Oscillations?

[rhfurniture]

Just noticed this on the woodweb forum:

"We run 1-1/8" PB with laminate on both sides at 750ipm and 18000rpm's. We would run at higher feed rates and rpm's if we had the horsepower to do so and a spindle that would spin faster. As far as tool life, we realy only get about 3500 linear inches per tool.You will find that most of the tool will remain sharp except for the small portion that cuts the laminate. When the situation permits, we will oscillate the Z height of the tool as it cuts so that the laminate will be cut by a broader portion of the tool. The life of the tool can be doubled or even tripled depending on how much the tool is oscillated."

I wondered if anyone had tried it out as a technique. It obviously has application for laminate or other covered board, but I wondered if it might reduce cutting edge heating anyway, like on belt sanders and cutter grinding. Just a thought.

[harryball]

I ran a project recently with laminate on top of what appeared to be regular MDF. I first ran the job as I normally would and the quality of the laminate cut degraded rapidly. I use VCarvePro and I hit on the idea of doing a spiral cut rather than a plunge and run.

I cut in a single pass but using the spiral ramp setting. The bit started cutting the laminate and as it progressed around the cut continued plunging deeper to spread the wear over the entire bit. Then it made the second pass to finish cutting the MDF it missed before.

So with a spiral cut you basically make 2 passes for the single pass to get the job done.

Did it make the bit last longer? Well... I finished the remaining 2/3 of the project on a single bit of the same type that did the first 1/3. By the time I was finished, the bit was done for, but it did appear to last longer.

Robert

[wooden_innovations]

You could use the tabs feature to ocillate the bit. These tabs would only be visable in the spoilboard and not in the finished product.

Set the bit to cut .05" into the spoilboard and tell the software to create a 4" tab .025" thick.

Put the tabs about every 8". The end result would be an ocillating bit. You can cut the material in one pass this way.


Rodney

[rhfurniture]

I kind of wondered if high end machines had it as a "feature", a switch on the panel or a particular G-code instruction. Maybe it is possible in 50k cam programs. As I use lisp to write sbp straight out of autocad, it should be possible for me to write a suitable algorithm - but of other languages I know nothing and it would be a lot of work and only worth it if there were real gains to be had.
I might have a go with your tabs idea Rodney as a trial. I've got some Wenge to cut and I know that will be tough on the cutter. I was thinking of every 50mm up or down by 5mm.

[rhfurniture]

From the same woodweb thread:
"As Matt suggested, you can program a ZI movement. Get a tool such as a Vortex 3160 or similar that has plenty of upshear and cutting length for the ZI. That will work well except for the guys who don't understand (G-) code and who can only draw their programs."
Has anyone used this ZI in G code on a big-iron, and is it a good idea??