Messages

6371

General Mach Discussion / Re: Problems threading on the lathe

« on: March 29, 2009, 01:40:37 PM »

ART,
sent you a  PM
RICH

6372

General Mach Discussion / Re: Problems threading on the lathe

« on: March 29, 2009, 01:04:07 PM »

ART,
I can do one later today and make some measurements. I just want to caution you on what you may see in a picture.
Just being very picky here but reading into what you ask for. 
First, a few comments about and from my testing and will admit that most are of short lengths of threading.

If you want to adjust lead error based on program number rounding it would be important that the test piece
be done on a very accurate alligned lathe, properly prepared piece, and the result will be only as good as the lathes screw. So if the screw has lead error, say .003 over a foot you may see that error in the pic.
But what are you seeing, error out of the program or error mechnicaly created (this would include the piece setup). Same goes for measuring it ( yes i can measure very accurately but wouldn't want to lead ya into
doing some thing based on bum info ).

If it's an adjustment to the flank cutting that is another scenario.

Here is some pics of A 0-80 and A 1/4-20 threading tests i did along with info as follows:

THREAD#    REMARK
1          This shows a taper because of setup and a poor / worn  tool
2           Same as above but  a better set-up
3           Good 0-80 thread, fresh ground tool, note the consistancy in the crest, root, pitch
3           30X mag of the good 0-80 thred
4           This is a 1/4-20, you can see good thread consistancy. Note that there are "two" scribed lines".
             The wider of the two was from wizard generated code and the other was picking up the thread
             and to deliberately do an offset of the Z start to test how picking up a thread would work usng G32.
             Tracked quite well.
4           30X mag of the tracking

Just wanted to clarify my caution noted above.

RICH
             

 

6373

Show"N"Tell ( What you have made with your CNC machine.) / Re: Miser engine

« on: March 28, 2009, 08:29:57 PM »

Good for you and wish you luck Vince. We are not ready to retire but there is
no harm in trying it out.   
RICH

6374

LazyTurn / Re: LazyTurn

« on: March 28, 2009, 02:18:38 AM »

Art,
A few minor comments,
1.View menu and status bar -The zoom out and zoom in are reversed in View tool box and also the
                                  associated prompts you get in the status bar.
2.Options menu - if the start Z is a positive value, a scale is not provided in the graphics area post importing a file.
3.When using the keyboard - ALT key will not highlight / underline the Options, Debug, and  Toolpaths
                                         - ALT is also use for changing the crosshair to windows default pointer ( no 
                                           problem but just wanted to mention this )
4.LazyTurn Project flyout - if you  close it, How do you bring it back without going out of and back into Lazyturn?
5.Do you have a listing of which Ctrl, Alt, and other keys combinations are intended to be functional in LazyTurn?
   
RICH

6375

General Mach Discussion / Re: Port addressing when using a smooth stepper?

« on: March 28, 2009, 12:06:26 AM »

 I assume that you have connected the SS to the other boards via PP cable or equal.
In Mach go to PlugIn Control>smoothStepper Data Monitoring  as that shows Pin out's.
I don't use other interface boards but others in here do and surely they will chime in
and can give you additional info as theye seem to be common choice boards.
RICH

6376

General Mach Discussion / Re: Problems threading on the lathe

« on: March 27, 2009, 07:19:11 PM »

So your done threading a piece and your not satisfied or maybe you just want
to tweek it some, maybe the piece has been removed out of the chuck or you just tried the nut and it's tight.
You can pick the thread up in cnc if you wish and tweak it.

Now just make note that threading depends highly on the mechanical aspects of your
lathe. You can tweek either side of the thread flank or follow the minor diameter lead depending on how you want to pick up the thread.

I am only using a single slotted disc. I align / center the slot to the pickup. Placing an fine scribed line on the disc as a reference would be even better.


HOW TO PICK UP A THREAD
-----------------------------------------------
The thread has been cut. Before you remove the piece align / center your index slot
and then place a very fine witness line on the piece with the cutter.

The following applies if the piece "has not been removed" from the machine.
---------------------------------------------------------------------------------------------------------------
The spindle is off, the cutter tip is not in the thread.
1.Align the disc slot to the pickup.
  - If your in MachTurn you may want to use the MDI line for a G80 & G94.
 
2.Move the thread cutter tip into alignment with the point you wish to pick up.
  - You can use the root at minor diameter of the thread V, front or back flank of the V,
     or even center the cutter tip with crest of the thread.
  - Zero the Z axis DRO
   
 Note: Move to your point such that backlash is taken out. Here is were that MPG
          with a nice feel and movement comes in handy. I have a 30x microscope attached
          to my lathe so that is a great assist also.

3. With the cutter out of the thread, now make - Z move in increments of the thread
    lead. ie; for 20 TPI you will move 1/20= .050 increments. You should move beyond 
    the end of the shaft by approx  3 to 5X  the lead ( ie; 3x.05=.150"). Single start
    thread so pitch =lead.
  - Zero the Z axis DRO

4.Make an additional negative Z move and return to Z=0 to remove any backlash.

5. With spindel on, now do a G32 -Z *********x  F.050 from Z=0 where *********x is some length of
    the thread and F value is the thread lead.
    - Turn off the spindle, G80 & G90, MDI to Z=0
   
6.Align your disc slot, do MDI moves in lead increments and see if the the cutter tip aligns      with the pick up point.If all alligned then no need for a Z adjustment. If not adjust the Z    start  value by the amount you may have needed to move to get into alignment with your    chosen point.
 
Now you can do G32 moves to accomplish what you want to do.

What you have done is the equivilant of picking up the thread on a manual lathe with an indexer dial. This dosn't take 5 minutes, and if you know what your doing it is rather quick to do. Simply put, you have closed the half nuts, picked up the thread using the coupund slide, tested it by dry running.

This applies if the piece has been removed from the machine.
------------------------------------------------------------------------------------------
1.Align disc slot.
2.Put the piece into the chuck and align the cutter to the reference line you put on the   piece. 1 & two must match.
3. Now do the same as if the piece wasn't removed.   

Sorry for the detail and hope it's right. My testing showed this to be accurate.
HAVE FUN,
RICH 

6377

General Mach Discussion / Re: Software or Mechanical Problem

« on: March 27, 2009, 02:14:14 PM »

I never used the axis calibration feature, but, another user i know just recently tried it out and said
it worked like a charm.

RICH

6378

LazyTurn / Re: LazyTurn

« on: March 27, 2009, 12:46:04 PM »

Art,
Just wanted to mention that any comments you post along with the updated
version, realy helps with the manual update.
 
To all others who have posted in this thread.
Each reply is reviewed for relevance to manual verbage. The comment may or not be included,
may be rewritten, or similar ones are grouped and a summary comment made which happens
to capture the context of discussion. To date a few hundred pages of comments exist.
Some replies just die over time as they are not applicable. So if i can get over CNCSDD
the manual may get an update in the near future.
  
RICH

6379

LazyTurn / Re: LazyTurn

« on: March 27, 2009, 11:28:23 AM »

Hi Dennis,
I quess the lesson learned on following Lazyturn is that when we are all focused great head way
is made. Unfortunately, as other things pop up and need attention something needs to to put
aside in order to address them. Before you know it, a month can disappear. I can only speak for  
myself and the name for the discontinuity is called CNCSHDD.

Computer Numerical Control Shop Diversion Disorder. 

Doctor Phil said there is no cure, sort of like a cold, just needs to take it's course over time. 

BTW, you can catch CNCSDD by breathing the air around the computer or from the shop. 
 
RICH

6380

Newfangled Solutions Mach3 Wizards / Re: CNC newb needs Wizard or Help with G code for K baffle

« on: March 26, 2009, 11:34:08 PM »

JAMIE,
There are a whole bunch, just piece them together for what you want to do or use individualy.
Welcome to the world of CNC. 
RICH