In this video I show and discuss the four gear sets I made using the various gears I created from the gears I cut in previous videos. The gear sets rely on creating compound (or ganged) gears to create gearing changes depending on what carriage feed rate or threads per inch are desired. The gear sets are patterned after the gear sets offered by Atlas for the 6" Atlas model 618 and the Craftsman 6 inch equivalent metal lathes since these lathes were never offered with a quick change gear box like the larger 12" metal lathes did. Before starting to make the gear sets I did price the four gear sets from Clausing Service Center but I found the price when converted to Canadian dollars to be more than I was prepared to spend and that is why I decided to try and make them. The advantage of the gear sets is that to change the desired carriage feed rate or thread cutting threads per inch the correct gear set needs to be selected and then it can be meshed with the gear mounted on the lead screw that has the correct number of teeth to produce the desired TPI or carriage feed rate. Once the gear on the gear set is meshed with the gear on the lead screw the banjo arm can be swung upwards and the driven gear on the gear set meshed with the 16 / 32 tooth compound gear directly below the engagement lever gears. This saves time by making one less gear teeth mesh engagement operation and also reworking compound gear sets ups used when working with the original gears supplied with the lathe.
The compound gears I made for the most part are pinned together using two 1/8" diameter roll pins and a 1/2" x 3/8" bronze bushing pressed into the inner bore so the gears can turn freely on their respective sleeves with one exception - the 56 tooth and 20 tooth gear that are ganged together to create the .0024" carriage feed gear set. The reason for this was that the 20 tooth gear would loose a lot of its integrity if it was bored out to 1/2" (and have a 1/8" roll pin on either side of the hole resulting in a 3/4" inner area where the two roll pins would be) so I am going to run that pair of compounded gears as steel on steel with lots of oil. Given the speed and amount of use it will get it will probably outlast me before it wears much. The two threading gear sets had the compound gears pinned together originally but I encountered more run out that what I desired after installing the bronze bushings so they were unpinned and separated again and the gears were bored out to 5/8" diameter. A piece of 5/8" diameter x 5/8" long cold rolled steel was then pressed into the two gears and the ends welded in. The centers were then bored back out to 1/2" and the bronze bushings pressed back in - this achieved a runout of approximately .002" which I was happy with. The other pinned compound gears appeared to run true when I checked them so I left them pinned and they appear to mesh quite nicely.
Hope you enjoy the video and thanks for watching.
Негізгі бет Discussing The Four Gear Sets Sep 17 2024
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