Benbox 1310

I do a lot of work with precious metals and, from time to time, have to drill lots of accurately placed tiny holes, typically 0.6-0.8mm diam. in small pieces. With my ancient eyes, and my trusty OptiVisor, I'm finding this more and more difficult.

A friend has a CNC mill which he controls with Mach3, and I've been using Fusion360 to generate tool paths for him. It occurred to me that a miniature CNC mill could solve my problem, so I looked around and it seems that the Benbox 1310 could possibly meet my needs.

According to the scant description, it uses GRBL. Does anybody have any experience with this machine? What is GRBL and how is it fed into the Benbox? Can/could I use Mach3 for it?

**LINK**

The system generates moves via Arduino control, best check it out at the link above.
You could of course add your own stepper drivers and control system as the basics are included.

Emgee

Edited By Emgee on 05/01/2020 08:24:42

Edited By Emgee on 05/01/2020 08:32:23

I can’t be much help, Gary ... but I spent some time with grbl v1.1f and g-code, over the Christmas period [driving an  XY laser machine rather than a drill/mill]

The software is very widely used and I’m sure would do what you need.

If the Benbox is sufficiently well designed and constructed mechanically, it looks ideal for your purpose.

Others, much more accomplished than I, should be along soon to advise !!

MichaelG.

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Edit: I’ve just found this, which I will be watching later:

https://youtu.be/ifM9UDTXsWE

Edited By Michael Gilligan on 05/01/2020 09:41:04

GRBL is open source software that you can load onto an Arduino or similar. To use it, you load a program, Universal Gcode Sender, into any windows pc. The pc is connected to the Arduino with a usb lead. Universal Gcode Sender will import g code from Fusion360. Universal Gcode Sender will give a preview of the tool paths. It will communicate with GRBL via usb, and drip feed the g code to the controller in the Benbox (presumably a micro controller like the one in the Arduino).

I've used GRBL in a simple cnc router setup, with GRBL loaded onto an Arduino Uno, and with an inexpensive driver board which plugged into the Arduino and ran the stepper motors. This worked very well. It's limited compared to Linuxcnc or Mach3, but I think it will do everything you need on a cnc router.

The accurate hole drilling will not be a problem for GRBL. The mechanics of the machine itself will be the limitation on accuracy. Hopefully someone else who has one of these machines will comment.

John

GRBL is as said in Emgee's link a G code parser and machine controller that runs on many platforms including in this case an Arduino. This is the same basic functionality as for example Mach 3, but the latter has lots of additional bells and whistles such as wizards. It would take G code for example from F360 though you might need to find an appropriate "post processor" for this machine.

I think I would have two concerns about using it as supplied for your application. First, the feed seems to be by standard screws whereas your friend's CNC probably has ballscrews. This means that either you need to have backlash compensation (BC); or carefully generate your G code to only have unidirectional moves to a desired coordinate; or correct any backlash in the machine. From a quick look, there seems to be a BC option in GRBL but it may need a higher spec Arduino (Mega?) than this machine has. Now Mach 3 does have BC but in my experience though it works well if the basic backlash is small (my Novamill has about 0.01mm), but can't properly cope with the level seen on ordinary feedscrews (such as my Super 7 leadscrew). (Or it may be possible to get F360 to allow for backlash.) But you may need to at least fit low backlash nuts (e.g. using a plastic material moulded to the screw) or even ballscrews.

The other thing is that the version of this machine I looks at seems to use just a DC motor with a collet chuck attached as the spindle. This won't have wonderful bearings and may not run quite true, not so helpful if you are using small drills and want accurate positioning. You could upgrade the spindle of course.

It also looks a trifle dear - there are other similar machines that have a larger working area for similar or lower cost. Search eBay for "3020 CNC".

Quite easy when in F360 go to the post processor as you have been doing for Mach3 but select the GRBL instead of Mach3 mill.

Simples

Forgot to mention ... I am using Universal G-code Sender, on a Mac

Highly recommended

**LINK**

https://winder.github.io/ugs_website/guide/platform/

MichaelG.

Emgee. With my friend's mill I generate Mach3 gcode as a text file which he loads into his Win10 computer and then uses the Mach3 program to control his mill via a usb cable.

Fusion can generate Grbl, but what do I then do with it? You mention Arduino. Is it built-in to the Benbox? Where is the Grbl text file located when the Benbox is working? As you can see, I'm really floundering here.

MichaelG. The Benbox appears to be very well built and I'm fairly confident that it would do the job. I watched the video you mentioned and am not put off by the lack of assembly instructions. My big stumbling block is the actual process of transferring the gcode generated by F360 into the Benbox.

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Gary,

The Arduino, which has grbl as firmware, is on that tiny controller board ... you just connect via USB to your computer. ... Have a look at the UGS page that I linked, and all should become clear.

MichaelG.

Edited By Michael Gilligan on 05/01/2020 11:03:45

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If you are buying one ... The red anodised metalwork looks a much better proposition than this version:

**LINK**

https://www.ebay.co.uk/itm/CNC-500MW-Laser-Mini-Milling-Engraving-Machine-3-Axis-Carving-DIY-GRBL-Benbox/153034450392

caveat emptor

MichaelG.

Thanks for your responses guys. I've ordered one and will report back when I've got it working.