CNC Waterjet cutting instrument holes

After designing the panel on AutoCAD, I sent the .dwg file to Severn Valley Sailplanes in the UK. They made the fibreglass panel and CNC cut the holes.. They did an outstanding job, produced a delamination-free panel and shipped it to my door. If I was to try to find a negative it would be the wait before starting as they had a number of jobs on. But for experienced pros, definitely worth the wait.

CJ
B3

I have cut a lot of fiberglass on waterjets. It will delaminate a small circle around the hole pierce, this can be avoided by drilling thru holes where they can start the cut. A backing board will not prevent it, it is a consequence of the waterjet pressure forcing between the laminate layers before the pierce is complete. The edge will be very nice and clean. You can also cut the panel in a conventional CNC machine, however fiberglass is pretty abrasive and so many CNC shops don't want to deal with it (dust gets into the machinery and wears it out). I will cut it on my open mill so I can vacuum up the dust and chips as it is cutting (but I still don't like it), I will not put in the VMC with coolant etc. - no way to collect the dust.

On Thursday, February 26, 2015 at 12:06:01 PM UTC-8, wrote:
Hey All,
Does anybody have any experience with getting a fiberglass instrument panel CNC cut with a waterjet (or any other CNC cutter for that matter)? I called several local shops and I couldn't get a definitive answer whether the waterjet will delaminate the composite around the cut holes or not.
I've previously cut with bi metal hole saws and the hole turned out quite a bit too large and I trust a robot to measure a lot more accurately than myself. I was also interested in laser CNC cutting, but I'm pretty sure that will burn the composite around the edges of the cuts.
Any input would be appreciated.

Thanks,
Omri

Holes saws are very inexpensive at Home Depot. 2 1/4" 57mm, 3 1/8" 80mm.

Use these instruction to draw the hole on the fiberglass panel. Center punch and be very accurate. Pilot drill with a small drill and then drill mounting holes and large instrument hole. Fiberglass cuts like butter. Use a drill press and plywood for backing drill from the back of the panel.

Instructions to make the perfect hole.

http://www.craggyaero.com/Drawings/I...0Templates.pdf


Richard
www.craggyaero.com

Hey All, I ended up having it CNC routed by a machine shop named AST Waterjet (they do CNC routing too) in Grand Prairie, Tx (in the Dallas area). Cost me $195 which was their shop minimum. It turned out really well, no delamination around the edges. I had them drill the 4 screw holes around each instrument undersized and I reamed the holes up by hand with a drill press after. Every hole lined up perfectly so I didn't need to oversize any of those screw holes which was nice from a hole edge clearance point of view and since some instruments used 3mm screws, some 3.5mm and some 6-32. Turned out nicer than I could ever imagine doing by hand and probably saved me a lot more than $200 of my time. Did a full trail fit of all instruments, switches and everything yesterday and it all fit well, I'm spraying primer on the panel later on today.

On Monday, March 30, 2015 at 11:02:51 AM UTC-7, wrote:
Hey All, I ended up having it CNC routed by a machine shop named AST Waterjet (they do CNC routing too) in Grand Prairie, Tx (in the Dallas area). Cost me $195 which was their shop minimum. It turned out really well, no delamination around the edges. I had them drill the 4 screw holes around each instrument undersized and I reamed the holes up by hand with a drill press after. Every hole lined up perfectly so I didn't need to oversize any of those screw holes which was nice from a hole edge clearance point of view and since some instruments used 3mm screws, some 3.5mm and some 6-32. Turned out nicer than I could ever imagine doing by hand and probably saved me a lot more than $200 of my time. Did a full trail fit of all instruments, switches and everything yesterday and it all fit well, I'm spraying primer on the panel later on today.

Great news. Thanks for the update & have a good flying season.

Craig
7Q