Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: Smtl on October 27, 2010, 07:26:40 PM
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I Guys
I am getting lost with the “steps per” calculation. I am kind of an artist who always dreamed about having a CNC to carve my 3d draw.
Now I have one, but calculation are not my business. I will if I must, but I’ll have no fun in it. And it will take me a long time.
Those are my steppers
http://www.xylotex.com/425ozin.htm
This is my controller
http://www.xylotex.com/XS3525V202.pdf
I have 10 treads per inch acme lead screw. Single start.
What do I need to put in the calculation? What did I lack? If you happen to have the result right away, ill take it!
And another question, my lead screws are in inches but I'll really like to set up my mach3 profile all in metric. Is there some problems with this?
TX
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TX,
Here is the link to a calculator:
http://www.machsupport.com/forum/index.php/topic,16315.0.html
RICH
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I'll really like to set up my mach3 profile all in metric. Is there some problems with this?
No problem and you can use the calculator in metric. Make sure you set Mach for metric.
RICH
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WOW looks very useful! TX
But there is a butch of abbreviation! Why did you put so much of them?
Ok I’ll start my investigations.
TX again
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The calculator should get you going but its easy enough to work out yourself.
10 TPI screw would equal a metric pitch of 25.4/10 =2.54mm
So to calc it will depend on what stepping the dip switch on the drive is set to but we will say 8 for this calc
200 steps for motor, multiplied by 8 microsteps for drive =1,600 per motor rev, assuming no gearing between motors and screw the pulses needed to turn the scrw one rev would be the same. So one rev of the screw moves the axis 2.54mm and it takes 1,600 pulses to do that so 1,600/2.54 is 629.92125965 which is the amount of pulses (steps) required per unit (mm in this case)
Hood
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Why did you put so much of them?
The spread sheet was done by another member. Every discipline has it's owne language, so welcome to CNC.
You can't escape it and need to have some understanding of what's involved to bring your artistic work
to reality. So enjoy the learning experience even if it is not your cup of tea ........ ;)
RICH
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YAAAHHHHOOOOO!!!
It worked!
I got on calculating myself, made a lot of mistakes, took a lot of time but I discovered that my CNC step per MM was exactly the number given by HOOD divided by 2.
So its 314,9606298 per MM.
Now, with a stupid G-code I just wrote, I can see my CNC going from home to the complete other side of the table and get back!!!!!!YYAAAHHHOOOOO
WOW. This is a very good Forum.!!!
TX both of you
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So that means the dip switches on your Xylotex are set to 1/4 stepping :)
Great news you have it running :)
Hood
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Yep I am running!
I made my first cut, a nice square on foam!
http://www.youtube.com/watch?v=PaaLoyeaCPs
YYYYÉÉÉÉ
Now the real work start. Understating G code and figuring how to carve my complex lightwave draws in wood or plastic!
TX again
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I can still remember the first cuts I did, its a great feeling :)
Hood
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The calculator should get you going but its easy enough to work out yourself.
10 TPI screw would equal a metric pitch of 25.4/10 =2.54mm
So to calc it will depend on what stepping the dip switch on the drive is set to but we will say 8 for this calc
200 steps for motor, multiplied by 8 microsteps for drive =1,600 per motor rev, assuming no gearing between motors and screw the pulses needed to turn the scrw one rev would be the same. So one rev of the screw moves the axis 2.54mm and it takes 1,600 pulses to do that so 1,600/2.54 is 629.92125965 which is the amount of pulses (steps) required per unit (mm in this case)
Hood
sorry for asking but im nwe in this and i want to learn, how to get the info if my machine doesnt have leadscrew, my machine have rack and pinion and a reducer gear box, how do i get the tpi or the number to get my math going? in order to use the calculator.
Thanks for the time
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Hi,
you'll need the following:
1) the pitch of the rack
2) the reduction ratio of the geabox
3) the bely reduction from the stepper to the gearbox, if there is one.
4) the microstepping you are applying.
Craig
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thanks a lot for your fast reply, let me confirm that dsta and ill let you know,the ratio im still confirmthat and the driver is leadshine driver im searching for the model so i can know the microstepping
sorry for this but pith of the track do you mean the number of teeth in an inch in the rack right? and what do you mean with bely redution? if my reducer gear box have a belt? or something.
Again sorry for the question, i just want it to learn more abouth this.
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Hi,
with most drivers you decide what microstepping you want and apply it by flicking Dip switches on the drive. About 8 or 16 microsteps is about right, that means
that it would take 1600 or 3200 pulses to cause the stepper to rotate one complete revolution.
The pitch of the rack is exactly that, so many teeth per inch or 1.5mm between teeth some such measurement.
If the stepper is hooked direct to the input shaft of the gearbox then don't worry about the belt reduction, you don't have it.
Craig
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Thanks again, let me confirm the data of what you told me and i will post it here but again thanks for the fast reply.
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may i ask you another question, if my machine is in metric, the tpi need to be divided in 25.4 in order to get the tpi in metric right? so if i get 2540 tpi will be 100 mm steps per in metric, am i correct?
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Hi,
may I suggest that you get the most accurate data you can and we can convert that to whatever is needed thereafter.
For instance you may have a manufacturers specification, say 8 teeth per inch, or maybe a pitch of 2.34mm or whatever. If its manufacturer supplied it is likely
accurate and prevents you making a measurement error.
In absence of manufacturers information you are going to have to measure it.
I would suggest taking a marker and marking the tip of a tooth. Then count ten 'gaps' and mark the tip of the tooth that bounds those ten gaps. Then measure
the distance between the marked teeth. The pitch will be (distance in mm)/10.5
Craig
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Hi,
tpi, or threads (or teeth) per inch was and still is a common way to specify threads and gears in inch units.
The norm in metric units is pitch, which is the distance between adjacent threads.
Both are a measure of the same thing but expressed in exactly opposite ways and causes a lot of confusion.
Imperial: number of features in a given distance
Metric: distance between adjacent features
I'm happy with either but what is important is that it be accurate.
Craig