[mxtras]

I don't think JFettig or I meant to reverse it WHILE it was spinning. When through, turn the motor off and use the spindle brake to stop the drive pulleys. THEN go for reverse.

Personally, I do not like Tap Magic for aluminum. It does not keep the aluminum from gradually building up on the face of the flute like the Tap Heavy or CinTap.

I have also used CinTap, Boelube(sp?) and this stuff in the past for aluminum:
http://www.nolansupply.com/bysubcate...lse&specs=True

Scott

[JFettig]

You can do blind holes, but only start them.

I know on bridgeports, you can flip them back and forth with no problems, I would assume that the clones would be made to that same spec.


Jon

[l u k e]

I have reversed the motor (on accident) and it didn't seem to be a problem, I just wasn't sure if it was acceptable or not...

[l u k e]

spiral point & cold forming taps.

Which one is best suited for this purpose?

Most tapping I do in aluminum 6-32 and less I use cold forming taps,

I was able to find forming taps but not "cold forming", is there a diffrence?

[JFettig]

cold forming(forming, fluteless etc.) are for non ferrous materials, you should try both and see what you like. I have never used a forming tap with a tapping head so I dont know how well that works.

I got my cold forming taps from mcmaster I think it was, mscdirect has them too, I wonder if coated forming taps would work significantly better than non coated?

One thing with forming taps is to make sure you have the right size hole to start with. 6-32 cold forming taps need something like a .122-.125" hole to start.

Jon

[little bubba]

You guys are making a big deal out of nothing, tapping on a manual machine with the tap in a drill chuck is easy. Doesn't have to be keyless, just don't crank the snot out of it, that will let it slip before breaking. I would use a cheapy chuck, not one thats your "baby". On a through hole let it go, on a blind hole, just get in far enough that when you hand tap, your threads will be straight.


On reversing the motor, its electric, there are no gears changing or anything, its just a magnetic field. Going from -300rpms to +300 rpms should hurt any more than turning your spindle on from 0rpms to 600 rpms. Granted, you might slip a belt a little on the reverse, but so then you have to change it after 5 years instead of 10.

[l u k e]

cold forming(forming, fluteless etc.) are for non ferrous materials, you should try both and see what you like. I have never used a forming tap with a tapping head so I dont know how well that works.

I have decited to pass on the tapping head for now, I thought I would give it a shot with the keyless chuck instead.

I got my cold forming taps from mcmaster I think it was, mscdirect has them too, I wonder if coated forming taps would work significantly better than non coated?

What I found is "HSS TiN Coated Thread Forming Taps" are these diffrent than the "Cold Forming Taps"?

[l u k e]

I opened up my MSC book and right away saw a big difference between the Enco taps and MSCs.

The more expensive ones (MSC) look more suited to high speed taping. They are shorter in length which I assume are more stout that the longer ones.

I notice that the “Spiral Point Taps” that MSC have very short cutting threads, that in it’s self isn’t a problem, but with high speed tapping the tap will quickly go through the part your tapping. Won’t there be a problem with cross threading when reversing the motor to remove the tap? Or do you try to reverse the motor before it pulls all the way through?

[little bubba]

Luke, good choice, the tapping heads are nice if your doing 6 million tapped holes, but its so easy just to run it in and let the quill float. You'll save a couple of hundred buck too.

cold forming(forming, fluteless etc.) are for non ferrous materials

I'll completely disagree with this statement. Form taps work wonderful in steels, anything up to about a 30-35C. I was scared of them at first, the concept doesn't really fit with traditional machining, and if you think about rolling external threads, it seems like it just can't be that simple, and cheap. But it is. Keep your hole size correct and I don't see why you couldn't run them rigid in a manual mill or with a tapping head. No packing of chips, no cutting edges to get dull, stronger threads, MUCH longer tap life, higher tapping speeds, less broken taps, not much more torque required than a cut tap. For me they win hands down, 1018, 4140, 17-4, 416 any aluminum, you can't lose.

[l u k e]

Is it safe to say that a Forming Tap is a better avenue than Spiral Point tap? (Like I said before 99% of what I do is 6061 alum.)

Edit: I re-read your post, and see the answer is yes.

[l u k e]

I placed an order for forming taps and spiral point taps so I can try both. I think I will like the forming tap, but I think both will have their purpose. I Also used this as an excuse (whether I need it or not) to buy a keyless chuck. I went with the one piece design...

Just wanted to say thanks for everyone's input, I learned a lot from this thread, many thanks....

[mxtras]

I usually pick up something from every thread I read!

That's why I"m here....it's always great to hear other's take on things.

Scott

[l u k e]

I've ran into a wall with the power tapping, for some reason my machine won't reverse directions after it's running, any ideas?

[PROTOTRAKFAN]

Luke,
I have been machining for over 20 yrs and have tapped many holes in many different materials. Where I have been employed for the last 9 years is a very high quality machine shop. Our inspection department is VERY thorough and checks EVERYTHING. I will tell you right now that if you "powertap" without a tapping head a "no go" thread gage is going to almost certainly go into your tapped hole. I used to powertap all the time when I worked in small tool and die shops however (there was never any inspection department in those shops). The best quality thread you can get comes from hand tapping and using a "spring center" . If you have alot of holes to tap this is not practical. A "tapmatic" tapping head works great in mills like yours - I cannot comment on the cheap brands because I have never used them. I prefer to buy name brands of everything, however, because I have found over the years that cheap brand tools are just not adaquate. I think cold forming taps are the best you can use in aluminum. Do not use them in cast aluminum or MIC 6 .
As far as drill chucks go I hate keyless drill chucks (including Albrect). They are easily ruined. I prefer Jacobs ball bearing drill chucks. I own two of them and use them in the NC mill all the time. They are less expensive than keyless chucks also and run very "true". Alright enough of my opinions.....
Patrick

[lakeside]

question to Prototakfan(my favoret machine the dpm) if your machine has ridged tapping would you still hand tap? I use it all the time without a promble just love those OSG fast spiral high performance taps even in those hard alloys

[PROTOTRAKFAN]

Mike,
The Prototrak mill that I use has a tapping cycle but, it is not true rigid tapping. A "floating" tapping head must be used with it. I use it alot without many problems. I still prefer using cold forming taps with it on aluminum. Usually if I am machining tough stainless steel or gummy copper I opt to threadmill it. We have threadmills in our shop down to M4. True rigid tapping is hard to beat ,however. Most all of our production machines have rigid tapping and it has replaced all threadmilling in our production lines. On a Bridgeport type mill I still prefer hand tapping with a spring center.....
Patrick

[lakeside]

the problem with a floating tap head like tapamadtic is that if the part is in a vise you will have run out when starting but if the part is on a surface like a table this should not happen when I use a floating head or a reamer for a tight hole size my part is never in a vise so spindle run out of tool is not an issue also we know if the part is being made in a prototrak it's not a high volume job and if you only have a few holes I would hand tap to nothing like a broken tap at the end of a part run (just hate it when that happens)

[l u k e]

Please pardon my ignorance on the subject, but it looks like the tapping head I posted can only be used for tapping (not drilling) and that brings up a question on procedure. Can I drill all the holes in the individual pieces (using a vice stop or jig) then change over to the tapping head to tap all the holes?

What I’m worried about is the slight miss alignment that happens when a part is removed then reinstalled in a vise or jig.


(Thanks for all the input)

[Halfnutz]

I dont know about cheap, theyre between 300 - 600 bucks, for a Tapmatic or an Enco. Theyre great if you can get your work up under a machine. I like cordfless drills for most stuff, because you can tap anywhere, and they work great. Set the clutch light so you dont break the tap.

[lakeside]

if you drill your hole and the tap the tap will follow the drilled hole when you tap your are cutting materail from the side of the hole you should have a chamfer on your hole after you drill if your going to tap a 1/4 hole thse chamfer should be about .265