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View Full Version : Black Cat 3020 CNC not cutting square problem



Fivetide
19-05-2015, 09:50 PM
Hi guys , ideas please , I'm attempting to cut some accurate stuff and I now realise the cnc is not cutting square. basically its cutting at angle on the y axis. Picture trying to illustrate this posted below. Should I just anchor it down and bash it till its square ? I know that sounds a bit brutal but often its the only way to straighten things..

http://www.mycncuk.com/attachment.php?attachmentid=15385&stc=1

komatias
19-05-2015, 11:20 PM
Oh dear...

firstly, you will need to get yourself an engineers square. These are cheap at machine mart, get one that will fit to the table of your machine.

You will need a dial test indicator too #(DTI).

Basically you will need to measure how out of square your machine really is.

So, watch this vid to see how to square your engineers square along the X axis. It is for a vise but it illustrates the point I am trying to make: https://www.youtube.com/watch?v=WR9tLu_nGxg

With that sorted, and you square trammed in, you should see how the DTI trams along the y axis. I would suggest all the movements of the axis be done by hand.

See this one too: https://www.youtube.com/watch?v=AzhmMp2fLSw

Do the measurements to see how far out you really are before you even think of bashing anything.

If you see that the machine is within 0.02-0.03mm square, then you are facing an electronics problem where you are losing steps, the steppers are stalling or your motion control hardware is on the blink.


If you need any help give me a shout.

HankMcSpank
19-05-2015, 11:24 PM
Did you by any chance, buy this machine secondhand? (tsk...you should never do that, there's just too much shite on the market that won't mill girders - my advice would be to sell it on)

Clive S
19-05-2015, 11:41 PM
That's what I like about this forum and the yanks don't understand it "sarcasm" :applause: ..Clive

JAZZCNC
19-05-2015, 11:52 PM
Depending how far from square Just loosen the bolts and tweak it square.

IF that fails don't bother bashing it square just Bash it flat and start again.!!:joker:

Fivetide
20-05-2015, 12:23 AM
Depending how far from square Just loosen the bolts and tweak it square.

IF that fails don't bother bashing it square just Bash it flat and start again.!!:joker:

Its only a mm or maybe 1.5, I'll try your method first :)

Fivetide
20-05-2015, 12:25 AM
Oh dear...

firstly, you will need to get yourself an engineers square. These are cheap at machine mart, get one that will fit to the table of your machine.

You will need a dial test indicator too #(DTI).

Basically you will need to measure how out of square your machine really is.

So, watch this vid to see how to square your engineers square along the X axis. It is for a vise but it illustrates the point I am trying to make: https://www.youtube.com/watch?v=WR9tLu_nGxg

With that sorted, and you square trammed in, you should see how the DTI trams along the y axis. I would suggest all the movements of the axis be done by hand.

See this one too: https://www.youtube.com/watch?v=AzhmMp2fLSw

Do the measurements to see how far out you really are before you even think of bashing anything.

If you see that the machine is within 0.02-0.03mm square, then you are facing an electronics problem where you are losing steps, the steppers are stalling or your motion control hardware is on the blink.


If you need any help give me a shout.


If was only that I could live with it :) Thanks for the replies everyone.. let you know how I go on.

Wal
20-05-2015, 01:35 PM
Always best to have a square machine, but if you're still out after days of tweaking and you're able to measure the discrepancies, you might consider software correction:

http://korovievskitchen.blogspot.co.uk/2010/07/x-y-table-skew-compensation-in-emc.html

That link's for EMC (Linux CNC) - I imagine that there's also a way to achieve this in Mach.

Once again, there's no substitute for a mechanically accurate, well set-up machine, but if you're only able to make ham-fisted adjustments that aren't working for you, then this might be an option.

Wal.

Fivetide
20-05-2015, 06:45 PM
Always best to have a square machine, but if you're still out after days of tweaking and you're able to measure the discrepancies, you might consider software correction:

http://korovievskitchen.blogspot.co.uk/2010/07/x-y-table-skew-compensation-in-emc.html

That link's for EMC (Linux CNC) - I imagine that there's also a way to achieve this in Mach.

Once again, there's no substitute for a mechanically accurate, well set-up machine, but if you're only able to make ham-fisted adjustments that aren't working for you, then this might be an option.

Wal.

That was my plan B but I might actually do as a plan A instead, I can actually compensate for it in AutoCad...thanks :fox:

Fivetide
22-05-2015, 03:50 PM
Bashed it straight, did a test, top male and bottom female with a -0.25 offset , fit was perfect.. sledge Hammer ftw !

Clive S
22-05-2015, 04:10 PM
Do you have a vid of the system you used:hysterical: ..Clive