Re: Ashiko construction tips
Robert Hartman (hartman@informix.com)
Tue, 2 Jan 1996 15:05:39 -0500
> Date: Thu, 21 Dec 1995 23:05:46 -0500
> From: jmillen@abs.net (John Millen)
> Subject: Ashiko construction tips
>
> For those of you who are interested in building ashikos, you might
> get into trouble if you use the formula: 180 devided by the number of
> staves equals the angle to cut on the staves. This would be the formula if
> the drum were straight sided, but for a conical drum the angle increases a
> bit. The more conical the drum is the greater the diviation from the above
> formula.
Hmmm ... All I can say is that when I follow the formula it works.
The djembe I made out of staves last year worked just fine, taper and
all. So did the 42" standing-drum (ashiko) shell I made last week out
of mahogany.
> >Make two gluing disks, one with a radius that's a bit smaller than
> >the smallest interior diameter at the top, the other with a radius
> >that's a bit bigger than the hole at the bottom.
> Robert, the fact that you are useing gluing disks makes me suspect that the
> angles on your staves are not true. See my earlier post on that ticklish
> problem.
Well, I should explain better what I mean. The disks are just
templates, I don't actually glue them in. After the staves have been
assembled and the band clamps are in place, I slip each disk inside the
drum and use a mallet to adjust the placement of the staves so that
they form (nearly) perfect circles at bottom and top. (It helps to put
a nail in the center of the disk so you can grab it while it's inside
the drum.) Although the glue and clamps do tend to hold the staves
together, they still slide around a bit both horizontally and
vertically during assembly. So they need to be adjusted. I use the
disks to check for true round, that's all.
> ...
> Mayday, Mayday. In this earlier post I have the direction of diviation
> wrong. Using the above quoted formula for a twelve sided drum, the proper
> angle for the staves would be a little *less* than 15 degrees, say + or -
> 14 degrees. In my head i was thinking of the angle on the saw which would
> be 75 degrees in the above example which would increase to 76 or more.
> Sorry for the miss-information.
I think you mentioned earlier that the compressibility of wood will
allow for a good glue joint even if you're off by a degree or so.
It just means turning those clamps down tighter to make complete
contact along the length of the staves.
Happy New Year everyone!
-r
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