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Discussion Starter · #1 ·
I am trying to router a channel in a 1.5" x 2.75" piece of cedar. The channel will be 3/4" deep and 5/8" wide. I would like to use a 1/2 double flute bit I have. The bit is 1 inch deep but my thought is to do three cuts in the middle of the channel to start. Each cut going 1/4 " deeper. I think trying to cut the full depth in one cut is too much ??? Once I have the center of the channel to 3/4" then I planned on doing a single cut on each side at full depth to get the right width. The single cuts on each side would take off another 1/16 " or so, so i would do them at full depth. Does this make sense??

thanks
 

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John
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I am trying to router a channel in a 1.5" x 2.75" piece of cedar. The channel will be 3/4" deep and 5/8" wide. I would like to use a 1/2 double flute bit I have. The bit is 1 inch deep but my thought is to do three cuts in the middle of the channel to start. Each cut going 1/4 " deeper. I think trying to cut the full depth in one cut is too much ??? Once I have the center of the channel to 3/4" then I planned on doing a single cut on each side at full depth to get the right width. The single cuts on each side would take off another 1/16 " or so, so i would do them at full depth. Does this make sense??

thanks

Hi - That would work... Are you doing this on a table?.. hand held? How are you guiding the router? edge guide? Some kind of jig? Fence? Is the groove centered?:blink:
 

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Discussion Starter · #3 ·
I have a table and would use a fence. I tried doing a full depth cut ( 3/4" ) yesterday with a 1/2" bit and it was rough. I think the bit may have been slightly dull but i have a new 1/2" for my next try. I am hoping to get smooth walls as it is for a sliding panel.

Thanks
 

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John
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I have a table and would use a fence. I tried doing a full depth cut ( 3/4" ) yesterday with a 1/2" bit and it was rough. I think the bit may have been slightly dull but i have a new 1/2" for my next try. I am hoping to get smooth walls as it is for a sliding panel.

Thanks
Hi Kevin - Ok, I assume you want the groove centered.
First off, the full 3/4" is a pretty big bite. If you have 1/2" shank bits, you should be able to handle a 3/8" bite pretty easily. With 1/4" shank bits I wouldn't go deeper than 1/4".
Now, if you set your table up right, you can make one pass, rotate the stock end for end and make a second pass to get your width. Change the depth and make two more quick passes and your done. A single fence setup and one or two depth changes. Easy stuff on a table. That will only work if the groove is centered in the stock though. In any case, when only working on one face of a groove, the face you are cutting must be AWAY from the fence or else you will trap the stock and shoot it across the shop. :yes: DAMHIKT
 

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If for some reason the first past ends up on the inside, meaning the second flipped pass is also on the inside, the safest way to run it is backwards or left to right. Hold it tight to the fence and it should cut fine.
 

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Discussion Starter · #6 ·
Thanks for the info. My router is indeed a 1/4". I thought going slow enough would be OK to do deeper cuts but I will try at 1/4" or maybe a little less. The channel is actually offset so my thought is to do one side of the channel in multiple cuts until i get down to the depth i need and then move the fence for doing the other side of the channel. When i am doing the other side of the channel i am thinking a single cut at 3/4" depth as i will only be taking off about 1/8" at that point to get the channel to the final width. Thanks for the advice on not pinning the wood when doing the second channel cut!!
 

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where's my table saw?
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deep offset channel with 1/4" shank bit

Here's what I'd do.
Determine where your offset is to the far side of the channel. Make a 1/4" deep pass. Then add an 1/8" strip spacer to the fence side of the workpiece. Make another pass at 1/4" height. This moves the channel over 1/8". Then raise the cutter 1/4" leaving the strip attached, and make another pass. Remove the strip and make a second pass at 1/2" height. Raise the bit another 1/4" and make a second pass. Attach the strip again and make the final pass.

When making a channel/dado it's very important to maintain "registration" or contact with the fence at all times. You will get divots along the channel if there is any variation. Use a feather board to help maintain the pressure evenly. Here's a magnetic featherboard I use on my tablesaw, but it only works on cast iron tops...of course. :laughing:

 

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John
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Here's what I'd do.
Determine where your offset is to the far side of the channel. Make a 1/4" deep pass. Then add an 1/8" strip spacer to the fence side of the workpiece. Make another pass at 1/4" height. This moves the channel over 1/8". Then raise the cutter 1/4" leaving the strip attached, and make another pass. Remove the strip and make a second pass at 1/2" height. Raise the bit another 1/4" and make a second pass. Attach the strip again and make the final pass.

When making a channel/dado it's very important to maintain "registration" or contact with the fence at all times. You will get divots along the channel if there is any variation. Use a feather board to help maintain the pressure evenly. Here's a magnetic featherboard I use on my tablesaw, but it only works on cast iron tops...of course. :laughing:

I would think you would want to reverse those steps. Run the first pass with the spacer in place and remove for the second. As written will definitely trap the stock and have it yanked out of your hand.
I'm also not a big fan of running stuff between the bit and fence in a left to right pass. While you would be running correctly with respect to bit direction, the stock is still trapped and susceptible to kickback, only this way instead of being taken away from the operator and tossed across the room, it is forced back toward the operator. Not saying it can't be done, just not the best idea from a safety perspective. :smile:
 

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where's my table saw?
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I suppose that's true

but either way, on one pass or the other, the work is "trapped" your term, between the bit and the fence. Unless the channel is a stopped channel I would prefer to do the entire operation on a table saw, nibbling away the material until the channel/groove/dado is the correct width and depth.
Making dados/grooves/channels on narrow pieces is risky no matter what your procedure. The piece can tip into the cutter from lack of support or twist etc. I certainly agree that feeding into the cutter rotation is safer than with it, a "climb cut". Any time the bit is in a dado there is one face of the cutter cutting and the other face riding the opposite side of the cut.
I have definitely had a piece go "ballistic" on the router table. :eek: It's a rude awakening. :yes:
 

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John
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but either way, on one pass or the other, the work is "trapped" your term, between the bit and the fence. Unless the channel is a stopped channel I would prefer to do the entire operation on a table saw, nibbling away the material until the channel/groove/dado is the correct width and depth.
Making dados/grooves/channels on narrow pieces is risky no matter what your procedure. The piece and tip into the cutter from lack of support or twist etc. I certainly agree that feeding into the cutter rotation is safer than with it, a "climb cut". Any time the bit is in a dado there is one face of the cutter cutting and the other face riding the opposite side of the cut.
I have definitely had a piece go "ballistic" on the router table. :eek: It's a rude awakening. :yes:
Not necessarily. Shim the fence first pass, remove shim for second pass, change bit height and reinstall shim for third pass, remove shim .....etc..etc.
On the odd number of passes, the bit is buried in the wood therefore the forces trying to throw it anywhere are balanced. On the even numbered passes, you are only cutting on one side of the bit so the forces are unbalanced in the direction of ripping it away from you if that side is trapped by the fence.
I agree the table saw may be a better way but setting up the dado stack for one cut is kinda frustrating and it's tough to beat a router for a clean dado IMO.
I very much agree that having parts launch themselves off a router table serves as a pretty dramatic wakeup call.:blink:
What the OP needs to do since his groove is not centered is run the 3 or 4 passes required to get the correct depth then move the fence BACK an eight of an inch to pick up the width.
 

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John
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The safest and most efficient way of doing this IMO is to make your first pass, then turn the piece around and run the second pass. Running each pass from right to left with the waste coming off to the right of the bit. Just hold against the fence when making the pass, and feed slow and steady.






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I agree, except in this case the groove is not centered in the workpiece.:smile:
 

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This is the setup that I use to route long thin pieces. I believe that it is much safer than using a router table. Both of my hands are on the router so they are safe. The miter box is clamped to the workbench and the workpiece is clamped to the miter box so nothing can move. The router slides easily over the top of the miter box and it is well supported and balanced. I usually put together a longer "miter box" with three pieces of MDF customized for the job at hand. The sides of the miter box form a blast wall in case of flying pieces.
 

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John
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It doesn't really matter...as long as the fence is set accordingly.






"then turn the piece around and run the second pass"

I'm afraid I don't see this working if the groove isn't the same distance from each edge, centered.:blink:
 

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Old School
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"then turn the piece around and run the second pass"

I'm afraid I don't see this working if the groove isn't the same distance from each edge, centered.:blink:
The groove edge will be oriented as to where the fence is set. You could center the groove, or it could be offset.




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John
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The groove edge will be oriented as to where the fence is set. You could center the groove, or it could be offset.








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That's what I'm getting at. I can understand that when the groove is centered you can simply rotate the workpiece to do the opposite edge. When it isn't, I can't figure out how to do it with the single fence setting.:blink:
 

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That's what I'm getting at. I can understand that when the groove is centered you can simply rotate the workpiece to do the opposite edge. When it isn't, I can't figure out how to do it with the single fence setting.:blink:
You can't do an offset groove with a single fence setting, it would take two. The way I said it was:
"as long as the fence is set accordingly."






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John
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You can't do an offset groove with a single fence setting, it would take two. The way I said it was:
"as long as the fence is set accordingly."






OK, I guess we were saying the same thing, only saying it differently.:smile:
 

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Unless this needs to be a stopped dado/groove, I think you're using the wrong tool. A tablesaw dado blade would be much better suited for this. ;)
 
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