MadModder
Gallery, Projects and General => How do I?? => Topic started by: ieezitin on September 12, 2015, 09:05:52 PM
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I have made my own tap now i want to cut flutes in it for chip relief, whats better a ball end mill or regular end mill.
it is .636 dia 26TPI i was thinking three flutes,
All advice is welcome.
Thank you.
Anthony.
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Anthony:
This page might help. Dean deals with cutting flutes in a counterbore and gives a formula to use as to how deep from the top of the counterbore to lower the end mill (if using a vertical mill on a counterbore held horizontally):
http://www.deansphotographica.com/machining/projects/mill/cbore/cbore.html (http://www.deansphotographica.com/machining/projects/mill/cbore/cbore.html)
I've used a regular end mill to do the same for cutters but can't say that I have a lot of knowledge in this regard.
John.
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Take not that Dean is also a wizard.
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Take not that Dean is also a wizard.
+1 :bow: :bow: :bow:
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Thats a great article on making your own cutters.
There really should be a knowledge base for definitives like this ( or is there one already ? )
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Well I made the tap.
(http://i721.photobucket.com/albums/ww212/ieezitin/COLLET%20DRAWBAR%20PROJECT/IMG_20150919_121725_zpsciehkzsq.jpg) (http://s721.photobucket.com/user/ieezitin/media/COLLET%20DRAWBAR%20PROJECT/IMG_20150919_121725_zpsciehkzsq.jpg.html)
I have used hand soap to stop the sparking that happens when you heat to a cherry red state, the threads are 26TPI which are pretty delicate .
(http://i721.photobucket.com/albums/ww212/ieezitin/COLLET%20DRAWBAR%20PROJECT/IMG_20150919_122237_zpsf6g4neev.jpg) (http://s721.photobucket.com/user/ieezitin/media/COLLET%20DRAWBAR%20PROJECT/IMG_20150919_122237_zpsf6g4neev.jpg.html)
Now I am covering the whole end with wire, again to aid the halting of the sparking problem.
(http://i721.photobucket.com/albums/ww212/ieezitin/COLLET%20DRAWBAR%20PROJECT/IMG_20150919_122907_zpss0bs3rza.jpg) (http://s721.photobucket.com/user/ieezitin/media/COLLET%20DRAWBAR%20PROJECT/IMG_20150919_122907_zpss0bs3rza.jpg.html)
Fully covered now ready for heating.
(http://i721.photobucket.com/albums/ww212/ieezitin/COLLET%20DRAWBAR%20PROJECT/IMG_20150919_125021_zpsfhfercp3.jpg) (http://s721.photobucket.com/user/ieezitin/media/COLLET%20DRAWBAR%20PROJECT/IMG_20150919_125021_zpsfhfercp3.jpg.html)
All finished. I now cleaned it and honed the cutting edge.
(http://i721.photobucket.com/albums/ww212/ieezitin/COLLET%20DRAWBAR%20PROJECT/IMG_20150919_132403_zpsjcoijiqt.jpg) (http://s721.photobucket.com/user/ieezitin/media/COLLET%20DRAWBAR%20PROJECT/IMG_20150919_132403_zpsjcoijiqt.jpg.html)
Tried it out on my project and it worked fine, I am very happy with it.
(http://i721.photobucket.com/albums/ww212/ieezitin/COLLET%20DRAWBAR%20PROJECT/IMG_20150919_135009%201_zpsns86d0jo.jpg) (http://s721.photobucket.com/user/ieezitin/media/COLLET%20DRAWBAR%20PROJECT/IMG_20150919_135009%201_zpsns86d0jo.jpg.html)
Anthony.
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Excellent result Anthony - well done. :thumbup:
Phil
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Glad to see that it worked out. It's a good reminder to me to use soap - had never seen the wire trick.
John.
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Very nice threads. What was the material threaded?
I'm not sure if I missed the info on making it, or if you skipped a few steps but I'd be interested to hear about your setup and procedures.
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The tap itself is made from a drop from the scrap bin, material unknown.
The thread form tooling is made from ends of small snapped taps, I grind them on a homemade tool grinder made from an old valve grinding machine, The threading tool fits in a homemade tool holder onto my QCTP.
I do not grind a flat on the end, nor did I grind a helix angle on it, for a 26TPI .636 dia it would have been minimal, the sharp-V seams to cut better especially on hard material like stainless, this was carbon steel and while cutting some of the first passes it tends to be rough but getting close to thread depth ( .031 in this case) it smoothed out, the spindle was in back gear low-rpm.
The tube you see is stainless steel instrumentation tubing, its .750 od I forget the wall but it's pretty thin, too thin to accept the thread so I inserted a previously made steel threaded sleeve and secured it with Loctite extra strength.
The sleeve, I load a steel blank in the chuck bore it out to size and thread it with the same form threading bit held in a small diameter homemade boring bar, because the diameter of the boring bar is small the spring is amplified so I tend to spring cut three times each to eliminate it, once the depth has been achieved I put it onto a threaded mandrel and turn it down between centers to get the od of the tube, remove and arbor press into place with Loctite.
This tap I made is really a chaser, this is allowing me to slightly under cut the thread cutting and I don’t have to worry about getting the desired size which is time consuming, I get it really close I finish off the final size with this tap.
Anthony.
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Steel wire and borax in the heating setup.. you don't happen to be Clickspring on youtube. ;)