[DENALI]

I am not sure where or who to ask this to so i am hoping you guys in here can help me out with what i need to accomplish or point me to where i need to go.
I am working with a 24 inch wide by 48 inch long by 3/4 inch thick sheet of hard plastic. Sort of like the same material plastic cutting boards are made out of. I am trying to figure out how the most cost effective way (or even how to do it in the first place) to machine in 1/8 inch grooves across the 24 inch width every 1/8 inch for the whole 48 inch length. These grooves need to be about 1/16 inch deep. So in other words there would be a 1/8" groove then 1/8" of original surface then another 1/8" groove etc for the entire 48". Also it needs to be a neat and clean finished look so just buzzing a radial arm saw across it every 1/8 inch or so wont work, not accurate enough.
Thanks for any help.

P.S. This needs to be a repeatable process IE hopefully I will be making 100's of these to sell over the next few years.

[WhiteTiger]

Personally I'd use a router with a shoe plate made for it that had a 1/8th brass strip screwed to it 1/8th of an inch from the cutting bit. Use it as a fence to make your first cut, then use the brass strip in the cut as a spacing guide.

Probably be easier to do it with the router free for hand use than to try to do that many grooves in that large a workpiece with the router mounted in a table. Too easy to get bogged or jump the track trying to horse a 2x4 foot workpiece around, imo.


Tiger

[wizard]

If you expect to do a lot of these you need a variant of a router based CNC machine. If you are on a budget you might even manage to do this on a 2 axis machine.

The biggest problem is the sheet size which would require a larger router and the corresponding room to place it. ideally the machine would incorporate some sort of dust/swarf extraction also.

Since this is plastic with a farily light cut you should be able to build an inexpensive machine. Or purchase something towards the lighter duty side. That is if you are cheap and don't see a future for the machine beyond this project. If you are in business though this might be a good justification for a heavier more versatile CNC router.

By the way the first response about a router with a custom skate attached is a good idea for limited production. It is labor intensive though. With a CNC router you should be able to step away from the machine for a few minutes for each panel. I would also tend to say that a CNC router will in the long run do a better job quality wise.

Thanks
Dave

[WhiteTiger]

The first suggestion was for a "foot in the door" means of getting the product into the market. Low investment (aside from labor time) way to test the waters as it were.

For large scale production you'd want to cut time per piece to minimum as well as machine/tooling costs, so a CNC is going to be out of the running as well on both counts (imo). Making a separate pass for every one of 192 grooves is silly, especially if you've invested a few $k in the machine.

It'd be cheaper, and yield faster production time to build a dedicated machine to do just the one job, imo. Something with a ganged horizontal axis cutter that will groove half of the sheet at once, then simply index the workpiece off of the grooves just cut and pass the gang cutter over the other half. Should be able to build both the cutter set and the body of the machine for less than what a cnc rig would cost.


Tiger