Topics

1

General Mach Discussion / Spindle Control Takes 70% of processing power??? (Cant run spindle and G-Code.)

« on: May 05, 2010, 02:26:47 PM »

Hi all,

So I have been having a problem with mach recently and I couldn't figure it out for the longest time.

What happens is it seems to load down the processor and then stutter through the tool path. I re built the system ( re installed windows, mach and all my drivers). I had assumed that something had become corrupted in windows ect.

I have been running spindle control on my x3 mill for a while now, it had seemed to be intermittent, and I though it related to the G-Code file. It is most noticeable with long G-code files - 10,000 lines +, or complex 3 axis tool path moves, such as helical entry.

After messing around I noticed that just turning on the spindle maxes out the processor, for a few seconds, then it drops to around 70%, and stays there. No G-Code or anything else running. I just hit f5 to turn on the spindle.

Some Other info that might relate.
At system Idel with mach running system processing is around 2-5%
Running the same (10,000+line) gcode program, complex helical entry tool paths, with mach spindle control turned off, it used 60% of the processing power. Spindle on manual control.

I am judging processing power from the Task Manager Screen.

Mach Version R3.042.040

I am using a controller from Cnc4pc, a C6 Variable Speed Controller. It uses Step and Dir Signals to drive the spindle. I don't use direction control.

Max Spindle Speed is 3,000 RPM. I used to use this same Pc on an X2, with a 4,000 RPM spindle. No problems then...

This seems like something is just wrong, It shouldn't take that much processing to run the equivalent of 1 axis?

Any ideas suggestions on how I can fix this? (other than buy a new pc which I considered but buying anything new with windows xp (32bit).......)

Thank you for you time,

TJ

Note : Attached it my config file, if I somehow have something set really wrong that would be awesome if someone sees it.

2

General Mach Discussion / Mach Ignoring Tool Change Macro

« on: April 26, 2010, 10:19:54 PM »

Hello,
Ok So pre questions
Version R3.042.040 (Latest I think)
General settings - Run Tool Change Macro - Checked

Ok so short problem story,
I run it in VBscript editor it works fine.

I run M6 T4... or what ever tool it changes both DRO's, and does nothing.
The screenset I am using has a set of buttons that call tool change commands, click one same as above.

Full Story,
Two Key Dro/Params for the tool change to work.
1. The Tool Dro (Default tool # Dro for Mach)
2. Tool in Spindle (OEM Dro #1200, User Assigned)

It checks if they are not the same, drops off the tool in spindle, then goes to new tool and then goes back to its business.

Macro Location
/Mach3/Macros/Mach3Mill/m6Start

I am using a tweaked version of Hoss Machine's tool changer script to work with my setup.
To test I change the Mach Tool Spindle by Clicking and entering my desired tool, Then Tool in Spindle to the correct tool in the spindle. With VB Script Editor Open, Click Play... And it works like it should....

Any other tool change command = Nothing.

What is most odd is that it changes both my user DRO, and the tool DRO without actually running the script.

Attached is my config file, and the macro.

Any Suggestions or ideas?

Thank you for your time/help.

TJ

3

General Mach Discussion / Advice on TTS Power Drawbar Design.

« on: March 30, 2010, 11:36:28 PM »

Ok So in consideration of using the Tormach Tooling System, I have embarked on the journey of some sort of a drawbar for a quill type machine. In my case it is an X3.
The unknown question is how much force is actually needed on the drawbar. So I have taken a different approach to how much force. Instead of trying to figure out how much torque is needed then the problems with the screw calculations. I solved how much force it would take to yield the drawbar. I think most of us don’t pull our drawbar our and find it necking from yielding. Referring to the AISC Manual for yield strength and data.

Assuming that the drawbar is of average quality steel. A36. The yield strength is 36 KSI. (if it works for skyscrapers, Ill take it)  My Drawbar has a nominal diameter of 7/16”. (Is this always the same? Or Close?) And a ф 0.9 Factor of safety /error. The resulting force to cause permanent deformation is 5411 lbs. Now taking the assumption we are not riding on this limit. 50% should suffice. So 2705 lbs, lets round to 3,000lbs of force and say no more than 5,000lbs. It can be increased later.

So here is the idea, a stepper motor, because it can hold the torque for prolonged period of time. I have a 420 oz-in Nema 23 Stepper motor (just an extra). Use the motor to apply the force to the drawbar while cutting, vs something like spring washers.

Now how to do it?
Basic Idea, the two primary plates would be pushed apart pressing on the top of the quill and bottom of the drawbar. The drive “screws” would be 5tpi Thompson ball screws. 0.625 Track Diameter. One screw on each side to ensure a symmetrical application of force. In the Force calcs from the ball screws I used an assumed efficiency of .8
Torque(lb-in) = Force(lbs)*Pitch(in)/(2*pi*eff)

Version 1. Use a series of timing belts to reduce the speed for more torque. Common SDP timing pulleys allow for a two step total ratio of 10.24 multiplication. Through the ball screws the motor would be able to well exceed the required force, and produce a maximum of 6755 lbs. Should cover it.

Version 2. Instead of using a complex scheme of timing belts use of a worm gear drive to create the torque multiplication, which can easily obtain the required torque or even use a much smaller motor.

It does require some guide to stop it rotating, but can be added later.

So here is the idea in more of a whole. Attached are a series of Solid Works Pictures to help portray my idea.

Is it feasible? Will it Work? Comments? Suggestions? Ideas?

Thank you for your time,
TJ

PS. The CAD is just a rough idea so it can be portrayed and seen better than I can explain.

4

General Mach Discussion / Tormach TTS Belleville Spring Washer Deflection (Not Force)

« on: March 13, 2010, 01:04:40 PM »

Hi All,

After reading as much as I can, and reading through all of the thread
What The World's Been Waiting For - Yet Another Power Drawbar Design
http://www.machsupport.com/forum/index.php/topic,11826.0.html

An interesting discussion on how much tension force is needed.

But my big question is how much total deflection is needed?

If anyone is using a TTS ATC System, how much travel in the spring washers is needed to ensure a good tool release?

Thank you for your time,

TJ

5

General Mach Discussion / Lathe Tool Compensation Is there a better way??

« on: January 15, 2010, 04:55:43 PM »

Hello All,
I have a 7x14 lathe and I feel I am dealing with tool changes the really hard way. So any advice or suggestions is really appreciated.

Ok I have a Quick Change Tool Post.
So attached is a picture to help explain if I am not using the correct terms.

If my tool post is always set at a Angular offset of 0 ( 90deg to the work piece) A standard offset can be made for each tool in the X and Z. This works in my mind.

Now if the tool post is anything other than 0. Lets say 30 deg. It happens alot for me to be able to work on larger pieces.
The X and Z offsets really become a triangle depending on the angular offset. Now I cant really find a good way to measure the angle of the tool post accurately in order to just do some math to find the new tool offset and get an accurate result.

Do you all just touch your tools every time you put a new tool on the post?
Does anyone use a Electronic Method of touching off the tool post?
There has to be a better way to set this up that I am missing.


Sorry the pic has all the chips I am mid project with many tool changes, hence why I am questioning a better way to do this.

Any suggestions are greatly appreciated.

TJ

6

General Mach Discussion / Spindle Speed Jumping on Axis Rapid Movement

« on: January 10, 2010, 04:19:15 PM »

Hello All,
This is happening on both my X3 mill, and 7x14 Lathe that are CNC. They are both hooked to the same computer, So only one runs at a time.
Simply when an Axis makes a full speed rapid, the displayed speed in mach 3 jumps up to around 6-8k plus. No matter what the current spindle speed is set at. Then returns to normal once the rapid is done.

Details.
Mill - Using an adjustable opto reflector sensor looking at a sanded and black line on the spindle pulley. Happens on any axis rapid movement.
Lathe - Using an opto interrupter style sensor looking at a missing tooth type wheel for its pulse. Happens only on the X axis.
The mill and lathe are on different parallel ports. Mill - On the mother board, Lathe - PCI board.
I am using shielded cable on all the sensors.
The pull up voltage is being supplied from the PC via USB for 5v.
My motor drives are enclosed separately using a xylotec 4 axis box for the mill, and probotix side step drivers for the lathe. Both use a common 24v supply.
Index De-bounce Lathe - 20 Mill - 10 I have tried all the way up to 50 on both with no change.
The mill spindle is speed controlled via cnc4pc's C6 - Variable Speed Control Board normally. I tested this with just manual control hooked up no change.

Notes,
I am using the most recent version of Mach 3. (Just downloaded and installed before coming here. )
Spindle Speed Averaging is turned on.

This has not been an issue that has affected anything I have done until now, but doing more threading work on my lathe, sometimes mid macro it will randomly change its Feed/rev rate. Consistent to the run, but no pattern as far as I can tell. Per example, two runs of 7/8 32tpi. The code did not change, just hit start again.
27 passes 3 spring passes
Run 1 results.
Pass 1-10 - Feed Ok @ .03 in/rev
Pass 11 - Feed changed to .06
Pass 12-14 - Feed .03
Pass 15 - Feed .06
Pass 16-30 - Feed .03

Run 2 Results
Pass 1-7 - Feed Ok @ .03 in/rev
Pass 8 - Feed changed to .02
Pass 9-20 - Feed .03
Pass 21 - Feed .02
Pass 21-24 - Feed .03
Pass 24 - Feed .02
Pass 25-30 - Feed .03

Any help, advice, suggestions or ideas would be greatly appreciated.

Thank you for your time,
TJ

Edit : Note the Turn Diagnostics plugin does not seem to show this as a variation.

7

General Mach Discussion / My Lathe has gone crazy, not on toolpath, Thread Cutting Issue

« on: November 19, 2009, 11:31:49 PM »

Hello,
I have a MicroMark 7x14, retrofitted to CNC. I finally got around to getting an index pulse so I now have spindle speed to do threading. I am using an opto interrupter, with a disc cut about 45deg to create the pulse.

I have been using both the simple and complex threading wizard, but it goes diagonally starting at the correct depth then moving away.
It appears to be making the correct step in each time, but then makes the triangle away from the piece in stead of making a thread.

I took a video of the screen to show what it is doing. And the machine path matches the new white line it is drawing in the video.
http://www.youtube.com/watch?v=etNtx_wk9D0
I have the taper set to 0 deg, and in feed is at 29.5 degrees.
I have tried it in both radius and diameter mode same results.
Why is it doing this?

It also doesn't appear to be starting at the same part of the thread, like using a thread dial gauge and starting on a different number every time. Any Ideas?

Also I don't have the spindle control done yet. So why doesn't it change the feed in proportion to the spindle speed? If I speed it up or slow it down, the feed remains constant. I am assuming that I have something set wrong, any ideas?

Any ideas or suggestions are greatly appreciated.
Thank you for your time,

TJ

8

General Mach Discussion / How many pulses for a lathe spindle encoder is really needed?

« on: October 29, 2009, 02:47:53 PM »

Hello All,
I have recently converted my MicroMark 7x12 to CNC, I have been happy with the results so far, but I want to add threading and have hit a hang up on the best way to do that.

I am debating between using a slotted wheel directly off the spindle with 50-60 slots in it, or placing pulleys to speed up the speed of the encoder disk relative to the spindle in the range of 3-27 times. (Happen to have some small pulleys and needle bearing that give that range, 3, 9, or 27 times) And one index pulse per revolution.
So the big question how many pulses off a spindle encoder do you really need to make accurate two cut direction threads? I saw one encoder that had almost 2,000 PPR, so I figured more is better, but does it even matter? Will 1350 PPR make any difference than 50 PPR? If so is there a threshold and where is it?

I saw someone say that they were cutting threads with just an index pulse? Is the whole multi-pulse encoder necessary?

Thank you for your time,
TJ

9

General Mach Discussion / Timed coolant pulse? ( Now with brain questions)

« on: July 09, 2009, 02:58:24 AM »

Hello all and thank you for taking the time to answer this.

Ok so I cant find it in the manual, I am a failure at searching forums, I never can find what i want.

Is there a way to configure Mach3 so that when coolant is on.. Standard Flood that it just gives a small squirt of coolant? For example, on 1 second every 30 seconds. Other than programming in coolant on and then off again every so often in my G-code?

Thank you for the help and time,

TJ