get a copy.

2.2 releasing shortly (waiting on updated PDF's and some parts edits from some other folks involved in testing) will contain three different types of modular, backwards-compatible endstops, as well as an official release for updated printed parts that include the mounts for MK3 types built in. As with the factory GG2, these mount to the right rear of the Y-carriage (containing both the Y and Z endstops) and right X-motor (for X).

Modular endstop mounts are mostly unchanged from the current 2.1 version if you just want the quick version ( https://github.com/EEMLLC/GGFlex/tree/master/QOL-package-2.1 contents)

dmbe11 wrote:

https://www.thingiverse.com/thing:3691917
I used this for both ends of my y axis.

Could you print some for me to purchase from you?

JB1979 wrote:

dmbe11 wrote:

https://www.thingiverse.com/thing:3691917
I used this for both ends of my y axis.

Could you print some for me to purchase from you?

Shoot me a message if needed, I've been providing courtesy printed parts packages for kit buyers as well as switches, blown drivers, and other small stuff free of charge.

Insurgent and I had originally intended to offer a $30-40 gift card code for the webstore with all the eBay orders so that folks could pick up updated stuff as they want it down the road, but obviously that all got left up to me... and I've just been providing stuff by request instead.

Sounds good what can you send me? I bought the $600 kit on eBay. I don’t have the jumpers for something they are small and black and go on the small red circuit boards . Want to buy end stops/limit switches and an emergency off button . Oh and the mounts for the switches…. Can you help with any of that?