resharpened bits...

Mark Taylor · Post by **Mark Taylor** » Sat, Oct 27 2007, 9:25PM

We recently received several 3/8 compression bits back after having them resharpened (vortex bits). They cut great in 3/4 material, but they are tearing up the cross grain edge of 1/2 plywood so badly we've changed to a down shear for outline cuts. They cut fine on 1/2\" before being resharpened...has anyone else had this experience or any info they can share with us?

Thanks
Mark

Nick M Singer · Post by **Nick M Singer** » Sun, Oct 28 2007, 12:25AM

Hi Mark. I have often had this problem, the quality of resharpening very often leaves little to be desired. Some tooling companies just can not do the job right either over grinding or getting the angles wrong. Get them to sit up and pay attention by with holding payment for any shoddy work but only if the cutter is on it first or second resharpen, you can not expect a cutter to be resharpened repeatedly and perform properly,

Mark Taylor · Post by **Mark Taylor** » Sun, Oct 28 2007, 9:59AM

Thanks Nick...

I guess I wouldn't be surprised with what you're saying if I had simply gone to a local fellow to have the bits resharpened - but this was the first time the bits have been sharpened and we sent them back to the vortex factory for sharpening.

I guess at this point we should make a call to them and ask why and/or what to expect if they are resharpening the bits for us. Like I said earlier, the bits do cut 3/4 material or hardwoods beautifully...

Mark

Mark Hesketh · Post by **Mark Hesketh** » Mon, Oct 29 2007, 6:24AM

be careful that you don't over-use the bits before sending them for sharpening. What I mean is when the bits get really hot for a long time, they tend to make the metal soft, and no matter how much you try to re-sharpen them, they just won't be able to hold the edge for long. Our guys have been pretty good with sharpening our bits, but we still get the occasional one back that just won't cut well again.

Mark Taylor · Post by **Mark Taylor** » Mon, Oct 29 2007, 8:56AM

Thanks Mark...

Certainly that makes sense...I did look at the bits before we sent them and they didn't appear \"burnt\"...in fact looking and feeling them I even questioned that they needed to be sharpened. However the guys running the machine assured me they needed to be resharpened.

Again, they really did cut very well in 3/4 plywood \"like new bits\" it was just the 1/2\" plywood that gets torn up...

Mark

Michael Kowalczyk · Post by **Michael Kowalczyk** » Mon, Oct 29 2007, 12:30PM

Hey Mark, (64)
If you are using Vortex bits you should have them sharpen them. They include a label in the box when you get them. I do not sharpen mine (yet) so I do not have to worry about cutter compensation (yet). It just allows me to have piece of mind so my Operator does not have check the bit's Diameter every time and adjust the program. I have saved almost every bit and one day I might just send them in and get bulk price for sharpening them all to the same size. But for now this works and I think machine time is more of a savings than having to change the tool more often because from what I have heard and my limited experience with tooling being resharpened back in the 90's, they never last as long as a new one. It may not work for everyone but it works for us. Just think of it this way. Where do you make your $$$$? Keeping the CNC running for longer periods of time or changing bits more often because they dull faster or have poor quality machining of your material? Just food for thought. But if you are going to resharpen. I would send them back to Vortex and see if that makes a difference.

We use 1/4\" and 3/8\" solid carbide compression bits on Russian Birch ply and 1/2\" PCD up down shear bits the most on Melamine and when it costs almost 70% of a new one to have a PCD sharpened, with no guarantee of how long it will last, I prefer to get a new one and know what I am starting with. We can sometimes get over 300 sheets of 2 sided MDF core melamine out of a bit running at an average of 700IPM and since I allow $3.00 USD a sheet towards the bit it works out good when it gets to 70 sheets. Anything over that is indeed a Blessing.

Hope this may help,

Nemanja Vujkovic · Post by **Nemanja Vujkovic** » Tue, Oct 30 2007, 8:13AM

We are located in STL, and have a local guy sharpen our bits. He sharpens them for $10 and they about 5/8 to a 3/4 of a life of the new bit.
Vortex is just way too expensive for sharpening!!!