Interested in Shapeoko v2 for PCBs

alexig
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Interested in Shapeoko v2 for PCBs

Post by alexig » Sun Dec 15, 2013 1:14 pm

Hi,

I'm looking into CNC mills (I've never used one before and I'm not very mechanical), found the Shapeoko v2 was released and wondering if anyone can post their experience here with the new version 2 of the full kit for milling PCBs? My main reason is that I'd like to do rapid prototyping, I know I could use a cheap PCB fab but for once off boards I'd rather have it quicker if it's work-able.

- How's the performance for PCBs?
- What's the smallest trace you've been able to do?
- How about pin width for QFP packages, have you been able to do 0.8mm, 0.5mm (or lower)? I read that it used the NMEA 17 stepper motors which should give 400 steps/rev (or 200 steps?) so that should be a few steps per mm?
- How long does it usually take to go from your PCB design to the finished result and is there much playing around with settings for each run? (I'm using Eagle)

Cheers.

WillAdams
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Re: Interested in Shapeoko v2 for PCBs

Post by WillAdams » Sun Dec 15, 2013 5:16 pm

There's been some discussion of using the v1 for PCBs, but nothing for v2 as-of-yet --- check w/ Inventables on their site and see if anyone there has made any yet?
alexig wrote:I read that it used the NMEA 17 stepper motors which should give 400 steps/rev (or 200 steps?) so that should be a few steps per mm?
This has been clarified a bit. We now have a page on this on the wiki:

http://www.shapeoko.com/wiki/index.php/ ... figuration

and the specifications on the http://docs.shapeoko.com/ site:
The work area is approximately 12" x 12" x 3.5" and precision is dependent upon the belts, pulleys, motors and electronics which are selected (for the default SO2, that is 1/40th of a mm along X and Y, 1/320th of a mm along Z
Shapeoko 3XL #0006 w/Makita RT0701 Router w/0.125″ and ¼″ Elaire precision collets
Nomad 883 Pro #596 (bamboo)

DanMc
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Re: Interested in Shapeoko v2 for PCBs

Post by DanMc » Sun Dec 15, 2013 6:21 pm

Check some of the other postings in this forum, you can get a good idea of what people have done with the older version, i.e. trace widths, accuracy, etc.

As far as your last point, I think that once you figure out your method you can save a template in your CAM s/w and maybe have a jig on your machine, especially if that's all you are doing. You should be able to get easily repeatable results.

conoral11
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Re: Interested in Shapeoko v2 for PCBs

Post by conoral11 » Wed Dec 18, 2013 12:48 pm

The Shapekoko, Shapeoko 2 and eShapeoko are all capable of milling PCB for prototype work.

I myself use a eShapeoko to make both through hole and SMD designs.

The key to getting a good etch from your CNC machine is height compensation if using V shaped bits and a low run out spindle.

I use (after dropping my own) the software that the Cyclone PCB factory uses for height probing and compensation which drastically improved the performance. If you look on my other thread in this form you'll see some of my earlier attempts and the widths I managed to get using a simlar method to the Cyclone PCB software.

The great thing about the 'oko's is that once you've finished your electronics design you can make an enclosure for it, either out of flat sheet or using a plastic extruder.

Conoral11

alexig
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Re: Interested in Shapeoko v2 for PCBs

Post by alexig » Sun Dec 29, 2013 12:34 pm

Thanks all for the replies, sounds like this could work well.

MeanderBolt
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Re: Interested in Shapeoko v2 for PCBs

Post by MeanderBolt » Sun Dec 29, 2013 8:18 pm

PCBs will be one of the early uses of my S2 when it gets here.
Link to the Cyclone GitHub page.

BTW, there is a lot of talk about the dangers of the kinds of dust coming of the PCB as it is being milled as it is fiberglass. Breathing protection is a must IMO. I use a face mask when drilling my PCBs due to some warnings I read back when I was learning how to make them. I am looking forward to skipping so many steps in the pcb process.
Shapeoko 2 # 3569 - DW660
Current tool chain > Draftsight > CamBam > ChiliPeppr
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conoral11
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Re: Interested in Shapeoko v2 for PCBs

Post by conoral11 » Tue Dec 31, 2013 5:46 pm

MeanderBolt,

You are indeed correct with regards to the dust from FR4 PCB stock material, nasty fiber glass dust will cause more headache later in life.

I actually use FR2 PCB stock material for this reason, made from Cotton and paper (It is also a cheaper source of PCB than FR4 is).

Always make sure you understand the risks with all the materials you'll be working with, whether it is the PCB material, flux, solder(leaded and unleaded) fumes and anything else you cut on your CNC. Eye's, ears, hands and lungs are very important to you!

Happy new year!

Conoral11

alexig
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Re: Interested in Shapeoko v2 for PCBs

Post by alexig » Wed Apr 16, 2014 11:31 am

Thought I'd post an update on this, I received the Shapeoko 2 about 2 months ago, built it up without any major issues but I did reference a quick video of someone building one too, to make sure I was doing it right - https://www.youtube.com/watch?v=42wzq5vG5rU

I firstly bought some 0.1mm 20degree V shape bits (ebay), played around with makercam and made some small boxes out of acrylic (shouldn't use V shape with this) to get a handle of things:
Image

Then I tried some PCBs and my results looked quite bad, for a while I was thinking that I would only be able to do DIP PCBs and would have to make my traces be 0.4mm/15.7mil or higher:
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My height leveling calibration isn't the best, it's maybe 0.1-0.2mm off or a bit more in some places, it noticeable in some spots more than others. I spent a while doing this and ended up stripping the screw threading on one of my makerslides at which point I stopped calibrating. I've also switched to a proper dremel too. After reading around a bit, it looks I was going to fast, I reduced my speed to 1mm/min. When placing the bits in the dremel, most times it seems that it's not inserted right at the center because when you drill down you can see it making a tiny circle when it rotates.

I tried to re-purpose a DVD-ROM drive to have it mount my PCBs, it sort of works but sometimes run into leveling issues:
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I'm now using some wood and sticky taping a smaller PCB to the wood and I just have WD40 to spray on the PCB when milling (I should buy proper cutting fluid soon):
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I tried 0.2mm carbide drill bits (ebay), they sort of work but broke very easy, I think it's because I had to drill a bit too deep due to the height inconsistency. I found some 0.1mm 10degree V shape bits (ebay), at first it didn't seem to make that much of an improvement, but after a few more tries I got a good result:
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Then I tried QFP just for fun and it worked, took about 30-40 minutes, there was a one trace that was shorted to ground, traces are 0.254mm/10mil wide:
Image

I'm probably drilling 0.3mm down in total because of height inconsistency, I'll need to do more testing, maybe try 0.3mm trace width but I'm very happy to have some success! :) Though I'm a bit afraid of changing the drill bit as I don't know if it will still be a good as it is now - I just don't want to touch anything :lol:

USB Microscope Pics of the QFP traces, not all seem to be width consistency.
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My PCB Gcode setup at the moment:
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And my Shapeoko 2 setup:
Image
(yes those two 12V batteries are holding the block in place :lol: )

edwardrford
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Re: Interested in Shapeoko v2 for PCBs

Post by edwardrford » Wed Apr 16, 2014 2:13 pm

Alexig -

Really nice writeup, thanks for all the info!

A couple of things that you can try to improve your results.

1.) Take a piece of thick (12+mm) MDF, roughly 150x150mm. We will call this your platen. Fix the platen to your wasteboard in a more permanent manner than the 12v batteries (just screw it into the wasteboard if you must. Be sure to countersink the holes a few mm (3-5))

2.) Now, do one of two things:
a.) If you always use the same size copper clad blanks - make a shallow pocket in the platen that is slightly larger than your blanks. This pocket only needs to be 1-2mm deep
b.) if you use scrap copper (or various sizes). Run a facing operation across the entire platen. This will bring your work surface exactly square with the machine.

3.) Download/Install/Use the autoleveler software: http://www.autoleveller.co.uk/ - Although your platen is going to be square with your machine, the thickness of the actual copper varies across any given piece by as much as .1-.2mm. The autoleveler software will help compensate for this.

4.) Dominate your PCBs!

5.) Post pictures to the forum so we can all drool.

-Edward
Shapeoko 1 #0 - a couple of upgrades.
Shapeoko 2 #0 - a couple of upgrades.
Shapeoko 3 #2 - Stock

alexig
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Joined: Sun Dec 15, 2013 4:36 am

Re: Interested in Shapeoko v2 for PCBs

Post by alexig » Wed Apr 23, 2014 1:21 pm

Thanks for the tips Edward. I'll have to take a look at the auto leveler in the new dev of GRBL soon.

Doesn't look pretty but I did make the platen and it seems to work fine. I've stopped using any WD40/fluid to help with the milling.
Image

Whilst my initial PCBs posted before look good however when soldering they are very suspicable for solder bridges. The traces are also a little rough. After a bit more testing and probably my V bit getting a bit more duller, I now run 2 passes and it looks better now (like the other pictures of PCB I see from other CNC users). As there is more isolation between the pins it's easier to solder. I just used the V bit to also drill the holes too slowly. Increased traces to be safe to 0.4mm.
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And the PCB is built, I used a thin solder tip, have to be careful after soldering header pins as they are easy to break the traces if you move them quite a bit.
Image

I have been experimenting with 2 sided PCB but the main problem is the alignment of holes especially with various sized PCBs but I might just stick with single sided PCBs for the time being and use jumper wires on the bottom or similar if need be.

Edit:
Updated PCB-Gcode settings
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Last edited by alexig on Wed Apr 23, 2014 1:41 pm, edited 1 time in total.

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