Replies

1. 
   hammer1 | May 21, 2009 01:39am | #1

   An oval is pretty easy to draw. You have a major axis and a minor axis. I typically use the string method. I have a couple of explanatory pictures. I didn't have a proper piece of string for the pics but you should get the idea. To set your pins, measure the length of half the major axis from the top of the minor axis. Tie your string so your pencil starts on the minor axis.

   Normally, you would cut out the shape so you run your router on the inside, of the cutout. You wouldn't cut out an oval and run the router around the perimeter since the router would be free to run away. You have to size the cutout larger if you use a template guide on the router base. It can be the correct size if you use a pattern bit. The template guide gives more options for controlling depth of cut and even different size bits for a step, if needed.

   Beat it to fit / Paint it to match

   
1. 
   CMyron | May 21, 2009 02:14am | #2

   Thanks hammer1!! I should have been more specific in my original post------ I'm hoping to find a way to remove the human error component of my jigsaw cutting after I draw the line. In the past I've used the string method to lay out the line, but then end up trying to sand to the line perfectly, with pretty wobbly results. My current project involves a stained glass oval that I'm supposed to inset in an exterior solid core door and then trim out. I suppose there's some kind of router attachment that accomplishes this, but I'm unaware of one, hence my search for a custom template. I'll have to add that I'm pretty nervous about blowing this one.....the door is the expensive kind. Whew!

1. 
   saschafer | May 21, 2009 02:43am | #3

   You can get jigs for routing ellipses. Rockler carries them.

   -Steve

    

2. 
   hammer1 | May 21, 2009 04:45am | #4

   Sounds like a cool project, CMyron. I don't have any experience with some of the elliptical router jigs but they may be what you are looking for.http://practical-technologies.com/http://www.rockler.com/product.cfm?page=17282&filter=ellipse%20router%20jighttp://www.amazon.com/dp/B001UQ5OZE/ref=asc_df_B001UQ5OZE787983?smid=ATVPDKIKX0DER&tag=nextag-tools-tier3-delta-20&linkCode=asnBeat it to fit / Paint it to match

2. 
   byhammerandhand | May 22, 2009 07:17pm | #6

   I find the string method a little prone to error with stretching and tilting. Before plunking down good money for a jig, they are quite easy to make. All you have to do is plow some dovetail grooves in some scrap, make dovetail keys that fit in them and make an arm to connect to the keys. A little math on the major and minor axes will tell you where the three points need to be placed.A similar toy is often called a "smoke grinder" This web site will give you the inspiration you need. http://woodenuknow.com/donothingmachines.htmlI often rough out the shape with a band saw or router set a bit wide,then come back with a router on a jig set at +0" and trim to desired shape.

2. 
   dmdnk | May 21, 2009 08:15am | #5

   Before spending alot of money on a jig, Why not give it a try on some thin template material like 1/4" mdf.  If you cut close to the line it's fairly easy to sand to the line on mdf by sticking some sandpaper to a piece of wood that is thin and flexible.  If you get the practice piece right, you can then use it as a template for the real thing and use a pattern bit or flush trimmer.

   David

3. 
   knuts | May 23, 2009 06:27pm | #7

   These are simple to make. This is a shot of the initial setup I sent to another fellow that may help if you make one.

   View Image

4. 
   SawdustSteve | May 24, 2009 06:39pm | #8

   Just a thought.... If you're working with a home-made stained glass insert, it may not be a 'perfect' mechanical oval. I'd make a template from a piece of 1/2" plywood and sand IT to the smoothest curvature I could. I'd use a jig saw to cut close to the outline shape and then use my router with a top bearing to clean up the hole.

   OK, now the harder question.... once you've got the hole in the door, how are you going to secure the glass into the hole? You need some form of a stop for the glass to sit against on the outside and again on the inside.

   Would it be easier to make a frame for the glass and then insert it into the door. The molded edge of the frame would cover any slight uneven-ness of the hole??
   SawdustSteve