1200 Oz-in Bipolar Mode, I am using it in Unipolar so Lets say I am getting 600Oz-in Torque straight away from the Motor..

Well it doesn't really work like that. The 1200 oz/in is HOLDING torque. i.e. the torque you'd need to apply to force a stationary or "held" motor to rotate. It tells you very little about the torque it actually "develops" while rotating. Drive a "big" motor less than optimally and a "small" one optimally and the small one will win every time. As for the rest - sorry - I'm not your man - what I know about drilling carbon steel could be written on a pin head. Anyway - good luck.

Cheers

Ian

Khalid
 I would say your problem is your torque is drastically reduced because of the gearing in the head, instead of increasing the torque it is the opposite way.
Your reduction in the first stage increases the torque by 3 times but then going by your steps per unit compared to motor steps the torque gets drastically reduced. From what I recall your input to the head is 1200 steps per rev and your steps per mm are 12 or there abouts so the quill will move about 100mm per input shaft rev, that is a very large amount, you really want it to only be a few mm per input shaft rev. I would imagine your axis are about 5mm per rev.
Or am I reading this all wrong?
Hood

Ian, I agree with you:) Using smaller Stepper is better comparing to bigger..This is my experience too...
Hood.. You are absolutly right.. The Pinion-Rack are very coarse and my whole torque increment is reduced by this rack component... I am going to install worm-wheel of 30:1 ratio or a little higher 50:1 to get maximum Torque to drill and mill CS and Stainless plates..

I am giving links of completed machine with some Failed drilling pictures.... You will see I couldn't get the drill 1mm inside carbon steel plate.. The Drill is of HSS brand new DORMER make...
http://www.cnczone.com/forums/attachment.php?attachmentid=107676&d=1274598084
http://www.cnczone.com/forums/attachment.php?attachmentid=107679&d=1274598084
http://www.cnczone.com/forums/attachment.php?attachmentid=107678&d=1274598084
http://www.cnczone.com/forums/attachment.php?attachmentid=107677&d=1274598084

As per HOOD instruction, I checked the Auto-Feed option on the radial drill...I found three speeds setting .. 0.06mm/rev , 0.21mm/revolution and 0.1mm/revolution... I have disabled the AutoFeed gearing and used 0.06mm/revolution worm set only.. I have to make new motor mount too.. I will soon post the pictures of the setup.. Now not only i will get the resolution on the Quill but the greater torque...

In the couple of days i will show some drilling work on Actual tubesheet of the exchanger:)...  Here in my Shop the Ambeint temperature shoot 49Celcius... yaa man it is in Celcies not in Farhenhite ..One of my controller have Heart Attack (Thermal Shutdown)..Now I am going to arrange some Cooling setup for the controller panels too;)

Thanks Hood and all the folks who solved my problems....

Glad to hear you are progressing
It was high 20's here a few days ago and I was welding Aluminium and I was hating it, I am a cold climate kind of person. Today its been great, probably 12 degrees C and I am much happier. 

Look forward to the pics
Hood

Thanks Hood...I wish i could have 20 degree celcius here.. yesterday we have 53 degree celcius.. I adjusted the POT on the modular card to 2.5Amp current.. Although i have 4Amp setting for high torque but the Ambient temperature is too high.. So I am running these beefy motors with 30% of their torque curve:(...

yesterday, i made some progress.. Following are the mock-up results of tube sheet drilling for one of our exchanger..
Program used:
1-AutoCad
2-VisualMill 5
3-Mach3

The feed was calculated for
1- Dormer centre drill A-201 HSS
2- Spindle RPM: 800
3- Cut feed: 215mm/min

Total holes: 220 Ea
Time         :52Minutes

New Pictures:
http://www.cnczone.com/forums/attachment.php?attachmentid=107978&d=1275044769
http://www.cnczone.com/forums/attachment.php?attachmentid=107979&d=1275044769
http://www.cnczone.com/forums/attachment.php?attachmentid=107975&d=1275044769
http://www.cnczone.com/forums/attachment.php?attachmentid=107976&d=1275044769
http://www.cnczone.com/forums/attachment.php?attachmentid=107977&d=1275044769

Looks great

Guys I am getting trouble...
http://www.cnczone.com/forums/showthread.php?t=106340

Yes i see

You say you have backlash. How much on each axis ?

Are you using conventional or climb milling ?

Phil

Hi Phil,
I currently don't remember the backlash values and also didn't  checked the rotation direction of tool.. Will answer you tomorrow:)
Regards