Harold Hall
Metalworking
Workshop Set Ups
Dial Marking, Setups. Harold Hall
All pictures can be clicked on to provide a larger view
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Photo 1 shows a dial being made whilst held in the three jaw chuck and indexed as show in Photo 2. The part having been turned in the chuck it was then running perfectly true ensuring that all lines were made the same depth, then the outer diameter could be very lightly surfaced to remove the burs made by the engraving process. These clearly seen in the large version of photograph 1.
All the lines were made the same length initially then every fifth lengthened. Line lengths being set using the saddle stop, bottom left.
The result is seen in Photo 3.
Photo 4 shows a dial mounted on a parallel mandrel in the three jaw and would have been indexed as in photograph 2. The engraving this time is being done using my lining tool This automatically sets the line lengths with no need to go round a second time to make the longer lines, making it an easy task.
The benefit for me of the setup in Photo 5 is there is no need to change the gear quadrants as the gear and dial are mounted on a two stage taper stub mandrel. I say “for me” as others will have means of securing the detent without disturbing the gear quadrant.
In both photographs 4 and 5 the outer diameter would have been machined to run true and then skimmed to remove the engraving burs as mentioned for that in photograph 1
When I made my basic dividing head I made it equal to my lathe’s centre height so that I could work between centres if I needed to but have never yet found this a requirement.
In the example illustrated, Photo 6, the dial would have been turned true on the lathe and then the chuck with dial transferred to the dividing head. This would no doubt result in a loss of concentricity but the amount would be very little if the chuck was a good fit on the lathe and dividing head spindles. The chuck was then returned to the lathe to skim the outer diameter to remove the engraving burs.
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