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Birdsouth bit what went wrong

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Forum topic by stripit posted 12-30-2019 09:27 PM 1198 views 1 time favorited 15 replies Add to Favorites Watch
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stripit

141 posts in 3166 days


12-30-2019 09:27 PM

Topic tags/keywords: hexagon problem birdsmouth bit router table

Hi everyone. Anybody out there ever use a birdsmouth bit?? I’m using Yonico birdsmouth 3 bit set. I tried the octagon bit with no trouble. I tried what I thought was the hexagon bit, I measured the cutting edges. This is what I ended up with as you can see it is closer to a pentagon, which is a 105 deg. hexagon is 120 degs.
What went wrong, this bit is not close to 6,8, or12 sided.

I’m trying to make a post for a lectern, and thought a hexagon would look more interestiing then just a square.

Thanks for any help you can give me.

-- Joel, People ask what I make. I tell them I make sawdust, and now and then a nice box or frame,or clock, or lamp pops out.


15 replies so far

View Madmark2's profile

Madmark2

2858 posts in 1711 days


#1 posted 12-31-2019 12:25 AM

You got a part # please?

M

-- The hump with the stump and the pump!

View Rayne's profile

Rayne

1319 posts in 2662 days


#2 posted 12-31-2019 06:07 AM

Read some of the reviews that it would be best to get the instructions from Yonico first. It looks like a setup issue rather than the bit since the bit apparently can do both 6 and 12 sided object.

View CaptainKlutz's profile

CaptainKlutz

4565 posts in 2617 days


#3 posted 12-31-2019 06:16 AM

Like you I attempted to use a birdsmouth router bit. There is trick to setting the location of the intersection point of the two angles. If not perfect, your board widths are wrong and angles won’t close.
I found getting it right took lots of test passes, and finally gave up; switched to table saw.

IMHO it was really easy to use table saw for cutting birdsmouth joints?
Set the angle per one of the many online calculators with digital gauge; make 2 passes – one horizontal and one vertical on one edge of each board.
Done.
Use a flat top ripping blade for perfect corner. But due the massive glue area, it’s not a requirement unless the ends and joinery will be visible.

The boating folks use the birdsmouth joint for wooden masts. This 'howto' site has lots of different calculators to calculate the angles based in lumber thickness, diameters, and board width. It also has a full length article on the math involved for making tapered wooden masts using birdsmouth. it’s fascinating reading if you want to learn nitty gritty math details.

YMMV

-- If it wasn't for bad luck, I wouldn't have no luck at all, Doom, despair, agony on me… - Albert King - Born Under a Bad Sign released 1967

View Fred Hargis's profile

Fred Hargis

7028 posts in 3616 days


#4 posted 12-31-2019 12:52 PM

They are not that hard to use, I’ve had good success with them. There are a number of internet guides one set up, and that’s all your problem is.

-- Our village hasn't lost it's idiot, he was elected to congress.

View Lazyman's profile

Lazyman

7145 posts in 2510 days


#5 posted 12-31-2019 02:33 PM

After modeling the bit and boards in Sketchup, the only way I can see that happening is if you tilted the board or router while cutting or the bit is faulty and the resulting angles on the sides of the cut are not 60 and 30 degrees. Non-flat and square stock could cause that too but it looks okay in your pictures. Measure the resulting angle of the external edge and make sure that it is 30°.

The only thing you can change about the setup is the height/depth of the bit and the only effect that has is whether the corners are flush from what I can tell.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

View Kazooman's profile

Kazooman

1540 posts in 3075 days


#6 posted 12-31-2019 02:50 PM

I do not have any personal experience with birdsmouth bits. I did look up the set of bits you are using. I think you might be using the wrong bit. Bit number 15137 is for 16 sided glue ups. Note that it cuts a 22.5 degree angle. Combining that with the 90 degree angle of the mating piece gives a total angle of 112.5 degrees. That is darn close to the result you get. I suspect that with an improper setup for the thickness of your stock you don’t get the 16 sided result either.

Are you certain that you have used the correct bit? It should be 15139.

View Lazyman's profile

Lazyman

7145 posts in 2510 days


#7 posted 12-31-2019 03:25 PM

Yup. That meshes with my theory. It didn’t occur to me that he was not actually using the 6/12 sided bit. If you assemble boards cut with 16 side bit inside out, you will get a result like what he showed in the OP.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

View bondogaposis's profile

bondogaposis

6000 posts in 3474 days


#8 posted 12-31-2019 04:04 PM

I have no experience with Yonico bits, but I have had excellent results with the Infinity birdsmouth bit for hexagons.

-- Bondo Gaposis

View WoodenDreams's profile

WoodenDreams

1321 posts in 1034 days


#9 posted 12-31-2019 04:50 PM

Here a good video link “how to use the birds eye router bit” . The height set up in the video starts at about 4:15
https://www.bing.com/videos/search?q=how+to+use+birds+eye+router+bits&docid=607997777401348405&mid=1282FF1ED5992EDEA7921282FF1ED5992EDEA792&view=detail&FORM=VIREHT

View Fred Hargis's profile

Fred Hargis

7028 posts in 3616 days


#10 posted 01-01-2020 12:16 PM

Stripit, did you use the wrong bit? I had not considered that as a possibility.

-- Our village hasn't lost it's idiot, he was elected to congress.

View Lazyman's profile

Lazyman

7145 posts in 2510 days


#11 posted 01-01-2020 02:24 PM

This is what happens when you use a 16 side bit and assemble inside out. Looks pretty familiar. Results will vary slightly depending upon the height and depth settings.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

View Fred Hargis's profile

Fred Hargis

7028 posts in 3616 days


#12 posted 01-01-2020 04:17 PM

Yep, sure looks like the outcome above to me.

-- Our village hasn't lost it's idiot, he was elected to congress.

View stripit's profile

stripit

141 posts in 3166 days


#13 posted 01-01-2020 09:45 PM

Thank you to all who took the time to write.
I just checked the bit (lots of light and large magimify glass) your right Ihad the wrong bbit, I’ll try the right one tonight.
I haave watched Dave henery many times, he is very good.

I’ll let you know how it turns out.

-- Joel, People ask what I make. I tell them I make sawdust, and now and then a nice box or frame,or clock, or lamp pops out.

View stripit's profile

stripit

141 posts in 3166 days


#14 posted 01-02-2020 12:14 AM

Hi. I’m back. It’s amazing how well thing work out whenyou use the right bit. Thanks again for the help. I’ll post the lectern when it’s done.

-- Joel, People ask what I make. I tell them I make sawdust, and now and then a nice box or frame,or clock, or lamp pops out.

View shipwright's profile

shipwright

8731 posts in 3921 days


#15 posted 01-02-2020 03:57 PM

This is also a very easy joint to cut on a table saw.
Set the angle and height, run the board through on the flat, run it again on its edge, assemble.
The board thickness isn’t limited by the bit size either, great way to make hollow masts.

-- Paul M ..............the early bird may get the worm but it’s the second mouse that gets the cheese! http://thecanadianschooloffrenchmarquetry.com/

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