Messages

4111

General Mach Discussion / Re: re:CNC Lathe program

« on: July 27, 2012, 02:41:55 PM »

Your answer is but an email away.

(;-) TP

4112

General Mach Discussion / Re: crashing....

« on: July 27, 2012, 01:08:15 PM »

HOW large of a pen plotter are you trying to build. Old Pen plotters (rarely used anymore) are extremely cheap these days. I still prefer the PEN drawn look for drawings as they tend to be a work of art not just a replication.

Just a thought(;-)TP

4113

General Mach Discussion / Re: Input 1.

« on: July 27, 2012, 11:54:09 AM »

I would use the Input 1 feature as it will stop Gcode program execution without positional loss  AND use a simple brain or macropump to turn OFF Jogging when the input1 is active.

(;-) TP

4114

General Mach Discussion / Re: BT30 spindle from scratch - with power drawbar and ATC of course

« on: July 27, 2012, 11:33:54 AM »

You can never have TOO much drawbar tension(;-). But you do have to consider design parameters. A real pull stud(stud only) is designed for up in the neighborhood of  100,000 lbs of drawbar pressure before failure. The upper end level depends on the material and design used before the stud stretches or the drawbar stretches and releases the pressure and the tool holder.

The other side of the design is releasing the high drawbar pressure. Also fitting in the Very TALL spring stack as high pressure calls for a very tall stack to get pressure and overall travel.

The overal weakness of MOST power drawbar systems is the SPRINGS that retain the pressure. The more you use them the sooner they loose tension or Break springs. Not unusual to change out stacks twice a year on 24/7 machines .

I would personally shoot for the 900-1000lbs level.

You mileage may vary, (;-) TP

4115

General Mach Discussion / Re: re:CNC Lathe program

« on: July 26, 2012, 08:39:43 PM »

There a many GOOD cams with LOUSY post for low end machines that do NOT work well for the low end applications.

(;-) TP

4116

General Mach Discussion / Re: Cut parts are wrong size, CNC knee mill problem

« on: July 26, 2012, 06:25:58 PM »

I had better find my glasses. (;-)

(;-) TP

4117

General Mach Discussion / Re: BT30 spindle from scratch - with power drawbar and ATC of course

« on: July 26, 2012, 06:18:18 PM »

3000 @7hp is really not a good combination, at 3000 rpm you are still limited to a certain chip load so the extra HP does not add much to the combination. You tend to just generate more heat that you cannot get rid of easily.

IF you set up the spindle with low drawbar pressure AND HIGH torque loads on the cutter you will probably RATTLE the tool holder in the spindle under heavy loads

Now gear it 2:1 then at 6000 rpm you are getting somewhere. BUT even that low your bearings, Sindle bearing alignment, grease and preload better be spot on(;-)

R8 collets now that is an exercise in anger management(;-)


Just a thought, (;- )TP

4118

General Mach Discussion / Re: re:CNC Lathe program

« on: July 26, 2012, 04:44:32 PM »

Email them and ask for a demo that can WRITE the gcode you cannot test it without being able to do so. You may have to remind them of that fact(;-)

I would NOT even consider a program test that could not write the Gcode as part of the test.

I have done that several times and the companies sent a limited time version that would write code.

Can't hurt to ask, (;-) TP

4119

General Mach Discussion / Re: Cut parts are wrong size, CNC knee mill problem

« on: July 26, 2012, 04:16:41 PM »

HERE is "simple" Code for an inside circle AND an outside circle. It is setup for a 4"center line .

Not saying it is BUT there may be a problem within MACH3s conversion to metric Gcode on the G2/G3.

Art always said IF you are going to normally CUT metric then set the machine to metric as well.

IF that cuts correctly both ways then we will try a metric Gcode via Imperial machine.




(Filename: Circle_4x4)
( Plasma Shape WIZARD )
(Date Created: 07/26/12)
(Time Created: 3:54:49 PM)
G20 G17 G40 G54 G80 G90
G0 Z0.5
G0X0Y0
G0 Y2
M3
G4 P3
G1 X0 F20
G0 Z0.0
G3 X0 I2 Z-.050
G3 X0 I2
G0 Z0.5
M5
M30


(Filename: Circle_4x4)
( Plasma Shape WIZARD )
(Date Created: 07/26/12)
(Time Created: 3:54:49 PM)
G20 G17 G40 G54 G80 G90
G0 Z0.5
G0X0Y0
G0 Y2
M3
G4 P3
G1 X0 F20
G0 Z0.0
G2 X0 I2 Z-.050
G2 X0 I2
G0 Z0.5
M5
M30

4120

General Mach Discussion / Re: BT30 spindle from scratch - with power drawbar and ATC of course

« on: July 26, 2012, 03:39:50 PM »

IF memory serves me I remember 30 taper drawbar pressures ranging from  from 900-1300 lbs depending on manf. and useage. The higher pressure were normally on machines that did a LOT of heavy hogging all day long.

You do realize that r8 does NOT have the same taper as 30 taper Just checking(;-)

(;-) TP