Joe Spackle
11-13-2008, 2:35 PM
== Making oval molding ==
I had the opportunity to create oval molding for a beveled piece of glass in an air lock door. The glass is quite old ( the door is a replacement in a historic restoration home) so I had to build the door from the glass outward to get it all to fit properly
the first thing to do is to template the glass
http://i243.photobucket.com/albums/ff168/BCStudios/molder/molder046.jpg
If I do not have a piece of glass I make the oval per the usual ways (string and three nails works well) this time I had to use the existing unit so I just trace it 1/8" larger than the glass
Next I set up a compass and scribed a line 1/2" inside the glass size (to create the rabbet to hold the glass) , then with a jigsaw cut close to the line and removed the center piece.
Then with a curved back sanding block and a coarse grit sanding belt I sanded the template to the line all the way around. Once I was satisfied the template was smooth and the edges clean to the line, I set the template on the panel the glass goes in.
I clamped it down against the reference lines I started with on the template and cut the panel center out using a 1/2" 1/2" long top bearing router bit made by Ocemco. I drilled a starter hole in the waste, and made a router cut all the way around the template. This is a bit hard on a router and bit and there is always the jigsaw, but in my experience the router generally leaves a very guideable surface without tearout in the panel done this way. Once this cut is made I use the rabbet made by the router to cut the rest of the way through then make a finish cut to take off the rest of the jigsaw cut.
Now for the oval moldings First I calculate the width of stock I need to make a four piece layup on the template This is a matter of width and about 5 extra inches of length to get the parts I need Next I determine the angle of the center joints and cut each piece at that angle ( this time it was 31° they all vary so you have to check) then I cut a 1/8" rabbet 1 1/2" deep on each miter on the back side of each piece so the joint would have more support than just a end grain butt joint. I made two splines 3/16" thick 3" long and 5" wide.
To glue these up I turn them upside down, and using hand screws to hold them flat on the table I then put glue on the end grain, clamp them to the table, put a bar clamp across the hand screws and pull the joint together. then I glue the spline and clamp it into the rabbets.
While the glue cures I build the carrier for the molder The process is not tough you need to make the lead and tail longer than the finished molding by 5-6" ( this allows you to get the molding started into the machine without the feed drive engaging) I make these legs straight for oval cutting arches I make follow the radius. Now lay the piece you are making the carrier with under the same template you made the window cut, and trim the inside curve Once this cut is made get the compass and mark out the width of the molding and cut the carrier just outside the line once again. Then sand to the line. Once this is done I take a piece straight molding and measure to the highest point of the molding and set the compass at this width, so I have a reference for drilling holes for screws to hold the molding to the carrier.
http://i243.photobucket.com/albums/ff168/BCStudios/molder/molder030.jpg
Now screw the molding to the carrier . I generally use a straight piece of stock to set the knives for correct width and to set the follower. the manual says to snug up the adjustable follower then add one to one and one fourth turns to be sure the stock stays in plane as it is fed . Now set the depth of cut thickness of the stock + the carrier+ 1/4" for the auxiliary table. I do something not recommended by any of the manufactures of these molders and that is I raise the cutter head 1/2 turn so I can run the cut twice. This will work but the feed rollers need to be set just a bit tighter than the manual recommends and the table as well as the carrier should be well waxed. the slicker the base is the better the feed acts.
now start the machine and align the carrier with the bearings and begin the feed. I have found the first inch or so tends to need a bit of wiggle to make the carrier go past all the bearings but once this is done just support the stock so it doesn't try to snipe once started.
The shots below are of the second pass, I babysit the first cut pretty intently
Start of the cut
http://i243.photobucket.com/albums/ff168/BCStudios/molder/molder033.jpg
just into the curve
http://i243.photobucket.com/albums/ff168/BCStudios/molder/molder034.jpg
Just about halfway
past halfway coming out
http://i243.photobucket.com/albums/ff168/BCStudios/molder/molder038.jpg
nearing the end
http://i243.photobucket.com/albums/ff168/BCStudios/molder/molder040.jpg
The finished piece
http://i243.photobucket.com/albums/ff168/BCStudios/molder/molder026.jpg
Notice the right end is blown off, this is why when you are running ovals you need the stock to be longer than the finish. you are molding completely cross grain on a narrow section and the knives don't particularly like this part of the cut, so be aware of this as you create your pieces.
http://i243.photobucket.com/albums/ff168/BCStudios/molder/molder029.jpg
Now to make the second half of the molding use the same carrier turned over and screwed down as before.
That is it for the molding except that the two will still need joined and I will make a similar rabbet as I did for the centers and glue up the same way. The cuts worked very well, I was pleased with the end results.
http://i243.photobucket.com/albums/ff168/BCStudios/molder/molder044.jpg
http://i243.photobucket.com/albums/ff168/BCStudios/molder/molder042.jpg
If pics are missing I am under site limitatations I cannot control (http://i243.photobucket.com/albums/ff168/BCStudios/molder/molder043.jpg)
I had the opportunity to create oval molding for a beveled piece of glass in an air lock door. The glass is quite old ( the door is a replacement in a historic restoration home) so I had to build the door from the glass outward to get it all to fit properly
the first thing to do is to template the glass
http://i243.photobucket.com/albums/ff168/BCStudios/molder/molder046.jpg
If I do not have a piece of glass I make the oval per the usual ways (string and three nails works well) this time I had to use the existing unit so I just trace it 1/8" larger than the glass
Next I set up a compass and scribed a line 1/2" inside the glass size (to create the rabbet to hold the glass) , then with a jigsaw cut close to the line and removed the center piece.
Then with a curved back sanding block and a coarse grit sanding belt I sanded the template to the line all the way around. Once I was satisfied the template was smooth and the edges clean to the line, I set the template on the panel the glass goes in.
I clamped it down against the reference lines I started with on the template and cut the panel center out using a 1/2" 1/2" long top bearing router bit made by Ocemco. I drilled a starter hole in the waste, and made a router cut all the way around the template. This is a bit hard on a router and bit and there is always the jigsaw, but in my experience the router generally leaves a very guideable surface without tearout in the panel done this way. Once this cut is made I use the rabbet made by the router to cut the rest of the way through then make a finish cut to take off the rest of the jigsaw cut.
Now for the oval moldings First I calculate the width of stock I need to make a four piece layup on the template This is a matter of width and about 5 extra inches of length to get the parts I need Next I determine the angle of the center joints and cut each piece at that angle ( this time it was 31° they all vary so you have to check) then I cut a 1/8" rabbet 1 1/2" deep on each miter on the back side of each piece so the joint would have more support than just a end grain butt joint. I made two splines 3/16" thick 3" long and 5" wide.
To glue these up I turn them upside down, and using hand screws to hold them flat on the table I then put glue on the end grain, clamp them to the table, put a bar clamp across the hand screws and pull the joint together. then I glue the spline and clamp it into the rabbets.
While the glue cures I build the carrier for the molder The process is not tough you need to make the lead and tail longer than the finished molding by 5-6" ( this allows you to get the molding started into the machine without the feed drive engaging) I make these legs straight for oval cutting arches I make follow the radius. Now lay the piece you are making the carrier with under the same template you made the window cut, and trim the inside curve Once this cut is made get the compass and mark out the width of the molding and cut the carrier just outside the line once again. Then sand to the line. Once this is done I take a piece straight molding and measure to the highest point of the molding and set the compass at this width, so I have a reference for drilling holes for screws to hold the molding to the carrier.
http://i243.photobucket.com/albums/ff168/BCStudios/molder/molder030.jpg
Now screw the molding to the carrier . I generally use a straight piece of stock to set the knives for correct width and to set the follower. the manual says to snug up the adjustable follower then add one to one and one fourth turns to be sure the stock stays in plane as it is fed . Now set the depth of cut thickness of the stock + the carrier+ 1/4" for the auxiliary table. I do something not recommended by any of the manufactures of these molders and that is I raise the cutter head 1/2 turn so I can run the cut twice. This will work but the feed rollers need to be set just a bit tighter than the manual recommends and the table as well as the carrier should be well waxed. the slicker the base is the better the feed acts.
now start the machine and align the carrier with the bearings and begin the feed. I have found the first inch or so tends to need a bit of wiggle to make the carrier go past all the bearings but once this is done just support the stock so it doesn't try to snipe once started.
The shots below are of the second pass, I babysit the first cut pretty intently
Start of the cut
http://i243.photobucket.com/albums/ff168/BCStudios/molder/molder033.jpg
just into the curve
http://i243.photobucket.com/albums/ff168/BCStudios/molder/molder034.jpg
Just about halfway
past halfway coming out
http://i243.photobucket.com/albums/ff168/BCStudios/molder/molder038.jpg
nearing the end
http://i243.photobucket.com/albums/ff168/BCStudios/molder/molder040.jpg
The finished piece
http://i243.photobucket.com/albums/ff168/BCStudios/molder/molder026.jpg
Notice the right end is blown off, this is why when you are running ovals you need the stock to be longer than the finish. you are molding completely cross grain on a narrow section and the knives don't particularly like this part of the cut, so be aware of this as you create your pieces.
http://i243.photobucket.com/albums/ff168/BCStudios/molder/molder029.jpg
Now to make the second half of the molding use the same carrier turned over and screwed down as before.
That is it for the molding except that the two will still need joined and I will make a similar rabbet as I did for the centers and glue up the same way. The cuts worked very well, I was pleased with the end results.
http://i243.photobucket.com/albums/ff168/BCStudios/molder/molder044.jpg
http://i243.photobucket.com/albums/ff168/BCStudios/molder/molder042.jpg
If pics are missing I am under site limitatations I cannot control (http://i243.photobucket.com/albums/ff168/BCStudios/molder/molder043.jpg)