Replies

1. 
   johnhardy | Jun 19, 2004 08:39pm | #1

   Mike, you might be able to get a thin kerf blade made with the proper thickness (perhaps Forrest would do this for you). You could set it up to cut 1" deep. Just a suggestion.

   John

2. 
   Jamie_Buxton | Jun 19, 2004 08:41pm | #2

   Two suggestions --

    1) You're willing to go 9 thou over with the 7/32 bit.   Are you willing to go 13 thou under?  If so, get a 5 mm bit.

   2)  Cutting nearly an inch deep with a straight bit is going to take several passes -- that is, lots of labor.   Can you do the job with two passes of a table saw blade?   If you need to be able to plunge-cut, you can do that on a table saw.  Use stops to ensure that the workpiece can't get jerked away from you.   With a little looking around, you can find saw blade diameters as small as 4".

3. 
   UncleDunc | Jun 19, 2004 09:16pm | #3

   >> The width of the slot has to be 0.210" ...

   Would it make sense to use a narrower blade and make two passes?

   >> ... does anyone make a 7/32" straight bit?

   A tool and cutter grinder will be able to reduce a straight bit to whatever diameter you like. Ask at local machine shops to see who sharpens their end mills.

   >> Any other suggestions?

   Go to the McMaster-Carr or MSC web page and look at metal slitting saws. If you're willing to modify a stock tool, there are candidates in HSS, cobalt and carbide. The tooth geometry is not ideal, but if you're planning on having it ground anyway, that can be corrected.

4. 
   RickL | Jun 19, 2004 10:06pm | #4

   Does it need to be for curves or is it just straight. Knowing the application would be helpful. A lot of the guys at work always ask me for certain tooling and I ask them what they are trying to do. Often we re-design it to use more standard off the shelf tooling.

   http://www.thewoodworkerschoice.com lists a 7/32" x 1" flute in their catalog as 0436 Viper # 732-4-DFS Couldn't find it in their online catalog but some sites don't search that easy.

1. 
   PlaneWood | Jun 20, 2004 04:56am | #5

   The slot is just a straight cut centered on the edge of a 13/16" thick board.  Whiteside makes a 7/32" straight bit but with only a 3/4" depth of cut.  The shaft is 1/4".

   I guess I could set up a dado blade on a table saw.  Only thing is that I gave my table saw to my son a couple of years ago!  He only lives a mile away though.

   The only dado blade I have is a real old sears adjustable dado that's not the best.  What dado blade would be advised to get an accurate thickness?

   PlaneWood by Mike_in_Katy (maker of fine sawdust!)PlaneWood

5. 
   KeithNewton | Jun 20, 2004 05:52am | #6

   If you are using a standard dado, the two outside blades will usually be .250, but I have used two regular sawblades of the same size and # of teeth before with good results.

   What are you doing this for anyway? Or what is the application? Maybe there or other options that we can offer that you may not have thought of.

1. 
   PlaneWood | Jun 20, 2004 07:17am | #7

   Making handles for reproduction #44 Miller's Patent planes.

   PlaneWood by Mike_in_Katy (maker of fine sawdust!)PlaneWood

1. 
   KeithNewton | Jun 20, 2004 07:00pm | #8

   The folks at Memphis Machine can make you a cutter for any application to your specification.

   I think you are going to get too much chatter from bit deflection to hold your tolerance with a router bit that small, and going that deep.

1. 
   PlaneWood | Jun 20, 2004 07:35pm | #9

   That was my thought too re: a straight bit.  I think I'll purchase a newer style adjustable dado and give that a try.

   PlaneWood by Mike_in_Katy (maker of fine sawdust!)PlaneWood

1. 
   MichaelPB | Jun 21, 2004 12:52am | #10

   Mike,

   Your right to go with the dado.  I would make long strips of stock and then a fixture that uses the slot to hold it and then route it to shape.

   I know, I know, you didn't ask me but I couldn't help it.

2. 
   johnhardy | Jun 22, 2004 03:07am | #11

   Mike,

   I've never seen a dado blade that went below 1/4". You need less than .25, so I'm not sure this'll be a viable approach. Or, I may just be smoking something?

   If the dado approach doesn't work out, something that might just fill your bill exactly would be a slot cutter for your router ... one that is set for exactly 1" deep, and is ground down to your desired width of cut.

   John

3. 
   Adrian | Jun 22, 2004 04:24am | #12

   If you are thinking saw blade, the tooling manufacturers make grooving blades in different kerfs, and could make one in whatever size you want. The advantage is the groove would be flat-bottomed, if that is important, and the geometry would be right....with dado blades, if you're just using the outside blades, you'll get the same ridge in the middle you get with an ATB.

   Same principle with a shaper, if you have one....you could get a grooving tool. That's a big cut for a router bit, if you go that way.cabinetmaker/college woodworking instructor. Cape Breton, N.S

4. 
   Jamie_Buxton | Jun 22, 2004 06:25am | #13

   I believe some wobble-type dado blades will cut less than 1/4".

   Another way to do it is with two passes of a standard saw blade.   So it takes two passes instead of one.  You can do a lot of extra passes for the cost of a custom saw blade.

6. 
   RickL | Jun 22, 2004 04:46pm | #14

   Guess you didn't read my post on the 7/32" router bit with 1" flute. Now I know the application I wouldn't suggest the router bit route anyway. Two passes with  a sawblade would be simple.  They used to sell wobble washers so you could make a blade wobble and get that 7/32" kerf or stack some thin kerf rip blades with spacers.

1. 
   mitch | Jun 22, 2004 05:12pm | #15

   adrian's response got me thinking-  maybe you could do it with a .210" width slot cutter on a shaper or a modified big router bit.  you would then have a 1/2" shank, maybe even with a bearing or rub collar for consistent depth.  it would also be a lot easier to run the stock lying flat on a table up against a fence than run a router down a narrow edge.  your rate of stock removal would be greatly improved as well.  cutting a 1" deep, .210" wide groove with a little router bit will be deathly slow- especially if you have a lot to do.

   m

7. 
   GeoA | Jun 22, 2004 06:03pm | #16

   How about stacking a standard width (1/8") rip blade with a thin kerf (3/32") rip blade and use a shim between the two to get the final slot width?  With 24 tooth blades, there should be enough clearance between the teeth to "interleave" them.