Thread: How to run a straight trench along a long dowel?

I'd use the hot glue method.

Interestingly I have to some something similar, but fortunately my "dowel" is about 45mm in diameter and only 175mm long and the trench is 8mm wide by about 10 deep so I'm going with a router and hot glued blocks at each end.

I'd hot glue 25mm square strips each side for the full length. Then you can use rip fence and hold downs for accuracy and safety.
Metho releases the hot melt.
Lyle

Run a board through and groove and cut a 1/8 slot half way through the right distance from the side . Half the dowel width.

Flip it over and and clamp it to saw table and bring the blade back up through from
the other side coming out through your slot.

Cut a 1/8 wide verticle grain , how ever tall? fillet to glue into slot behind the blade to act as a guide that the sawn dowel can follow .

Use feather boards as well. One from the side and one from the top .

I do wonder if the saw cut in dowel could twist over a long length doing this .

A good fit and waxed fillet guide would be the go .

Andy....if you were to fix onto your bench 2 lengths of 18mm thick material with the dowel between them, to hold the dowel straight then attach another thicker piece as a fence then run a router/trimmer down the dowel. You would of coarse have to pin down the dowel, probably.
Yeh its a bit of mucking around for just one dowel but to me it is a way to get the groove straight and even for the full 2mtr

Just cut the groove in my cylinder. It was more like 225 mm long. Hot glued a block at each send and put it through the router easy peasy.

Pardon the Imperial. . . .

Get a 2x4 and cut a 18mm trench (dado) down the center about 19mm deep, using your table saw fence. It doesn't matter much if you are not exact to the center just DONOT MOVE THE FENCE.

Hot glue or carpet tape the dowel into the dado. Don't glue the entire length of the dowel but rather 3 or 4 spots.

Install the normal blade or 1/8 kerf blade in the table saw.
BTW - Here in the US a narrow kerf blade is 3/32 inch wide and a normal blade is 1/8 inch.

Raise the blade to the desired height and cut your trench.

Here a KD 2x4 is about $4. IMHO a cheap expendable to do it right the first time.

Similar to how "next level carpentry" fixes crooked boards, could you hot glue the dowel across its whole length to some 1x1 moulding or some offcut you might have.

Just run this jig against the fence.


How to Cut a Straight Edge on Crooked Boards - YouTube

Thank you, it looks like there's a few variants on the same principle.

I'm intrigued by Auscab's spline idea... that could be very handy for other pieces I have in mind.

But time 'n experimentation is required for that, so tomorrow I'll give the hot melt glue a run to move this job along.

shouldn't the riving knife basically hold the cut in place? or stop it from being able to rotate?

Originally Posted by havabeer69

shouldn't the riving knife basically hold the cut in place? or stop it from being able to rotate?

What riving knife

A riving knife should and would... but as Rod said above: only if ya have one.

My go to would be a router as described above.

Another solution is to cut a number of say 100mm long 42 x 19 mm blocks. Drill a series of 18 / 19 mm dia holes through the stock board then cross cut each block so that the hole is in the same position in each block. Keep the hole as close to the edge as is possible or alternatively rip the stock after drilling so that they are.

Slide them over the dowel and hot melt glue in position say every 300 mm. Use your fence as a guide. Aris the leading edge of each block so they don't catch on the fence.


Personally I would not attempt this without a riving knife - way to risky for me!

TS Dowell trench blocks.jpg

ps I perform similar tasks ripping much shorter lengths of dowel; plus squares to make octagons etc using purpose built TS sleds that run on my sliding table. The nature and position of the cut determines the hold down method. Scrap waste blocks are cheap, way cheaper than fingers. How far you want to go, and how much time you "invest" depends upon how much you value your fingers.

I would use a table saw to create a 19x19mm (or a little over this) section ... and as long as you wish. Then use the table saw blade (typically 3.2mm thick) to cut the groove.

Now chuck the grooved, squared section into the lathe and turn the dowel. 19mm is substantial enough to do this.

Regards from Perth

Derek

Originally Posted by rrich

Pardon the Imperial. . . .

Definitely not; its too hard for us colonials.

I had a job where I needed to put a flat edge on a piece of dowell 1.2 m long. Tried the table saw but it was not precise enough, and the jointer was just scary....

Eventually I made a jig similar to that advocated by rrich and Mobyturns from a length of framing pine. Just cut a trench, secured the dowell in the trench with hot glue to stop it twisting, put an end mill bit in the router table and ran the jig along the fence. Easy; almost foolproof.

Dowell Jig.jpg

Replace the end mill with a spiral cutter and it should cut a nice neat trench; neater than most table saws.