. .
  1. #1
    Hi
    I'm a total newbie living in Manchester with a sudden need to get up to scratch on CNC machining. Basically, I'm working on a research project (UAV/drone) which requires components to be cut from 1.5 x 400 x 500 mm and 2 x 400 x 500 mm carbon fibre composite boards using a CNC router. Unfortunately, I've recently found out that a couple of our workshop guys are off on long term sick leave (hopefully not carbon fiber dust! ), meaning that there is a several month backlog on jobs on our CNC equipment (this basically kills my project deadline). I do have access to alternative facilities (ShopBot PRS standardCNC), but will only be able to get limited training on the equipment. I realize that CF is not a straight forward material to machine in terms of quality of finish, tool life and health and safety, so I thought I best come to the experts for advice.

    The setup does have an extractor and is in a well ventilated area, and I intend to use a respirator with Hepa filters and disposable clothing during operation. The CNC does not have any intrinsic cooling for the end mill as far as I know (i.e. air/water jet) so this may be a concern given the abrasive nature of the material. However my main concern lies in the choice of end mill needed to cut the CF. I know that the pros use diamond coated tooling, but I cannot really justify the expense (I will probably need 1 mm and 2 mm (and possibly 3mm) cutting diameter to cut the different levels of detail in the design [see attached]). Also, given that this is a one off, I don't want to pay £50+ for bits when they could still snap anyway. The cutting run will probably be a few meters max (nb: cutting sheets in the diagram are 400 x 500 mm).

    I was thinking of using a carbide two flute end mill (see below) running at 15000 RPM with a feed rate of ~ 500 mm per minute.
    Carbide End Mills 2 Flute - Arc Euro Trade
    I have read that people have had some success using diamond cut router bits and diamond burrs in CF, but have not seen any results close up. I do not mind ruining a few carbide bits, as long as I have enough to complete the production run of two sheets. I do, however, require the edge to be decent (no chips, splinters), and want to avoid clouding the CF with overheated tools.
    So in summary, I'm wondering....
    · What is the best low cost tool to achieve the job in hand and how many will I need to complete it (specific products would be very helpful).
    · What is the best feed rate-RPM combo to use
    · Are there any DIY methods to keep the bit cool

    To be honest, I would be happier having a third party do the cuts, but I just haven't budgeted for this eventuality (I'm on a doctoral grant which is pretty lean and not being able to use in-house facilities is really killing me).
    Apologies for the length of this post, but I would greatly appreciate any advice that members would be able to offer me
    Thanks
    Thomas
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	cuts.jpg 
Views:	442 
Size:	260.5 KB 
ID:	8321  

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Seeking some practical squaring advice.
    By Wal in forum Gantry/Router Machines & Building
    Replies: 12
    Last Post: 09-01-2014, 12:04 AM
  2. Which of these bits for carbon fiber and fiber glass?
    By craigrobbo in forum Tool & Tooling Technology
    Replies: 5
    Last Post: 28-02-2013, 01:03 AM
  3. NEW MEMBER: Hi all - Seeking advice for a new project
    By julian in forum New Member Introductions
    Replies: 3
    Last Post: 23-06-2012, 02:53 PM
  4. NEW MEMBER: New member seeking advice
    By Rob Wol in forum New Member Introductions
    Replies: 14
    Last Post: 02-02-2012, 10:54 PM
  5. Carbon fiber keyrings...
    By Jonathan in forum General Discussion
    Replies: 4
    Last Post: 08-03-2011, 02:39 PM

Tags for this Thread

Bookmarks

Posting Permissions

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