I thought I'd start building my first marionette by constructing a articulated hand and start the hand with the fingers.  I'll be working on it on and off over the next couple of weeks and will post my progress as I go along.  Comments, questions and suggestions are most welcome.

The finger will be held  straight in its neutral/default position by a loop of line under tension.  This loop will run through two holes drilled in each joint.  The joints will be joined by fabric "ligaments."  The control string will run in slot cut length wise in each digit. At the end of the slot the string will run through a small bead glued into it (I hope).

The slot is cut on a sled on a table saw.  I'll post a picture of that tomorrow.  A jig is required to allow quick and accurate drilling of the holes for the tensioning line as they must line up exactly between joints.  The jig has a key which fits into the slot in each joint.

I'm starting with 1/2 inch dowel material as working at that scale seemed a little less daunting to start with than something smaller.  I'm planning for my marionettes to be about 30" tall and I'm not sure what scale I will want for the actual hand so this first hand is a test of concepts.

Can't wait to see the progress.....

Have you seen this video....it may give you some ideas.....his is much more simplified materials it looks like you are planning with wood..




Daryl H

Thank you very much and  no I had not seen it.  It certainly looks like the way to go for most styles of fabric covered hands.  At present I'm thinking that I will not use fabric covers and that exposed flesh will be painted wood and Super Sculpy.  But at this point everything is open to revision. 

Thanks again for the really interesting and informative video link.

Amateur, this is looking very good so far. I was recently trying to explain this basic concept to someone; any chance there is a higher resolution scan of that diagram available?

Thanks!

I posted these publicly on Flickr where you can find a higher resolution image.  There I use the "name" asdfgfdsa under which you should be able to find them.

Though it may be counter intuitive one of the safest ways to cut small pieces of wood is on a table saw, but using a sled and clamps.  This is how I cut the slots in the joints.  If I were going to make a lot of hands I'd build a jig specially designed for the purpose that could be clamped to the table saw and which would allow and entire dowel to slotted at one time.



Here is a joint test fitted into the jig.



I drilled the holes for the tensioning strings today.  This only took a few minutes.  Setting up the vise and getting it square with the drill press took much longer.  Part of that process involved selecting, cutting and positioning a brass shim to make the vise orthogonal/square with the mandrel of the drill press.  The vice is on a slide table.  Once square the jig was position for the first hole and those were drilled for all the joints.  The the slide table was then repositioned for the second hole and those were drilled in each joint. The holes align to within 1/2 a millimeter.



The next step is to make the jig used in forming the bevels on the joints.

AWESOME pictures!!!  Thanks for sharing them.  I am trying to make the same slot as you have done with a dowel but I am trying to do it on a ball of wood.  This gives me hope.

Thanks!
Nikole

The joints for a prototype finger are complete though they have bee roughed up a little in the experimentation process.  The relationship between angular center line and the two tensioning holes is off a bit.  I've traced that back to two problems but primarily to the key-slot not being cur exactly in the center of the dowel.  If the prototype works I'll build a sled for the table saw dedicated to slotting the joints and holding am adjustable jig for cutting bevels on joints of varying lengths.  This time I just formed the bevel on the disk sander.  The ligament slot was cut on the band saw hand holding the jig used for beveling.  Not a satisfactory for producing joints for 6 or 8 hands but OK for a prototype finger.





I have glued beads into the slots in the joints.  Two of the holes are slightly obstructed by glue and I will have to try to drill them out but I think they are going to work.  Next step is to experiment with gluing in the ligaments.  This is likely to be the most difficult step in the whole process.

Just a note to remind people that wood working tools make it excruciatingly easy to cut off your fingers and other body parts of which you may be quite fond.  The careful design and use of jigs is your best defense against these unhappy occurrences. 

Very nice job and very clean design