Author Topic: Sienci Mill One  (Read 9921 times)

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Online Kean

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Re: Sienci Mill One
« Reply #25 on: September 13, 2016, 01:19:02 am »
I have a 6040 CNC router/engraver and use it regularly for cutting plastic and aluminium parts.  I started with a CNC Taig mill, but found I needed a much larger work area.

I've also done lots of "etching" of prototype PCBs down to 0.3mm (8mil) tracks and 0.5mm pitch QFN parts.  Useful for quick footprint checks and breakout boards, but you have to layout for the limitations (large vias).

I've upgraded the 6040 to use a Gecko G540 driver, running from Mach3 or Grbl, and added a 400W brushless (ebay) spindle that can do 12000 RPM.  For the small drills a higher RPM would be nice, but I generally stick to 0.6mm or larger.
It does take some work and experience to get to this point, but accurate drilling and milling of PCBs is one of the best features.  I mill 2 0.8mm thick single sided PCBs and mount them back to back, and use tiny rivets from LPKF to make vias.

Here is a PCB I did recently - https://twitter.com/KeanM/status/768673907717001216
This week I've made one for a tiny 46 "pin" leadless GPS module to check operation before finalising a new design.
 

Online Kean

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Re: Sienci Mill One
« Reply #26 on: September 13, 2016, 01:27:30 am »
Oh, and good idea to go with the 3040.  I've helped set up a few friends with them.  It should be useful for many years with a little care.

I wouldn't touch a "CNC" made of MDF.  It may work OK at first after some adjustment, but over time it will absorb moisture and loose all tolerance, and the lead screws will just start binding and everything will go to hell.
 

Offline janekm

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Re: Sienci Mill One
« Reply #27 on: September 13, 2016, 02:47:13 am »
I second (nth) the other comments regarding getting a Chinese CNC3040 (or similar) "engraving" machine.

They're widely used in the ornamental wood / stone engraving industry afaict, and have a decent amount of refinement by now, they're machines that work. I recently started making simple molds / enclosures etc cut from aluminium on a CNC 6040 class machine and it performs well for that task (cutting depth around 0.5 - 1mm keeps it happy depending on size of milling bit).

In the makerspace I'm in I set it up with control from an Arduino Due running TinyG G2 firmware. They are normally designed to be operated from a PC running Mach3 software.
We got the 2.2kW spindle since it was a small cost increase from the 800W one (the smallest one needing an inverter). I think 2.2kW is overkill in the end but 300W might be a bit puny for aluminium.

If you really want a toy like the Sienci Mill One, I recently bought a toy engraving machine from a seller on Taobao which is a much more sound implementation of that concept of barebones machine: https://item.taobao.com/item.htm?spm=a1z09.2.0.0.xBweLa&id=531855133304&_u=dk1rlm9cff9
Price is around 700RMB (but shipping to Canada would add a lot of course, probably more than the price of the kit). Amazing price given that's for the full kit including power supply, spindle, and custom Arduino-based control board!

It works amazingly well for milling PCBs actually... I got very good results down to 0.5mm QFN by using Z-axis mapping using a contact probe. It's a much more sensibly designed kit than the Sienci one though, aluminium extrusion frame and dual guide rails with linear bearings on each axis. And what's not aluminium is some kind of milled engineering plastic.

 

Offline Xenoamor

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Re: Sienci Mill One
« Reply #28 on: September 14, 2016, 12:25:08 pm »
We use a 6040CNC with a 800W water cooled spindle. With a 0.2mm Endmill we can mill 0.5mm pitch pcb components

Pro-tip
Use Linux-CNC. It's awesome
Attach ground to your drill bit, and 5v to your pcb. Use this to act as a switch to compensate for the height difference across the board
This works well for that: http://www.autoleveller.co.uk/
 

Online Kean

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Re: Sienci Mill One
« Reply #29 on: September 14, 2016, 04:14:07 pm »
Another suggestion/tip...
Rather than using auto-levelling, I get great results by having a "spoil board" (sacrificial plate) made from 10mm HIPS (high impact polystyrene) which I mill flat with a 6mm cutter.  I used to use a wood spoil board, but it would warp over time.
The spoil board gives me a known flat surface, plus I have something soft to drill into without breaking my tiny drill bits.
I then use very thin double-sided tape to hold down my PCB for milling, and some thin paper as a shim to set the tool heights.
Every few months (depending on usage) I need to mill the spoil board flat again - usually taking 0.5mm off it.
I do it this way as I mill lots of different parts from plastic and aluminium as well as PCBs, and although I also have a probe I can mount in the spindle, this saves me that extra levelling step on each job.
I recently got a spindle mount camera, and am looking forward to see how well I can line things up again with that.
 


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