PCB CNC machine

Hello everyone,

I am looking for an advice how to overcome a problem.

The problem looks like this. I need to produce relatively large number of parts made out of 4 mil (0.1mm) copper sheeting. I already made a test run of 10. They are very small (approx. 40 X 80 mil, 1 X 2 mm). In order to prevent them from being sucked by the vacuum system I used a double sided “Scotch tape” from 3M (P/N 34-8518-3091-8). This was good and works fine. The problem comes when I have to remove them. Due to the sticky tape they come out bent and it is slow and difficult process to remove them.

I will be very happy if someone has an idea how to solve this problem, having in mind, that I need to make a few hundreds.

rolmix:

It is very easy. Simply leave some slack tape outside your work piece that will allow you to remove it together with

the parts. Then soak the entire thing in mineral spirits (turpentine) for more than half a day. All of your parts will

come completely loose without any effort.

Try it and let me know how it comes.

I did this in the past for another reason using double sided tape, but I think it will solve your problem.

BTW shallow aluminum pans sold for baking cookies are the best container to do this :slight_smile:

Great!!! It works perfect!

Thanks!

For cheap and easy holding, double sided registration and making cheap pcbs see:

http://www.millpcbs.com/index.php?optio … &Itemid=46

Stencil making see:

http://www.millpcbs.com/index.php?optio … &Itemid=49

To see the results of the pcb process, make sure to look at the end result of the size at the end of the video:

http://www.millpcbs.com/index.php?optio … &Itemid=51

Unfortunately, there is a big difference between a professional machine like A365 or S60 and DIY. Seems to me that it is coming from the dynamic tool penetration control that LPKF and Accurate have on the Z axis. Accurate even offers a SW that generates a G code to be executed on other CNC systems.

In any case you hardly will achieve something better than 10/10 mil trace/space without this tool penetration control.

It is about a month ago that I have sold my A365 to a friend and I am now a proud owner of A606 :dance: http://www.accuratecnc.com/A406_A407_A606_A607.html

This machine is a miracle. Once you start the program you are free to do something else until the time comes to flip the board. This takes a minute or two and next attention is to get the finished board.

I was very happy with my A365, but this machine is amazing.

The only thing that I am sorry about is that I didn’t select A607 with 100K RPM spindle…

rf333:
… and I am now a proud owner of A606 :dance: http://www.accuratecnc.com/A406_A407_A606_A607.html

I am very interested in a machine that can work on these new substrates that are aluminum backed in order to be heat sink to the power LED’s. The volume that I am planning to run is definitely small, but boards have complicated shape and internal cuts.

I would like to get more info about the “peck mode”.

Is it fully automatic as the manufacturer insisting or it needs operator settings on each pass?

This is important to me, because I do not see any chances to cut 1.2 – 1.5 mm aluminum at once.

Rob

RobPb:

rf333:
… and I am now a proud owner of A606 :dance: http://www.accuratecnc.com/A406_A407_A606_A607.html

I am very interested in a machine that can work on these new substrates that are aluminum backed in order to be heat sink to the power LED’s. The volume that I am planning to run is definitely small, but boards have complicated shape and internal cuts.

I would like to get more info about the “peck mode”.

Is it fully automatic as the manufacturer insisting or it needs operator settings on each pass?

This is important to me, because I do not see any chances to cut 1.2 – 1.5 mm aluminum at once.

Rob

Yes, the ‘peck’ is fully automated in A606. The operator just has to set the increment of the tool penetration and final depth of cutting. Just run it and it will do the job to the end.

No intervention is needed!

Ok so i have been having this problem with my pcb design. For some odd reason i don’t get errors when i check my files back in eagle but when i export my gerber files to batchpcb it fails. What i’m looking for is some help.

This is my Gerber files that i exported.

http://www.mediafire.com/?yzj0b2wzlcvek7l

This is my board layout/ schematics

http://www.mediafire.com/?sy29meywx2skwtg

http://www.mediafire.com/?7iivp7yrx5tmkd3

This is my job that i use for the gerbers.

http://www.mediafire.com/?6z1zntbzf3fel9g

Please help me and tell me whats wrong. If you could, you can edit mine to make it work and post a link of it so i can download the files and upload them. Or you can email them to me at josh12persaud@yahoo.com

ragingenferno:

Hi @ragingenferno,

Have checked your Gerber files with PhCNC (The software of my machine) and didn’t found any problems.

I do not use BatchPCB (making prototypes my self), but under the conditions mentioned here: https://www.batchpcb.com/faq#question_2

There are some problems with your Gerber files:

  1. clearance is lower than 8 mil (one mil=0.001 inch=0.0254mm).

“… 8mil (~0.2 mm) spacing minimum …”

You can see the problems in pink (measured clearance 7.8 mil):

You have to increase the clearance between the traces and pour copper to 10 mil. The board is simple. I don’t see any problem to do so.

  1. There is internal hole in your mechanical layer (the green arrow above), they consider this unacceptable, but may not be a problem.

"… No internal routes, no v-scoring, only drill files are sent to the fab house … "

Seems that you can remove it, because it doesn’t matter.

Your drill file is in 2.4 TZ, so it is right on the requirements:

“…Figure out how to make your PCB software output an Excellon/NC Drill file with 2.4 trailing format. …”

I am using Altium 09 and didn’t know well Eagle (didn’t use it for years), … but what you have to change is the clearance to pour copper from 8 to 10 mill (menu Tools/Drc of Eagle 6.2.0!)

This way the clearance is 10 mil (there are problems only in the text – pink marks):

I can try to attach the new Gerber files, but definitely think that it will be better if you do this your self (I have generated them in a JOB file).

What I don’t like in the project is the text in the copper. You can move it away from the pads or simply move them to the screen print (if any).

Ok thank you do much for your tips. I will try and do it myself. But if I can’t then I will use your gerbers…

30mins later: ok so I did what you told me and I even moved the letters to the silk screen. I would have never

Did it without you. Thank you so much for your help. I uploaded it and it passed. Now my controller will be better. Thank you once again.

Dear, rf333 if possible could you please answer - how do you fix the foil on your 360 mill when you work with stencils? If possible - can you post some photos. We have good source for fast pcb production but no source for cost effective stencil production. I also interesting in the ni-coated brass 7.5mil foil you are talking about. Thanks in advance!

diymonster:
Dear, rf333 if possible could you please answer - how do you fix the foil on your 360 mill when you work with stencils? If possible - can you post some photos. We have good source for fast pcb production but no source for cost effective stencil production. I also interesting in the ni-coated brass 7.5mil foil you are talking about. Thanks in advance!

Hi @diymoster,

I am really sorry about the delay, but I am in vacation now and hundreds of kilometers away from my office.

Unfortunately to me, the vacation is close to its end :).

I definitely will post pictures next week.

The material used is Ni coated brass, actually the coating does noting to do with the process.

Typical brass sheet sold as material for shims will do the job. You have a choice of different thickness depend of the amount of the solder paste you like to deposit.

The best way to mount it on the machine table is to use double sided sticky tape, cheap phenolic or paper based sheet as a backing material and the same tape to mount the brass sheet on backing material.

Thank you for your reply, @rf333. Hope you are satisfied with your vacation=) Sorry to trouble))

Will wait for your photos, as i can understand - it is not simple task to remove the tape from the back side of the stencil…

Hello @rf333,

Do you have an idea what is the maximum depth of drilling/cutting of your machine. I am looking for an ATC machine for drilling holes in very thick 9.5mm (fiber epoxy material, garolite). The drill sizes are different, but many of them are 0.68 mm. High precision is required. The holes will hold pogo pins.

For the volume of production that I am facing it will be better to have something new and definitely ATC.

I have contacted lpkf about s63, but it can’t drill that deep.

Hi @marianmp,

The maximum depth setting that the SW allows me is 11.4 mm , but this is actually the entire travel of the pressure foot (looking at the reading of the gauge). I definitely believe that machining depth of any kind up to 11 mm is not a problem. In your particular case the aspect ratio is quite impressive 9.5/0.68 and definitely will require the use of peck mode. In my model it is completely automated, but still adds up to the machining time.

On the other hand it is impossible to do this ratio with standard single pass drilling. You definitely will break the tool on the first hole.

You better contact accuratecnc for more details.

I notice that they have bunch of new models… and mine is already an old one :frowning:

Hello @rf333,

Thank you for the help. Finally I ordered the top model http://www.accuratecnc.com/Specs/A637.pdf with vaccum table and expect to receive it for Christmas :slight_smile: