Replies

1. 
   Scooter456 | Jul 05, 2004 08:18pm | #1

   Fir is a pain the hindquarters to mill with any form of cutter, other than a saw blade.  I know of no "sure thing" tips, but as a remodler, I can tell you what I do:

   *  First, I buy about one third more stock than I need.  If I am making 5 pieces, I will probably buy 7, maybe 8.  If there are mutiple set ups, I might start with 10.

   *  Second, feed rate is important.  Too slow and it tears out; too fast, and it tears out.  You will have to judge yourself, but be prepared to speed up or slow down.

   *  Incremental Cuts.  If I am taking off three quarter of an inch on a molding, I will start the process with the fence way out and "sneak up" on the finished molding elevation.  This means running all 10 pieces through the router table incrementally, a real pain in the hindquarters.

   *  Reverse Final Cut.  When I am within a 16th, I run the stock through backwards.  This sounds crazy, and I am likely to criticized by many in this forum, but this works for me.  No more than a 16th mind you.

   *  Cherry Pick Pieces.  Even verticle grain Doug Fir will take a turn now and then.  The grain is not perfectly straight.  If the grain takes a turn toward the edge of the board, well that is well tear out will occur.  You really need to look at the pieces and get the straightest, non-bowed, lack of crown, and straight grained stuff you can get. 

   Those are my tips.  Maybe someone with better experience than me can chime in.  I am just a lowly remudler.

   Kelsy

1. 
   ErikU | Jul 05, 2004 08:31pm | #2

   Thanks for the tips.  The reverse milling sounds interesting; I can see how that might mitigate tear-out.  I'll give it a try (with caution).

   Cheers,

   Erik

1. 
   Michmesquite | Jul 06, 2004 02:39am | #3

   Erik

   For soft woods like VG fir use HSS knives. They are the sharpest. Being HSS they may only last one job, but it is the material you want to save, not the knives._________________________________

   Michael in San Jose

   "In all affairs it's a healthy thing now and then to hang a question mark on the things you have long taken for granted." Bertrand Russell 

1. 
   ErikU | Jul 06, 2004 07:06pm | #6

   Thanks Michael, I should have known about the high speed steel knives.  I have lot of experience with metalworking machines and the same thing applies.  The only problem of course is that I don't want to invest in another rail/stile cutter set!

2. 
   SgianDubh | Jul 06, 2004 09:44am | #4

   I won't give you hell for saying this, Kelsey,

   "Reverse Final Cut.  When I am within a 16th, I run the stock through backwards.  This sounds crazy, and I am likely to criticized by many in this forum, but this works for me.  No more than a 16th mind you."

   But I will warn inexperienced users of routers, used freehand or in a table, overhead pin routers and spindle moulders or shapers that this is known as a climb cut.

   In climb cutting the cutting edges are rotating away from the feed direction and the tendency is for the wood to be sucked in faster than expected which might cause the hands to be pulled into the cutter. With a hand held router in climb cutting mode you can feel the router running away from you along the edge being profiled.

   In a normal cut the cutting edges are chopping into wood as it's fed into them. The danger to be aware of with this conventional feeding is kickback where the cutters hits a knot, too big a bite is taken, etc.. With a hand held router you'll feel it jump back at you if you get a minor kickback.

   Generally I frown on hand fed climb cutting particularly with table inverted routers, powerful overhead pin routers, and with spindle moulders (US shapers.) With any of these tools the only way I'll allow such an operation in our workshop is with a power feeder.

   Freehanding a sizeable climb cut with large hand held router-- 1500 watts and above is likely to be dangerous in inexperienced hands too. 

   Freehanding small mouldings with a climb cut is relatively safe (and I say that with all sorts of proviso's) with a small router-- less than about 1200 watts, but even here caution has be exercised and experience is necessary. Slainte.RJFurniture

1. 
   macalex | Jul 06, 2004 01:23pm | #5

   Amen on climb cutting - it works, but you really need a power feed or a strong constitution. Not for the faint-hearted, or the inexperienced. Don't try this at home!

   Fir will split out. Sometimes worse than others. Depends on a variety of factors, from cutter sharpness to the orientation of the growth lines to the degree of contrast in hardness between early and late wood to ... lots of variables.

   A try-out not mentioned above is to back up the cut (maybe not an option on a shaper/router). If you can, back up with a sacrificial piece so that when the cutter/saw exits the wood, the last fibres are supported and they don't rip out.