machine tapping advice needed

Can't comment on much else but I've heard Kerosene works better... Or any heavier oil - even motor oil.

WD-40 is not really a lubricant. It is "slippery" just like soap is, but just like soap, it also was not made as a lubricant...

Regards, Joe Agro, Jr.

V8013

This sounds real tricky. You are going to have to stop the lathe pretty much on a dime. I suspect after the lead-in of the tap, there is barely one inch of threads on it.

You'll have to remove the tap manually? I guess that will work. How are you going to hold and feed the tap? Let it draw the whole tailstock in toward the headstock? You shouldn't have to stop and break the chips with these taps. They certainly don't do that with tapping heads or CNC rigid tapping. I usually

Alum-tap is what I use. I have a 1 pint can that has lasted me for years. Or, pipe threading oil. I doubt WD-40 will be real great for this.

Why don't you just single-point thread this? That would probably be my choice for such a deep hole. Then, I might whip the tap through by hand after the thread is almost to full depth. You can hold the tap with a tap handle and just let go if it binds.

Jon

I would hold the tap in a drill chuck that is in the tailstock.

Use about 100 or 150 rpm.

Leave the tailstock loose on the ways.

Gently push the tailstock into the drilled hole.

The tap will start cutting and start drawing the tailstock towards the part.

Stop the spindle when the tap is through the part or before the drill chuck hits the part.

Loosen the drill chuck and finish tapping by hand if required.

Remove the part and tap from the lathe.

I would use kerosene or some kind of oil. I've not tried wd-40, it may work ok. MikeH

Hi Brian

Was just reading some of the advise and things didn't add up for me. Correct me if I am wrong, but I thought you said that this was a through hole and that you said it was 1" deep. So I see no reason why you could not tap right through the part without having to stop in any particular place.

If this is the case. I would try to find a square drive to fit the tap (either that or use a chuck) and motor right on through the hole if the tap shank is small enough to permit you to. Otherwise just stop short of the end of the thread on the tap.

In the first case the tap would fall out when you change the part and in the second case you could back out the tap with a cordless drill.

Hope I haven't misread the situation.

Bill

WD-40 works great on aluminum. 100 or so rpm. I'd suggest a reduced diameter tap like a pulley tap so you can go completely through the hole. Leave the tailstock loose on the ways, get the tap chucked in the tailstock close to the hole, turn the spindle on, start cranking tailstock. You can observe the rate to crank by watching the tailstock to see if it is being dragged towards the chuck or pushed away. Since you have no reverse, this method allows you to go all the way through without stopping & without damaging the tapped hole's exit point. Once you're through, stop the spindle, stop cranking, unchuck the tap, unchuck the part from lathe. Everything ends up loose in your hands & no manual spindle reversing is required. Pulley taps are longer so it works good this way. If your reduced diameter tap is a shorter length just stop the spindle once you're through the material, unchuck the tap & either run it through by hand or back it out.

"Brian" wrote in news:MIKmd.84453$ snipped-for-privacy@nnrp1.uunet.ca:

You really need a floating tapping attachment for your tailstock, no need to break the chip, and use Castrol Moly-Dee for tapping fluid.

Greetings- My standard practice is to power tap in the lathe by placing the lathe in back gear and holding the tap in the tailstock chuck. I manually push the loose tailstock and the tap into the work , stopping the spindle at the desired tap depth. I f ind no need to break up the chips- your spiral tap will push the chips ahead of itself. In your application I would counterbore the hole about 1/4 inch so I would not run out of tap. To remove the tap, loosen the chuck, back up the tail stock, put a tap wrench on the tap, and reverse the spindle. I would use Kerosene. Regards, Jim.

Go to lowes or home depot and get a guart of dark thread cuting oil .As for the spiral tap I would start at the lowest rpm chuck the tap in the tail stock and feed the tap in, remember to keep light presure on the tap turning the quil screw . Sence you have 20 of these I would take out the feed screw in the tail stock an let the tap feed itself.

Beleave it or not i use soluable oil and pine-sol allso makes that black sulfer cutting oil smell good if you try it let me know

I tried it and was monumentally underwhelmed. The second best I've used is A-9 but by far the best is d-limonene. Ernie L posted: " the entire world sees the light of day. The best cutting fluid for aluminum, bar none, is industrial strength Citrus based solvent. I don't care what brand. The one I use is made by ZEP, and is called Big orange. The active ingredient is D-Limonene, and is extracted from orange, lemon, lime, and grapefruit skins. It is the same stuff in Fast orange hand cleaner , and all the citrus based cleaners. The greater the percentage of active ingredient, the better. Big orange is 98% D-Limonene. Take Off ( a floor cleaning solvent) is 45%, and is ..."

Looking for a Canadian source, I found

I've used this for turning, milling and threading aluminum and definitely agree with Ernie. In addition, I recently turned a copper commutator and used the stuff as cutting fluid. The commutator came off the lathe with a great finish and no smearing.

Ted

Taps are available with the shank smaller than the minor diameter of the threads. These could be allowed to go in as far as neccessary to fully thread the hole.

Ted

Thanks for all of the replies. The taps I ordered "should" have reduced shanks to allow through tapping, if not I will overcome...it seems to me that "goo gone" may well be a citrus based solvent, I have a bottle on hand and I't try it for tapping these.

Cheers, Brian

While cutrus solvent may be a great cutting fluid for machining aluminum and copper, I would recommend keeping solvents and lubricants of any kind away from commutators. Cut them dry, then undercut the mica, and scarf the edges of the undercut grooves by hand. Commutators and solvents are a very bad combination.

Mill

We made the wheel-nuts on the weekend, and the tapping went great. The spiral tap went in with almost no load on the machine, you could just about tap the entire hole by spinning the chuck by hand and letting the tap self feed as the cuck spun under interia. Very high quality holes, too.

Cheers, Brian