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+--- Thread: custom tap (/thread-2125.html)
custom tap - chucketn - 05-29-2014
I am making a custom 1/4" x 40tpi tap for a friend. He had the change gears for his lathe disappear during a move.
I have the threads cut, and a 5 deg taper on the end. I'm getting ready to mill flutes and the square end for the tap wrench. Can I cut the flutes with a regular 1/8 end mill? I don't have a ball end that small. How deep should they be? He'll be cutting threads in cast iron. I have to also make a matching screw, so I will be taping a piece of hex steel stock for a test nut.
I have printed out an article on making custom taps with just a filed obelisk (think Washington Monument) shape for the tapered start and no flutes, but I think flutes would be better.
Chuck
RE: custom tap - PixMan - 05-29-2014
Why wouldn't you just buy one? They are available for as little as $1.62 (plus shipping.)
http://www.amazon.com/s/?ie=UTF8&keywords=1%2F4-40+tap&tag=googhydr-20&index=industrial&hvadid=31282152445&hvpos=1t1&hvexid=&hvnetw=g&hvrand=10695610322451538623&hvpone=&hvptwo=&hvqmt=e&hvdev=c&ref=pd_sl_6cfhq0r3rg_e
RE: custom tap - chucketn - 05-29-2014
Well, first cause the guy that needs the tap couldn't afford the prices I found on Amazon. I didn't see the $1.62 price, I saw $15 and up...
Second, I've already made and tested the tap. And I didn't have to spend any money other than the electric to run the lathe, already had some 1/4" drill rod...
Why buy when we can make it? Took me all of 2 hours to make, including heat treat! Noe I know I can make just about any tapI need!
Chuck
RE: custom tap - f350ca - 05-29-2014
Thats the whole point of having machinery, to make things, its a hobby so time shouldn't enter into it.
But curious, if you were tapping the hole and making the bolt why not a standard thread?
RE: custom tap - PixMan - 05-29-2014
I can't make a tap because I'm way too picky about thread geometry, clearance angles, cutting angles, chip flow geometry, and thread tolerances.
RE: custom tap - Mayhem - 05-29-2014
picky?
Some would say anal retentive but lets go with picky
Of course, I would never say such a thing - I simply posted in the interest of social commentary!
RE: custom tap - PixMan - 05-29-2014
Now Darren, to suggest I am anal retentive would mean I'm FOS. I am most definitely FOS, but not about most machining oriented stuff.
I am, however, overly critical of things that really don't matter a bit in a home shop. On that list are time (spending too much of it on simple tasks a primary irritant), not using the right tool for a job, and not using the tool correctly for a job.
Could I make a 1/4"-40 UNS tap? Perhaps. I'd be so concerned it wasn't the correct thread form, that it wouldn't curl a chip correctly, might make an out-of-tolerance thread, could bind in a hole, and so on that I just couldn't make one and accept that "It should work fine for this job."
I guess you're right after all. I'm anal retentive.
RE: custom tap - EdK - 05-29-2014
I've been thinking about this whole "that's good enough" and would like to bring my skill level up a notch to the point of being able to machine something to a known spec rather than to match one piece to another piece. This is purely a hobby for me so I can afford the time necessary to take the time to do that. Pride in workmanship rather than that's good enough. Sorry for the ramblings.
Ed
RE: custom tap - chucketn - 05-29-2014
If you build something from a drawing, do you change specs to what ever you want, or do you make the part to plan? My friend is making an engine to the designers plan. That's why a 1/4-40.
I'll be the first to admit I'm still at the "that's good enough" stage. I'm getting better, and my setups and tooling is improving. I made the tap as close to spec as I could get. I made a nut with it to use as a gage for the screw thread I need to make. The screw will mate with the tapped hole made by the tap I made... Whooh, I'm getting dizzy...
Chuck
RE: custom tap - Highpower - 05-29-2014
(05-29-2014, 07:57 PM)EdK Wrote: This is purely a hobby for me so I can afford the time necessary to take the time to do that.
Ed
I can afford the time as well. My problem (one of many, I know) is I can't afford to buy all of the precision tools that go along with verifying the work that's been done meets those high "standards" in the end.
![[Image: limitgage%20thread%20plug.jpg]](http://precisiontoolsandgaging.com/Assets/images/limitgage%20thread%20plug.jpg)