router bit for metal cutting help

[sabastion]

I am needing help in selecting a router bit for a project I am working on.

I will be using a hand held router. I need to draw a template on paper then transfer the drawing to 1/8" (inch) lexan and cutting out the drawing to use the 1/8" (inch) lexan as a template (repeatable).

I will then be using the lexan template, taped to computer case side panel, and cut out the shape from the drawing by following the 1/8"(inch) thick lexan inner contours of the template.

I know I will need a router bit with a bearing. What I dont know is...is there a specific one for use with 1/8 inch thick material template and do I need two different bits for cutting the lexan and 1 for cutting the metal side panels? I am also assuming that I should be using a drill bit type router bit?

what I am picturing is something like this EZ-Change Replaceable Head Router Bit - Template (Assembly) -Toolstoday.com- Industrial Quality Router Bits but with drill bit type cutter.

Any help you guys can offer is appreciated. links and or pictures would also be awesome...ty
Richard

[J.Lord]

Hi Richard.
I would find another method for cutting your metal panel. I would not recommend using a router for this. Metal work generally needs slower speed than routers produce. If you want to cut sheet metal maybe draw your shape on the side panel & use sheetmetal sheers to cut out shape. Then clean up with a file. You could also try a jigsaw with a metal cutting blade to cut the shape out.

[sabastion]

the drill bit would only need to be 1/16" (inch) in diameter...It wouldn't need to be a huge bit.

What about a variable speed handheld router..could be as easy as installing a Pot.

[ger21]

Unless you enjoy razor sharp shards of steel burning into your arms, you don't want to use a router to cut a steel case.

[sabastion]

Unless you enjoy razor sharp shards of steel burning into your arms, you don't want to use a router to cut a steel case.

I appreciate the thought but I have welding sleeves, welding jacket, leather apron and some routers come with clear debris shields that enclose the open area from router to work surface so this wouldnt be a concern at the moment

[flyinchips]

Sabastion

What you are attempting to do is outside of "generally accepted machining practices". That doesn't mean you can't do it. It does mean most of the people here will have no experience with this. You will have to experiment on your own to create the magic sauce to get this done.

For instance: To machine mild steel with a 1/6 2 flute high speed steel cutter at a depth of .040, the recommended cutter speed is 3000 RPM, well below the peak torque band for your router. Furthermore. the feed rate is .5 inches per minute, so one would expect to take 2 minutes for every inch of material that need to be cut. Cutter deflection is the reason for the slow running; any faster feed and that tiny cutter will snap. A 1/4 inch cutter would need to spin at 870 RPM and the feed would be 1.7 IPM. We have improved our ability to get it done, but we have moved further away from the sweet spot for the router.

These are some of the reasons for push back in the responses. Again, it doesn't mean it cant be done, but you'll probably be the one telling us how it's done after you have figured it out.

I would think water jet cutting would be a better approach, but I guess that takes this out of the DIY category and removes the fun. Another way would be to purchase a nibbling tool and fashion a guide system for the nibbler. We would still be in the DIY category, but you might need to invest in a pricey air compressor to support the nibbler.

[aarggh]

Machining through steel will be noisier and vibrate like mad more than you could imagine, but if you have to do it, I'd make the template, and then use it to draw the cutout on the panel, and use hand cutters to cut the panel just a few mm shy of the cutting line, and then run a HSS bit around it with the template to trim the rough edges. You'll find this much safer, and easier to accomplish than routing right through a steel panel.

Good luck Richard!

cheers,
Ian