Which bits to use for PCB milling? - Page 3

Page 3 of 14 FirstFirst 12345613 ... LastLast
Results 25 to 36 of 167

Thread: Which bits to use for PCB milling?

  1. #25
    Member
    Join Date
    Jul 2012
    Location
    Danmark
    Posts
    82
    Downloads
    0
    Uploads
    0

    Default Re: Which bits to use for PCB milling?

    Hmmm ... ok, thanks for your feedback ... Just pondering

    Cheers,

    Jesper



  2. #26
    Member
    Join Date
    Jun 2010
    Location
    Australia
    Posts
    3887
    Downloads
    4
    Uploads
    0

    Default Re: Which bits to use for PCB milling?

    That's the problem in this game: too many possibilities and not enough $$.

    Cheers
    Roger



  3. #27
    Member
    Join Date
    Jul 2012
    Location
    Danmark
    Posts
    82
    Downloads
    0
    Uploads
    0

    Default Re: Which bits to use for PCB milling?

    >> That's the problem in this game: too many possibilities and not enough $$. << ... Well, indeed. And IMHO (one?) of the most challenging disciplines here is to clearly define my needs so as to get the needed/desired machine. Not that easy not coming from the CNC world ....



  4. #28
    Member
    Join Date
    Jun 2010
    Location
    Australia
    Posts
    3887
    Downloads
    4
    Uploads
    0

    Default Re: Which bits to use for PCB milling?

    At the risk of being legitimately accused of contradicting myself, thi is actually the only valid argument for buying a real cheap Chinese machine - IF you have the mech and electronic skills and tools to make the wretched thing work.

    After all those hassles you will have a far better idea of what you want - and you should be able to sell the Chinese machine locally as a going concern as well.

    Cheers
    Roger
    PS: no-one ever said CNC was a cheap hobby.



  5. #29
    Member
    Join Date
    Nov 2013
    Posts
    304
    Downloads
    0
    Uploads
    0

    Default Re: Which bits to use for PCB milling?

    Hi Jesper,
    I've been through my email and deleted all of the junk. The companies name was Mentor, when they email again I'll forward you a copy.

    All of the routers use deep groove ball bearings. In order for them to spin 25000 rpm they must have quite a bit of clearance and consequently they
    'rattle'. I would expect TIR no better than 15-20um. Doesn't matter how good the collet is if the shaft has that much play.

    All high speed mill spindles have matched and paired (or multiple matched pairs) of P4 grade angular contact bearings, steel to about 24000 rpm, ceramic balls
    through to about 42000 rpm and ceramic balls and races beyond that. Above 60 000 rpm you are in air bearing territory.

    The manufacturer of my spindle claimed less than 5um TIR with the steel bearings fitted. It made sense then to get a good collet, the ordinary collet was about $15.00
    whereas the Rego-Fix one was about $30.00. Rego-Fix is the Swiss company that invented the ER collet system. Their toolholders are beautiful.

    I bought a Rego-Fix cylindrical ER25 toolholder from the New Zealand importer and it cost $460NZD, about $350US! I nearly died when I realized what I had committed
    myself to, on the other hand it is the core of my servo driven high torque spindle. The angular contact bearings are about the same money. I made this spindle myself,
    I couldn't afford to have it made for me and while its not perfect its not too bad either and it sure rips into steel and stainless. I'm quite proud of it and glad now that
    I elected to make it myself.

    The original purpose for the heavy copper board was for an AC servo drive board. The output is 15A per phase continuous and 48A overload. I'm using TO247 MOSFETs and needed
    fairly small width (3-4mm) traces to maintain the creep distance between traces thereby avoiding a flash over. As it turns out it is really nice to be able to use a traces as narrow
    as 1mm and still carry 10A. Once you get used to designing boards with that capacity you tend to become hooked on it and so I've made a few projects which are by no means
    as demanding as the servo drive but still take advantage of the heavy copper.

    Craig



  6. #30
    Member
    Join Date
    Nov 2013
    Posts
    304
    Downloads
    0
    Uploads
    0

    Default Re: Which bits to use for PCB milling?

    Hi,
    this company:
    https://www.mechatron-gmbh.de/en/

    An I got this model...it was the cheapest:
    https://www.mechatron-gmbh.de/filead...FS-6508-AC.pdf

    This is the same size and power, 800W but watercooled and up to 60,000rpm with a 1000Hz VFD and look at the TIR<2um, probably cost a fortune:
    https://www.mechatron-gmbh.de/filead...FP-6508-60.pdf

    Craig



  7. #31
    Member
    Join Date
    Jun 2010
    Location
    Australia
    Posts
    3887
    Downloads
    4
    Uploads
    0

    Default Re: Which bits to use for PCB milling?

    Nice unit, but only ER-11. Understandable for 24k rpm of course.
    I would love it, but sadly it would not handle my fly-cutter: 43 mm radius and a 12 mm shaft. Other cutters at 12 mm too. Usually spun at about 2,500 - 3300 rpm. VFDs have no power at those rpm. Can't have everything.

    Cheers
    Roger



  8. #32
    Member
    Join Date
    Jul 2012
    Location
    Danmark
    Posts
    82
    Downloads
    0
    Uploads
    0

    Default Re: Which bits to use for PCB milling?

    Hi all - or good morning as it is now here in Denmark ...

    @Craig: Thank you once more for describing what you are doing and giving various links. BTW I notice that you are also relatively new to this forum (22 posts) and so I reckon that most of your posts may have been in this thread - helping me out. Appreciated Craig

    >> I nearly died when I realized what I had committed myself to, on the other hand it is the core of my servo driven high torque spindle. << ... I just took a look at the ER series from Rego-fix, and yes, I would also have been surprised that it cost USD 360. On the other hand - have you ever been to Switzerland? To my memory Switzerland has the highest price index for living of any country in the world. I would expect this is reflected in the price level of the goods they manufacture. And then I assume there's shipping and customs to New Zealand (?)

    BTW maybe this ebay vendor is interesting to you:

    https://www.ebay.de/sch/heinle-zersp...p2047675.l2562

    About Mentor it would be fine if you can email me a copy of their promotional email when you get another one. The only Mentor I've found in China making PCBs is Mentor Graphics and they appear to have a couple of subsidiaries that do not describe in too much depth what they actually do:

    https://www.mentor.com/pcb/service-b...?country=China

    However, one possible advantage is that they appear to be part of Siemens so just maybe they have reasonable environmental and employee policies ...

    @blinkenlight: You gave me a couple of links in a previous post to companies within the EU who sell CNC mill bits. I have not yet thanked you for this - but thanks ... I have taken a look at them and will keep them in mind for future purchases.

    @RCaffin: >> Usually spun at about 2,500 - 3300 rpm. VFDs have no power at those rpm. Can't have everything. << ... Good to know that it may be so.

    Now off to milling - first aluminum milling today

    Cheers,

    Jesper



  9. #33
    Member
    Join Date
    Jul 2012
    Location
    Danmark
    Posts
    82
    Downloads
    0
    Uploads
    0

    Default Re: Which bits to use for PCB milling?

    Hi again ...

    Just wanted to briefly share the result of my first aluminum milling today. From looking at the picture (attached) of the milled aluminum I wouldn't exactly call it a success - BUT when using a 6 mm HSS steel end mill the end-to-end material thickness difference is less than 10 um - more like 5 um. Which IMH (and maybe uninformed ?) opinion is quite good - not least because the Z-axis for me also is the most important axis.

    That said I wonder if I can make you more experienced people look at the picture and say what you think is amiss here?

    * The milling trial to the far left was done with a 2.4mm "hartmetall" 2 flute end mill running at 24000 rpm and a feed rate XY of appr. 340 mm/min. The milling strategy is called "peel" and I think it looks worse on the picture than it actually feels when running my fingers over it.

    * The middle milling trial is with the 6mm HSS 2 flute end mill running at appr. 8700 rpm and 240 mm/min. Again "peel" strategy which appears to end the milling process with milling the sides of the area to be milled, thus creating a center-to-sides level difference.

    * The right-most milling ended before being completed because the milling process heated the aluminum which then released from the double-sided adhesive tape otherwise holding things in place. But this is where the mostly end-to-end Z-axis level difference is about 5um to 10 um.

    My impression of the mill while milling was that things were actually vibrating/shaking. And also that there was some XY-axis "chatter" which seemed to cause the grates on the sides of the milled tracks. This may of course be because I have used less than feasible end mills and less than feasible feed rates/spindle rpms, although I tried to adjust the spindle rpm up and down a bit during the millings. In any case I'd appreciate a couple of your suggestions for end mills (2-2.4 mm & 5-6mm) that I can use to face mill and 3D mill mainly smaller copper items - and wood items.

    Also - just out of curiosity - and if it's interesting to you! - do one of you have a link to a small CNC mill that will at least do aluminum perfectly - and also be ok/fine with steel and stainless? Could be interesting to see what is prioritized in such a design ...

    Have a good day wherever you are

    Jesper

    Attached Thumbnails Attached Thumbnails Which bits to use for PCB milling?-milling-jpg  


  10. #34
    Member
    Join Date
    Jul 2012
    Location
    Danmark
    Posts
    82
    Downloads
    0
    Uploads
    0

    Default Re: Which bits to use for PCB milling?

    ... Well, not to elaborate too much on my own stuff but it seems that it is the Z-axis that is very "flexible" in the Y-axis direction (rotating "around" a Y-axis direction) ... ... Will have to find a work-around for this ...

    Cheers,

    Jesper



  11. #35
    Member
    Join Date
    Jun 2010
    Location
    Australia
    Posts
    3887
    Downloads
    4
    Uploads
    0

    Default Re: Which bits to use for PCB milling?

    The photo:

    I suspect that the 6mm cutter may be too big for your router. Especially on the RH cut.
    I suspect that trying to do full-width cuts with that 6mm cutter is too much.
    I suspect that you need some lubricant on the cutter. If all else fails, try some WD-40, or even SAE-30 oil.
    I also suspect you need sharper (and new) cutters optimised for aluminium. Chinese carbide is not always 'sharp'.

    It may also be that you are trying to machine soft gummy bending-quality Al - which is rarely successful at the start.

    HTH
    Cheers
    Roger



  12. #36
    Member
    Join Date
    Nov 2013
    Posts
    304
    Downloads
    0
    Uploads
    0

    Default Re: Which bits to use for PCB milling?

    Hi Jesper,
    Rego-Fix is expensive not only because its Swiss but its also superbly made and you pay for quality no matter from where.

    The Ebay listing shows a toolholder very similar to the one I used for about 130 EURO. The price I paid in New Zealand dollars is somwewhat inflated by virtue of going
    to the New Zealand importer but not hugely so. I would do some more research were I to consider another purchase like that.

    Craig



Page 3 of 14 FirstFirst 12345613 ... LastLast

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


About CNCzone.com

    We are the largest and most active discussion forum for manufacturing industry. The site is 100% free to join and use, so join today!

Follow us on


Our Brands

Which bits to use for PCB milling?

Which bits to use for PCB milling?

Which bits to use for PCB milling?