Show Posts

1

Tangent Corner / engineer..circiut design help, automatic run/stop 1axis

« on: February 01, 2012, 11:44:34 PM »

I am using mach3, would like to make a simple circuit to do a repetitive motion on 1 axis, and eliminate the computer.I am using stepper motor, with drive. I have a variable pulse generator to control speed. have home switch and high end switch. thinking of starting with a flip flop rs to send signal to drive 0/1.(cw/ccw) the problem is the tool needs to stop at the home position, then restart the cycle when start is pushed. I am somewhat familiar with components and ic's I need a logical schematic. also does anyone know of a good freeware program for pcb design that can pe printed to a laser printer.. also may opt for a ne555 ic to go a specific number of pulses from home. then return to home..... any help would be appreciated, I love mach3, but am looking for a bulletproof circiut

to use the machine without a pc. case you are wondering it as a machine to turn a tenon on a log. so fairly repetetive, and accuracy is not a must. the only adjustment would be the length of the cut, which I was going to just use a switch, but toying with the idea of using a transistor,capacitor and a vairiable resistor (or a ne555) for the length. If you have an electronics background and are willing to help, please let me know....... thankyou, Steve

2

Mach4 General Discussion / Re: New people welcome !! Come in here and introduce your self!

« on: May 13, 2010, 04:08:23 AM »

Hi, this is Steve from north central Minnesota. I would like to know as much as possible about almost everything......I would like to meet up with local Mach users in Minnesota, I am a Machinist by trade.....am familiar by text ( motorola library) electronics.... guess looking for what most everyone else is....
build a cnc machine , call it my own? (with a little help from my friends)

9

3

General Mach Discussion / Re: mach's rounding of measurements?

« on: April 24, 2010, 01:03:52 PM »

thankyou for explanation guys

Stevo.....

4

General Mach Discussion / Re: mach's rounding of measurements?

« on: April 23, 2010, 10:31:59 PM »

Your math is correct, and your reasoning is also correct,that it doesn't realy matter.
however the answer is not 100% clear

from what i understand.......... mach will go to the nearest step without going over 410.1= 410, 410.2= 410, 410.3=410, 410.4= 410
410.5=410, 410.6=410, 410.7=410, 410.8=410, 410.9=410, 410.912432=410.

so my understanding is correct mach rounds down to the nearest whole decimal?

? without going over?

my machine has an accuracy of .0024375....

i understand that it is not a cumulative problem as all measurements are from home!!!!!!!!!!!!!!!!!!!!!!!

the question is DOES MACH ROUND UP OR DOWN!

I am sorry if i am hashing this over like crazy, but........ I am more interested in the answer, than if it really matters...

Hood, I did the math you posted... it is good.... and probly cant even measure it....... and doesn't matter, the fact it carries out to 16 digits there is only one choice .0023475 plus or minus when it hits the magical 410.500000000000000000

5

General Mach Discussion / Re: mach's rounding of measurements?

« on: April 22, 2010, 01:52:36 AM »

Am I understanding corrrectly? as in my first post all measurements are from home ( obviously).

410.34058 pulses per inch, say i need to go 1" and .003 thousandths? what if my encoder is in english, and I am using mm, how does mach handle the difference?

from your previous - post hood, mach will never go over a step.... always under?

i am not sure anyone undertsnds the question? i am not trying to move in 1/2 steps but the fact is 10 divided by 3 is what? how does mach deal with it?

the machine cannot possibly line up on 9.5 because 10 divided by 3's 3,6,9 only not 7 not 4, not 5, I am thinking prime number thing.

I am not asking mach to go to an irregular position, but the fact the gearing is irregular, mach has to choose where it will or will not go.

perhaps rounding was not correct...... linear interpolation of axis movement?

6

General Mach Discussion / Re: mach's rounding of measurements?

« on: April 20, 2010, 12:19:58 AM »

sorry .04875 div by 20, none the less, no rounding? if i was walking towards a doorway and took 2 foot steps i would need to program myself somehow because i can only walk in two foot steps, and the door is closed, so i need to stop out of the door knobs reach or walk through the door? maybe that is all those posts ( i am losing steps) . am I correct im saying the only way this program will work is to use a drive that only runs in thousandths, what if you have a metric screw? or visa versa, a metric screw wont match a us. so the program just wont work and will crash if everything doesnt matc > exactly?

7

General Mach Discussion / Re: mach's rounding of measurements?

« on: April 19, 2010, 11:49:31 PM »

.375 inch times 26 tooth gear(sync) equals 9.75 inches per revolution divided by 200 steps per revolution equals .004875 divided by twenty equals .0024375 per step of stepper motor. so my calculations i believe are correct? ( a .2 pitch gear [ a 5 tpi lead screw] will round, end up with even numbers) divided by 200 .001 per step......... i didnt think it was rocket science but maybe it is?

8

General Mach Discussion / mach's rounding of measurements?

« on: April 19, 2010, 10:44:56 AM »

How does mach handle the rounding of decimal points I am looking at using a .375 pitch 26 tooth drive gear(belt) with a 20:1 reducer, with a 200 step stepper. anyways, any formula using a .375 pitch belt vs. a .200 pitch will result in a long carried out decimal number. does mach round up, I assume all is from home. so .375 x 26 = 9.75 divided by 4000 = .0024375 per step in full step. I am not using or going to use micro-step. so to go one inch i need to move 410.34058 am i correct it will move 410 steps with an accuracy of .0024375

9