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Gallery, Projects and General => How to's => Topic started by: chipenter on November 01, 2014, 03:39:06 AM

Title: Replacing a worm wheel
Post by: chipenter on November 01, 2014, 03:39:06 AM
My rotary table needs a new wheel and this thead is more about how I made the cutter , I have been making involute cutters on my mill ,

The worm is 1\2" made from silver steel so the cutter needs to be 1\2" as well , the wheel measured to be 37DP 72 teeth  50.8mm blank required ,pin dia 9.452919mm the nearest to that is 3\8" and adjust the centres , a peice of silver steel milled to a hex then the 3\8" cutter feed in 2.475946mm  :jaw: and the carridge locked  the cut is made virticley
Title: Re: Replacing a worm wheel
Post by: awemawson on November 01, 2014, 03:48:34 AM
Nice work  :thumbup:

I'm impressed that you can work to six decimal places, I struggle with two  :clap:
Title: Re: Replacing a worm wheel
Post by: chipenter on November 01, 2014, 04:10:20 AM
The pin centres are 10.16667mm and the in feed is 2.475946 acording to the computer program I downloaded from Marve Klots web site , gashed with a woodruff cutter just past centre to give the teeth some rake , hardened and tempred to straw , the worm eyeballed to 4 degrees so set the wheel to that , tooth depth is 1.51 fed it in and started cutting , the worm fitted well straight with no back lash and just one heigh spot that will polish out . 
Title: Re: Replacing a worm wheel
Post by: chipenter on November 01, 2014, 04:21:16 AM
Nice work  :thumbup:

I'm impressed that you can work to six decimal places, I struggle with two  :clap:

Thank Andrew thats a jaw dropper when you see it the first time , with the flex in my mill I may be closer to one decimal place . :coffee:
Title: Re: Replacing a worm wheel
Post by: BillTodd on November 01, 2014, 05:42:38 AM
Six decimal places!  You might want to read about schlesinger limits...

http://www.stevenson-engineers.co.uk/files/Schlesinger%20limits1.pdf

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0CC8QFjAC&url=http%3A%2F%2Fwww.totallyscrewedmachineshop.com%2Fdocuments%2FTesting%2520Machine%2520Tools%2520(Dr.Schlesinger).pdf&ei=3KpUVJimAa_B7Aa_tIDYBg&usg=AFQjCNFpECv4NjQoicn1A4OPgrRVGa7VxA&sig2=X4BOIn9xcbjlszd-1ZG60Q&bvm=bv.78677474,d.ZGU