New GRBL Gcode Sender: gSender

Hey everyone! Today is a very momentous day for Sienci Labs as we’re now ready to announce: gSender

As you may deduce, gSender is our new and very own g-code sender which is meant to act as a UGS or CNCjs equivalent and is actually based on CNCjs. Though it’s still in its infancy, it has grown quite a lot in its few months of development thanks to our awesome development team and the feedback of a small group of Alpha testers who we were able to speak with one-on-one over the many weeks that they used gSender themselves.

Why make our own g-code sender?
There are a whole host of great options out there that we recommend for use on the LongMill, but with that being said we’ve seen hiccups manage to crop up from time to time that can really have an effect on ease-of-use and reliability throughout the LongMill community. In the ideation phase, we wanted to lay out some ambitions we saw as being attainable if we were to build our own sender:

  • reliability of operation
  • accommodates all ranges of computing systems (low-end PC to RasPi | ‘light mode’)
  • highly easy to use
  • makes available all normally expected sender functions
  • addresses common error throwing conditions automatically
  • built-in gadgets for surface probing, stock flattening, firmware editing
  • built-in g-code editing
  • 3D cutting visualization

Now, many of these are still works in progress at this time, but I outline them to show that we’re shooting really high with this Program. We want it to be the next-level open-source sender that’s available for all green CNCers to turn to whether they own a LongMill or otherwise: guided and easy to approach as a beginner yet customizable and feature-rich for higher-tier hobby CNCers.

What stage is gSender currently at?
This post is to announce that we’ve now reached the Closed BETA testing stage with gSender.Closed BETA means that the program is now completely available for download to anyone who wishes to try it: though you must first agree to be a Beta tester (which means that we will send you requests for feedback and let you know when new features are released), as well as you must understand that gSender will be provided as-is with no guarantee against incorrect or unreliable operation as it is still in active development. We expect this stage of development to last around 1.5 months starting today.

If you have read all the text above and would like to check out our new gSender as well as help us to make it better, please click the link below! (you’ll just need to answer a short survey and then we can send you the link to download it and give it a try)

As of now we only have a version for Windows, but we should have a Mac version ready for next week gSender Closed BETA sign up

@trust_level_0 @trust_level_1 @trust_level_2 @trust_level_3 @trust_level_4


Incredible news.

So there will eventually be a raspberry Pi / Linux version?

Yep! It’s built very similarly to CNCjs so it should lend itself well to many platforms :slight_smile:

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Since it’s based on CNCjs, does that mean it’s something I can (eventually) run headless on an RPi and connect via a browser as needed? Not leaving my laptop in the garage to collect sawdust is pretty key.


Spot on, yeah it’s javascript based and should be able to run headless.

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I can be your tester. Sign me up!

Sounds great. I am a CNCjs user already so gSender sounds right up my alley. By any chance are you incorporating any keypad/controller/keyboard capability like UGS? Would be nice addition. Unfortunately not in a position to test at the moment. Another few weeks when the weather warms up.

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Would be glad to have you on board @msparks916, click through to the signup survey!

@Heyward43 already have some keybinding functionality set up for common movements with plans to better integrate controllers down the line

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Beta installed and ready for use (soon)… Looks great and very user friendly…

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I have the Beta, but don’t see the keybinding functionality. Could you give us a little documentation - I’d be happy to write macros to allow me to use my existing USB numeric keypad with it…

@falviani Frank: If you click the gear icon in the upper right of the opening screen, you will see a menu item for keybindings in that window.

FWIW, not all of the keybindings are working for me, using a keyboard.

And it works with what I have done so far. Not much but having to make a new layout of my 22 key keypad. Unfortunately with mine I can’t use the Num Lock key or the Calculator key. So that cuts me back to 20 keys. Should be enough since there are a couple of functions I won’t need now. Great job Chris and crew.

@Heyward43 Interesting H. I didn’t get all the key mappings to work. For example, I can reduce the step size of x and y, but I can’t increase it. Plus, even reducing it is limited. If I set the step to 5000, then hit shift - to reduce it, it reduces to 1000. I can’t reduce it to 4000, for example. And shift + does nothing. It should increase it. I need to do more testing, but so far, that’s what I’ve found. This is all with a keyboard. I’ve not tried to use it with my numeric keypad.

Is there any preview pictures or short videos that can be shared to get an idea of what this will have? i use CNCjs on a Pi 4 and it runs great. some more functionality would be great of course. if i had a spare pi 4 lying around i would sign up for the beta but i need to be running daily to fulfill orders. Great work to the Sienci team.


@gwilki I think you are further along than I am. I haven’t gotten to that point yet. I’m still on the basic keys. I jumped on the keypad to start. Shouldn’t be that much different than a full keyboard though. As you’ve figured out there are some bugs so what we are doing will definitely help the development team get it straight. Like you I am using my test arduino set up. Still too cold to get back into the garage/shop. Do we just post our test results and bug findings here? I’m thinking that’s the case for now. I think Chris mentioned a new “BUG” category going up soon.

@carmine80 - First welcome to the forum Carmine. No videos yet that I know of. Do you by any chance have a Windows computer sitting around. That’s the only version right now. If so at least you could get an idea what it looks like and play around with it. Several of us have set up an Arduino Uno as a test unit. No cnc connected to it but it will run the gcode just like it was connected. Just a thought.

@falviani - Frank, I don’t believe you will need the macros as you do in CNCjs. There is a section for key binding that a few of us are already testing. So far so good for me and my keypad but I haven’t gotten that far yet. @gwilki has already found an issue using his keyboard with increasing/decreasing feed speeds but that’s why we are testing in beta mode. There is even a probing section for 3 way probing similar to UGS. Click on the gear icon upper right corner and select keybinding on the left column.

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I haven’t had a chance to dig too far into gSender just yet but since it’s built off CNCjs does it support tool change gcode?

Great point. I mainly use a windows pc to design my cuts using Easel Pro. i will be signing up for the Beta.

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I have been using the Gsender a couple of days now and one thing I am having trouble is when I set the speed and distance to jog it works fine in the UI, but then trying the keyboard it jogs but not to what is set in the UI.