Weave with your handspun singles! With this shuttle , go directly from the charkha to the loom.
The shuttles hold either the spindle from the charkha or a bobbin or paper quill on the removable rod that comes with it.  These shuttles are made exclusively for New World Textiles by Bluster Bay Woodworks.  Ask about availability of woods--shown are Machiche(top) and Walnut (bottom). 
The first difference between this special shuttle and an off-the shelf boat shuttle is the removable rod.  While a bobbin can be placed on the rod, the rod was made removable in order to accommodate the charkha spindle. A latch holds the spindle (or rod) in place without restricting its rotation.  

The second difference is in the action: by virtue of the yarn being on the spindle rather than on a free floating bobbin, the free floating aspect is removed. This means there is no continued rotation of the spindle when the shuttle stops. This is an advantage as far as tension is concerned. Selvages are much better with this shuttle than with a shuttle holding a free floating bobbin.  Tension does increase with the decreasing diameter of the yarn on the spindle, but this does not affect the selvages.  However, there is a point at which either the yarn will break or the shuttle will go off course if you are weaving at high speed.  This is the point at which the spindle is almost empty and should be replaced with a full one. The use of this shuttle requires careful buildup of the yarn on the quill in order that it will feed evenly during the weaving. 

Some ballpark estimates:  it takes me about 10 minutes to fill a spindle using about a yard of sliver, and another10 minutes to weave it off.  One spindle full weaves approximately 80 to 100 square inches.  Translate this to spinning the weft and weaving a 10" x 72" scarf in about 3 hours using about 9 yards (1.5 oz) of sliver.