[l u k e]

How well do these "cheap" (Enco) tapping heads work?



What exactly is their purpose, besides the obvious?

[JFettig]

I have a non enco tapping head that I bought and they work pretty good overall, mine is the grey boddied one(I forget the brand).

mainly with those you would tap on a quill driven machine and its easy to do some really fast tapping. I was planning on setting mine up on my cnc but my travel isnt enough to clear much(X2 mill)

At the place I use to work, we bought combination tap drills and drilled and tapped tubes with one bit in a tapmatic and it worked pretty good.


Jon

[KEYTEEM]

I have used tapmatics but never the enco brand.
if you have a lot of holes to do you can't beat em
they are fast and accurate

[l u k e]

Thanks.

What are the requirements in order to use one?

How many RPM's do they run at, and how do you stop them inorder to reverse the spindle to remove the tap?

[JFettig]

Some can actually run up to 2000rpm, but typically they would be run around 500rpm or so in most materials, You must have the torque to tap the peices and if your running a cnc, the feed it takes to bring it in and out.

no, you dont have to stop and reverse the spindle, when you lift the spindle it has a reversing mechanism and changes direction and turns itself out.
You also need to controll the feed it goes in and out, but if your running something like a quill, thats not a problem usually, just takes a little practice.


Jon

[l u k e]

Yea, I'm running a manual Mill, but I have power down feed, will that work?

Most of what I do is in aluminum, 6-32, 8-32, 10-32 threads.

[JFettig]

power downfeed? does it have like a quill or something you can manually opperate decently fast?



Jon

[smoregrava]

We use tapping heads have 8 in production 24 hours. These are of the brand Suhner GSX50. They are OK but we have some problems with them. The torqe mechanism tend to loose up. So we have to pay attention. When they have been used for a while the chuck get very lose (eccentricity). And when doing blind holes we get a little unstable thread depth. But I think these problems is because the quantity 2000-4000 holes each day. For small production I tink they would be allrigth

We have started to use Rigid tapping instead. But this is ofcourse machine/controll dependent. We do M6 and M8 up to 2000 rpm.

[l u k e]

This is the mill I have.
Features:

One-shot Pump Lubrication
Auto Down Feed
Quill Feeds / Spindle Rev.: .0019", .0035", .0058"
Auto Stop w / Micro Adjustable Stop
R-8 Spindle
Longitudinal Power Feed
Hardened & Ground Table Surface
Chrome Plated, Precision Ground Quill
Adjustable Micrometer Quill Depth Stop




I guess mine does have the "quill" feed, which I believe is the "auto down feed". (?)

I've only been at this for a few years and I'm 100% self taught so I'm not failure with all the terminology, sorry.

[JFettig]

what you have will work great, and you dont want to use the auto feed, you use it like a drill press for these tapping heads.

Jon

[mxtras]

No - you can not use the downfeed for tapping on a machine like that.

The typical selections for auto downfeed on these machines are .001", .003", and .006" per spindle revolution. That is one fine thread!

You will have to have a tapping head or just put a center in the spindle and tap by hand.

Scott

[JFettig]

In reality with a mill like that you dont even need a tapping head, you can just chuck it up and turn down the speed as low as it goes, turn it on, bring it down ito the material, let it grab and it'll go in on its own then you reverse the spindle and it comes up and out and you lift itup. you want to run it less than 100rpm if it can.

Thats something you gotta be careful with, not to screw it up or anything but it does a good job.
I havent done it with taps under a #10 but have seen it done, Im sure it takes a lot more care to not ruin threads or break taps.
Regular bridgeports at about 80rpm can take a 1/2-13 tap through steel without much problem.


Jon

[l u k e]

In reality with a mill like that you dont even need a tapping head, you can just chuck it up and turn down the speed as low as it goes, turn it on, bring it down ito the material, let it grab and it'll go in on its own then you reverse the spindle and it comes up and out and you lift itup. you want to run it less than 100rpm if it can.

Thats something you gotta be careful with, not to screw it up or anything but it does a good job.
I havent done it with taps under a #10 but have seen it done, Im sure it takes a lot more care to not ruin threads or break taps.
Regular bridgeports at about 80rpm can take a 1/2-13 tap through steel without much problem.


Jon

I tried tapping on the machine once and ended up breaking the tap. I'm not sure if the speed was to fast or what. I'll have to try again.

Do the tapping heads have a torque setting that will help prevent snapping taps off?

[JFettig]

yeah, they have a torque setting, I havent really played with it enough to know how well and how it works.


Jon

[mxtras]

Tapping in the manner suggested by JFettig is very possible - true. But it is risky for someone new to machine tapping. It requires the appropriate tap and tapping fluid also.

If you are a relative beginner and tapping small holes, I would suggest NOT tapping under power. Use the machine to keep things straight and tap by hand - especially if it is a blind hole or if you do not have the proper machine tap.

Scott

[l u k e]

I'm fairly new, but I've tapped 100's (if not 1000's) of holes over the years.

I regularly use a tapping machine, hand taps, or I tap "manually" on my mill. I wouldn't mind learning how to power tap on my mill though. Can you give me some tips to consider before I start snapping taps?

Like I said before, most of what I do is small machine threads in aluminum, what taps and tapping fluid should I use?

Any pointers would be appreciated.

[JFettig]

use something like tapmatic fluid, something specifically for tapping.
Using a quality tap also increases likelyhood of it working well, like a spiral tip tap should push the chips down(what you want unless you use spiral flute to push them up)

Whats the lowest rpm your mill will go?(its a step pully model as it appears in that pic right?)

basicly what I typically do is use a keyless chuck so it has possibility of slipping, use a brush to apply the lube to the tap, depending on material and stuff I sometimes add some to the hole. Turn on the spindle if its not already on, use the quill(NOT AUTO FEED) and bring it so the tap touches the hole and grabs and then let go of the handle so it can bring the quill down on its own. When you want to stop or are through the hole or whatever, flip the switch to reverse and let it back out, I usually hold the handle with nearly no pressure, hold it up so that when it goes to the top it lifts all the way out of the hole rather than mashing the first threads.

The taps that I have used are the spiral point taps and spiral flute taps. The spiral flute taps seem to take more power sometimes and that would result in broken taps if not careful.
Most tapping I do in aluminum 6-32 and less I use cold forming taps, they push the material rather than cut it. You start out with a bigger hole than you use for cutting taps but it typically taps much nicer and easier than cutting taps. The force it takes to turn is nearly nothing with the correct size hole. You must have lube on these types.


Jon

[mxtras]

I would suggest using a true running keyless chuck and chucking the tap so that it will slip just a bit beyond the force required to cut (will be a trial and error thing and it may screw up the shank of the tap if it slips too many times). Spin it slowly and there's not really much else to it - except don't try to pull it back out too hard - the tap will cut on the way out, too. If your quill moves freely, just let the tap feed itself of give it just a little help on the way in and let it feed back out by itself. Just make sure your quill lock is no on.

Are your holes through or blind?

My most used tapping fluid is called "Tap Heavy" but I am not even sure where to get it now. I got a bunch of it from a sales rep a few years back and have never had to buy any. I am sure that a bit of research will uncover a tapping fluid suited for your conditions - aluminum can puke up the flutes of a tap so I would ensure that the fluid you choose is specifically made for aluminum. Tap Magic seems to be popular and it works well on steel - never used it on aluminum. Beolube is good, Cintap is good....

The taps I prefer are spiral flute machine taps made by Titex, Emuge or Balax - there are many styles to chose from. The Balax taps are quite nice for the money and are available through MSC. One benefit to spiral flute taps is that the chips can be extracted upward so they do not clog the hole. You can also get taps that extract the chips downward if that suits you better. One drawback is that a spiral flute tap can break easier as the web is not a bulky as a straight flute tap. If you go the straight flute route, at least get a spiral point.

I would also recommend a three flute tap if they are available in the size you want. Three flute taps start truer and cut smoother than 2 fluters. The more flutes, the weaker the web so there is a trade off.

Scott

[l u k e]

Whats the lowest rpm your mill will go?(

80 and 135 rpm is the 2 lowest settings.

its a step pully model as it appears in that pic right?)

Yes.

basicly what I typically do is use a keyless chuck so it has possibility of slipping, use a brush to apply the lube to the tap, depending on material and stuff I sometimes add some to the hole. Turn on the spindle if its not already on, use the quill(NOT AUTO FEED) and bring it so the tap touches the hole and grabs and then let go of the handle so it can bring the quill down on its own. When you want to stop or are through the hole or whatever, flip the switch to reverse and let it back out

Humm, I would have "guessed" that reversing the motor while it was running would be a no-no. (?)

I usually hold the handle with nearly no pressure, hold it up so that when it goes to the top it lifts all the way out of the hole rather than mashing the first threads.

Makes sense...

The taps that I have used are the spiral point taps and spiral flute taps. The spiral flute taps seem to take more power sometimes and that would result in broken taps if not careful.
Most tapping I do in aluminum 6-32 and less I use cold forming taps, they push the material rather than cut it. You start out with a bigger hole than you use for cutting taps but it typically taps much nicer and easier than cutting taps. The force it takes to turn is nearly nothing with the correct size hole. You must have lube on these types.

Good info, thanks.

[l u k e]

I would suggest using a true running keyless chuck and chucking the tap so that it will slip just a bit beyond the force required to cut (will be a trial and error thing and it may screw up the shank of the tap if it slips too many times). Spin it slowly and there's not really much else to it - except don't try to pull it back out too hard - the tap will cut on the way out, too. If your quill moves freely, just let the tap feed itself of give it just a little help on the way in and let it feed back out by itself. Just make sure your quill lock is no on.

I'll have to look into getting a keyless chuck, I've been wanting one anyway.

Are your holes through or blind?

Most of what I do is "through", I likly wouldn't attempt a blind hole at this point but any advice is good.

My most used tapping fluid is called "Tap Heavy" but I am not even sure where to get it now. I got a bunch of it from a sales rep a few years back and have never had to buy any. I am sure that a bit of research will uncover a tapping fluid suited for your conditions - aluminum can puke up the flutes of a tap so I would ensure that the fluid you choose is specifically made for aluminum. Tap Magic seems to be popular and it works well on steel - never used it on aluminum. Beolube is good, Cintap is good....

I use Tap Magic, but I'm not real sure about the "magic" part, I'll look into the others you mentioned.

The taps I prefer are spiral flute machine taps made by Titex, Emuge or Balax - there are many styles to chose from. The Balax taps are quite nice for the money and are available through MSC. One benefit to spiral flute taps is that the chips can be extracted upward so they do not clog the hole. You can also get taps that extract the chips downward if that suits you better. One drawback is that a spiral flute tap can break easier as the web is not a bulky as a straight flute tap. If you go the straight flute route, at least get a spiral point. I would also recommend a three flute tap if they are available in the size you want. Three flute taps start truer and cut smoother than 2 fluters. The more flutes, the weaker the web so there is a trade off.

More good info thanks..