Messages

2781

General Mach Discussion / Re: Encoder Problem

« on: March 17, 2012, 09:08:22 AM »

Just want to put this discussion into perspective.
There is part tolerance and then there is a some reference point tolerance.

You currently say the reference point can be found at a repeatable tolerance of  0.0001 to 0.0002" and you desire a
"last word " or confirmation of that. So if using the encoder,12000 pulses, and the resolution would be
0.000083". So if you had a dro which displayed .000100 difference based on a move and another that displayed .000083 there would be a difference of  0.000017" just based on resolution. I won't even get into the +- of the resolution and practicality for talking purposes.

So from an absolute value which one is correct? Answer is neither.

One needs a standard to relate to. What is the standard you want to use?
The only traceable standard I have for reference in the micro range ( $1250 for a calibration and i think around $3500 new and calibrated) glass standard. You need to view using a 1000x microscope. It's accurate to .000003" @ some defined calibration conditions.

So one may touch off say a 100 times, and then using  some displayed value compared to  the  traceable standard,  figure out just how how accurately / what tolerance / repeatablity they have  in touching off.   Unless you just want to use the encoder as your "standard" which really dosen't have a absolute defined basis and is rather meaningless when compared yet to another non defined value.

Nice stuff to play with on a rainy day and nothing to do.........
RICH

2782

LazyTurn / Re: Threading Deviation

« on: March 16, 2012, 04:48:11 PM »

To attach something, after you click the preview button, click the Additional Options, then Browse button which will provide for selecting the file you want to upload.
RICH

2783

LazyTurn / Re: Threading Deviation

« on: March 16, 2012, 04:34:16 PM »

What version of Mach are you using?
Post the gcode file.
Post your xml file that you are using.

RICH

2784

General Mach Discussion / Re: Encoder Problem

« on: March 16, 2012, 06:27:25 AM »

Brian,
What do you want to do accomplish by adding the encoders?
RICH

2785

General Mach Discussion / Re: Can't raise feedrate past 50 in./min. without messing up... suggestions?

« on: March 15, 2012, 06:41:12 AM »

Mike,
Here is a link to a stepper calculator:
http://www.machsupport.com/forum/index.php/topic,16315.msg110286.html#msg110286

You can vary the axis inputs and see the affect of the changes as it relates to steps per , IPM and  motor rpm, resolution, etc.
Than you can use the info to see where you are on the motor curve. Multi start screws give you increased axis speed
and lower motor rpm which allows for increased torque. Actualy you are interested in power. All of this is a comprimise since each change affects another.Be carefulll on the motor curves as to what they are based on. I didn't even mention servos since you have G201's. What modifications you want to do to achieve something is up to you. Each part of the SYSTEM must be comlpiment  the rest of the system.  
RICH

2786

General Mach Discussion / Re: Can't raise feedrate past 50 in./min. without messing up... suggestions?

« on: March 14, 2012, 07:16:25 PM »

Mike,
Didn't see a motor curve for the 425's but did find one for the 156's you currently have.  Without a motor curve  at the supplied voltage, amps, and pulse rate one would use we would be only guessing the preformance to be had by a motor unless you had a very similar system to compare to. So i am going to ramble some in general.

Using a G201, micro stepping at 10,  2:1 ratio, 8 tpi screw gives you the 32000 steps per inch.  At 50 ipm your current motor
rpm would be 800. At that rpm you are on the bottom of the motor curve in terms of torque. At 50 IPM you have about 55 in oz
available and at 70 ipm you skip because the torque drops to maybe 40 - 45 in oz. That suggests that you need 50 in oz to move
the axis and it leaves no power for acceleration and machining. Make note that the motor curve is for 30V & half step, But irrelevent your motors are just turning fast with no torque. 40 oz in can be achieved with two fingers  and light pressure to turn something.

Should you change out the screws to multi start you can reduce the rpm and move the motors operating rpm into a higer torque region. 2 start screws would almost / maybe double the torque available. The calculated resolution is still good but you'll never achieve it with the screws you currently have. Would  guess that you could live with .001" resolution with wood working and probably even less.  

If you look at the 382 in oz you'll find a curve but that curve is for a differnet motor 500 in oz and Keling can't confirm what it's for. You can still look at the curve to see it's affect  on incresaing the torque and feedrate. Never found anything which provides power required to do wood working.

There are router users in here and probably someone will be additive to this post.

RICH


  

2787

General Mach Discussion / Re: Can't raise feedrate past 50 in./min. without messing up... suggestions?

« on: March 13, 2012, 04:33:22 PM »

Just making a pit stop on the forum so maybe get back tonight ( boys monthly night out takes precedence).
RICH

2788

General Mach Discussion / Re: Consistency

« on: March 13, 2012, 12:17:22 PM »

Your questions are being addressed in another thread. Please do not start another one on the subject.
RICH

2789

LazyCam (Beta) / Re: LAZYCAM Pro - Permanent Beta

« on: March 13, 2012, 12:10:45 PM »

might ArtSoft give out a FREE license for LAZYCAM Pro so we can actually use it for pocketing, offsetting, etc. ?

Only Artsoft can answer that question.

Is there a way to transfer a license if someone would like to sell theirs?

Not that I know of.

guess I may have to go evaluate CamBam

It's free. Don't be so lazy......

RICH

2790

General Mach Discussion / Re: Consistency

« on: March 13, 2012, 06:52:46 AM »

You first need to get the steps per unit correct. Find the correct setting based on going one direction and distance only, make sure you take out any backlash. Then you can check for backlash by doing two opposite moves for that same distance.

Are you using steppers or servos?
RICH