Creating Nested Bowl Blanks, by Mike Guyre

hi I'm Mike Boyer with the woodworkers Association we're here at Rock shop today to talk about different methods of coring Bowl blanks so the purpose of the demo today is to show how to take a piece of wood and create multiple bowls by luring that piece of wood this comes in really handy when you have a really nice specimen piece of wood with some really nice screen it can use it to create nested Bowl sets and frankly it you know wood Turner's are known as wood wasters because of all the chips on the floor and this is one way of recycling some of that wood and making another Bowl out of it so there's three basic sets of plying systems available on the market today wood cut makes a bowl saver setup there's the McNaughton Kelton Center saver and the one way ez core would cut Bowl saver you're talking around four hundred dollars for the set it comes with two knives I you can cor three inches to 12 inches with a maximum depth of five inches and the replacement knives are in the 50 to 60 dollar range the bowl saver mounts using the banjo and it also can optionally use the tail stock for additional support you can't use a live Center to support your work the advantage is this is probably one of the easiest systems to use McNaughton Center saver you're talking about 320 to 500 dollars typically it's a three knife set that comes with each and it comes with a handle and a post that mounts in your banjo the micro set will cor 4 to 10 inches the standard set will call also core four to ten inches and the large set will core ten to twenty four inches replacement knives run fifty to eighty dollars again the post that supports the knife's mounts using the banjo and advantages you can use a life center to stabilize your bowl blank with this system this system is probably the most flexible system there is as far as bull sizes and bowl shapes it also has a little steepest learning curve the one way easy core which is one of the systems we're going to show today this is basically the Cadillac of coring systems it's definitely the most expensive the base unit runs about two hundred dollars each knife ranges between 150 and 190 dollars there are four knives the smallest knife will cut a nine and a half to eleven and a half inch radius the next knife cuts twelve to fourteen inch then there's fourteen and a half to sixteen and a half and the largest knife will cut 16 and 3/4 to eighteen inches one nice thing about the ez core is that the cutters are replaceable which also makes sharpening them much easier with ez core you can use the live Center to stabilize the bowl blank and my feeling is this is a little easier to use than the McNaughton so we're going to use the one way ez core system today I've got the pieces here set out in front of me the heart of the system is the base the base has two posts on it one post is for the knife and the other post is for a support finger underneath it's got a mounting block with a screw to mount it to the lathe ways one way makes four different sets of knives for the system they have a nine inch radius which is the smallest one that's this knife they have an eleven and a half inch knife a 13 inch and a 16 inch knife each knife comes with a support post when you're turning the support post is gonna hold the knife so that you don't get a lot of vibration or a lot of you know unsupported tool hanging out when your chlorine so we need to make sure that the knives are set up for the lathe so we're going to mount the base I'm just gonna finger tighten the nut here so they can slide this up and down then as you can see it on the bottom of each of the knife is a set screw with a locking nut this is how you adjust the height of the knives so you want the knife set up so that the cutting tip is just at or slightly above Center which I've got there so this knife is set up if you have to change the height of the knife then you also have to change the height of the support post and you want to make sure that the post is set up so that the knife will just rub over the top so this is set up good so the first thing we're going to do is we're going to prepare a blank to get it on the lathe it's a lot easier if you start out with a round blank rather than a piece of log like we have here so basically we've got a nice big hunk of maple here the first thing I want to do is I want to get this in round so I've measured it and it's about 16 inches bark the bark so I have a plywood template I've got a set of these all the way from 20 inches down to about 6 inches that I use when I'm cutting the circles see I've got a center pivot point and I've got holes to put screws in the reason there's four holes in this one is sometimes I do a natural edge Bowl when I'm doing the natural edge Bowl you don't want holes in the foot of the bowl so we use the outside screw positions for that so basically we just pick where we want on the wood and we're going to screw this down you're gonna see that it rocks a little so a trick I was shown by a good friend of mine will just throw some shavings down here to fill in the voids and then when we screw this down it's going to be nice and flat grab my screws okay the other thing you need to do is we need to drill the quarter inch hole into the blank a little bit to make room for the post find it later on when we put it on the lathe so this is a sled I built that helps me cut the circles on the bottom you can see we've got a runner strip that fits in the runner on the saw I've also got a stop plate here so that when I slide this in it keeps me from cutting all the way through the jig so basically we have to set this pivot point to the radius of the block drop everything on it and then just start cutting set this pin up and that's a 16 inch so I need it just a little over 8 so this isn't the screw is on a tee track you can just slide it and tighten it where you want it to be let's get moving on okay we just slide it back I'm going to drive our blank and this is the fun part okay so we've adjusted the height of the rollers here to make sure we clear both ends of the log basically we're going to start the blade is not touching the log yet we're going to slide the table in to the stop and then we'll start spinning the wood to create the circle get rid of this part get off the bleed and now we've got a circle that's gonna be nice and balanced on the lathe the other advantage to using the plywood I mean you could just drill a hole in the blank and spin it on the pen but because it's uneven you're gonna have places where the wood wants to bang down as the blade goes through and you kind of tensions the blade this is a nice flat surface that everything just slides down easily so when we go to put this on the lathe we don't want to try and use the center on the bark or anything so here's a real easy way to debark the log this is a Harbor Freight $10 special and it works very well for getting the bark right off the lot if the springs don't get in the way the nice thing is the truth the bits so dull and hurt the woods that's about all we need to get off so when you're working with something this big you want a heavy-duty Chuck with a good 5 inch jaws in it or you want to be using a 4 to 6 inch faceplate on the work chlorine does produce a lot of stress on the wood so you want to make sure this is securely mounted to the lathe so we took this blank we headed on a worm screw we could cut a tenon on the back I put the Chuck on the tenon and now we'll mount it on the lathe okay so the first thing we're gonna want to do is we're going to want to face this off get rid of the chainsaw marks so always that's why you'll always find your work before you turn the lathe on make sure it's not going to hit the tool rest and I'm going to put a face mask on for this so I'm going to bring this up slowly to about 400 or so and you can start facing off the fun of this end just a little bit more to go here okay so we get a nice smug face now we're ready to start laying out for the different bowl sizes we're not going to be a full rest anymore one thing you can do with the one-way system as long as you're careful is you can use it to waste away the outside of the bowl blank by using the larger knife to cut that piece off you do have to be very careful with this there's a good chance that something could break and the piece could come flying off so we're gonna make sure that we use all our safety guards for this operation so I've set up the largest knife and I've set up the support post right now we have the fat part of the post nearest to the wood as you'll see as I start progressing the knife in you'll see me change the knife so that the knife starts following the blade into the cut okay so what I'm doing is I'm just gonna hold the handle I'm gonna put a little bit of downward pressure on the tool rest and you start advancing and then can be not using a lot of it they will stop here once you get to the top part of this taper on the cutter then you want to start advancing the knife blade in so we'll loosen this up this swings all the way around and then you can start advancing the finger of the support into the cut when you do that you want to make sure that the radius of the knife matches the radius of the support finger so go to the bottom then just back it out just a little bit so it's not rubbing and then tighten it back down and one thing I forgot to mention is with coring the greener the better this wood is only what about a week old now so it's got a lot of moisture in it makes it a lot easier to pour the drier of the wood the more difficult the corns going to be so we're gonna we'll rotate this backwards to make sure that there's no chips on the end of the knife blade and then we're gonna continue on okay once the handle of the knife gets over the large part of the post you need to advance it back in some more the same thing just go dia to hit the bottom back it off a little bit make sure the radius of the night.the support matches the blade and while we're here you're just going to make sure that this Chuck's not listen them up on us vents and support again so you're almost there that's why you have the safety shield on the nice thing about doing this is then the outside of your bull Blanc got the same knife radius and it'll match all the insides it's a lot less work doing that then shape and all of that with a bowl gouge once we have the blank bowl shape we have to figure out where we're gonna core the other sections out of and we have two choices we can either do a twice turn bowl where you're gonna turn it cut the bowl blank here you're gonna let it dry for a period of time once it's dry you put it back on the lathe and turn it to final shape or you can do a one stern Bowl where you're gonna do the final turning while it's green and let mother nature do whatever she wants with the bowl we'll set this up for twice turn bowls so the rule of thumb is that you want the wall thickness to be about 10% of diameter of the wood so we've got a 15 inch blank here that means I want it about an inch and a half in so I'll put a mark there I'll put a mark 3/16 down and that's where we'll do our first cut I've now got about five and a half so I've got an 11 inch blank so we'll make the next mark a little over an inch down and again we'll add the 3/16 for the cutter and that'll be our second blank where now I've got an 8 inch Bowl so I'll mark just a little bit over three quarters of an inch and add the three sixteenths okay and these will be the three cuts we're doing when we do actually do the cuts we're going to start with the center and then we'll move out to the outer bowls the outer bowl is what they call the money Bowl you know that's what you're gonna be able to get the most money for so that's the one you really want to make sure you've got enough wood on you can skimp on the inner ones but the outer one you want to make sure you've got the proper wall thickness for it now what we have to do is we have to transfer these three cuts to the top of the blank so if I measure in here again I've got about an inch and a half to the cut so I'm going to measure off the back of the chuck an inch and a half okay then another three eighths okay and that will be one of the cuts then another two inches up from that will be the bottom of the next Bowl I take that back an inch and a quarter up from that I thought two inches was a little big so right about there and then another three eighths that will be the bottom of the next Bowl and then this other piece is basically just going to be a core we're gonna take out so four and three quarters from the bottom one yeah it puts us right about there so that one's gonna be a real shallow bowl okay so back out to this so we've got our marks on the front which is where we're going to hit with the cutter we've got marks on the back which are where hopefully the bottom of the bowl will end up once we do the cut so on the Powermatic i've got five and a half inches to the top of the chuck and i know that the first the bottom of the smallest ball is about nine inches from there so i have to do a whole bunch of math and i have a little cheat sheet here so what we have to determine is where this knife post goes okay so we know what the distance from the Chuck to the headstock is and the bottom of our cut to the headstock so we can calculate exactly where we want the bottom of we want the knife post based on the lowest cut and it's a whole bunch of math and I don't always get it right so I'm gonna show you a trick that my mentor John hat and it showed me it makes life a whole lot easier involves using a laser so for the smallest cut we're going to need to use a six-inch knife you so put the six inch knife on the base put the tool post holder in you get this moved up to where it needs to be somebody over tighten that maybe me there we go so what we're gonna do is we're gonna mount the post close to where we're gonna hit will just snug it down a little bit then I'm going to take a pencil and I'm gonna site down the cutter I'm gonna put a line on top of the post and I'm gonna take the knife out so I've got a homemade jig here it's just a piece of PVC pipe with a laser adapter I think this is our Ron Brown laser I'm gonna turn on the laser and I'm gonna make it so that that light hits the mark I made for the center of the cutter which is right about there okay now instead of a whole bunch of measuring I just have to line up the laser marks so I've got the laser adjusted for the mark on my tool post now all I have to do is move the base until I the laser hits the mark for my first cut so just bring it up and we're right on center there now I just continue to rotate the laser to the marks on the top so I've rotated the laser so that now it's showing at the marks and reference marks I made on the back I can see that I'm a little too deep so I'll just slide it out till I hit that cut mark and I'll go back to the face again and then back to the top so what I've got now is this laser is simulating the arc of the cutter so theoretically we ought to end up with a bowl this deep in that diameter when we're done cutting so I'm going to lock down the tool rest I'm gonna have to advance this post a little closer so for the small bowl we use the six and a half inch knife total just isn't quite where I want it to be I'm gonna rotate it make sure we don't hit anything here put the handle on so we've got the tool post adjusted and I'm tightening up the handle on the cutter and we're ready to start pouring the first bowl I'm going to bring the speed up to around 500 or so right and you can start the putter in the hole I think I've cleared enough here where I can probably get a life center in for additional support so I have a a live Center on a number two Morse taper extension you should be able to slide right in over the handle then I can lock this in place just to give it a little bit extra support and that should also help with that vibration that we were getting and once again when we hit the top of the taper on the knife we have to advance the tool in so we all it that's all most advantageous now you can see what's happening inside of it so obviously that piece broke off in the middle and we're almost down to the point where we're cut all the way through here's the piece that was left what I'm gonna put this on now I have the inside of our first bowl and one thing I like to do after I've got that taken out is just to advance the live Center and just tighten it up a little bit to give me a center reference so that if I do want to reverse chuck this I know where the center of the blank is and I could go from there so our second Bowl we said was going to be 8 inches in diameter so I need the next knife up for that so we'll just do the same trick again I've already got a mark on top of this tool post that I've adjusted to be right underneath the cutter get the laser out and we'll adjust it to hit the mark on the tool post that's good then we'll find our mark on the wood okay so that's the center of the cutter on the side and then we'll rotate the laser around to the back get it centered on that mark and then bring it around back to the front okay so right on the mark on the side and we're a little off on the front so I'll just slide this hopefully fairly straight centered on that mark and we're centered on the back mark so that's good to go with this position just lock that down you need to adjust until post a little and getting a little closer to the wood make sure nothing hits now the nice thing about the one way is you can change the depth of the bowl by offsetting the post off of Center and bringing it out for some bowls you're not going to be able to use the tailstock because the bar is gonna be in the way but this is gonna fit in there nice so this is where the Morse taper extension comes in handy being able to get past the knife bar will just snug that up double-check everything and we're ready to start the first Bowl it's the same speed about for 450 to 500 rpms that's the ninth half foot pass the bevel point so we'll turn the support around and get the finger under the cut sometimes when you're turning the corner from side grain to end grade and things will get a little catchy on you this is gonna go in the bloopers partly you can't get the finger there we go okay if you clear the chips Oh Oh got two knots in there that's what's giving us trouble so there's your first bowl blank back this off to get the knife out of the way I'm gonna dance the headstock in to give us a mark for center I'm out of the way thank you thank you so I'm switching to the next larger knife to do this in the middle ball I need to move the post so that I can get the laser reference here again just sighting down the cutter tip just going to put a mark on the post if the loser turned on here we go so we're right on the mark that I made on the post and now we can find our mark on the side which were a little towards the center and we're not deep enough yet so this is up the base we've got the mark on Center on the depth that way just a little and we run Center on the face too so that's where the lots of cutter pivot to be looks like we're gonna clear sometimes you have to pull it off of a tail stock to get the smaller part of the taper over the tool post okay and we're all locked down this thing looks good sign up to the top of the taper so we need to advance the post in again and we want to make sure that the post radius matches the knife radius so when the shaft of the knife gets to the post it's time to advance it in some more sometimes you can tell by the sound when that core is about to come loose obviously that one didn't happen so there's a middle bowl along here I'm just gonna mark the center this one too okay so from this one bowl blank we were able to get three balls out of it all the shavings didn't end up in the floor so we're not quite as bad a wood waster as they say we are but this will make a really nice set of nested bowls now when it comes time to turn these the second time around obviously you're going to lose a little bit of depth when you go to turn the tenon on the bottom of these bowls so you have your choice of either just putting the tenon on turning the bowls and then when you go to stack them they won't line up on the face so if you want them to look nice and line up on the face what you'll end up doing is taking a little bit off the rim of this one a little bit off the rim to that one so that when you put them all in together and stack them up it's nice and flat across the top so what we're gonna do now is we're gonna put these in paper bags we're gonna set them aside in a nice neutral temperature place the rule of thumb is what it an inch a year so given that this guy is a little more than an inch he's going to have to sit for a while unless you want to try speeding up the drying through using DNA or you know kill them drying it if you want but I just put them in a bag and leave them and come back and turn them the second time

Channel: Gwinnett Woodworkers

Views: 24,979

Keywords: gwinnett woodworkers association, gwinnett woodworkers, gwa, woodworking, woodworking clubs, woodworking projects, woodworking classes, nested bowl blanks, easy core, wood turning

Id: TFpZ8Ta7cWw

Length: 47min 50sec (2870 seconds)

Published: Thu Dec 17 2015