7/27/2023 0 Comments Goodell pratt hand drillfirm, and the company relocated to Greenfield. In 1892 Albert left the company to establish Goodell Tool Co. Goodell they had been employees of Millers Falls Co. Goodell-Pratt qualifies for this listing because they made a small lathe for both metal- and wood-working, and a small bench-mounted drill press. Hand tools are outside the scope of this web site. The company primarily made hand tools (such as drills, calipers, braces, and levels) and high-precision metalworking machinery. It should be possible to calculate that by measuring the depth of the holes in the jaws and working out how many coils will fit in the two jaws but I just used trial and error.The Goodell-Pratt name was in existence from 1895 to 1931, as detailed below. I used the longest length that I could fit into the holes in two jaws and still squeeze the jaws together. I eventually bought a 100mm length of spring 3.18mm (1/8) diameter with 0.5mm wire diameter off ebay and cut three matching lengths of that. First I used three that looked the same but the jaws didn't close evenly. I had to have a couple of goes at the springs. I suppose there is a possibility I found a worn 8mm x 1.25mm bolt. I found a bolt to match, but I don't know what it came from, it measures 5/16 with 20tpi. Do you know what size they are and how long. The springs in the chuck are also missing. What size are the threads? I get a bolt to match I hope (I don't have a metal lathe). Russell, I just bought one of these and it is missing a couple of things. Last edited by Russell Talbot 10-29-2019 at 7:59 AM. Then I cut the slots on the back to engage with the dogs on the drill. I hardened and tempered the home made cutter and tried again on the milling machine. I have assumed the missing gear was originally made from cast iron as if it were steel it wouldn't have broken so I bought a piece of cast iron and made another gear blank. It fitted reasonably well and the drill worked. This time the teeth seemed to mesh a bit too deeply so I skimmed the top of the teeth in the lathe. I made a second one using the same technique but using measurements from the first attempt. It turned out to be too small - but since it's tapered I could make it seem larger by removing material from the small end and much to my delight it actually meshed quite well with the existing gear although it was now too thin. The only remaining difficulty was the diameter which was difficult to measure. I made a cutter out of silver steel and mounted it to an arbour and cut the teeth so that the gaps between teeth were about the same size as the teeth. At this point I realised that the gaps between the teeth are parallel sided and the wider gaps are created by deeper cuts at the larger end of the pinion so only one cut should be needed. Best approximation methods for home cutting of bevel gears suggest three cuts for each gap would be needed so I decided to make a cutter the shape of the smallest part of the gap using the other pinion as a model. What shape should I make the gaps between the teeth. I made a gear blank on the lathe with an angle of 39 degrees and setup the milling machine to cut 20 gaps between the teeth at an angle of 28 degrees using a home made dividing head (another product of procrastination) which used a lathe changewheel to index 20 positions.Īt this point I had to confront the main problem that had been putting me off this job. Because of limited space around it I had to make a sort of mini bevel gauge but I ended up with angles of 39 degrees and 28 degrees. One was the angle the top of the teeth made with the axis of the drill and the other was the angle the bottom of the gaps between the teeth made with the axis. I measured two angles from the drills handwheel. I decided to try making one in plastic first as it would be much quicker to machine and it would be an experiment. So having exhausted all avenues of procrastination I decided to try making a pinion. All that revealed were that these were not theoretically correct gears. I read up on gear cutting and mitred bevel gears in particular. I set up a search on eBay which only found me drills that were in better condition than mine. There has been a lot of procrastination going on. I am shocked to see how long it is since I last reported progress on this.
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