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Offline BR549

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Re: Rigid Tapping
« Reply #20 on: January 05, 2014, 02:01:36 PM »
Those were NOT your standard VFDs they were Vectored VFDs where the VFD is connected to the encoder directly. I have access to a Mazak that runs it.

Those vectored VFDs are virtually a servo drive that uses a 3ph motor, very expensive and were later replaced by true ac servo drives.  The last Vectored drive that was replaced here was well over $5k just for a rebuilt unit.(;-) OUCH. The servo drive drives were only $3k.

IF mach through a controller can do synchronous tapping it will serve in most cases but it it NOT rigid tapping where it can stop on a dime.

IF you google Route66 rigid tapping you will see a version that does Synchronous tapping well with a controller that supports it. But as you see it is NOT doing blind hole tapping just through hole. It cannot do true RT as it cannot stop on a dime either.

In most cases with a compression tapping head and through hole tapping you can do just about as well without the encoder enterface Just G84 it .  If you do a LOT of tapping the same size you CAN get down to a 1-2 thread depth tolerance.

I use a compression tapping head WITH a clutch to prevent broken taps on blind hole. NOT the best solution but it works.

(;-) TP


Just a thought, (;-) TP

« Last Edit: January 05, 2014, 02:04:19 PM by BR549 »

Offline Hood

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Re: Rigid Tapping
« Reply #21 on: January 05, 2014, 02:24:45 PM »
TP, I was talking about modern Mazaks, my neighbour who is in charge of a place with quite a few Integrex reliably informs me that there is rigid tapping in his machines but also their is the synchronous tapping option. The difference he told me is rigid tapping he can tap reliably but if he needs to go in again and adjust depth then unless he has the sync option he is out of luck. Now he is likely totally wrong so I will let you win as obviously he doesnt have a clue what he is talking about :)

Hood

Offline BR549

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Re: Rigid Tapping
« Reply #22 on: January 06, 2014, 01:15:43 AM »
With true rigid tapping the spindle SYNCs to the index signal to give it a starting point of reference of rotation that sets teh home on spindle rotation. The drive is setup with parameters JUST like the other axis servos are. The control knows exactly where the spindle rotation is as compared TO  the index signal. It can repeat or retap or peck tap a 100 different times and the depth will always be exactly as programmed and the thread pitch will always match up as long as the tap has not moved in the holder.

Around here we have only been working with these type or things  for about 45 years now so you are right we might not know what we are doing over here yet.  

So ends another discussion, (;-) TP

Offline Hood

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Re: Rigid Tapping
« Reply #23 on: January 06, 2014, 02:52:59 AM »
No Terry I already said you win and that my Neighbour doesnt know what he is talking about :) Didnt say what you were the winner of but...
BTW had a look at your route66 thing, better tell them they are falsely advertising, they refer to it as rigid tapping and as you quite rightly say it is most definitely not :)
Hood
Re: Rigid Tapping
« Reply #24 on: January 06, 2014, 08:42:12 AM »
............ my spindle is controlled by an analogue voltage so in theory it should be the same as a VFD. The CS-Lab website says that rigid tapping is possible with the CSMIO/IP-A and CSMIO/IP-S when using the Encoder module. There is no mention of it having to be a servo, I will however ask them and I will update here with their answer.
Hood

Dear Hood,
  I'm interested in the response from CS-Labs, will appreciate the update.
Thanks,
Russ

Offline Hood

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Re: Rigid Tapping
« Reply #25 on: January 06, 2014, 08:55:12 AM »
Will do Russ, no reply as yet but as this is likely their first day back it may be a while before they can get a reply out to all that have emailed.
Hood

Offline Hood

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Re: Rigid Tapping
« Reply #26 on: January 08, 2014, 06:39:02 AM »
Russ,
  got a reply from Wojtek at CS-LAB,
Question asked was
"Hi Wojtek,
    can you tell me, is rigid tapping possible with the IP-S & IP-A and the Enc
    module when using a VFD to control the spindle? "

The reply was

"Hi,
Yes, sure it is"

Short and sweet but my question was asked prior to all the extra info required by some  ;D

I have asked for some info on how closely the Z will be observed or whether that would be dependant on the VFD and its setup.
I have also asked if peck tapping is possible with a VFD.

Hood


« Last Edit: January 08, 2014, 06:40:48 AM by Hood »
Re: Rigid Tapping
« Reply #27 on: January 08, 2014, 08:14:07 AM »
Thanks Hood.
Wondering if this would require/use the  index signal ... or if it is a one shot deal with an inverter.
Also, guess the enc. index would negate the need for the normal spindle speed sensor ?

Thanks again,
Russ

Offline Hood

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Re: Rigid Tapping
« Reply #28 on: January 08, 2014, 08:34:33 AM »
Russ,
 I would imagine an Index on the encoder would be required, definitely if wanting to do peck tapping (if that is possible with a VFD)  and as you suspect if you have the Enc module with an encoder attached the spindle speed is obtained from that, so no need for an additional Index.
Hood

Offline BR549

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Re: Rigid Tapping
« Reply #29 on: January 08, 2014, 02:05:24 PM »
HIYA Hood I guess the difference is the some of us have a  great deal of 1st hand experience using and testing tapping on a mill and others just rely on 2nd hand info from others. (;-)

But I will let you continue to advise users as to how it really works (;-)

Been there done that, (;-) TP