Although my fly cutter is an 8 inch radius, I have two cutters on it. It can be tricky making sore they are both exactly equidistant from center (at my level of compotence) but it does help ofor some balance. I got it from McMaster Carr supply.
On Sun, 25 May 2008, Dale Leavens wrote: > A fly cutter is a drill bit set into a thicker mandrill which is to be > mounted into the chuck of a drill press. There is a bar which runs through a > square hole in that mandrill laterally which can be slid further out from the > shaft and tightened into place with a set screw. This lateral bar has another > rectangular bar extending down with a beveled sort of sharpened chisel tip > which revolves around the bit center as they both turn and which describes a > circle the radius of the amount of the lateral beam protruding from the > mandrill.This sharp chisel then is spinning at the radius from the center > which has been selected by the user and of course the entire thing is > necessarily unbalanced. > > In a drill press it does at least maintain it's position relative to the work > being cut, on the end of a hand held drill though, just the off-center > vibration makes it near impossible to keep steady. Once it begins biting into > wood, and remembering at two points in the rotation it is cutting cross grain > while at two other points it is cutting with the grain, the rotation torque > is constantly variable. As hard and strong as the steel is, the possibility > of any number of things failing is very high. > > Because of the design too, the depth of the fly cutter is only about an inch. > They do come in different sizes, the one I have probably cuts up to about 4 > and a half maybe 5 inches. > > My experience is that regardless of how much care I use one or other of the > set screws fails during the process and usually it is the radius which begins > expanding. I had such a problem when cutting to form a nice arch shaped > cutout on the fence I made for my router table. My idea was to cut the hole > just centered a little below the radius of the hole then with the table saw > cut away the edges to form what would look like a very steady handed ban saw > operator had formed a fine archway for the dust collection. > > From one side it turned out like that, the other side ended up having a > quarter inch deep curved line about 3/8ths outside the circumference of the > arc. I hid this from view by making that the back side of the fence and > covering it with the construction into which the dust collection hose gets > fitted.I then ordered two sets of what should be good quality hole saws. > > > > ----- Original Message ----- > From: John Schwery > To: blindhandyman@yahoogroups.com > Sent: Sunday, May 25, 2008 9:10 AM > Subject: Re: [BlindHandyMan] cutting a circular hole > > > What is a fly cutter and what sizes of holes do they cut? > > earlier, Dale Leavens, wrote: > > >Fly cutters in anything other than a drill press which keeps it > >running true are prone to breaking apart or having bits fly off if > >they aren't kept running absolutely true. You are warned never to > >use them outside of a drill press. > > > >A broken wrist is only one of a number of serious injuries one can sustain. > > > >----- Original Message ----- > >From: <mailto:spiro%40netaxs.com>[EMAIL PROTECTED] > >To: <mailto:blindhandyman%40yahoogroups.com>blindhandyman@yahoogroups.com > >Sent: Sunday, May 25, 2008 12:49 AM > >Subject: Re: [BlindHandyMan] cutting a circular hole > > > >spade bits and fly cutters, (hole cutter for drill press here) are > >similarly difficult to 360 center and can wrench a wrist if they hit a > >knot in the wood. > > > >On Fri, 23 May 2008, Dale Leavens wrote: > > > > > You should never use a hole cutter in anything other than a drill > > press for reasons of safety however you can safely use a hole saw. > > These come in a number of sizes, I think my largest is 4 and a half > > inches. These can be used in a hand power drill. There is a central > > twist bit which is longer than the peripheral ring with saw teeth. > > The twist bit guides the rotating saw into and on through the wood. > > > > > > I suggest that once the bit comes out the far side and before the > > rotating saw part cuts through that you remove the hole saw and > > complete the cut from the other side to keep it from tearing the > > wood as it exits. > > > > > > You can buy individual hole saws or a set. If not readily > > available where you live I bought my sets from Leevalley.com. > > > > > > I doubt you will find a spade bit big enough but you could get a > > large auger bit for a hand brace & bit. > > > > > > Hope this helps. > > > > > > ----- Original Message ----- > > > From: Robert Riddle > > > To: <mailto:blindhandyman%40yahoogroups.com>blindhandyman@yahoogroups.com > > > Sent: Friday, May 23, 2008 2:19 PM > > > Subject: [BlindHandyMan] cutting a circular hole > > > > > > > > > I need to cut a circular hole in one of the boards comprising my > > picnic table for the umbrella. Everything I've read says to use a > > circle cutter in a drill press, which I don't have. Are there any > > other options? > > > > > > [Non-text portions of this message have been removed] > > > > > > > > > > > > > > > > > > > > > ---------------------------------------------------------- > > > > > > > > > No virus found in this incoming message. > > > Checked by AVG. > > > Version: 7.5.524 / Virus Database: 269.24.0/1462 - Release Date: > > 5/23/2008 7:20 AM > > > > > > > > > [Non-text portions of this message have been removed] > > > > > > > > > >---------------------------------------------------------- > > > >No virus found in this incoming message. > >Checked by AVG. > >Version: 7.5.524 / Virus Database: 269.24.1/1464 - Release Date: > >5/24/2008 8:56 AM > > > >[Non-text portions of this message have been removed] > > > > > >No virus found in this incoming message. > >Checked by AVG. > >Version: 8.0.100 / Virus Database: 269.24.1/1464 - Release Date: > >5/24/2008 8:56 AM > > John > > [Non-text portions of this message have been removed] > > > > > > > ------------------------------------------------------------------------------ > > > No virus found in this incoming message. > Checked by AVG. > Version: 7.5.524 / Virus Database: 269.24.1/1464 - Release Date: 5/24/2008 > 8:56 AM > > > [Non-text portions of this message have been removed] > >
