Replies

1. 
   saschafer | Dec 16, 2007 02:05am | #1

   Even more important than going down hill is going against the rotation of the bit. It sounds like maybe you're making what's called a "climb cut," which is difficult to control when you're hand-holding the piece to be machined. See the attached sketch. (The sketch shows the geometry when looking down on a router mounted in a table.)

   So what do you do if going against the rotation means that you're cutting uphill against the grain? The ideal situation is to have two router bits, one with the bearing at the top and one with the bearing at the bottom. That way, you can make part of the cut with one configuration, then switch bits (and flip the workpiece over) and make the remainder of the cut. That gives you the freedom to cut downhill with the grain while always cutting against the bit rotation.

   Another thing you can try is to remove most of the material while cutting against the rotation of the bit, and then take one last trimming climb cut that removes a very small amount of material. However, you have to be very careful when doing this, as it is very easy for the workpiece to get away from you.

   -Steve

    

   
1. 
   cbrazik | Dec 16, 2007 02:19am | #2

   I am using a 1/2" shank top bearing router bit.  I changed bits to another a "Bosch" instead of the Rockler and made one good cut.

   That is a good suggestion to try another and flip it with a bottom bearing bit.  I am going in the direction of your diagram.  Taking a little bite would help.  I did sand almost to the line and then used the bit.

   Thanks.

1. 
   hammer1 | Dec 16, 2007 06:07am | #4

   If I'm reading your description correctly, you are using a straight flush trim bit in a router table, you have a template on top of the work piece, and it's riding on the bearing, which is on top of the bit. You are hand feeding against the rotation of the bit and you are getting kicking. In hard maple.When doing shapes, it often helps to have a starting pin. This is can be something simple, like a 1/2" dowel, that is placed vertically in the table top to add an extra point. I often place one after the bit so work can't get trapped and sucked in between it and the bit. Placement can depend on the shape, size and whether you have a plate insert. This really helps when starting the cut and can assist throughout. Maple is a hard material. Obviously, slight movement of the template will cause problems. The less material you have to trim, the better, 1/32" would be ideal, 1/4" would not. I would strongly advise against climb cutting when freehanding. It's a real good way to get your fingers trimmed. The only way you can take incremental cuts is by changing the bearing or neatly wrapping the existing one with some tape. I would also try some different router speeds, if you can. Full tilt would be a little too much for me.Beat it to fit / Paint it to match

2. 
   Routerman | Dec 16, 2007 04:23am | #3

   Will not ask about the cutter. Would not expect a temporary hold fast such as tape to be good for the forces you're into.

   The work has to butt up agianst stops and be pinched down on that templet for success. Once the work begins to squirm it's curtains up or down grain.

   Routers

1. 
   cbrazik | Dec 16, 2007 08:21pm | #8

   Thanks to all for the suggestions.  So far I have all of my fingers.  I did try the hot glue but as one of the respondents said it might need a pin for a starting point.  Both router bits were new.  The one that bit the most was the one that did two others but the Bosch bit and was brand new.  It did make one good pass.

   I will do some cautious experimenting.  Thanks again and have a great holiday.

3. 
   BruceS | Dec 16, 2007 06:50am | #5

   Some may disagree,  but I never ever go back to a piece of lumber with an edged tool after it has been touched with any abrasive papers.  Just MHO.

   Work Safe,  Count to 10 when your done for the day !!

   Bruce S. 

    

4. 
   [email protected] | Dec 16, 2007 07:40am | #6

   Sounds to me like the bit dulled.  It was sharp for the first one, and has dulled to the point you are starting to have trouble. 

5. 
   woodhacker | Dec 16, 2007 05:27pm | #7

   For temporarily attaching templates, I use double-sided carpet tape. It's a lot stronger than office-grade double-sided tape. Hot melt glue would be another option, or you could glue the template to the piece with a separation layer of brown paper between as is done when turning half-spindles on a lathe.

   Instead of using a traditional flush-trim bit, try a spiral bit with a collar in the router. The spiral bit will do a shearing cut, much less likely to tear out the end grain.  This will of course require that the template be a small amount undersized, and unless the router table is equipped to handle guide collars will only work with a hand-held router.

   Another option would be to use a guided sanding drum such as robo-sander if the contours of your cutting boards don't require a cutter/sander diameter of less than one inch.  With this you should have no problem with tearout or grabbing.