Replies

1. 
   SCFrankland | Jun 27, 2002 02:59pm | #1

   I know that installing a fence with two bearings as the riding surface wouldn't work in your case because of the difference in the radius around the table. But I have seen a jig from Micro-Fence that would allow you to do such a cut with ease. It was reviewed in April 2001 FWW issue 148, page 32. It does have step price tag but I figure that one can be made fairly easily if need be.

   Scott C. Frankland

   Newfoundland Wood Worker

   
1. 
   eddiefromAustralia | Jun 27, 2002 03:27pm | #3

   Hi rdl,

   Just saw Scott's picture - this looks alot safer & more controllable - would use something like this in preference to a homemade jig.

   Cheers,

   Eddie

2. 
   eddiefromAustralia | Jun 27, 2002 03:15pm | #2

   Hi rdl/Scott,

   Deleted post 2 as I misread your problem.

   I have seen this done, but I have safety and quality concerns at the way it was done. However, for what it's worth, I'll post the idea.

   The way I read your prob, it sounds as though the table may or may not be in pieces, this way will work for either.

   Have seen a false 1/2" MDF top put onto a router table, with two 1/4" dowel guide pins located in the surface as your 'fence'. These pins were located approx 1 inch apart, with one being on the infeed and one on the outfeed side of the router bit. The distance from the edge of both pins to the centre of the bit matches the distance that you want the centre of your groove to be located from the edge of the board.

   Still a little confused - look at this photo of the curved marking gauge (Ulmia 0029K) to give you the basic principle. http://www.fine-tools.com/streic.htm

   From then, just feed the segment into the bit to cut.

   My safety/quality concerns were:

   1) this works fine at the middle of the board, but what about the ends where there is no support - poor alignment and poor control?

   The job I saw had the guy glue false block onto the end of his work to provide the necessary support

   2) no matter which way you go, if you have a straight bit, you're climb cutting = loss of control = poor quality and safety concerns. (the only way I can think around this is shallow, multiple cuts)

   3) unguarded router bit, with your hands close to the work by necessity. Makes my mental alarm go off! safety!! Trade training gives ways around this, but this is too complicated for me to explain simply - perhaps someone else has a better option.

   Should all else fail and you decide to give this a go, please remember that if what you are doing makes you feel even slightly nervous, listen to your nervousness, STOP and think of another way.

   Cheers,

   Eddie

3. 
   quatersawn | Jun 27, 2002 11:30pm | #4

   You could try to set up your table router as a pin router. You need to mount a pin or dowel directly over the bit to be used. then develop a template to fit the back of the piece, that way you can position the bit over any part of the frame, since you don't want it centered somewhat on the frame. You would then have to gently lower the piece down onto the bit, and then just follow the template. This is the poor mans version of an over arm router. True over arm routers have a top mounted router with a pin in the table to follow templates, and a pedal to pneumatically lower and raise the router, hands free, so to speak. This method simply inverts it, minus the pneumatics. Let me know how you eventually accomplish it. Another thought, is that you could make a template and place it on the frame with double sided tape, and then use a plunge router to make the groove. That might be a better way come to think of it.

1. 
   rdleecw | Jun 28, 2002 03:56am | #5

   Mark-thanks for the suggestion.  Makes since and I know what you're talking about.  I've been experimenting and just found that grooving it out by hand is pretty fast and a lot safer than risking blowout on a piece that has taken a while to make.  I'm working with mahogany and it cuts nicely with the chisel.  I just treat it like a long mortise so I score with a curve mortising guage and drill out between the lines on the drill press.  I do plan to make more of this design so I might just try out your suggestion though if I decide I need a little more speed.  Thanks again. 

1. 
   quatersawn | Jun 28, 2002 11:09pm | #6

   That's a good idea. It also helps hone your chiseling skills as well.