Thread: Monitor Riser - splayed/compound dovetails

Dan, if you have not dovetailed before, you are aiming very high!

Try this ...

http://www.inthewoodshop.com/Furnitu...tWeekend8.html

Regards from Perth

Derek

Originally Posted by derekcohen

Dan, if you have not dovetailed before, you are aiming very high!

Story of my life mate haha, not afraid to fail! Gonna have a crack anyway, worst case I trim a couple of inches off the ends of boards and wind up with a 90 degree angle with a regular dovetail. Will be fun trying anyway

Thanks for the link, I was actually watching some of your videos last night to see if I could glean any useful info.

Originally Posted by bueller

.......
Alternatively I'm happy for you to tell me I'm crazy, I've never cut dovetails before and i'll probably screw it up but want to get building again.

Must agree with Derek, Dan, but I do like crazy! I tried to do the splayed dovetails about five years ago and failed miserably.

Why I failed:

The pins were cut first, exactly the same as for conventional dovetails (First Figure). Then I rotated the board by 15 degrees (Second figure) and extended the dovetails to the new horizontal Third Figure). As soon as I rotated the dovetails, the faces of the pins are no longer vertical, so after this point the mark out failed. The magenta line is a vertical to show the change in alignment (Fourth figure).

Splayed Dovetails 2.jpg


What I would do now:

Practice in radiata pine, first, second and third until it works.

I haven't used sketchup for over 5 years and no longer have it on my computer. [Mostly I use Rhino, occasionally Autocad, and their drawing technique is different fron Sketchup.] Thus I cannot really show you the drawing steps.

Basically, I would now do the following:

• Draw the splayed boards, as you have done,
• Draw the dovetail pins on the horizontal surface,
• Extrude these lines down the splayed face until the bottom of the horizontal board, [It is absolutely essential that these new planes are absolutely vertical.]
• Copy those new planes,
• Separate the horizontal and vertical boards so that one copy of the dovetail planes remains with each,
• Trim out the waste around the pins and tails in the drawing,
• Reassemble drawing to check everything fits.

Then, the even harder stuff:

• Cut 15 degree bevels on both pieces of timber,
• Transfer dovetail drawings to the timber,
• Cut and trim very carefully,
• Pray like hell.

This job will be really hard to get your head around. A standard crazy person would probably do Marque 1 with standard vertical sides!

Thanks for the rundown Graeme! Love the *pray like hell* step haha

I watched this video a few times yesterday trying to get my head around the angles, it's kind of coming together in my head.

I think I might just grab some offcuts and start practicing some regular dovetails. If I struggle with them I'll shelve this (pun intended) till my skills improve. But I think I can make it work if I really slow down, think things through and prepare.

YouTube

Originally Posted by bueller

I've watched a couple of videos and saw differing techniques, one guy left his boards square and laid out that way, another put the angles on the ends of the boards and laid out from there. I'm thinking I'll have the tails on the top board and pins on the sides, am I right in assuming this is the strongest construction? I'll be using some walnut I've got prepped so was going to use 1:8 ratio.

Alternatively I'm happy for you to tell me I'm crazy, I've never cut dovetails before and i'll probably screw it up but want to get building again.

I'd be doing the cut angles first . I'd mark the pins out on the top bit , cut them out and butt them up against the leg position to mark them out . Cut the tails and fit . keep some fine sawdust and glue handy . Its pretty straight forward and not to far off a standard 90 degree join .

The cut angles and the marking out are the first steps and the Marking out is not as straight forward as a normal 90 degree job . No Gauge can do whats needed because of the angle at the ends. Not a problem though. Id be using the thickness of one of the legs as the gauge . Lay it on top of the top and scribe a line , flip top lay it on the under side and do the same. I quite often do that rather than walk for the gauge sometimes with drawers.

It is your first try though and as Derek and Graeme have said . Your are aiming high . With a couple of test runs you'll get it worked out though . Go on, Entertain us .

I download this article from somewhere a couple of years ago. I would give the link if I could find it again but google image search can't even find them. This may help...
angleddovetails_zpse40738de.jpeg angleddovetails2_zps7db31965.jpeg angleddovetails3_zpsb1aea6d2.jpeg

Thanks everyone! Lots to ponder, lots to practice.

This is probably the article.