Messages

71

General Mach Discussion / Re: Mach 3 Lathe setting up tools and offsets. hair already gone...teeth next...

« on: December 12, 2012, 01:40:45 PM »

Great, so what I propose should work if I have home/limit switches installed?

Additionally, does drawing the parts in cad at the -Z location as I described make sense?

I think I might be getting a bit closer to understanding this...

72

General Mach Discussion / Re: Mach 3 Lathe setting up tools and offsets. hair already gone...teeth next...

« on: December 12, 2012, 12:17:58 PM »

if the above method would work, would it make sense then that when I draw lathe parts in CAD/CAM, that I draw them at a Z(negative) position that has the part face at the distance from the Z home position that it needs to be, when it is set out from the spindle face enough for the turning ops and cutoff.

Example-

Program part in CAD/CAM with a 1.5 inch long part held out .5 for clearance from spindle face. Total material stickout would be 2" and this 2" face location from the spindle would actually be -16" from the Z home position(knowing that my spindle face is -18" from the Z home position(Z0)) .

To do this, I would draw my part with its face at Z-16" in CAD/CAM.

This making sense?

73

General Mach Discussion / Re: Mach 3 Lathe setting up tools and offsets. hair already gone...teeth next...

« on: December 12, 2012, 11:54:57 AM »

I have a few good quality switches that I can install on my machine. I should do that.

When I turn on the machine, I could home x and z and then the machine will know exactly where the cutting points of the tools are correct?

The tools would just have to be recorded in the tool offset table as the distance each one is from X0, Z0 (the homed position) does this sound correct?

Example.

Home-
Table moves to X0 about 5 inches out from centerline of spindle.
Saddle moves to Z0 about 18 inches away from spindle face. 
Both positions recorded as Z0, X0.

Then, I could move the master tool over to a workpiece and touch in Z and record the travel distance as the master tool Z offset. I would then take a skim cut, measure and move the tool in in X until it was at 50% of the X number I got from the skim cut. This would put the master tool tip exactly at X0. I could then enter the X distance travelled from the X home position to the master tool tip at X0 location, into the master tool X offset box.

Then I could measure the distances from the other tools in the gang from the master tool tip's Z and X offsets and add the measurements to the master tools offset numbers and then put the total intoi each tools offset table.

This all seems to make sense to me. Is it correct? and is this doable in Mach3?

   

74

General Mach Discussion / Re: Mach 3 Lathe setting up tools and offsets. hair already gone...teeth next...

« on: December 12, 2012, 10:50:53 AM »

Also, I should add that I am not running limit switches.

75

General Mach Discussion / Re: Mach 3 Lathe setting up tools and offsets. hair already gone...teeth next...

« on: December 12, 2012, 10:50:01 AM »

DB-

Thats actually the way I have run the prog in the past. It works, but is not simple and I imagine that it should be easier to just use mach 3 tool offsets as designed.

I never could figure out why my G52 offsets ended up being ~1.9 inches away from each other per tool, when the tool block is on 1" centers. Never made any sense....

76

General Mach Discussion / Mach 3 Lathe setting up tools and offsets. hair already gone...teeth next...

« on: December 12, 2012, 12:31:05 AM »

I have been loosing my mind trying to get Mach3 to run a lathe program as I intend it to.

Some basics-

Retrofit Hardinge CHNC1 running steppers, SmoothStepper, G203V's.
No toolchanger. Running Gang tooling on a tooling bar at 1.000" centers (Omni turn style)


I have the gang tool bar set up like this-

1st position. master tool holder. tool 1.
2nd position. NO TOOL. BLANK.
3rd position. tool number 2.
4th position. tool number 3.
5th position. tool number 4.

NOTE: 1st position is closest to operator.


I have a relatively simple file I created in BobCad ver 25 lathe that has the following-

1 spot drill op. done with tool 2, a spot drill in the 3rd bar hole.
1 through drill op. done with tool 3, a jobber length drill in the 4th bar hole.
1 roughing/finishing profile op. done with tool 1, a cutoff style tool in the 1st (master tool) bar hole.
1 cutoff op. also done with tool 1.
1 chamfer in prep for bar pull, done with tool 1 also.
1 bar pull done with a puller, tool 4, in 5th bar hole.
Loop.

I know that my locations of tools 2,3 & 4 are 1 inch apart from each other and they are tools that do not use an X offset (because they are drills and a bar puller.)
I know that tool 1 (master tool) is not on a center and is at an arbritrary place.

If my stock is .5" dia, and I want to setup the master tool, and then the others how do I go about this?

I have RTFM like 10 times and have been trying things for hours...

I suspect that this is all so much simpler than it seems. but with several diff coordinate systems, offsets, touch offs, entering cut diameters in the X axis DRO, Etc. I am so confused...

Can someone lay it out from start to finish?

Note-
I have used G52 to run this part in the past, but I think this is less than ideal on a ton of levels. for instance- wear offsets. also- I am calling a tool, but not really. more like I pretend to call a tool and just shift the part location. Seems wrong to do that.

77

General Mach Discussion / Re: How much stepper power do a 1-1/2 HP Bridgeport need to do a good job ?

« on: December 11, 2012, 09:31:35 PM »

I can say that good brand name steppers and Gecko 203V drivers have left me with nothing but good performance. I can run for hours at 50ipm and never loose a step.

Very happy with my setup, and it was affordable. (I bought the motors surplus- new take offs from demo machines, I cant imagine what they cost new...)

78

General Mach Discussion / Re: How much stepper power do a 1-1/2 HP Bridgeport need to do a good job ?

« on: December 10, 2012, 04:02:31 PM »

I have 870in/oz Pacific Scientific Hybrid Nema 34 single stack stepper motors on my series 1BP.

I retrofitted ballscrews and run a 3-1 reduction. PS is 70v 800W(IIRC) and I run G203V drivers.

I get 80 IPM rapids and regularly cut at 20 to 50IPM.

870In/OZ in this setup has been plenty! No need for monster motors!

79

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

« on: December 03, 2012, 12:23:00 AM »

having studied how you did your stepper/planitary gearbox PDB, I will now eat crow and tell you that it is genius. I now get the relay selecting the current limiting resistor and that is really smart.

Does it tighten at 25ftlbs by rotating a set number of degrees/rotations, and if the motor stalls (stall point set by current limiting resistors) then it is tight?

Opening is at 75ftlbs, rotating a set number of degrees/rotations and it does not stall, just rotates a certain amt to effect release?

Am I getting this right?

I use G203V's, and if I were to do this, I would have to make sure the motor did not hard stop, as this would fault the drive (red light) and require a reset. Now I do resets by de-powering, It does not look as if the 203V's have the ability to be reset except for by de-powering...

is the air cyllinders down force suficcient to lock the air cylinder in position on the loosen stage, so that the R8 toolholder is forced into the fully loose position? if not, how did you accomplish the downward hammering motion to effect loosening of the collet?

80

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

« on: December 03, 2012, 12:04:59 AM »

"You're creating solutions in search of problems."

Might just be... You are not the first person to tell me that... lol...