Replies

1. 
   sschefer | Apr 27, 2002 12:16am | #1

   Test it and see. If it doesn't have enough poop then step up to the PC 7518 3 1/4 hp variable speed. I highly recommend a 7518 in the table and a plunge for everything else. I have this configuration and it swings a set of big old ugly raised pannel bits with no problem at all.

   Steve - in Northern California

1. 
   UncleDunc | Apr 27, 2002 02:41am | #2

   Or make multiple passes. If you already have the 690 and are happy with it, it might not make sense to upgrade for just one project. I have the 7518 and I like it a lot, but I'll freely admit it is big and expensive.

   Edited 4/26/2002 7:41:55 PM ET by UNCLEDUNC

   Edited 4/26/2002 7:42:54 PM ET by UNCLEDUNC

1. 
   BLJII | Apr 27, 2002 09:34pm | #3

   Can't make multiple passes with a lock miter bit...will have to hog it out all at one time.

1. 
   UncleDunc | Apr 28, 2002 12:00am | #4

   >> Can't make multiple passes with a lock miter bit.

   I admit it would be tedious, especially on the pieces that you have to hold vertical against the fence. The process I had in mind was to adjust the fence so just the bottom corner of the bit is sticking out, run all the horizontal pieces through, run all the vertical pieces through. Then move the fence back so a little more of the bit is sticking out, and repeat. You could do it in two steps or three or sixteen.

   If the workpiece drifts away from the fence a little, no problem, the bit just doesn't have anything to cut and you have to take a little more off on the next pass. If the workpiece rises up off the table, then sure, it's ruined, but it shouldn't be too tough to keep that from happening. That's what holddowns are for.

   I didn't actually go out and put my lock miter bit in my router and cut a joint, but when I do the thought experiment, I don't see anything that would prevent me from cutting the joint with multiple passes. What am I missing?

   Edited 4/27/2002 5:01:29 PM ET by UNCLEDUNC

1. 
   JasonMI | Apr 28, 2002 12:32am | #5

   I use a lock-mitre bit for 3/4" material...and the instructions say very specifically to cut a 45 degree angle on the wood. Now that I've read these posts, it makes sense...by running the wood through the saw first, you're already getting rid of probably 70% of the wood that would have to go through. I use a crappy little Dewalt 610 for lock miters without a problem.

2. 
   cheapwood | Jul 30, 2003 07:45pm | #14

   I don't see how that would work. On my lock miter cuts the little male projection is proud of the miter. If it wasn't it wouldn't engage the other piece. It seems to me that cutting the 45 degree miter on the table saw is an illusion because to create the lock miter the bit still has to remove wood to the depth of the part of the bit that creates the male projection. Does this make sense?

3. 
   alexlisa | Apr 28, 2002 04:08am | #6

   I think the architecture of the cut profile would prevent multiple passes on a lock miter, wouldn't it?

4. 
   SCFrankland | Apr 28, 2002 04:55am | #7

   Check out the link below. I think it will answer any questions you may have.

   http://www.leevalley.com/shopping/Instructions.asp?SID=&ccurrency=1&page=45828

   Scott C. Frankland

   Newfoundland Wood Worker

5. 
   UncleDunc | Apr 28, 2002 07:08am | #8

   Thanks for the link!

   The way I read the last two pictures, I can feed either workpiece horizontally into the bit in arbitrarily small increments. Vertical increments would clearly not work. Once again, what am I missing?

   It's really frustrating not to have a tool to make simple line drawings.

6. 
   user-290897 | Apr 29, 2002 05:35pm | #10

   Thanks for the wbsite link.  It answered alot of questions.  Although the literature with the bit indicated that I should not cut a 45 degree angle on the ends, I probably will just to reduce the amount of material that the bit needs to remove.  Keeping in mind, of course, that I can't cut the 45 to the edges of the pieces due to the fact that there is a small tab protruding which makes the joint lock.  Thanks again.

7. 
   sschefer | Apr 29, 2002 05:55pm | #11

   Just an FYI, I've tried multiple passes with locked mitre bits and it is nearly impossible. Thats not to say it can't be done, but all of the things that you have to watch out for that have been previously mentioned, combine themselves into one tough situation. My experience has been that once that bit is finally setup properly, don't change anything until you've made all of the routes you need to do.Steve - in Northern California

8. 
   Indigo1557 | Apr 30, 2002 01:07am | #12

   I would agree with Steve.  Get everything set up and make sure it is dead bang on.  This is best done as a one pass cut (I think I have the lock mitre bit you refer to).  I have a 2.5hp router, which seems to do fine but anything lower would make me a little concerned. The bit has alot of work to do, it needs the hp.

   If you haven't used this bit before, take the time and lots of scrap to get it figured out and set up correctly.  You may want to take a look at:

   http://www.woodshopdemos.com/cmt-lm10.htm

   It's a little hookey, but I like this site.

9. 
   user-290897 | Apr 30, 2002 06:24am | #13

   The site was fine.  I ran my lock miters today and they seemed to turn out alright.  It sure makes a lot of dust and shavings!  Hopefully I'll glue them up tomorrow. 

   Thanks for your help.

2. 
   jeffn7 | Apr 29, 2002 06:17am | #9

   what speed does the mfg recomend for this bit? It's probably not an issue with a lock miter bit, but I would check it just in case as the 690 is not a variable speed router.