Tapping Head

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Mike_Beau
Posts: 13
Joined: Sat Jan 04, 2003 6:21 pm
Location: Upland, CA

Tapping Head

Post by Mike_Beau »

I'd like to get a tapping head for my home shop, but never having used one, I'm at a bit of a loss. Looking at the Tapmatic, Procunier etc, web sites gets me some info. I work mostly with aluminum and mild steel. No holes larger then 1/2", some blind. I'd leave the head attached to a Rockwell floor drill press, so I'm not concerned with ease of taking it on and off. Any thoughts on what I should look for, recommendations, horror stories, etc. And I guess maybe the most important question is tap styles. What do you guys use in these tapping heads? Thanks in Advance.

Mike
gezr
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Re: Tapping Head

Post by gezr »

Ive used both the procuner air feed auto tappers and the tapmatic auto reversing units. both have a place. the procuner with the lead screw or heck its been a while, if its the air driven engagement type can only feed at one set rate, that is you put in the lead screw for what type of tap you will be using. and then depth can be exactly set and it goes in, reverses and comes back out. we used them a lot for tapping investment casting ss. typically using a roll tap. we also used spiral point gun taps and a few 2 fluted straight taps.
the tapmatic models are nice because you are only limited by the size it can cary, ie you dont want to put a larger tap in a unit then it was designed for, other then that they are fairly sensitive to the process, where once the quill is lifted just a bit back up the tap will either stop rotation sorta like a neutral or go into the reversing phase. they are nice to use also and are less trouble some, the auto feed units tend to be a bit for forcefull about tapping.
both units are nice i suggest using moly-dee as a cutting fluid ive seen it do wonders in all sorts of materials. but as for taps you would want to use machine type taps, that will help evacuate the chips either in a down thrust or a back out of the hole, high spiral taps or a helical type tap will tend to eject the chips back out of the hole your tapping and since it is a semi or fully automated process it is a wise choice to by a tap that will last for more then 10 hole and be able to operate at a 10-40 surface foot per minute range. In all but the hardest materials. osg sosner makes good taps, greenline also just to name 2 companies that make solid machine operation taps. just work to avoid hand taps. if its alluminum, you may find a roll form tap will be better suited to your application. it all depends, cast iron is about the only thing you dont really want to ram one of those things into. or something that has an incredibaly high level of britality like brass for example. I hope i was able to give you some suggestions. tapmatic for on the fly changes with the jacobs collest or the procuner(and I might be wrong about this, but its high volume exact feed/lead setups for a specific job. both are fine units.
if the operator leave a auto unit unattented and the tap breaks, it will continue the down feed.
on a tapmatic type unit unless total disreguard is made will tend to just bounce on the top of the broken tap, they almost are self feeding in a lot of ways.
phil
Bryan
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Re: Tapping Head

Post by Bryan »

I have a Tapmatic and love it... I do lots of 1/4"-20 in 1/2" 6061-T6... the tapping operation is now quicker than drilling the hole in the first place...
The price of a genuine Tapmatic is up there a little, but there are knock-offs at about half price (if that's the way you're inclined)... even at full price, the time they save will pay for it in no time at all...
[b]Bryan[/b]
[i]"Simplicity is the ultimate sophistication."[/i] Leonardo da Vinci (1452-1519)
Mike_Beau
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Location: Upland, CA

Re: Tapping Head

Post by Mike_Beau »

Thanks guys. The Tapmatic sounds easier to use and more forgiving. My application is not high volume, but I'd like to take advantage of a semi-automated process and achieve a better result. Question gezr, the 10-40 surface foot per minute range you're speaking of, is it the relationship between the tap size, threads per inch and the rpm it's spinning? I'm assuming there is a formula to figure this out. And different materials would have different requirements.

Mike
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willjordan
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Re: Tapping Head

Post by willjordan »

I bought a Telco on eBay that seems to work well in my drill press. It's got a maximum capacity of 1/4". I got it for doing things like cylinder heads in small engines and pumps.

So far have just used it with 8/32 in aluminum, but it certainly made tapping multiple holes easy.
grace & peace
will

[url=http://willjordan.com]Will's Web Pages[/url]
jan3
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Joined: Sat Jan 04, 2003 12:45 pm
Location: Mt View,CA

Re: Tapping Head

Post by jan3 »

Hi Mike Have used both Procunier & Tapmatic over the years for about any application.Procunier is my favorite,to me they are much more exact.The taps are driven via a steel collet,not a flex collet like Tapmatic and depth control seems easier.One disatvantage is size. If you need to tap .500 or larger ,the Procunier is a larger unit.Far as taps roll taps work great fo blind holes,plug taps are fine for through holes.
gezr
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Re: Tapping Head

Post by gezr »

Mike,
Yeah [img]/ubb/images/graemlins/smile.gif"%20alt="[/img] as with all cutting tools they are designed to work within a range, pending both cutting and whats being cut. now, hand tapping for example you could never generate enough rotation to realy generate any surface footage taps can be ran in a range of speeds baised on the diamater and whats being cut. say the material is good ole t6061 aluminum, it has a nice chip forming rate and is generally easy to machine. were going to be putting a 1/2 13 tap about an inch deep. so we know a few things, tap size and material, the tap is just a nice hss tap maybe with a grey coating(friction coating basicly) because its aluminum were going to run the tap at lets just say 40 sfm. so to calculate the rpm needed to obtain that rate of rotation.
(sfm/dia of cut)*3.82=rpm
(40/.5)*3.82= 305 rpm keep in mind this is hauling some butt
for a hand driven op 10sfm is a good place to start or slower,
at 10sfm a .5 inch tap will require a rpm of 75.
taps can always be ran slower, ive seen this sort of hole done at a blazing speed. 200sfm and higher.
now for the handfeed operation its just a matter of applying the cuting fluid and driving the tap into the hole, interesting thing is if the tap is allowed to stay at the start of the hole it could become a bit of an endmill and cut the hole larger, so its best to go ahead and get it driving into the hole, because we want to give it a chance to grab and begin its own self feeding operation so we can be ready to reverse the motion to begin tap extraction. because its such a short hole a physical stop may be put under the tapping head so that as its lowered the tap pulls its self into the reversed position by the time it reaches full depth. this can also provide a bit of a safety measure. once you get your tapmatic or clone unit play with it, put a rod in it that you can grab with your hands so you get used to the reversing motion. the higher rates of speed are for machines that can control depth rather close.
be carefull if your driving the thing through a through hole, you may not want to try putting the tap all the way through for it may not want to come back out. remember slow is always better, and when your comfortable try not to excede 40sfm in steel. these are just some decent places to think about what a good tap can do. when you break one, or it screams a lot your probably running to fast. sfm for taps does not take into accound the pitch of the tap. thats just a feed thing, and where the try not to excede 40sfm comes from, the chip load can become execssive rapidly and cause breakage. a tap running at 305rpm with a pitch of 13 on a cnc machine with ridgid tapping will feed at 23.4615 inches per minute and to tap to a depth of 1 inch and start moving to the next hole takes about 5seconds. and when they break they really break.
but all that info really doesnt matter in terms of a home shop, whats important is safety, keeping it slow, well lubed, and not held in the hands. I think youll love having one, they are handy. and now you have an idea as to what can be done.
be safe
phil
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