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View Full Version : x,y and z axis problems on 3040T



zxrjohn14
11-10-2017, 08:40 PM
Hello all.
I have a Cncest 3040T, using Autocad to DXF, SheetCam for GCode and Mach3 for Machining.
There is a thread on here where kev2960 has a similar problem, but it's not solved.
when cutting a circle within a circle in 9mm MDF, at 1mm plunges, the first pass is perfect, then with each plunge it shaves a bit extra off the south side of the piece and steps the north side of the piece, by approx 0.3mm, giving an eliptical shape when finished, and when returning to the home position, its not where it started, it's north east of its original point by some 6mm or so. The DRO reads 0,000 on all axis.
the settings ive tried in mach3 motor tuning are:
steps per velocity acceleration notes
400 2000 300 all as per set up manual, awful results
410 2000 300 same rusults
405 2000 300 a tiny bit better
405 1500 200 same as before
405 1000 100 awful and really really slow
410 1000 200 same as the rest but landed no where near its home position

any advice or settings much appreciated

Kev2960
14-10-2017, 06:07 PM
Hi there, Yes your quite right it has been a mission to get my machine running as it should, but now i can't fault it. mine is a 6040 but try the settings i've figured out.
Port 1 35000 Hz
Motor Tuning;
X Axis 320 1500 400
Y Axis 320 1500 400
Z Axis 400 1500 400
Set The step Pulse & Dir Pulse both to 5

Motor Outputs
screen shot won't upload at the moment but these are the settings i've got

X En (green Tick) 2 3 dir Low Active
y En 4 5 dir Low Active
Z En 6 7 dir Low Active

(Your pins may be different from mine)

When you start Mach3 change the feed rate from 6 to 100, this will give you 1500 mm/m rapid

Hope this helps
Kev

zxrjohn14
14-10-2017, 08:08 PM
Much appreciated, Kev.
I'll try those settings when I get back from holiday.
Was it the settings that were causing your issues?
Was it trial and error to get to those figures?

Kev2960
15-10-2017, 01:00 AM
Yeah kind of methodical trial and error, that doesnít really make sense but by changing one thing at a time I got there took about a month. In a recent post of mine I made some pointers to check that each stepper was returning back to zero. Just put a felt pen mark on the wheel of the stepper and a piece of cardboard as a pointer youíll probably find the steppers donít return to zero.

Kev2960
15-10-2017, 01:11 AM
Can you send me a photo of your machine or a link so I know what it looks like?

zxrjohn14
15-10-2017, 10:00 AM
Awesome idea Key.
This is the exact machine I have Look at this on eBay http://www.ebay.co.uk/itm/282545167242
I bought it from a guy who didn't manage to use it so was brand new.
It seems weird with mine as when the first plunge is cut, it's perfect but the more plunges it does, the further it creeps north East.
I'm going to try your settings for it though and see what it does.
Edit:
I've ordered the Kress 1050 which should be at home when I get back

Neale
15-10-2017, 10:13 AM
One slightly odd thing I see in your settings. You appear to have "active low" selected for step and direction on all axes. That's fine for direction - change this and the machine reverses direction on that axis. However, "active low" for the step signal is unusual for the usual breakout boards/stepper drivers. The effect is that everything seems to work fine, but each time the machine changes direction on that axis you lose one step. Enough direction changes and the axis gradually seems to drift in one direction, fairly repeatably. Your test pieces don't seem to have that many direction changes compared with the overall error but as it's such an easy thing to change (and change back if it makes no difference) you might like to try it. I had this problem on the Z axis on my own machine; didn't notice a problem for simple profiling constant-depth cuts but when I started some complex 3D cutting, the cut depth gradually increased.

(Misread post - Kev's post says "dir active low", not "step". But worth checking that step is active high anyway.)

Kev2960
15-10-2017, 11:23 AM
Youíve ordered a Kress 1050 ?
Didnít your machine have a spindle when you got it

Kev2960
15-10-2017, 01:51 PM
Here are the screen shots of my set-up, i'm not saying they will work for your's but it's worth a go

Photo 1 Motor Outputs
Photo 2 Input Signals (for home and limit switches, I have only home switches)
Photo 3 Output Signals
Photo 4 Encoder/Mpg's (handwheel, if you have one)
Photo 5 Spindle Set-up

zxrjohn14
15-10-2017, 04:50 PM
The "motor" is a Dremel type of thing and is utterly useless for my needs.

zxrjohn14
20-10-2017, 09:28 PM
I received my Kress 1050w today and put Kev 's setting into mach3 as he suggested and did an air cut first followed by my first aluminium piece. All is perfect!
I'd like to say a massive thank you to you Kev for helping me. I don't know how or why it's working but it is.
I'm very happy :)