Connect without resetting printer

[wfcook]

I've had a print working for the last 27+ hours, printing from the SD card. It was almost done and I decided to go ahead and load Simplify3D and prepare a file for the next print. Unfortunately, doing so with the printer connected automatically connects to the printer and resets it, in this case destorying a 27-hour print and almost $30 worth of plastic.

How do I stop it from (a) connecting automatically, and (b) resetting automatically when I *do* connect?

Printer is a reprap delta of my own design using Repetier and RADDS V1,2

[JoeJ]

Many of the cheap electronic control boards that are used for 3D printer will automatically reset when a new serial port connection is initialized. On many of the boards, this is actually electronically hard wired into the circuitry. For example, on one of my 3D printing control boards, I literally had to modify the circuitry and remove a trace on the PCB to get it to stop doing this. So just know that that is the default behavior and it's frequently wired that way on the PCB.

Now for your other question, you can easily disable the automatic connection stuff in S3D by going to Tools --> Options, and then checking the "disable automatic USB device detection" option. However, this means you will need to go into the machine control panel and hit Connect every single time you plug in your printer.

[wfcook]

Many of the cheap electronic control boards that are used for 3D printer will automatically reset when a new serial port connection is initialized. On many of the boards, this is actually electronically hard wired into the circuitry. For example, on one of my 3D printing control boards, I literally had to modify the circuitry and remove a trace on the PCB to get it to stop doing this. So just know that that is the default behavior and it's frequently wired that way on the PCB.

Now for your other question, you can easily disable the automatic connection stuff in S3D by going to Tools --> Options, and then checking the "disable automatic USB device detection" option. However, this means you will need to go into the machine control panel and hit Connect every single time you plug in your printer.

I know for a fact that it is possible to connect without resetting it, because Repetier-Host is able to do so. And I would not describe the RADDS shield for Arduino Due as a cheap control board. It has to be ordered from Germany, and with stepper drivers, LCD, and the arduino due (and I have an authentic one, not a clone) the setup costs a little over $200. That isn't a ton of cash, but this isn't a cheap Chinese knock-off.

I have disabled autoconnect, thanks, but would still like to be able to connect without a reset. I did read that the reset signal is different on the programming port than it is on the regular port, but I am unable to connect with Simplify3D on the normal port (again, Repetier-host is able to do so).

[Leo_Aguiar]

Where is the Tools --> Options, "disable automatic USB device detection" option on the Mac OS version?

[CompoundCarl]

On the Mac, the options screen is always found by clicking on the program name and choosing preferences (Simplify3D > Preferences).

That's pretty standard for Mac apps