Replies

1. 
   mwenz | Jul 01, 2007 06:05pm | #1

   No.

   And when using, do not do consecutive holes. Do both ends. Space the remainder just a bit apart and then do the stuff between.

   Take care, Mike

1. 
   citrouille | Jul 01, 2007 10:44pm | #4

   Why ?Why not do consecutive plunges ?
   A plunge that cuts only 3 sides goes much easier than one that cuts all 4 sides.
   Why make it harder on the machine ?C.

1. 
   mwenz | Jul 01, 2007 10:53pm | #5

   Didn't say it was harder on the machine. It's the auger that is in question.The auger bits are a bit flexible and especially so on the smaller sizes. If there is an unsupported side it can encourage the bit to rub into the inside of the chisel portion, which causes burning of the bit/chisel from the metal-to-metal contact and or failure to eject chips properly, which also can cause the bit to overheat.Take care, Mike

2. 
   forestgirl | Jul 01, 2007 07:02pm | #2

   Dan, if you have access to the "paid section" of FWW.com, you can view this article on using a benchtop mortiser.  If you don't, it's in issue #185 and contains tips on sharpening, setting up, and cutting sequence for the operations.

   forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-) 
   
3. 
   frenchy | Jul 01, 2007 07:08pm | #3

   danfromsaskatoon.

      yes!  I do all of the time prior to mking my mortice pockets..

     Now to be fair I use Milwaukee's self feeding bits (they're kinda big forsner bits up to 4 inches ) and remove about 70% of the waste wood. I then go in with my chain morticer and remove much of the rest leaving only a tiny bit for removal with my chisels..

      Oh! did I mention I'm building a timberframe house and my tenions are usually around 4 inches?

    I used to do most of the work with the chain mortiser, but once I switched from pure chain morticer to predrilling the time to cut the mortice has been reduced  by over 1/2  

4. 
   chairmannz | Jul 02, 2007 02:40am | #6

   Hello Dan,
   As a chair maker I do a lot of mortises, I have never predrilled them, My machine can do up to 19 mm (3/4 inch) in Oak and that is hard work.
   I let the machine do the work, use just enough pressure to hear the machine work hard but not overstrain, in this way you learn that the timber is sometimes denser in spots and it is going slower other spots it is like cake and it a brease.
   My pre 1900 mortiser is better then one of those new machines, it has less flex in the machine that is important when I somethimes make big doors and the mortise is over 8 inch long.
   Or when I do a bread board end for a table, I run the whole lot on this machine.
   Its important to set the chisel in straight so as to minimize chiseling the uneven cheeks.
   In mortises I do the end holes first and the in between in this way those end holes are always nice and straight.
   Have fun Bernhard