We are trying our hand at getting v-fold/miterfold solid surface parts to cut on our Morbidelli SCM router but not sure where to start with RPM and feed speeds. We are using an Amana RC-1102 90° v-groove bit with general purpose insert and our first attempts were rough. A new insert cuts better, but goes to junk within a few feet of starting. That and the lack of chips (just dust mostly), leads me to believe feedrate is too low. We are at 5000 mm/min (197 IPM) @ 18000 RPM.

I think we have to speed it up and have the horsies to do it but I'm not sure if we're where we're supposed to be to start. We're already feeding faster than recommended too according to Amana's charts.

Does anyone have experience with this and have a good recommendation?

We use 9000mm/min @ 16000 (same bit) in 3 passes.

Bob, thanks for the info. Curious if you tried single pass or went straight to three passes? My guess is that spreading out the load in three passes plus speeding up the feed rate will significantly reduce heat and bit destruction.

I run a vortex integrated v groove on my Anderson CNC . I run a first pass at .4 in and a second pass at .095 leaving 5 thousandths to the spoilboard so that the vynal packing tape layer is still there for the miter fold.

The cuts are absolutely clean and perfect and the inserts last a long long time. I also miter fold MDF core venir for floating shelves, end panels etc. with the same bit but leave the last pass at about .2 - .25 inch on the 3/4 thick stuff.

I have yet to change an insert and have made a lot of tops with it.

Perhaps the stability of the integrated HSK tool is helping me out, but I have been thrilled with our quality and production.

I will get in the computer at the shop tomorrow and give you the spindle speed and feed rate I am using.

Here is the bit we carry for the Miter Folding

Part # SECS143IR

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When we miterfold SS we hog out the bulk of the material with any tool possible just to save the tip on the V groove. As with any V bit the tip is pretty much just rubbing away material and wasting the tip and adjacent cutting edge on pre-passes is just eating that tip. Even just plowing 1/4" groove down the fold line leaving just a whisker of material at the tip would make a world of difference.

What Mark said is spot on.

To all those who want to mitre fold with router that are currently looking for a machine, I would recommend looking at machines that have a saw. 9"-12" diameter will improve cut quality and speed over the insert router bits. I still use the router bit option when necessary, or if the cut angle is different from 90°. Solid surface is pretty forgiving, but mitres on laminated or veneered material are tough to get a clean edge with a router bit. Many salesmen will claim that you can get the same results with an aggregate and a smaller V-groove saw, but I am still waiting to hear success stories of those who have tried that method.

Further to Mark B's point about the tip of the miterfold bit pushing and not really cutting, the following technique would work well for some. You need a saw on your machine but the integrated saw on a lot of drill heads is enough.

Have the tip of the insert for the router bit ground, leaving a 3-4mm flat on the bottom edge. Have the tips of the saw blade ground to 45°. Run the router bit first and blade second.

Tool life of the router bit is better since there is a small diameter at the bottom, cut quality in the bottom is good since the saw blade finishes it and reasonable dust collection is possible.

The aggregate/saw option is great if your running a mile of these daily in which case I would imagine it would be the option the OP would be using. Not in any way shape or form is it a viable option for the volume we do.

I have found that the geometry of the insert that I have is actually cutting as the angle at the tip is sharper than 45 degrees . And also for the increase in speed of assembly and sanding it's a no brainier for me. That being said, like most things it is not a silver bullet. When you have tops with a lot of inside corners the miter fold doesn't help you and requires clamping and glue up of corner blocks etc..

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QuickTrim,

Are you cutting through the miter? Or did you apply something to the other side of the sheet before running to hold it together?

Gary,

I am applying tape from Betterly to the back side centered on the cut pattern , then cutting through the ss to the adhesive layer of the tape but not through the tape.

Based on your experience with the Amana RC-1102 90° v-groove bit, it appears that increasing the RPM and feed rate might improve results. Experiment cautiously while monitoring cut quality and tool condition.