Re: [Emc-users] 5-axis table-table kinematics: G54 offsets (Andy Pugh)
2011/12/27 Rudy du Preez r...@asmsa.co.za:
I am confused with G54 to G59. Look at the following code and run it on a
simulation setup with Axis C rotation added:
G10 L2 P1 x0 y0 C0
G10 L2 P2 x10 y10 C0
G10 L2 P3 x0 y0 C-45
o100 sub
G0 x25 y0
G1 x30 f200
G1 y5
G1 x25
G1 y0
o100 endsub
g54 G0 x0 y0 C0
o100 call
g55 G0 x0 y0 C0
o100 call
g56 G0 x0 y0 C0
o100 call
G54 x0 y0 C0
m30
In trivial kinematics it does three squares, the first one in untransformed
coordinates, the second one with a shift of origin to x10 y10, and the 3rd
one with a rotational shift of -45 degrees. All seems as expected.
Good to hear. So do I understand that the issue is solved?
In world mode of a 4-axis system, with the inverse kinematics:
joints[0] = cos(C)*x - sin(C)*y; joints[1] = sin(C)*x + cos(C)*y
and forward kinematics:
x = cos(C)*joints[0] + sin(C)*joints[1]; y = -sin(C)*joints[0] +
cos[C]*joints[1]
it does the first and second squares in the same way as with trivialkins,
but the 3rd square is placed in the original world coordinate position, even
though the C-axis has been turned -45 degrees.
My question is: why does the G55 shift work the same but not the G56?
Short answer to Your last question - because You are screwing it up.
For a longer answer to Your question I would urge You to return to my
initial question - to disclose full information of what You did and
what results did You obtain. The same goes here:
1) from Your email I do not understand, if You have noticed, that it
is completely different kinematics module. And I am sure that You
definitely have not noticed that it's goal is to _simulate_ rotary
table.
2) You have not said, if You did load rotatekins with appropriate line
in Your HAL file - if the module is not loaded, You cannot expect it
to work :)
3) You copied out 2 lines of totally different kinematics module and
ignored everything else. So I would like You to take account _all_
lines that are in rotatekins forward and inverse kinematics:
http://git.linuxcnc.org/gitweb?p=emc2.git;a=blob;f=src/emc/kinematics/rotatekins.c
18 int kinematicsForward(const double *joints,
19 EmcPose * pos,
20 const KINEMATICS_FORWARD_FLAGS * fflags,
21 KINEMATICS_INVERSE_FLAGS * iflags)
22 {
23 double c_rad = -joints[5]*M_PI/180;
24 pos-tran.x = joints[0] * cos(c_rad) - joints[1] * sin(c_rad);
25 pos-tran.y = joints[0] * sin(c_rad) + joints[1] * cos(c_rad);
26 pos-tran.z = joints[2];
27 pos-a = joints[3];
28 pos-b = joints[4];
29 pos-c = joints[5];
30 pos-u = joints[6];
31 pos-v = joints[7];
32 pos-w = joints[8];
33
34 return 0;
35 }
36
37 int kinematicsInverse(const EmcPose * pos,
38 double *joints,
39 const KINEMATICS_INVERSE_FLAGS * iflags,
40 KINEMATICS_FORWARD_FLAGS * fflags)
41 {
42 double c_rad = pos-c*M_PI/180;
43 joints[0] = pos-tran.x * cos(c_rad) - pos-tran.y * sin(c_rad);
44 joints[1] = pos-tran.x * sin(c_rad) + pos-tran.y * cos(c_rad);
45 joints[2] = pos-tran.z;
46 joints[3] = pos-a;
47 joints[4] = pos-b;
48 joints[5] = pos-c;
49 joints[6] = pos-u;
50 joints[7] = pos-v;
51 joints[8] = pos-w;
52
53 return 0;
It is not very hard to notice, that in forward kinematics in c_rad
definition there is minussign before joint[5] value. And from
inverse kins we see that joints[5] = pos-c.
What does it all mean? It means that both rotations cancel each other
out and that is why You would not get any rotation. As the description
of that kinematics module says: Simple example kinematics for a
rotary table in software. It is not meant to be used with machines,
which do actually have rotary table.
So if I understand correctly, You already have a working solution with
trivkins. Is that correct?
Viesturs
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Re: [Emc-users] Another off the wall thought
On 12/26/2011 12:34 PM, gene heskett wrote: I guess I've finally reached that age where everything I like is either illegal, fattening, or immoral. Sigh... Or broken... ;-) Cheers, Gene mark -- Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Servo drive?
2011/12/23 Viesturs Lācis viesturs.la...@gmail.com: Hello, gentlemen! I have 3 servo motors and I am looking for appropriate servo drives for them. I managed to get a technical specification of my servo motors: Motor type: T3-0130-60-560 Winding number: 01-00111 Rated Speed: 6000 min^-1 DC Bus Voltage: 560 V Nominal AC Voltage: 330 V Rated Motor Voltage: 309 V Rated Torque: 1,00 Nm Rated AC Current: 1,40 A Stall Torque: 1,30 Nm Stall AC Current: 1,67 A Peak Torque: 5,2 Nm Peak Current: 7,2 A Max. Speed: 12000 min^-1 EMF Constant: 47,0 V/1000 Torque Constant: 0,78 Nm/A Terminal Resistance: 12,7 Ω Terminal Inductance: 21,5 mH Number of poles: 6 El. Time Constant: 1,7 ms Mech. Time Constant: 2,4 ms Thermal Time Constant: 30 min Rotor Inertia: 0,65 kg*cm^2 Can any one suggest me, what is the rated power of these motors? I thought that it is calculated this way: Rated power = rated voltage * rated current Andy Pugh told me that motor power could be calculated also this way: Power = 2 x pi x torque x rps How do they actually calculate that? Thanks in advance! Viesturs -- Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Another off the wall thought
On Tuesday, December 27, 2011 11:52:23 AM Mark Wendt did opine: On 12/26/2011 12:34 PM, gene heskett wrote: I guess I've finally reached that age where everything I like is either illegal, fattening, or immoral. Sigh... Or broken... ;-) Well, with my sugar, I'd prefer to call it worn out. :) Cheers, Gene mark Looking at the current integrators manual, encoder modules pages, I am wondering how hard it would be to develop a stop signal that would be a combination of the spindle not on, but getting output from the encoder indicating the spindle is still coasting at some very slow speed? I'd like to be able to sequence the following set of spindle states: 1. Spindle off, nothing from the encoder = false 2. Spindle enabled, nothing from encoder in 50ms or so = e-stop error true 3. Spindle on, pulses from encoder = false 4. Spindle off, pulses from encoder = true So that is 2 signals, one of which goes to the e-stop, the other to enable a relay that will feed maybe 2 amps dc through the motor to effect a 'suicide braking' effect on the motor for as long as its turning even if the spindle is being positioned by hand. The idea would be to achieve the quickest reversal of the spindle motor of this lathe I'll buy in the next couple of months, so the sequence in the g- code would go something like this: Hit end of fwd threading motion loop programed, stop spindle, which will make condition 4 true, back out x by .1, make interpreter wait until condition 4 above = false, the spindle has effectively stopped. enable spindle in reverse to retract to start of thread, with z following the encoder in all cases, or... It might be better if z stopped following spindle lock at the stop point, then became locked again, when the spindle has retraced to that point in the reverse direction. This would prevent digging into an adjacent, larger diameter section at the end of the loop while x is retracting and the spindle hasn't quite stopped. I have no clue just yet, if hal can actually sequence such a scenario or not, so much study of my fresh manual printout will need to be done. If it can't, no use me spinning my wheels. Or, since threading is dependent on the index pulse to synch z to spindle anyway, would it actually be better to just stop/unlock z, retract x, retract z to start, then lock on the next index pulse to start the next cut? I can't see this as workable unless the entry of the thread is at least a turn out into empty space just to let z accelerate and get in step since there will be a large following error at the start. Not having any really effective way to speed adjust this induction motor so the spindle can be effectively stopped in the last 1/4 turn to the end point, from perhaps 1000 rpm when doing small threads, may be making the problem worse in my mind than it is in practice. Discussion? Or should I spend umpty bucks for a 1.5 hp vfd toss this 1 hp motor into the pile in the corner to run a cooling fan someday? Googling says this option starts at about $400 for 1.5hp, rising rapidly. Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene Vote anarchist. -- Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 5-axis table-table kinematics: G54 offsets (Viesturs)
Viesturs No I did not screw it up. My kinematics equations are an abstract from a full XYZACkins program with dx,dy,and dz axis offsets, which have been tested and has worked for a long time cutting impellers and other stuff. I wanted to keep it simple to address the issue of G54, to G59 offsets. What you did not notice are the signs of the sin(C) functions. It is a well known fact that sin(-C) = -sin(c) And cos(-C) = cos(C). I think my XYACkins is correct. It is the same as rotatekins when A, dx, dy and dz is zero. I want to be able to use offsets of C (and possibly A) while in world mode. Whereas it works OK in joint coordinates with trivkins, it seems to function differently in world mode using XYZCkins. My example code in the previous mail explained all that. Try the example code with rotatekins and trivkins and see what you get. Rudy -- Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Another off the wall thought
On 27 December 2011 17:53, gene heskett ghesk...@wdtv.com wrote: Not having any really effective way to speed adjust this induction motor so the spindle can be effectively stopped in the last 1/4 turn to the end point, from perhaps 1000 rpm when doing small threads, may be making the problem worse in my mind than it is in practice. Indeed you are. G76 simply stops moving in Z, rapids out, and returns to the start of the thread. No need to stop/start the spindle. You get a partial-turn run-out at the end of the thread, but the full thread can go basically as close to the shoulder as you dare. -- atp The idea that there is no such thing as objective truth is, quite simply, wrong. -- Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Another off the wall thought
On Tuesday, December 27, 2011 01:46:39 PM andy pugh did opine: On 27 December 2011 17:53, gene heskett ghesk...@wdtv.com wrote: Not having any really effective way to speed adjust this induction motor so the spindle can be effectively stopped in the last 1/4 turn to the end point, from perhaps 1000 rpm when doing small threads, may be making the problem worse in my mind than it is in practice. Indeed you are. G76 simply stops moving in Z, rapids out, and returns to the start of the thread. No need to stop/start the spindle. You get a partial-turn run-out at the end of the thread, but the full thread can go basically as close to the shoulder as you dare. That is good Andy, so its obvious I am looking at the wrong book. I need to setup 2 libraries I guess. I'll see if I can fix that, its time I did some housecleaning in the shop anyway. I'd like to get rid of a radial arm saw, its oversized table is nothing but a mess collector and has been since I got a table saw about 8 or 9 years ago. Its a 10 Dewalt, decent shape, runs fine smooth but probably 35 YO, somebody make me an offer and help me carry it to your vehicle, please! Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene So why don't you make like a tree, and get outta here. -- Biff in Back to the Future -- Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 5-axis table-table kinematics: G54 offsets (Viesturs)
On 27 December 2011 18:38, Rudy du Preez r...@asmsa.co.za wrote: I want to be able to use offsets of C (and possibly A) while in world mode. Whereas it works OK in joint coordinates with trivkins, it seems to function differently in world mode using XYZCkins What does XYZCkins do that trivkins doesn't? Is it creating a virtual C-axis, or do you have a physical one? I assume by your statement that you see a rotation in your example in trivkins that you are talking about a physical C-axis? I am nowhere near my EMC2 machines until the 3rd, so this is conjecture but: I am fairly sure that coordinate system offsets are stored as an axis set, not a joint set. If you can run a non-trivial mechanism with cartesian offsets then that suggests that all the numbers inside the kins module are un-offset machine coordinates, and that G54 et al are added on post-kins. (and subtracted in the inverse kins). This may have a bearing on your assumptions. -- atp The idea that there is no such thing as objective truth is, quite simply, wrong. -- Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 5-axis table-table kinematics: G54 offsets (Viesturs)
2011/12/27 Rudy du Preez r...@asmsa.co.za:
I want to be able to use offsets of C (and possibly A) while in world mode.
Whereas it works OK in joint coordinates with trivkins, it seems to function
differently in world mode using XYZCkins. My example code in the previous
mail explained all that.
Then I do not understand, what exactly is the problem.
You wrote that You have a 5 axis machine.
You have not explained, how the kinematics of the machine are designed
- are rotary joints tilting the tool or table etc.
You mentioned that everything is fine with trivkins, I explicitly
asked about it in my last email, but You did not answer.
Just like Andy, I do not understand, why exactly You do not want to
stay with trivkins. Where exactly is the problem?
BTW trivkins is using kinematics_identity which renders Your
statement that it works OK in joint coordinates with trivkins to be
false as there is no joint mode in trivkins:
http://git.linuxcnc.org/gitweb?p=emc2.git;a=blob;f=src/emc/kinematics/trivkins.c
67 KINEMATICS_TYPE kinematicsType()
68 {
69 return KINEMATICS_IDENTITY;
70 }
I am afraid that none of EMC users can give You detailed answer, if
You do not share Your details. Starting with Your machine (preferably
in pictures).
Viesturs
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Re: [Emc-users] Another off the wall thought
Its a 10 Dewalt, decent shape, runs fine smooth but probably 35 YO, somebody make me an offer and help me carry it to your vehicle, please! I used one of the DeWalt over arm saws way back in the early 1970's post it to me for free (UK) :) Last time I looked they dont seem to be making them anymore. I used to cut aluminium section for lorry tipper bodies with it. It was noisy, probably the cause of my tinnitus. Occasionally would throw metal a hundred yards, somehow I still have all my fingers. Dave Caroline -- Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Servo drive?
2011/12/27 Viesturs Lācis viesturs.la...@gmail.com 2011/12/23 Viesturs Lācis viesturs.la...@gmail.com: Hello, gentlemen! I have 3 servo motors and I am looking for appropriate servo drives for them. I managed to get a technical specification of my servo motors: Motor type: T3-0130-60-560 Winding number: 01-00111 Rated Speed: 6000 min^-1 DC Bus Voltage: 560 V Nominal AC Voltage: 330 V Rated Motor Voltage: 309 V Rated Torque: 1,00 Nm Rated AC Current: 1,40 A Stall Torque: 1,30 Nm Stall AC Current: 1,67 A Peak Torque: 5,2 Nm Peak Current: 7,2 A Max. Speed: 12000 min^-1 EMF Constant: 47,0 V/1000 Torque Constant: 0,78 Nm/A Terminal Resistance: 12,7 Ω Terminal Inductance: 21,5 mH Number of poles: 6 El. Time Constant: 1,7 ms Mech. Time Constant: 2,4 ms Thermal Time Constant: 30 min Rotor Inertia: 0,65 kg*cm^2 Can any one suggest me, what is the rated power of these motors? I thought that it is calculated this way: Rated power = rated voltage * rated current This is consumed electrical power, actually. Andy Pugh told me that motor power could be calculated also this way: Power = 2 x pi x torque x rps And this is output mechanical power. And I guess this is the rated power you seek for. Andrew -- Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Servo drive?
Rated power = rated voltage * rated current This is consumed electrical power, actually. So ~749 W (1.4A x 309V x SQRT(3)) in (assuming A is A RMS per phase) Andy Pugh told me that motor power could be calculated also this way: Power = 2 x pi x torque x rps And this is output mechanical power. And I guess this is the rated power you seek for. and ~628W out About 83% efficient so the motor needs to dissipate ~121 watts of heat at full load Andrew -- Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your ()_() signature to help him gain world domination. -- Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Servo drive?
2011/12/27 Peter C. Wallace p...@mesanet.com: 2011/12/27 Andrew parallel.kinemat...@gmail.com: Rated power = rated voltage * rated current This is consumed electrical power, actually. So ~749 W (1.4A x 309V x SQRT(3)) in (assuming A is A RMS per phase) Andy Pugh told me that motor power could be calculated also this way: Power = 2 x pi x torque x rps And this is output mechanical power. And I guess this is the rated power you seek for. and ~628W out Andrew, Peter, thank You! Viesturs -- Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Another off the wall thought
On Tuesday, December 27, 2011 05:35:46 PM Dave Caroline did opine: Its a 10 Dewalt, decent shape, runs fine smooth but probably 35 YO, somebody make me an offer and help me carry it to your vehicle, please! I used one of the DeWalt over arm saws way back in the early 1970's post it to me for free (UK) :) Sorry Dave, local pickup only. Last time I looked they dont seem to be making them anymore. The original people to build it are still advertising in our wood rags on this side of the pond, but I've not seen anybody else for quite a while. I used to cut aluminium section for lorry tipper bodies with it. It was noisy, probably the cause of my tinnitus. Definitely could be a factor. :( Occasionally would throw metal a hundred yards, somehow I still have all my fingers. I've had the table saw throw it harder. Unforch, I was in the way, took about 6 weeks to lighten up the color of the bruises on my ribs too. 1x4, 2 feet long. That was the day I tossed the worthless blade guard in the bin, and ordered 2 different thickness of the shark fin. Now that is the cats meow. I left a 2 wide piece of wood laying between the blade and the fence just to see if it would ever catch and throw. 5 minutes later it was still sitting there so I took a stick and pushed it on by, no problem. Its a hair fussy to adjust but when you have it, you have it unless you switch blades to a thinner or thicker kerf version. No table saw is complete until it has one of those. Dave Caroline Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene Hire the morally handicapped. -- Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Another off the wall thought
On Tue, 27 Dec 2011 17:48:43 -0500, you wrote: I've had the table saw throw it harder. Unforch, I was in the way, took about 6 weeks to lighten up the color of the bruises on my ribs too. 1x4, 2 feet long. Yup - my broken left shin would concur. Ryobi table saw on floor, instead of it's stand, flung half an 8 by 4 sheet of 3/4 ply at me. Caught it with my legs - it hurt!! Steve Blackmore -- -- Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Another off the wall thought
On Tuesday, December 27, 2011 08:49:15 PM Steve Blackmore did opine: On Tue, 27 Dec 2011 17:48:43 -0500, you wrote: I've had the table saw throw it harder. Unforch, I was in the way, took about 6 weeks to lighten up the color of the bruises on my ribs too. 1x4, 2 feet long. Yup - my broken left shin would concur. Ryobi table saw on floor, instead of it's stand, flung half an 8 by 4 sheet of 3/4 ply at me. Caught it with my legs - it hurt!! Steve Blackmore That may even be the same saw, a BT-3000? A shark fin, a decent homemade zero clearance insert, a coat of formica on its top plus a $40 CMT ATBF blade and its the sweetest saw you'll ever use though. FWIW, Snears Takeitback has apparently bought the patterns and is selling a much improved version of it for a bit less than $500 right now. The ONLY reason I haven't dropped the card is that its now a Sears/Craftsman. You can't get parts for anything more than 2-3 years old from those bards. I may go and get the aux tables while they have it though, being able to use a std miter gage on it, could be pretty handy. Other than that, I have fixed most of the originals warts over the years and its working well ATM. Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene This is a country where people are free to practice their religion, regardless of race, creed, color, obesity, or number of dangling keys... -- Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] pcb artwork
Greetings all; I managed to score some double sided blank pcb today, enough to make a few boards to hold the ABX photo-interrupters (Honeywell HOA2001's) 3x per board for making encoders. But these encoders have an extra .05 hole pattern spacing, so the whole 3 pin socket pattern for the transistor side of it is only .1 wide for the whole 3 lead pattern with a .05 offset in the center for the third, output pin of the detector. This is getting a bit teeny to mill, so my thought is to bore a .125 hole under each end of it just run a trace to the edge of the hole, laying the lead down in a puddle of eutectic solder. I have visions at 4AM of this whole thing being about an inch wide and not more than 1.25 long, hopefully by cobbling up a pattern and doing a step repeat to get 3 of them on the same board, while somehow leaving room to condense the 15 leads into the 5 headed toward emc. With led current limiting r's in 3 of them. Do any of you that have done these conversions several times perchance have some artwork in gcode that could be adapted for this and that you are willing to share with beggars like me? Thanks Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene The worst part of having success is trying to find someone who is happy for you. -- Bette Midler -- Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] 5-axis table-table kinematics: G54 offsets
In a recent posting I did say where photo's of my machine and an impeller cut with it can be looked at. It is in groups.yahoo.com under group SA-CNC-CLUB in photos. This is the discussion group for our local CNC club (South Africa), which I started about 2 years ago (SA-CNC-CLUB) and has about 40 members. Most of the members are using EMC2 and we have converted probably more than 20 machines to EMC2 already. I personally have done 6. I have not been able to find a way to post photos to this forum. Lets focus a little on the process of going from world coordinates to joint coordinates. Starting from a toolpoint position in part or world coordinates xyz and unit tool vector ijk, these have to be transformed to joint coordinates XYZAC, with C the rotation angle of the top rotary table and A the rotation angle of the rotary table on which the top rotary table sits. The rotary axis of the A table is along the X-axis of the machine. X sits on Y which sits on Z (look at my pictures if necessary). The world coordinates I supply to EMC is the original xyz and the two angles A and C which have been computed in the CAM post-processor from ijk by: A = -arccos(k) and C = arctan2(i,j) Some adjustment of C is necessary to go beyond -180 deg and +180 deg. This is transformed by the inversekins: J0 = cos(C)*x - sin(C)*y j1 = sin(C)*cos(A)*x + cos(C)*cos(A)*y - sin(A)*z j2 = sin(C)*sin(A)*x + cos(C)*sin(A)*y + cos(A)*z j3 = A j4 = b (not used) j5 = C This is a working process for me so far as you can see from the photo of the impeller produced. If I use a G55 transformation of say G55 x10 y10, then EMC seems to add these values to x and y before it sends it to inversekins. The world coordinate origin is shifted to the new position. That seems fine. G55 is set by a G10 L2 P2 command. If I use a G55 of say G55 c45 nothing happens. It would have worked for me if EMC also added 45 to the value of C before it passes it on to inversekins. Practically I would only want to shift the C-axis when cutting parts like impellers with a number of blades. The GCODE for only one blade is the provided. I could also have passed on the ijk values as abc values to the inversekins. It would then have to work out the AC values, but there is quite a bit of checking and adjustment to C to be done. I am not sure if EMC could then pass on transformations. I hope the problem is now clearer and look forward to some response. Rudy -- Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
