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Messages - Dan13

351
Hmm... strange, you are right it doesn't rotate the part and actually does some odd moves here too. Could be that I had a different version of the code on the machine itself, may be I modified it there though I can't see something wrong with this one. Will check later if I have a different version there as it did work and produce the above.

Yes, seems like arcs would make it a lot easier. A bit hard to visualise, but it makes sense.

Dan

352
No. I think we are on the same page. My code works exactly like in this video. In the picture above, the square rotates counterclockwise so at first I start from point A and go outwards towards point B and as I go past point B, I start to move inwards. This is why I have to subs in the code - O101 for the first and O102 for the second.

What's interesting is that in the end of the video they show the white plastic parts and their square looks pretty similar to mine - with corners rounded and flats not being flat but rather a bit concave in the middle (see attached photo. Not the best quality, but you can see what I mean). Only difference is that mine was twisted in the Z in addition to this (again see the picture). Then what's interesting is that on the next photo they show perfect polygons in metal which don't look like have been made on this machine.

Dan

353
Looks like it just fits there. Are you going to rotate it or leave it that way, facing the gate, so you have access to the cabinet?

I too didn't realise the table didn't move at all. You posted it earlier, but I thought the column was only moving in the Y and the table was doing the X. It is interesting to have a closer look at the mechanism and especially the guards.

Dan

354
Hi Terry,

Took a look at the code. Since the X axis has to change speed as the A rotates (since tangential speed changes as you change distance from centre) I broke the X axis moves into fractions and used a sub to repeat it. Please see attached screenshot, I hope it will clarify what I meant. In the picture, a, is my X variable and it changes with the angle. I call in the code the ABsegment as single segment and this is then broken into smaller segments depending on the resolution.

I have also made a couple of changes to the code so it will match the sketch and be more readable. Here is the revised one:

%
G0 G49 G40  G17 G80 G50 G90

(A axis is in revolution mode)
(Program in Diameter mode)

#1 = 6   (number of sides)
#2 = 10  (distance across flats)
#3 = 120 (feed: mm/min)
#4 = 0.1 (Z feed per revolution)
#9 = 10 (length along Z)
#17 = 10 (resolution - number of segments in half flat size)

#5 =  [360/#1] (root angle)
#6 =  [2*[0.5*#2]/cos[0.5*#5]] (distance across corners)
; Not used #7 =  [[0.5*#2]*tan[0.5*#5]]  (half side length)
#10 = [0.5*#5] (single segment revolution angle of A axis)
#11 = [#10/#17] (single rotation fraction angle of A)
#16 = #11
#12 = [[-1*[#4/[#1*2]]]/#17] (Z advance per segment)
#13 = #12

G0 X[#2+1] A0
G0 Z1
G1 X#2 Z.1 F#3

#14 = [-1*[#4/#1]] (Z advance per main subroutine execution)

#15 = FIX[#9/#14] (Number of subroutine executions required - 'L')

M98 P100 L#15

M30

O100
M98 P101 L#17
#16 = #11
M98 P102 L#17
M99

O101
G1 X[2*[0.5*#2]/cos[#16]] A#16/360 Z#13 (A converted fromdegrees to revolutions)
#16 = [#16 + #11]
#13 = [#13 + #12]
M99

O102
G1 X[2*[0.5*#2]/cos[0.5*#5-#16]] A#16/360 Z#13  (A converted fromdegrees to revolutions)
#16 = [#16 + #11]
#13 = [#13 + #12]
M99
%   

355
Terry,

The code cuts all sides per revolution - spindles rotates continuously in one direction only. I will have a look later and try to refresh my memory of the math I did.

I wouldn't trust the toolpath display either. I was experimenting with a delrin bar and it was cutting the shape, but the corners were getting rounded and it was getting twisted along Z.

Dan

356
Hi Terry,

I didn't really care it being slow. Sometimes it's better leaving it for 15 minutes to do its job than switching for a second operation on the mill.

Here is what I had:

%
G0 G49 G40  G17 G80 G50 G90

(A axis is in revolution mode)
(Program in Diameter mode)

#1 = 6   (number of sides)
#2 = 10  (distance across flats)
#3 = 120 (feed: mm/min)
#4 = 0.1 (Z feed per revolution)
#9 = 10 (length along Z)
#17 = 10 (resolution - number of segments in half flat size)

#5 =  [360/#1] (root angle)
#6 =  [2*[0.5*#2]/cos[0.5*#5]] (distance across corners)
#7 =  [[0.5*#2]*tan[0.5*#5]]  (half side length)
#10 = [[0.5*#5]/360] (single segment revolution amount of A axis)
#11 = [#10/#17] (single rotation fraction of A)
#16 = #11
#12 = [[-1*[#4/[#1*2]]]/#17] (Z advance per segment)
#13 = #12

G0 X[#2+1] A0
G0 Z1
G1 X#2 Z.1 F#3

#14 = [-1*[#4/#1]] (Z advance per main subroutine execution)

#15 = FIX[#9/#14] (Number of subroutine executions required - 'L')

M98 P100 L#15

M30

O100
M98 P101 L#17
#16 = #11
M98 P102 L#17
M99

O101
G1 X[2*[0.5*#2]/cos[#16*360]] A#16 Z#13
#16 = [#16 + #11]
#13 = [#13 + #12]
M99

O102
G1 X[2*[0.5*#2]/cos[0.5*#5-#16*360]] A#16 Z#13
#16 = [#16 + #11]
#13 = [#13 + #12]
M99
%

See if you can read it. It has been sometime since I wrote it and it will take me sometime to understand what I meant myself ;)

Dan

357
Yeah, very nice!

Dan

358
Some time ago I was playing with the idea of cutting squares and hex shapes on a lathe using a servo spindle and a synch move of all it with X and Z. I wrote a parametric Gcode but never got it perfect - a square was coming out with rounded corners and was twisted along the Z. Was not able to figure what was wrong with the code. Would you be interested contemplating this?

Dan

359
General Mach Discussion / Re: Beginner Questions
« on: October 13, 2012, 11:26:47 AM »
Did you download the PDF manual? It will answer all (or most) your setup questions.

Regarding the Reset, Mach3 checks if the Estop input signal is active and if it is it wouldn't reset. So unless you have an actual Estop input just set in Ports and Pins the Estop to Active low.

Da

360
Glad for you brother :)

As to beta testing, I think you will have to contact Brian directly. He mentioned on the Yahoo group some time ago that beta phase is close, but I don't think they got there yet.

Dan