David Posted January 19, 2005 Report Share Posted January 19, 2005 Hey for part of a school project I have created a crank extractor (well nearly). Now I have done my research and I know creating the outer thread on the tool which turns into the crank is going to be quite difficult as it is too large to be tapped using a die. The thread needs to be cut on a lathe but my teacher said its a bit complicated for GCSE hehe. :S" Just wondering if anyone has any knowledge of this?? I can get the measurements of the thread (pitch etc). Thanks for any help at all, Dave Quote Link to comment Share on other sites More sharing options...
011001000110010101110010 Posted January 19, 2005 Report Share Posted January 19, 2005 My exerperience is that you clamp the die in the die stock then turn the clamp of the lathe by hand. Forward one turn, back half a turn. But if you cannot find a big enough die then you are a bit stuck. As far as I know there is no tool apart from a die which can cut a male thread. Quote Link to comment Share on other sites More sharing options...
Will Arnold Posted January 19, 2005 Report Share Posted January 19, 2005 what is the bars diameter, the one for tapping? Quote Link to comment Share on other sites More sharing options...
David Posted January 19, 2005 Author Report Share Posted January 19, 2005 My exerperience is that you clamp the die in the die stock then turn the clamp of the lathe by hand. Forward one turn, back half a turn. But if you cannot find a big enough die then you are a bit stuck. As far as I know there is no tool apart from a die which can cut a male thread. ← Thats the problem I dont think theres a big enough die....Errm the diameter is 20mm off the top of my head but I could well be very wrong! Quote Link to comment Share on other sites More sharing options...
on that? u must be joking Posted January 19, 2005 Report Share Posted January 19, 2005 Page with M20 thread die for sale Quote Link to comment Share on other sites More sharing options...
David Posted January 19, 2005 Author Report Share Posted January 19, 2005 Just looked, its a 1.00mm pitch thread. Ill just double check diameter. Quote Link to comment Share on other sites More sharing options...
David Posted January 19, 2005 Author Report Share Posted January 19, 2005 It looks like 22mm with a rule but I dont have a micrometer handy at the moment (or my work to check!) Quote Link to comment Share on other sites More sharing options...
David Posted January 19, 2005 Author Report Share Posted January 19, 2005 Just been reading up, it looks like ill be needind a 'thread chaser' which inserts into the lathe??? Quote Link to comment Share on other sites More sharing options...
dave85 Posted January 19, 2005 Report Share Posted January 19, 2005 Screwcutting :S Go away and read about it, its not overly difficult if you're confident with the lathe (and you must be by now if youve got it mostly finished). 2 things to note about it: 1. Take your time over setup, getting the tool at centre height and square to the work, checking the changewheels/QC gearbox are set right, check the work is running true. 2. Take your time when your cutting, small cuts avoid the tool springing, and avoid the work ending up in the scrap bin. Yeah, your teacher is right, it isnt standard GCSE stuff, but if you can do it, it should impress the examiner :P Edd :P Quote Link to comment Share on other sites More sharing options...
David Posted January 19, 2005 Author Report Share Posted January 19, 2005 Screwcutting :S Go away and read about it, its not overly difficult if you're confident with the lathe (and you must be by now if youve got it mostly finished). 2 things to note about it: 1. Take your time over setup, getting the tool at centre height and square to the work, checking the changewheels/QC gearbox are set right, check the work is running true. 2. Take your time when your cutting, small cuts avoid the tool springing, and avoid the work ending up in the scrap bin. Yeah, your teacher is right, it isnt standard GCSE stuff, but if you can do it, it should impress the examiner :P Edd :P ← Cheers, Ill look into it! Quote Link to comment Share on other sites More sharing options...
David Posted January 22, 2005 Author Report Share Posted January 22, 2005 I am now unsure if the thread is metric... I have googled for screwcutting but i can't find any specific info on the actual technique.... Quote Link to comment Share on other sites More sharing options...
OnzaNewbie Posted January 22, 2005 Report Share Posted January 22, 2005 Hey for part of a school project I have created a crank extractor (well nearly). Now I have done my research and I know creating the outer thread on the tool which turns into the crank is going to be quite difficult as it is too large to be tapped using a die. The thread needs to be cut on a lathe but my teacher said its a bit complicated for GCSE hehe. B)" Just wondering if anyone has any knowledge of this?? I can get the measurements of the thread (pitch etc). Thanks for any help at all, Dave ← Mate what the hell is your teacher on about?? I'm doing engineering at GCSE and we have been taught how to do this a little while ago. I'll see if I can find the handbooklet for you, I think around here some where!! I can't quite remember how to do it but.... My exerperience is that you clamp the die in the die stock then turn the clamp of the lathe by hand. Forward one turn, back half a turn. But if you cannot find a big enough die then you are a bit stuck. As far as I know there is no tool apart from a die which can cut a male thread. ← This sounds correct. I think but I will try to find that booklet. Hope this helps. Marc >_< Quote Link to comment Share on other sites More sharing options...
David Posted January 22, 2005 Author Report Share Posted January 22, 2005 Mate what the hell is your teacher on about?? I'm doing engineering at GCSE and we have been taught how to do this a little while ago. I'll see if I can find the handbooklet for you, I think around here some where!! I can't quite remember how to do it but.... This sounds correct. I think but I will try to find that booklet. Hope this helps. Marc >_< ← I dont think youve understood what im saying. I know how to tap threads using tap and dies etc thats easy. I am talking about cutting a thread using a lathe! Quote Link to comment Share on other sites More sharing options...
OnzaNewbie Posted January 22, 2005 Report Share Posted January 22, 2005 I dont think youve understood what im saying. I know how to tap threads using tap and dies etc thats easy. I am talking about cutting a thread using a lathe! ← I didn't find that booklet, but I think I know what your on about, Add me to msn, it will be easlier. Marc_powell89@hotmail.com Cheers Marc >_< Quote Link to comment Share on other sites More sharing options...
Todge Posted January 23, 2005 Report Share Posted January 23, 2005 Cutting threads on lathes is dead easier, in fact much easier then by hand. What i do is just put the lathe on a slow speed, and let it feed itself in from the tailstock. Remember to use cutting fluid though. Shouldnt your teacher know all this and be able to tell you? Quote Link to comment Share on other sites More sharing options...
Bonney@X-Street Posted January 24, 2005 Report Share Posted January 24, 2005 Cutting a thread on a lathe is pretty tricky, slow and painfull if you cock it up. BUT if you do it on a cnc lathe, creates a perfect thread in moments, does all hard work for you....sorted! just need to know how to program the lathe, only tricky bit lol Bon Quote Link to comment Share on other sites More sharing options...
dave85 Posted January 26, 2005 Report Share Posted January 26, 2005 Cutting threads on lathes is dead easier, in fact much easier then by hand. What i do is just put the lathe on a slow speed, and let it feed itself in from the tailstock. Remember to use cutting fluid though. Shouldnt your teacher know all this and be able to tell you? ← Thats with a die though, isnt it todge? Quote Link to comment Share on other sites More sharing options...
Todge Posted January 26, 2005 Report Share Posted January 26, 2005 Yes, i spoke to david the other day and apparently he doesnt have a die in the correct size, so he would have to do it the other way. But im not sure whether the fine pitch of the thread is possible the other way, because i have never personally used that method before. PS the other way is hard to explain (you know what i mean) :"> Quote Link to comment Share on other sites More sharing options...
dave85 Posted January 26, 2005 Report Share Posted January 26, 2005 Yeah, i know. Fine pitches arent really a problem with screwcutting, they only become a bitch when you cant actually see the things without a watchmaker's lens :) David, add me to msn if you like, and i'll do my best to help :) e.d.potts-03@student.lboro.ac.uk Quote Link to comment Share on other sites More sharing options...
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