Index Table - Dividing Head
Index Crank Handle and Sector
Click to enlarge pictures.
The sector assembly consists of four parts, a center collar, the two dector parts and a locking nut. The locking nut and sector parts are made of brass. The other parts of mild steel. With most factory units the sectors stay on his place by a flat spring. Since I could find no suitable spring material, I changed my design and replaced the spring by a locking nut. My experience with this method is very positive.
The two sector parts are made of 5mm thick brass. The openings are made on the lathe.
The parts were clamped in the independent four claw juck and cutted out.
Then, the parts are clamped in the center of the turntable and the outer circumference
machined. The sloping sides of the sectars are cut with a 90 degree countersink bit.
NOTE that the two sectors run smoothly together.
The center collar of mild steel and the brass lock nut was made on the lathe and require no further comment.
The two sector parts are made of 5mm thick brass. The openings are also made on the lathe.
The circumference was milled on the turntable.
The components of the crank handle are made according to plans and require no further explanation.
The spring is made of
Spring Wire 0.8 mm in diamater.
Length 45 mm
Inside diameter 7 mm
Number of turns 15
To making a spring it is not so difficult. You can wrap them off on the lathe.
Make a shaft with a diameter 30% smaller than the insite diameter of the spring. Drill a hole in this shaft from about 1 mm. Put in this hole the spring wire. Let the lathe running at lowest speed and keep the spring wire stretched. Make sure the turns are nicely next to each other. When this is done cut the spring and stretch them to the desired length.
To assemble, slide the spring over the index pin. Insert the index pin in the crank boddy and insert the pin of 3 mm through the hole in the index pin. Slide crank boddy into the crank handle and screw it together with a M4 bolt. Place the crank in the crank plate and secure it with a M4 adjusting bolt.