PATTERN MAKING 95 



wood. A better method, however, is to glue twelve blocks, each 2 

 inches long, 2 inches wide, and f inch in thickness, to the face of 

 the chuck, in the same way as that described for the small hand 

 wheel shown in Fig. 168. 



When the rim is finished it may be sawed or cut off through 

 the blocks without injury to the chuck and its future use. The 

 segments to form the rim should be six in number for each layer. 

 They should be % inch wide, and cut from f-mch or -|-inch stock, 

 lengthwise with the grain of the board, so as to avoid end wood. 

 The first layer is fitted and glued to the blocks (or to the face of 

 the chuck with paper between), and securely clamped with small 

 hand-screws, three to each segment. When the glue is dry, one hour 

 being sufficient for thin -inch segments, place the chuck in the 

 lathe, and carefully turn off the face of the segments true and 

 straight to receive the second layer. 



This layer, in turn, is turned off in the lathe and the third 

 layer is glued on, hand screws being used on each layer as on the 

 first, and the joints of the segments so broken that no two will 

 be directly opposite each other, all joints being carried to right or 

 left of all preceding joints, thus securing the greatest possible 

 strength to the rim. 



No nails should be used in any work of this description. 

 Having glued on a sufficient number of layers to form half of the 

 rim, turn it to the required external and internal diameters, making 

 the thin or outer edge of the half rim next to the chuck, and care- 

 fully giving the required draft to each side. 



Before removing the half rim from the chuck, turn a groove iV 

 inch to ^ inch in depth and of about one third of the width of its 

 thickness in the edge of the rim, as shown in Fig. 173 at a. Re- 

 move the half rim from the chuck (or cut from the blocks), and 

 proceed to build up and to turn the second half 1) in the same way 

 as the first. Instead, however, of turning a groove on its edge, 

 carefully turn and fit a small projection, or tongue, to the groove 

 in the half , as shown in the drawing. If the work has been done 

 with care and accuracy the groove and tongue will bring the two 

 halves into perfect alignment. 



The arms nre next fitted centrally to each half of the rim, and 

 the two halves glued togetner over the arms in the same way as 



