2015 POTD Thread Archive

[savarin]

. And for storage and access, I'd make a few separate boxes rather than one monster unit. A box for #12 and below, another for 1/4" and up. Anybody got ideas on this? (My metric taps and dies are a rather new Craftsman set, and are in a molded plastic case.)
Greg

I made a wooden container for all my whitworth taps and dies that was subsequently stolen (another story)
I just used a wide wooden plank, drilled the holes for the dies with a forstner bit and routed the troughs for the taps with a straight sided wood router bit.
I then soaked it all in clean engine oil till it wouldnt take any more.
The lid was a thin ply sheet held on with a brass piano hinge.
I kept each die with its taps and laying them all out on a sheet of paper first I got them into the smallest space possible.

 

[francist]

One of those "aha" moments that might benefit someone else down the line:

I'm having to drill and tap about eighty (80) blind holes #2-56 partway through some 3/8" brass rod for a project at work. All of my tap handles, even the smallest, felt too heavy and bulky -- I was scared of breaking the little tap from the weight of the handle alone. So after a bit of head scratching I came up with this. I have three full sets of clock winding keys (previous life/previous hobby) at home and darned if one of them (coincidentally a #2 american key) didn't fit the square on the tap just perfectly. Very light, easy to slip on and off, but still a good solid feel for two-finger operation. Works like a dream, and one of those ideas I thought just had to be shared.

-frank

 

[T Bredehoft]

If you can hold the tap in a secure driver (drill chuck on a drill press, perhaps) and the brass rod to be tapped in a vise, you can turn the chuck by hand and not really worry about snapping the tap (unless you bottom it, of course). I was amazed at how straight and not at all nervous making this arrangement is compared to really tapping by hand. Yes, I tapped 20 5-40 holes yesterday in my new PM25 mill in hot rolled 4140. Power in and power out. One wasn't deep enough, had to do it by hand.

 

[francist]

Agreed Tom. Drill press at work isn't great though, and even my tapping fixture that use at home seemed a bit on the heavy side for the #2 thread. I already have in mind a smaller, more sensitive fixture to build but who knows if I ever get around to that.

-frank

 

[Strtspdlx]

I attempted to make the QCGB on my atlas work with incorrect gearing. I knew it wouldn't be right but I wanted to try cutting some threads. I managed too. Didn't have a specific size or anything just wanted to get into the motions.


Regards-Carlo

 

[chevydyl]

Looks like you still have a little ways to go on the thread depth, the flats are a little wide yet, but other than that they look like a good start

 

[roadie33]

Threads look good if that is an ACME thread.

 

[Strtspdlx]

I wasn't trying to actually make precise threads for. Specific purpose. More or less I just wanted to check operation of the gearbox and see if I could actually make more than a scratch pass without messing up. Which I did somewhat.


Regards-Carlo

 

[chevydyl]

I get that, but, I would wanna make sure there is no issue cutting to full depth, as you will be increasing the tool pressure with every pass, and if there are any issues with binding that's when it could show it's face... the diameter don't matter as you said cause they are just practice... don't stop short, finish the thread

I Don't know if your brand new to threading but when I thread if it's possible per the job I cut an angle on the start for lead in, 30deg is fine and make the small part of the angle your minor diameter for the thread pitch, that way when it scratches it you know your close to being done
I have experience with binding while threading, at almost full depth it stopped and broke a gear, ruining the job....

 

[Rob]

I attempted to make the QCGB on my atlas work with incorrect gearing. I knew it wouldn't be right but I wanted to try cutting some threads. I managed too. Didn't have a specific size or anything just wanted to get into the motions. View attachment 107451


Regards-Carlo

Which gears were incorrect? Most of the gears are just idlers and do not affect the tpi. The only critical one is the 16/32 compound gear. Other than that any gear that you can make mesh correctly will work.