Planter box - 8 -sided sloping

[LCHIEN]

Got a 8-sided birdmouth bit from Amazon, only $18. Seems like a pretty easy way to make a planter. MLCS has a nice article on how to do it. plans-8-sided-planter.pdf
Need 8 identical staves, use a taper jig to make sloped sides if you don't want a cylinder look.
Just needs the profile routed on one side. The other side is straight which makes it easy. Also when gluing, you are gluing two orthagonal faces instead of just one - I think that makes a better joint than a single face at an angle and also makes it easy to line up without slipping off! Basically pushing the edge into a corner. Tape was suggested by MLCS, a good idea. It was a lot easier to wrestle into a shape and clamp it than I had expected. Imagine trying to get 8 135 degree miter joints all lined up!

This one is 12 " diameter, 8-3/4" high and just 4 degree sides.
Very easy to get these pieces backwards, though! (DAMHIKT) Make sure you triple check what is the inside & outside of the staves when beveling and routing. Its hard on the brain cells.

8-3/4" was the height to get exactly 8 sides from a 72 inch dog eared cedar fence board. This cedar was really coarse grained! the stave width is the diameter/2.4 so the 5.5" planks were ripped to 5". I intended to put a 10" pot inside.

Overall this turned out to be very easy and pleasing for me, even though I'm not yet finished.

Special tools:

• 8-sided birdsmouth bit, $18 from Amazon, $30 from MLCS, $43+shipping from Lee Valley; I just used the Amazon bit with next day delivery.

Other tools

• BT3000 table saw
• taper jig for table saw
• miter saw (vertical bevel is nice)
• Table mounted router with fence with about a 2" opening.
• Assorted bungee cords for clamping... have them ready!
• bandsaw
• disk sander
• Drill and 3/8" bit

Still need to cut a bottom piece to wedge into it.


Next time I'll select a better piece of wood!!! {edit 11/14/2023 this turned out to be a blade with a bent tooth made this horrible cut - since repaired the blade]

[LCHIEN]

One last hint:
The routed edge becomes a knife edge and it rides along the fence so is it easy to lose the reference and get sniping. Then the joints don't meet right and you have problems.

I messed around and found that what made it easy to prevent was to attach a board to the top of the stave which would leave enough meat to follow the fence solidly once the stave was mostly past the bit.
IT doesn't need to be attached in a major way - I just used a spare unrouted board of the same size and drilled five holes in it, screwed in 5 wood screws just far enough so that the points protruded 1/8th inch or so and held the boards together for the ride. Pressing down on the workpiece make sure they were fully engaged as long as I had pressure on it. and guided it through the cut. The little dents it made were not noticeable in the final work.

[leehljp]

I have thought about doing that for ages, but never bought one of those bits. You make it look simple. Well done! Thanks for posting!

[LCHIEN]

I have thought about doing that for ages, but never bought one of those bits. You make it look simple. Well done! Thanks for posting!

There are three commonly sold Birdsmouth bits. 6/12 sided, 8 sided and 16 sided.

MLCS calls them multi-sided glue joints.
The 8-sided seems most reasonable to me to start with. Since I was messing around, I tried the cheap one on Amazon. Works OK.
The real magic is being able to glue them up without 8 glue joints at once at weird angles shifting and sliding all directions.

.

[LCHIEN]

Just cut and glued a 10" x 10" piece to mark for the inside bottom.




Just following directions to mark cut lines 1/8" oversize and 4° bevel cut to drop in from the top.
Might be a couple of days before I get to cut it. Will also need some drain holes.

[nicer20]

Nice design and write-up, Loring !!

Looks interesting and worth trying .....

I am a bit confused about the 4-degrees & 2-degrees tapering cuts mentioned in that MLCS PDF.

Is the 4-degree cut mentioned in Fig. A about crosscutting the top?
& then the 2-degrees tapering is for ripping the stock - I guess. Still scratching my head if the blade needs to stay tilted at 4-degrees when rip-cutting the 2-degrees taper.

You bet it is hard on braincells.

[LCHIEN]

Nice design and write-up, Loring !!

Looks interesting and worth trying .....

I am a bit confused about the 4-degrees & 2-degrees tapering cuts mentioned in that MLCS PDF.

Is the 4-degree cut mentioned in Fig. A about crosscutting the top?
& then the 2-degrees tapering is for ripping the stock - I guess. Still scratching my head if the blade needs to stay tilted at 4-degrees when rip-cutting the 2-degrees taper.

You bet it is hard on braincells.

The vertical sides of the staves, you have to cut one side at 2 degrees taper. Which 2 degrees off the vertical. But the blade is vertical.
When you do the opposite side you are 2 degrees off to begin with so you need to do 4 degrees to get a matching taper which will be 2 degrees to the bottom and top edges. Blade still vertical.
And you have to make sure that you flip it the right way on the second cut wide side up or wide side down? I did it wrong once.or twice; I cut 11 staves to make 8 and I ruined 1 and sniped another.

Yeah, you have to cut a 4° bevel on both the top and bottom horizontal edges as well. But I used the Miter saw bevel cut to put it on them when I cut the vertical staves saving Step A. (and a very small amount of wood)

1. set the miter saw for a 4 degree bevel cut. Trim the top. cut 8 staves 8-3/4 long and then rip to 5"
2. taper cut 2 degrees, all piece
3. taper cut the opposite side 4 degrees.
4. Stack the staves all the same way to route. I set wide side to the left and narrow end to the right, and outside face up. If you stand the stave on the narrow end it will want to lean because of the bevel on the end; the outside is the direction it wants to lean to.
5. Set the router bit height to the proper value.
6. Route one edge of the staves paying careful attention to which in or out side of the stave is up and which end bottom or top gets cut first. Stacking them all in the same way helps. Fortunately there are no R-L or mirror pieces to keep track of. For the 8-sided bit, the outside face of the stave is up when routing on the table. It doesn't matter which edge you route, just do them all the same.

My process was simpler than the MLCS... I saved the top and bottom 4° bevel cut of fig A by bevel cutting the stave lengths and I eliminated snipe so I cut the stave pieces to final length to begin with.

Once done its not too bad fitting them all up, I thought it would be a race against the glue but it all stood up easily even the first two staves and the stopped edge kept it from slipping and just did it on a flat surface to line up vertically. Taped it to hold it together after each joint and then it was easy to slide some bungee cords over it (narrow end up)

[LCHIEN]

Hoping to score some points with the wife but she doesn't seem too impressed.

[nicer20]

Hoping to score some points with the wife but she doesn't seem to impressed.

That's because you have already set your bar very high with a lot of awesome projects.

[LCHIEN]

Got after this again after two weeks on vacation. Cutting the bottom from a 10x10 glueup of two boards.
instructions said to tilt the saw table 4 degrees and cut the blank 1/8" larger than the outline marked with the bottom inside set on it.
Not wanting to realign the bandsaw table carefully set square I just cut the octagon 1/8" over and then went to the disc sander and put a 4 degree bevel on the edge. Because sanding a 4° bevel is almost nothing on this soft cedar.

One thing they suggest is to mark the orientation so after the cut it can returned to the same orientation. I suppose that is because you might not have a perfect octagon if the stave widths are slightly off or the angles varied. That's a real good idea.

[LCHIEN]

Here's the 4° beveled edge from the disc sander


The instructions did not call for these but I added support ledges so that the bottom would not tilt or sink. You can see how I marked the intended orientation for perfect fit (three black marks). The instructions just said to set it in the bottom where it would wedge itself in apparently.


Drilled 3/8" drainage holes as suggested. I put in 9. The instructions just said evenly spaced and did not specify a number.


Reinstalled the bottom, it just sits on the ledges.


Final assembled

[leehljp]

That is excellent. This is the first time I have seen a personal write up and picts using those bits from MLCS other than the MLCS Ad itself. Thanks!

[nicer20]

Wow !! - This is a great article. Detailed step by step photos. Thanks a lot, Loring.

[LCHIEN]

Recap:

I made this to see how involved it was. I sized the diameter and height to hold/hide a 10" clay pot. With the bottom the pot sits a bit high; without the bottom, its exactly right.
To be honest I sized it to use just one piece of 72" cedar fence picket.(8 staves of 8-3/4" long)

Pictures with no bottom (left) and the bottom installed (right)
if I want to use the bottom, I need to make the staves 1.5" longer or so.

What I learned:

• This is really pretty easy to use. It only takes one router cut per stave, and all staves are identical, no right left mirrored parts confusion
• The router bit is clever because it fixes all the angles you need.
• Because the router cuts two faces in one pass, not only are the angles precisely fixed and you have one pass, the glue joint is strong because of 2 orthagonal faces and it self registers - does not slide around in all dimensions like a typical mitered joint, you just have to get the ends aligned and the edges seated and the whole thing stands up nicely with a bit of masking tape on each joint. -
• assembly is easy with just 2 hands and it doesn't take four hands and 8 clamps.

Tips and tricks beyond the MLCS instructions:

• Cutting the staves, I just made a 4° bevel cut to length using a stop. This saved the waste and step of beveling the ends of the staves
• The routed edge rides on a thin edge after being routed. I found temporarily attaching a supporting block on top to maintain spacing from the fence prevented snipe
• Add a bit over an inch height if you use the bottom they recommend.
• Run outer face of stave up when table routing (for the 8-sided)
• Height of bit side point recommended 1/8" for 1/2" stock or 7/32" for 3/4" stock

They have 6/12 side bit, 8 side, and 16-side bit models. 8 seemed like a good compromise of appearance for effort.