Messages

5271

General Mach Discussion / Re: Drifting in the Y axis

« on: December 17, 2009, 01:55:09 PM »

Sounds like a loose ball nut or backlash.
RICH

5272

General Mach Discussion / Re: Help with Spindle Index please

« on: December 17, 2009, 01:48:34 PM »

John,
You may want to try the fix that is in the following link:
http://www.machsupport.com/forum/index.php/topic,8314.msg87047.html#msg87047

That fix was supposed to be incorporated into a new version of Mach, but...., I have yet to see it posted.
All know threading specifics that you need to be aware of, up to and including ver 032, are so noted in the Threading on the Lathe write-up.  I never updated the write up because i thought a new version would be out
and only wanted to do it once.  Oh well....sorry about that.

If the fix takes care of your readout i would stick with ver 032 for threading.
RICH

5273

General Mach Discussion / Re: Peck Drilling macros for the Lathe

« on: December 17, 2009, 01:27:32 PM »

Thanks Melee that was quick,
I'll try them out. Here is a link on what i am up to

http://www.machsupport.com/forum/index.php/topic,12484.msg88231.html#msg88231

RICH

5274

Show"N"Tell ( Your Machines) / Re: CNC CONVERSION - 6" ATLAS LATHE

« on: December 17, 2009, 01:18:12 PM »

Been experimenting  drilling holes. Manualy using the MPG's,  G83 canned cycle and some macro's. Good allignment, just the right pecking, and quality

drills are mandatory for accurate drilling and hole size. You will break a small drill in a heart beat if things are not right.
Feeds( F.01 TO F1) can be increased once a starter hole is accomplished.
A 0.020" drill is shown against a 0.001" feeler gauge in Figure #1.

Figure #2  shows ( 12 equaly spaced 0.020" holes into a .375"  diameter piece. The manual indexing band on the chuck ( Fig 3 ) was used and each division

is 1 degree. I have a veneer that can be used to bring it down ot 5 minutes of an angle.But in the future ...never ends.... a stepper will be used to rotate the

spindle. Figure 4 shows two mounting options i am considering. A removable bracket along with a spindle adapter will provide quick setup and removal.
 
At 200 steps / unit and 10us, resolution would be 10.8 minutes, or if i use the stepper with a precison 10:1 gear box ( no backlash in it ) then resolution

goes to 1 minute.
1 MINUTE = 0.0003" @ 1" distance
So if the you can hold the drilling location to 0.001" @ say .25", that would be equal to approx
13 minutes. To eliminate rotation inaccuracy the geared unit should be used.

RICH

5275

Show"N"Tell ( Your Machines) / Re: CNC CONVERSION - 6" ATLAS LATHE

« on: December 17, 2009, 01:15:45 PM »

Got side tracked for a while and back to making and testing out some of the assessories for the lathe. Here are some pictures of the drilling / milling  attachment that will be used on the lathe.

FIGURE 1&2 shows  the drill in a holder and the adapter plate. Setup is quick as no shimming is required. The base can be attached to the carrage on the X, Z axis or even on an angle. Machining can be done via a coded program or manualy by using the MPG's. The drill and not shown matching collet model were modified to remove axial play. Figure 3 shows additonal air driven grinders ( made by Dotco and Ingersoll Rand ) some of which  have an adjustment for speed. So rpm range is up to 60,000 rpm. The same holder is used for all of them just that an adapter is reguired for use of the air driven ones in the holder.

Figure 4,5  shows how the drill is alligned. A piece with a precision reamed hole is mounted in the chuck or collet. Using a extended eye relief microscope,  MPG's are used to allign the ground pin into the hole. The slightest movement of the pin can be detected. You can see .001" easily. The axis is then moved into the reamed hole some .5" deep.

RICH

5276

Share Your GCode / Re: Spindle speed increaser for engraving...

« on: December 16, 2009, 11:35:12 PM »

Bill,
The small end mills break in a heart beat especialy if you have any backlash. They are just plain end mills and most are HSS. I made adapter plates off the bottom of the quill and can mount a small high die grinder or drill from it. Don't use it much  because i buit a small engraving machine.
RICH

5277

Show"N"Tell ( What you have made with your CNC machine.) / Re: MODEL 629 S&W MAGNUM

« on: December 16, 2009, 11:23:07 PM »

Yes, they can do some neat and accurate work.

I am thinking about how to do the barrel rifling at the small scale. I am hoping i can do a long lead thread and
kind of line bore it with a special cutter on the lathe. The manual way way is painfull and don't feel like making the jigs to do it. But that is a long way off.

RICH
 

5278

General Mach Discussion / Re: Peck Drilling macros for the Lathe

« on: December 16, 2009, 11:13:40 PM »

Melee,
Tried the maco's out but they didn't work for what i was trying to do.
They will only peck one time for small values of Z & Q and values must be the same or you will get an error message.

G20 examples:  ;M831 X0 Z-1 R.01 Q0.2 P1 D1 F10   this will peck 5 times
                      ;M831 X0 Z-.01 R.01 Q.002 P1 D1 F.1 get an error message "no digits found where real             
                                                                           number should be"
                      ;M831 X0 Z-.01 R.01 Q.01 P1 D1 F.1   this will only run 1 time
                      ;M831 X0 Z-.02 R.01 Q.01 P1 D1 F.1   get an error message "no digits found where real             
                                                                           number should be"

I am just experimenting on how to drill 0.020" holes  at 20,000 rpm on my lathe.
The following works: G83 X0.0 Z-0.010 R.010 Q0.001 F.04 but is painfully slow and the G83.1 won't rapid as you as you already know.

RICH

 

5279

General Mach Discussion / Re: Use Spindle Feedback in Syn Modes ? Experiences

« on: December 16, 2009, 05:51:35 PM »

I switch it off in a different way but requires an additonal  knowlegable control person.      
Timing is everything when threading. 
RICH

5280

General Mach Discussion / Re: Use Spindle Feedback in Syn Modes ? Experiences

« on: December 16, 2009, 05:36:05 PM »

Ok my bad,
Spindle speed averaging was for use when timing was available. It would average the speed of multiple slotted discs
as compared to a single index over a few rpm. Now multi slotted discs are not provided for in the latest version of threading / MACH3 Turn. Timing should  be disabled in configuration. Amazing what you find in the manuals. 
 
BUT......I still need to look in the volume of info on threading as that dim light bulb above my head is still flickering for some reason.  Maybe it's an indication that the brain is still active! 
RICH