Best way to cut board on edge?

[Dengue]

I have a board 300L x 140W x 20 thick. I need to cut it diagonally on edge so that I am left with a long wedge shape 300L x 140W with one edge being 20mm thick and the opposite edge being 5mm thick. So the angle of cut is 6 degrees off vertical
Can anyone please suggest a good and safe way of doing this?

[Chrism3]

Use a bandsaw with the table tilted by 6 degrees.

[Skew ChiDAMN!!]

If I understand you correctly, you want to cut through the 300x20 faces, to make wedge with the 'pointy end' having a 5x140 face?

For something like that I'd be more inclined to use a jointer but it'd depend on your jointing skills.

Second choice would be to buzz it down with a power plane and tidy up with a hand plane.

At those dimensions I wouldn't go anywhere near it with a circ saw, table or otherwise. At 140mm thickness you'd need a very good bandsaw... and would probably need to plane it to final size anyway.

If the cut is through the 140x20 faces then a TS with the blade tilted 6deg would be the go. You'd need to rip as deeply as possible through one face, flip the board over - and reset the fence to align the cut - then rip the other half. If you don't have a full 70mm depth of cut (or better) then a band-saw - with the table at 6degree - can be used to seperate the two halves. And, again, hand-planing to clean up.

Or you could make a sled that holds one of the long edges up 15mm higher than t'other, and make multiple passes through a thicknesser. (This would be my preference, but it takes time to set up.)

[ian]

at 300 mm long, the quickest and safest way is with hand tools.
as others have said if you use a band saw you will have to clean the cut surface up by hand anyway.

my process would be
mark the finished cut line on the three edges.
take off the bulk of the waste with a scrub plane working with the grain.
finish dimensioning with a #5

[joe greiner]

I doubt you could safely hold it on a tilted bandsaw table, and get a reasonably flat surface.

Although it would be time consuming, I'd make a narrow 15mm high shim with a 6-degree bevel and attach it with hot melt glue to a lower edge, and take multiple passes through a thickness planer, stopping when the top crease disappears. Bake the wood to soften the HM glue, and remove the dregs with acetone.

BTW, always use a push stick with the planer.

Cheers,
Joe

[Chrism3]

How much you have to clean up after a bandsaw cut depends on your blade. Some blades do a mighty fine job.

[Fumbler]

Use a bandsaw with the table tilted by 6 degrees.

Lets not get too technical now, I would've just said outright 'bandsaw' but you've got the whole box and dice and calculated the angle needed. Nice work.

[Chrism3]

Lets not get too technical now, I would've just said outright 'bandsaw' but you've got the whole box and dice and calculated the angle needed. Nice work.

You flatter me - I didn't calculate anything - he said it was 6 degrees (not that I couldn't have worked it out you understand!)

[Kuffy]

I would be using the thicknesser. It's probably the safest, easiest, most consistent method available and it gives a pretty decent surface finish requiring minimal clean up. A simple sled to run the boards through at a 6° angle with a guide on one edge so the board doesn't slip off the jig. Though it is best that the jig supports the full width of the board, otherwise there is a significant chance of the roller pressure cracking the board which is overhanging as in this image. Image lifted from this post ​Updating a old garden shed with cottonwood siding in General Woodworking
IMG_1950.JPG

[Lappa]

Making a jig with a 6 degree angle by machining it to 6 degrees ( as shown in the picture) to machine a board to six degrees would be ok if you had a big run, but for 300 mm? However the idea of a jig and a thicknesses was how the timber yard machined my cedar door architraves.

[RossM]

As some others have said, hand tools in this case will be safest (and probably quickest) way to achieve this. I would lay out lines on the edges of your board to define the wedge, hog off the bulk of the waste with a scrub plane, then tidy up with a jack plane.

(300mm is really too short to safely run through the thicky - of course you could run a longer board, then trim to length afterward!)

[elanjacobs]

300mm is really too short to safely run through the thicky

Why? As long as the length of the board is at least the distance between the centre of the infeed and outfeed rollers it should be fine.

[Lappa]

For future reference, the Dewalt 735 manual states “Never plane timber shorter than 12” (304.8mm)”

[elanjacobs]

Eh, you could round that down to 300 I reckon

[Kuffy]

Why? As long as the length of the board is at least DOUBLE the distance between the centre of the infeed and outfeed rollers it should be fine.

Although I agree in theory that we should be able to thickness boards that are as long as the between centers distance, I don't have a set of brass balls big enough to try to thickness a piece @125mm long But at 300mm, pfft, all day every day, never any dramas. I also run 250mm long offcuts from time to time. Occasionally it ends with epic snipe, but if ya wanna get rich, ya gotta save those pennies using up the burn pile!