Replies

1. 
   ron61 | Dec 31, 2002 02:07am | #1

   I'm making a Blanket chest the sides slope out from the bottom and the lid will have a arch top with short sides and ends. Looks like a pirate chest made from red oak.

   Thought someone might have had some experience doing dovetails on a curve.

   Thanks Ron

1. 
   TomMGTC | Dec 31, 2002 02:09am | #2

   I don't know of anyway of doing that other than by hand. As far as I know all of the commercial jigs will only work with flat stock.Tom

2. 
   SgianDubh | Dec 31, 2002 04:28am | #3

   Well, I did see the question first time, Ron, but as I've never used or even seen a Keller dovetail jig in action, I rather ducked the question, ha, ha .

   I can't see an application here for curved dovetails though, and I suspect no-one else can either which might explain why you've got only two response. Are you wanting to dovetail a curved coopered lid into the ends? Most people would simply run a curved groove in the ends, a straight groove into the sides, work a tongue in the coopered part, perhaps with a moulding along the edges to disguise and allow for expansion and contraction, and assemble the job.

   Now with (all?) the sides sloping out from the base, hopper style, it crossed my mind that you might ask how to calculate the necessary angles required to form the corner joints of the the box, and how to mark out and execute through dovetails at the corners. :-) Slainte.Some stuff I've made.

1. 
   Elcoholic | Dec 31, 2002 11:58pm | #4

   Ditto, it's a hand job (heh, heh).  Unless you make the ends in sunburst pattern there will be some serious short grain issues.  I remember seeing something like this a while back.  Did you check the FWW index?John O'Connell - JKO Handcrafted Woodworking

   Life is tough.  It's tougher if you're stupid - John Wayne

1. 
   ron61 | Jan 01, 2003 08:33am | #5

   Well guys maybe its hard to visualize what Im doing.

   I know how to do the angles on the bottom section. On the top Im going to rip the red oak stock in to segments and heres the formula for the angles """  number of segments divided by 360 divided by 2""" the ends of the chest will  be at 90 degrees only the front and back will be sloping. Im going to dovetail the ends of the chest to the arched top. Hears a pic. simallar to what Im doing .

   How would you hand cut the dovetails on the curve?

   Thanks

   Ron

   Edited 1/1/2003 12:48:49 AM ET by ron61

   Edited 1/1/2003 9:46:39 PM ET by ron61

   
1. 
   MStehelin | Jan 01, 2003 11:33am | #6

   First of all if you contact keller they will send you info on how to dovetail on the curve. Second: there is a FWW book on traditional furniture which features a completely curved chest. I have done dovetails one the curve. I did the ends first and then transfered to the curved sides. You will need to make a curved base for  the sides so that you don't split or splinter the sides when you chop them out.

   Cheers

   Mitt

2. 
   ron61 | Jan 01, 2003 06:43pm | #7

   Thanks Mitt for the  info.

   Ill check out the book and get in touch with Keller

   Ron

3. 
   SgianDubh | Jan 01, 2003 06:55pm | #8

   Now I see what you're up to, Ron. I'd cooper and form the curved top to match the curved end, mark out and executed the pins in the top first, offer up the cut pins to the end and transfer their position, followed by cutting the tails in the end piece. Many of the tails, as Mitt mentioned, will be pretty fragile at both the time of cutting and in service.

   I notice that the long sides join the ends with the grain running perpendicular, i.e., the end of the horizontal grain orientated side joins the long grain of the vertical running grain side. This will restrict the expansion and contraction of the front and back likely leading to splitting. All the dovetails in the end pieces are fragile because they are all short grain. It's not generally a construction method that I would recommend.

   I still know nothing about the Keller jig though. Slainte.Some stuff I've made.

4. 
   ron61 | Jan 02, 2003 05:44am | #9

   Sgian

   You are right about the swelling, it would fall apart.I need to do something different with the top. I want the top to be strong in case some sits on it.

   The first pic. I posted has a very circular top.I finally found the pic. of the 1800's chest I was looking for the other day its like what I want . Doing the panel top maybe the only way to go. 

   Edited 1/1/2003 9:45:30 PM ET by ron61

5. 
   SgianDubh | Jan 02, 2003 06:01am | #11

   Ron, that's more along the lines I imagined you were after in the first place. I think a similar curved top to the image you found will be more than strong enough. Think of a curved top like a sheet of paper rolled up into a tube-- press down gently with your finger somewhere near the middle of the length of the tube. It's pretty tough really as compared to a flat piece of paper spanning the same distance.

   The chances are the lid on the original was nailed down with thin shanked nails (and maybe some glue blocks rub jointed underneath.)  Nails are flexible allowing for a bit of expansion and contraction of the top. Anyway, it looks to have held together pretty well. You could do the same, or get a bit fancy like I suggested in my first post and fit the lid as a panel within the framework. Slainte.Some stuff I've made.

6. 
   ron61 | Jan 02, 2003 05:49am | #10

   Sorry heres the pic

   Ron

   
7. 
   ian | Jan 02, 2003 06:18am | #12

   Ron

   I see two machine cutting options.1    make the lid, then cut the pins (or is it the tails) in it using a band saw.  Use a frame to position each pin perpenticular to the bandsaw's table.  then cut the tails again using the band saw2    if the lid will be a series of flats, cut the pins using your jig in the boards before clue the lid up.  you will need to be very precise in your joinery.