Messages

21

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

22

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

« on: October 29, 2009, 04:17:11 PM »

Is there type of threading you cant do? Or any limitations you have found using only 1 pulse per revolution?

Thank you,
TJ

23

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

24

General Mach Discussion / Re: Timed coolant pulse? ( Solved mostly)

« on: July 09, 2009, 03:52:36 PM »

Wow never mind I just decided to try and see very easy.

If anyone wants to use a timed pulse setup here is how to do it.

Set the flood on output to an unused output.

Make a new brain.

|Input - Led - 13 - Flood on | -> |Timer Module A = 0, B = Pump On Time, C = Off Time, Accumulative - Off, Single Shot - Off| -> |Terminate - Output - Your coolant pump output number |

and voila

Can I use a brain variable from a dro to change the pulse times?

Thanks,
TJ

25

General Mach Discussion / Re: Timed coolant pulse?

« on: July 09, 2009, 03:35:24 PM »

Is there anywhere I can go to see some documentation on the brains? My brain is having issues with this brain....(yeah I know its probably been said 100 times)

So I found I can look at the coolant LED status.

I am thinking I can start the timer module based on that.

But is this like linear logic?

For example Input Coolant LED -> Timer Module -> Coolant Pump Output (Will this simply be on or off based on the timer status? eg abc settings)

Do I need to reset it each time?
If it hits a false will it stop and then go back to the start or do I need to force it to loop?
Will it stop mid timer action if the LED is no longer on?

Do I have to compare it to a variable to get a true of false to move on?
Coolant LED -> Timer Module -> Comparator action (see below) -> Coolant Pump Output

 (What is the timer passing in here? Its current time? The pulse count?) - > Comparator Action
-> |Formula - A % 30 (A modulus 30, so its 0 every 30 seconds) | -> | Compare Imm - A == 0 if this does not satisfy does it just stop here or will it wait until it does satisfy the conditions? |  - > |Output - Will this be on if it makes it here and off if not? Or does it have to be turned on and off? |

Thanks for the help with this.
TJ

26

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