I just purchased a bowl and tray bit for my router and am anxious to make all sorts of different designs. Eagle America sells a slew of templates, but at $25-30 each they are somewhat pricey. I was thinking I could make my own but the process has not gone well so far.
I used a drawing program on the computer to draw the templates, then I printed out and used spray adhesive to attach to MDF, then I jigsawed and sanded up to the lines, but the problem is that it seems very difficult to get perfectly straight lines, or to avoid creating flat spots when sanding around corners.
I am sure that the commercial guys probably use some sort of CNC process to create their templates, but I was wondering if anyone had any suggestions on how one could do it themselves cost effectively. I assume that a CNC shop would probably be happy to do it for me but at a cost that would probably be 20 times what it would have cost to buy the template in the first place.
I know I could go the route of using a straight piece of something coupled with a pattern bit to route straight lines, and I could cut circles and do the same thing to cut curves, but that seems like a lot of work.
Not trying to sound like I want something for nothing, but I thought maybe there is a simpler solution that I am not seeing. Any advice?
If you already had something that you wanted to use to create a bowl shape (plastic decoration, wooden puzzle, serving dish), you might be able to use a pattern bit to transfer the shape to a piece of MDF, which would become a "master" template that you could use to transfer the shape to yet another piece of MDF. You could try perusing some Goodwill stores for odds and ends that might make interesting shaped bowls.
With careful selection of guide bushings and bit diameters, you could use the "master" to transfer larger, or smaller, versions to a second piece of MDF, which would become the actual template used for your bowl. You should first make several MDF blanks that are all the same size and have square corners (i.e. the corners are all 90°). This would make it easy to line up templates if you need to (like if you need 2 templates to make one bowl). Also, having MDF blanks the same size will permit use of holders like the ones many members have made.
For many of these decorative templates (e.g. Christmas tree tray), it doesn't really matter if you get the exact shape that you created on the computer. As long as the template looks good, it will make a nice bowl. It might require additional sanding, cutting, or even starting over but once you have the template, you have it forever 9and you can make copies of it too). One thing to remember is that when 2 inside straight sides (edges) meet, the corner will be the diameter of the router bit. This means that you don't have to make inside corners on your templates unless you want the corner radius to be larger than your router bit.
All that said, you will have to decide if you want to spend time making jigs and fixtures, or making bowls (i.e. by buying the template). I'd suggest buying a simple one first, then make a few bowls so you see how everything works together, then if you want to make your own templates after that, you'll have a better understanding of what would be required to make the template work.
I hope all this is understandable. If not, I can try to clarify, along with many others on this forum. If possible, post some pictures of what you end up making (including templates).