Non-CW cutting bits?

[DDV]

I assume that there is a set length that the cutting bit sticks out of the adapter. The two that came with my machine are 1.522 and 1.540 inches. So I assume that the factory length is somewhere above and below this reading.
Does anyone know how much this length can vary and keep the machine dumb. I find that non-cw bits vary in length from maker to maker as much as 3/8" in their OAL. Also if I don't need 1 1/2" length for deep cuts and can keep this length toward the short side the less likely it would deflect and/or snap off.
Thanks
DDV

[liquidguitars]

Ok "with in spec" long as the bit hits the index cam.

One thing to look out for is the depth of the bit's flute can not be smaller than the thickness of the cut or you will damage the truck.

Lig

[Digitalwoodshop]

I have been using the following bits including the cut down 6 inch long Rotary Engraver bit with no problem. I think the length of the bit is not an issue as the bit plate comes out and establishes the length in the computer.

Unless I am missing something..... Is it written what length the bits should be?

AL

[Jeff_Birt]

The length of the bit DOES matter. Any run-out (wobble) in the chuck/adapter will become more pronounced (larger) as the bit gets longer. Try this, hold a piced of stiff wire, say 12" long, vertically between two fingers and wiggle it very slightly. Notice that it moves much more at the end 12 " away. Now try it with a 2" piece of the same wire.

The new carving bit by precisebits.com, http://www.precisebits.com/products/carbidebits/taperedcarve250b4f.asp?txtsearchParamTxt=tapered&txtsearchParamCat=ALL&I1.x=0&I1.y=0&txtsearchParamType=ALL&iLevel=1&txtsearchParamMan=ALL&txtsearchParamVen=ALL&txtFromSearch=fromSearch
has a 1/2" shorter shank, samge length of cut. They did this to reduce the run-out to "Runout (TIR) - max 0.0002 in.".

[DDV]

The length of the bit DOES matter. Any run-out (wobble) in the chuck/adapter will become more pronounced (larger) as the bit gets longer. Try this, hold a piced of stiff wire, say 12" long, vertically between two fingers and wiggle it very slightly. Notice that it moves much more at the end 12 " away. Now try it with a 2" piece of the same wire.

The new carving bit by precisebits.com, http://www.precisebits.com/products/carbidebits/taperedcarve250b4f.asp?txtsearchParamTxt=tapered&txtsearchParamCat=ALL&I1.x=0&I1.y=0&txtsearchParamType=ALL&iLevel=1&txtsearchParamMan=ALL&txtsearchParamVen=ALL&txtFromSearch=fromSearch
has a 1/2" shorter shank, samge length of cut. They did this to reduce the run-out to "Runout (TIR) - max 0.0002 in.".

Are you using this bit? Is the shank shorter above or below the location of the flats or did you have to grind your own flats?
DDV

[Jeff_Birt]

Are you using this bit? Is the shank shorter above or below the location of the flats or did you have to grind your own flats?
DDV


Yes, I am using one of their bits. I recieved one of the prototype bits already mounted in the adapter. The one I have is the same length as the OEM one but mounted higher up in the adapter so less of the bit protrudes below the adapter (shorter below the flat spots). It's my understanding that the production bits have the extra bit above the adapter removed. The depth of cut remains the same.

I got to do a bit of testing with a dB meter tonight and found that this bit does indeed a bit quiter than the OEM. I hope to have a review written up the first of the week.

[Navigator]

Just received some back ordered carving bits from CW. They are the shorter length (2") but what I noticed was there is only 1 flat on the shank and it is gound deeper into the shank. The set screws do NOT reach the flat. Further, I was able to easily unscrew the set screws on all 4 bits without applying heat. I first noticed the problem with the deep flat when I loosened one screw and the bit dropped down somewhat into the chuck, even though the I had not touched the other set screw yet. With the one screw still "tight" I could slide the bit up and down the length of the flat.

The fact that the thread locker was not securing the screws and and only one set screw was snugged up to the round side of the shank could spell trouble. It was obvious that the red thread locker was applied after the chuck was oiled thus preventing the thread locker from curing. At first it also appeared that the set screws were too short as the head of the set screw bottoms out on the chuck before the end reaches the flat, however, I checked and they are the same length as originals. To correct this I simply used a countersink and opened the holes in chuck a little and now the set screw will tighten onto the flat. I soaked the chucks and screws in mineral spirits to remove the old thread locker and oil then rinsed them in acetone before resetting the screws with red thread locker. The parts must be clean and dry before applying the thread locker or it will not cure. I slid the bit into the chuck, snugged the one setscrew, and then pushed the bit up until the set screw was against the bottom edge of the flat. This way the bit is held so that it cannot move up into the chuck and change the depth of cut. I will wait until the thread locker cures before oiling them.

[oju392]

We have similiar problems with Limitorque valve actuators at the power plant with setscrews and a bulletin from the manufacturer recommends Loctite, spot drilling and staking the threads. This usually ensures the setscrews from slipping on the shafts. However it can be tedious spot drilling into the hard steel the bits are made of and caution has to be taken not to mess up the threads in the collet when drilling.

[MetalCutter]

Hello All,

Just thought I'd add my $.02. If you do use a cutter with a shorter than factory Length Out Of Holder, be sure to check the 3/8" wide flat cable that's in the Z truck belt drive channel. A shorter bit will increase the distance the Z truck travels to make a cut in thinner stock. If this cable doesn't have enough slack to handle the extra Z movement you're machine WILL BE DAMAGED. What gets damaged depends on which part is weakest, the cable or the circuit board. If you're lucky you might only get a "Z Axis Stall" alarm.

Gee, I wish I had a machine.

Happy Carving!

[DDV]

Hello All,

Just thought I'd add my $.02. If you do use a cutter with a shorter than factory Length Out Of Holder, be sure to check the 3/8" wide flat cable that's in the Z truck belt drive channel. A shorter bit will increase the distance the Z truck travels to make a cut in thinner stock. If this cable doesn't have enough slack to handle the extra Z movement you're machine WILL BE DAMAGED. What gets damaged depends on which part is weakest, the cable or the circuit board. If you're lucky you might only get a "Z Axis Stall" alarm.

Gee, I wish I had a machine.

Happy Carving!

Sometimes a $0.2 part can crash a $100,000.00 machine (splitpin, seen it happen). Makes you wonder about all the Z Axis Stall's don't it. Something to think about. Wonder what the official answer is? DDV

[liquidguitars]

The bit holders seem to get damaged /worn out quickly so I just put the
lock tight on all the surfaces including the router bit shank. Works ok, just press them out when replacing.

Any one knows will wd40 loosen lock tight over time?
Lig

[Ted Grinnell]

I have not known wd40 to loosen or desolve locktite. The method of loosening locktite involves melting it. Just put it in the oven at 400 for a half hour and, using gloves, remove or loosen locktited items.