New Member

[DaveJ]

Hi,

I am a new member in the NE of England and new to CNC. I am a chemist by profession and we regularly make carbon fiber composite panels, my focus is very much on the resin chemistry, varying it to change the mechanical properties. I've finally convinced my colleagues that we should buy a CNC to divide up our panels into smaller pieces that we can fit into mechanical testing machines. Currently we make panels about 90 x 90 cm.

I am completely new to CNC, but I am currently looking at what is available. Primarily we'll need to be able to cut through carbon fiber epoxy to create dog bone and rectangular shapes (circa 8cm x 1 cm). Many of my colleagues are skeptical having in the past paid bottom dollar (<£2000) and found them to just tear up the carbon fibres so much that the cut pieces are useless (jagged edges). Browsing this forum I am starting to realize how much there is to this (e.g. calculating the CNC stiffness?).

If anyone can recommend any books, websites or point me to the correct threads I'd appreciate it. Also if anyone has any advice on what I should be looking for in terms of CNC specifications for this application it would be really helpful. I am hoping we can get what I need for £10-15k.

Dave

[Kitwn]

Dave,
Without knowing details of the materials you make, the previous CNC machines you have bought and how hard you tried to make them work correctly it's difficult to give a definitive answer, but my gut reaction is that your first resort is more experimenting with the choice of cutting tool and the feeds and speeds used on your existing machine(s).
My apologies if you've already spent several days on that and proved that it really is junk.

It should not be difficult to build a very rigid machine at reasonable cost for the small size pieces you want to cut out, especially if you can reduce the 90 x 90 panels down to a smaller size on a table saw or similar. For a given level of stiffness, the price rises exponentially with the size of the cutting area.

Kit

[mekanik]

Hi Dave
Welcome to the forum
As Kitwin has already mentioned for the size of machine you require the budget you mentioned should more than suffice, you could build it yourself but there are members on the forum that would also do this and save you the hassle so you could concentrate on another major concern, the collection of carbon fiber dust. If you would rather have someone make your machine make a post in FREELANCE JOBS AND REQUESTS stating your machine requirements.
Good Luck
Regards
Mike

[JAZZCNC]

Dave, I sent you an email as I cannot private msg you for some reason. If you don't get it send me private msg with your contact details and I'll get in touch.

[Lee Roberts]

Hi Dave welcome to the forum and good luck going forward.

You would be in good hands coming to an arrangement with Jazz, he will be able to give you great advice and a machine i'm sure.


Dave, I sent you an email as I cannot private msg you for some reason. If you don't get it send me private msg with your contact details and I'll get in touch.

Dave's account restricts have now been lifted Dean so you should be able to PM him now, for some reason the user promotion system skipped his account, not sure why as everything looks to have been business as normal, sorry for any inconvenience.

[routerdriver]

Is there a particular reason why you favour a router over a waterjet?I have seen very clean edges on pieces cut that way and I have seen pieces from a router that started off clean and got a bit fuzzy as the edge wore.I would also be curious about how you would propose to hold a piece as small as 8cm X 1cm against the force of a router.It seems very close to the size of a tensile strength test piece as I recall.

[JAZZCNC]

Is there a particular reason why you favour a router over a waterjet?I have seen very clean edges on pieces cut that way and I have seen pieces from a router that started off clean and got a bit fuzzy as the edge wore.I would also be curious about how you would propose to hold a piece as small as 8cm X 1cm against the force of a router.It seems very close to the size of a tensile strength test piece as I recall.

You try an find a waterjet for 10K.!! . . .Intensifier pump alone will be 10K.

Work holding something so small is tricky but can be done with good vacuum fixtures.