Topics

1

General Mach Discussion / ScrewMapping

« on: May 06, 2013, 02:26:07 PM »

Hi Everyone,

I have DMM tech servos and would like to use the screwmapping function with the servo encoders.  My first question will this work?  Or do I need a DRO installed.

Second how do I get the feedback from the encoder into mach3?

Thanks,

Andy

P.s Interesting that there is little documentation or support on ScrewMapping

2

General Mach Discussion / Servo Basics

« on: January 19, 2013, 05:33:19 PM »

Hi There,

I have bought a servo system (DMM tech) I am now in a process of learning how to set this up.  Here is my problem:

I have bought oversized motors, so I can direct drive the mill.  I am trying to work out the steps per value, I have been told to use the value of 2000 as my ballscrew is 5mm pitch and 1:1 ratio this seems right to me. However this seems to limit the mill to 750mm/m do I need to modify the kernal speed or is there another way to get higher speeds?  The encoder is a 14bit enconder, any help would be appriciated as I would like to understand how to set these values and the DMM documentation is of little help in this area.

Thanks,

Andy

3

General Mach Discussion / Probing

« on: March 21, 2011, 06:47:33 AM »

After two years of modding my mill I finally have a working CNC machine (Big thanks to all here who helped me over that time)

I have a touch probe that works perfectly - however I would like to use it for edge finding.  I used to have a screen for that but now I cant seem to find it.  Does any one else have a way to edge find & center find a circle/round stock?

Many Thanks,

Andy

4

General Mach Discussion / Touch Probe skew angle?

« on: February 17, 2011, 10:01:44 AM »

Hello,

If i have a touch probe and I wanted to edge find a rectangle in a vice that has not been clocked in...can mach 3 compensate for the angle...and therefore account for the minor differences when it comes to make the cut? i.e say the rectange is not at 90 degrees on the table, but a 87.

Thanks,

Andy

5

General Mach Discussion / Enco probe stopped working

« on: November 14, 2010, 12:51:26 PM »

Hi,

I had a friend come over and wire up an Enco (Wild horse innovations) probe.  All worked and there was no problem.  I down loaded a blue screen set that already had probing built in.  I installed the screen on my workshop PC and put the probe in a chuck - Started the probe and when it got to the edge it did not trigger anything...I took the probe out and checked it over.  Visually everything seemed fine except now its not triggering anything.  Got a friend over with a multi meter and discovered that there was nothing coming out of hte port I had chosen to use.  So we move ports - this did not work either!

Is there some hidden switch or setting I have to tick to make the probe work under a different screen?

Any other ideas? 

....Help!   

Andy

6

General Mach Discussion / Steps per confusion

« on: October 17, 2010, 03:49:06 PM »

Ok s I have spent the better part of a year converting my mill to CNC, and sucess 3 weeks ago as it moved for the first time.

I had lots of problems during the conversion that were just unfortunate but hey ho I got there in the end, with pure bloody mindedness and the  help of the good folks over at CNCzone.

So now I have a problem, I have DTI'd the X and the Y axis and found that I have backlash on my new ballscrews (bugger!) the x is .2 and the y is .22

When I cut a circle I have a verry small flat on the circle, sadly even with backlash comp on (at least this time its only one side).

Hence the question about steps per...could this be the problem...I only ask as got my current figure by trail and error (160)

The ballscrews are supposed to be 5mm but as I bought them from china direct I think I have some problems with pitch they seem to measure 5.4, unless my digital calipers are broken.
Ok so 5mm pitch. 200 revs of the motor, direct drive no blets or gearing. 16 microsteps.  can anyone who is better at math than I confirm that htis should be 160.  Any other possiblites that could explain why i have one flat side one a circle.

Thanks for any help.

Andy

7

General Mach Discussion / Mill cutting too big

« on: October 31, 2009, 11:43:01 AM »

Hello,

I have recently converted a chineese mill into a cnc mill.

I have set the config up in mach 3 to run as metric.

The part I designed was done in bobcad, this is inteded to be a watch face.

as I cut the part I could see that it was not comming out as a 28.8 mm diameter but a 72mm diameter.

Can anyone help, I posted the problem in the bobcad forum and they reckoned there was somthing up with mach 3.

attached is my xml file of the mill.

Any ideas what could be wrong?

Thanks,

Andy

8

General Mach Discussion / Muti-start threading....

« on: March 31, 2009, 05:18:56 PM »

Hello All,

I have played around with normal threading and I am starting to get some confidence, I am now looking at multi start threading via cnc and mach 3.

I last spoke to Hood about this here :

http://www.machsupport.com/forum/index.php/topic,10385.0.html

My questions are as follows:

1) Do I need to have controll of the direction of the spindle?

2) Do I need a special gear train for multi start?

3) Does mach 3 multi start thread by coming in at a different angle?  Will I need to vary the speed?

I am using a cnc Sherline.

The thread I would like to cut is a four way o.75pitch 9.5mm dia - straight, not on a taper...yet.

Thanks,

Andy

9

General Mach Discussion / My First Mill and first CNC upgrade

« on: February 10, 2009, 06:08:09 PM »

I am about to buy a Milling Machine, I have selected which one I want however due to its lack of CNC I plan to convert it almost immediately.

It is an Eastern Mill so I was planning to replace the leadscrews for ball screws and then fit ... servo motors on each axis.

Two questions:

1)  I am only looking at Servos due to our 'workshop guy' at work recomending them over steppermotors...is there a real gain?

2) Can mach3 controll Servos?  If not what would be a good set of stepper motors? (I am in the UK)

Thanks,

Andy

10

General Mach Discussion / Fitting an encoder

« on: January 27, 2009, 08:31:52 AM »

Hi,

I am planning to fit an encoder (optical) to my sherline and using a slotted disk to detect what speed I am going at.

I have little electronics experiance and thefore have asked a friend to help me!

He would like to know what pin to connect the encoder to on the parallel port?

I will get this machine threading eventually.....

Thanks,

Andy

p.s A big thanks to hood for recomending and showing me this method.