Need help flipping jobs.

[Mattyvdv]

Hi everyone.

Im very new to the cnc side of machining. Work recently brought a multicam router and so far i have been practically teaching myself how to use it with very good results. However, i have one big problem i cant seem to figure out and im sure the answer is so simple.

Basically, i have trouble doing jobs where i need to machine on both sides of the sheet. I do one side fine. Then i flip the job and cant seem to align it perceftly again to machine the other side. its always close, but not perfect. ANY help or ideas will be greatly appreciated.

Thanks alot.

[kendo]

machine a feature through the sheet like a couple .5" bores then you could later use pins through those bores to align once its been flipped

You can only do this of course if you have material to spare like an unused area of the the sheet that you can poke holes in

Or maybe one of the features you're already machining could be used for this
purpose

[Mattyvdv]

Thanks heaps for that idea. Will definately be tring that one.

Anyone else got any other suggestions?

[diycnc]

you could allways have got a machine big enough to do what you want. multicam will make a machine virtually any size.

i would go with the pin idea thou seeing as you allready have the machine.

with our multicam machine we had to add some stops to be able to accuratly locate parts. you may want to consider doing the same.

[Cartierusm]

What I do on my CNC router is drill some holes in the X0 Y0 corner of the machine, drill with the machine of course so it's straight, then from the bottom push up some aircraft threaded inserts, you can find these as McMaster Carr. Glue the inserts in with a touch of super glue. Then take a 1" x 1/2" x 1/4" thick aluminum Angle stock, that's the stuff that looks like an "L", but one leg is 1" long and one leg is 1/2" long. Screw that onto the router aligning it the best you can with the 1/2" part sticking up. Then use a good 1/2" endmill and run it along the edge until the entire thing is milled flat. You need an "L" for both the X and Y axis but make sure there is a gap between the two, meaning don't have them but up against each other in the corner, leave 1/2" space. When you mill them flat you only need to take off a hair so there is a little material removed from the entire surface. Do that for x and y then those will be a square for your machine. Don't remove them use them to align parts square to the machine. Now the only problem is the workpiece must be perfect size or when you flip it, it'll be off.

Now that's for general setup when doing one side. If you need to flip something definatley go with the dowel pin suggestion. Because the holes are machined with the rest of the part it will as accurate as your machine.

When doing the above with aluminum fences you have to make sure you're not going to crash into them.