Post by ChrisCrosskey on Aug 13, 2005 22:07:21 GMT
One of the tools I use a fair bit with my ML7 is a lever-operated collet chuck. It takes the standard MA99E (well, standard to Myford) collets, but I recetly realised that other collets would fit in the chuck and could be used. B+S number 10's seem to go straight in and several others are close enough to use with proviso's attached. One of these is the smallest of the sliding-head Ward collets. THis has the same rear register diameter as the MA99e, is approximately the same length but has a deeper angled section and can be had in sizes up to 3/4". The deeper angled section means that the stadnard closer nose on the chuck won't screw over the top, however today I made a deeper nose-piece thatt allows them to go in.... this leads me to my question.....
As part of the operations I had to screwcut the inside of the piece 1 15/16" x 20tpi.... As my Myford has a gearbox I set it up as per what I thought was the right way only to discover (long before the tool went anywhere near the work) that it appears to cut threads twice the pitch it should. I checked the settings, checked the 19/57 gear was set for threading and not fine feed or anything like that. My question is what gear should be on the end of gear after the tumbler reverse?.... this is effectively the mandrel output gear, adn I thought it was supposed to be 24 teeth. I'd always assumed that the single-piece gearpair that has a 12-tooth output there was for fine-feeds, but now it appears that it is the one that gives proper thread readings off the gearbox chart...... which is worrying cos I can't make the maths work......
chrisc
As part of the operations I had to screwcut the inside of the piece 1 15/16" x 20tpi.... As my Myford has a gearbox I set it up as per what I thought was the right way only to discover (long before the tool went anywhere near the work) that it appears to cut threads twice the pitch it should. I checked the settings, checked the 19/57 gear was set for threading and not fine feed or anything like that. My question is what gear should be on the end of gear after the tumbler reverse?.... this is effectively the mandrel output gear, adn I thought it was supposed to be 24 teeth. I'd always assumed that the single-piece gearpair that has a 12-tooth output there was for fine-feeds, but now it appears that it is the one that gives proper thread readings off the gearbox chart...... which is worrying cos I can't make the maths work......
chrisc
