Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: MJR on July 16, 2006, 11:36:15 PM
-
Howdy all:
Recently purchased V-Carve Pro from Vectric. Great program. I seem to be getting Jerky Motion & Poor Quality in Curves. Mach3 has never done this to me on it's own when I have converted dxf files.
Just wondering if anyone may have some suggestions as to what might be going on.
If I slow the feedrate down to about 10 inches/min as less the quality greatly improves and the jerkiness is to a minimum, but now it takes forever to cut.
I have the Constant Velocity already selected.
Thanks.
-
I have had this problem in the past. There was a few issues. Curves in exact stop mode were jumpy, or smooth in constant velocity mode. The problem with constant velocity mode then meant that the corner was lopped off squares etc.
One of the problems on my machine was the gearing down of the motors was not enough. I seem to remember a temporary solution was to lower the acceleration and deceleration setting on each motor helped.
I also wonder if the resolution setting in VCarve is very high and is causeing this http://machsupport.com/forum/index.php?topic=621.msg3461#msg3461 to happen. It may pay to reduce the Vcarve resolution setting.
-
i have an answer and a question.....
MJR: there is a new post processor in VCarve Pro that outputs true arcs instead of lots of little linear moves. i spoke with Brian and he allowed me to download a beta. it seems to help me. i am having other issues on my mill so i cant tell you for sure if it will be a total cure for you.
Mach experts: it seems that you can select constant velocity for the "soft" curves and set a limit to CV for "hard" corners. the Setting tab looks like it allows this, but the actual values are not clear to me and the mach document help was not much help. can anybody clear up what each of those settings do? the default angle is 180 which seems odd, and there seems to be a multiplier of some sort, defaulted to 1. any help would be great.
Ben
-
FastCote:
I was directed by a V-Carve Pro user to look into exactly what you are talking about. I am just waiting to get verifcation from that person to tell me if that box in question should be green & what values should be entered.
Go to this post on Vectrics forum:
http://www.vectric.com/forum/viewtopic.php?p=2694#2694
Does that make sense?
Thanks.
-
ya, i read that already, but i figured this was a more appropriate place to get good Mach Answers. As far as i can tell, you enable constant velicity ono the STATE page from the CONFIG menu. Once enabled, that page you showed (from the SETTINGS Tab) allows you to restrict how sharp an angle before the CV is suppressed. What the numbers actually mean are a mysetry to me. 180 degrees does not make sense, and the number below it??????
-
If the angle of the two lines is less then 180 (the angle in the box) it will do the CV. this is for the plasma users and router users...
-
FastCote:
Thanks for that. I seem to be getting conflicting opions about the CV settings. I quess I will just have to experiment.
I did go into Motor Tuning & reduce me acceleration numbers. That made some differenence to the good until I decided to up the feedrate. Anything over 30 inches/min starts the jerking motion again. Very eratic & extremely jerky at 100 inches/min. This is only happening when I use V-Carve Pro, not when I use Mach3 by itself. To get a good finish really adds to my cutting time.
Why does no one know exactly what those CV settings mean? 180 & that mysterious number below.
I am hoping that Vectric will soon solve this problem. Is this problem only affecting Mach users or does it also affect other post processors?
Talk to you later.
Just read Brians post.
Does that mean we should change that 180 to something else? Don't quite understand.
-
Set it to about 60 and that should do you...
-
Thanks Brian, I will try that tomorrow.
So, why is it that I have no problems when running just Mach3 on it's own? Can cut very fast with smooth/clean results.
What is the number below the 180?
Later.
-
That is the feedrate that the machine will slow down to when it goes around a corner
-
What is your recomendation for this setting?
Mine is currently at +1.
Thanks.
-
This feed rate will tell Mach3 how much to round the corner... So I woudl think about 25% the max feedrate of the machine should do.
-
I sure am glad I purchased Mach3. Will be worth the cost.
The forum & fellow users have helped to make my introduction into the cnc world alot smoother.
I am a little overwelmed with the gratious replies. Many thanks to all. They have allowed me to be pointed in useful directions to try & resolve this jerky problem. Someday I will be a knowledgeable source to contribute back to this forum.
Back to the problem:
Did one simple test. Drew a 3 inch circle in TurboCad & also drew a 3 inch circle in V-Carve Pro. Loaded the TurboCad dxf into Mach3, did the g-code conversion, then cut the circle at 100 inches/min. Great cut, very smooth x & y movements. NO jerkiness whatsoever. Generated the toolpath in V-Carve Pro (profile cut only), loaded the g-code into Mach3 & cut the file. Movement of the x & y was somewhat jerky. Within Mach3 I engaged & disengaged the CV settings (60/20). Got the best cut with the CV settings turned off.
Result: there is something different between how things are drawn then coded, then cut.
Eventhough the V-Carve file was a little jerky is was nowhere near how aggressively jerky my main project was. Still no closer to resolving that issue, but here is what the difference was:
Project drawn in AutoCad 2000, saved as Version 12, loaded into V-Carve, drawing was editted slightly, toolpaths were created, files loaded into Mach3, then cut. Tried all sort of recomendations by the forum replies with no noticable improvement.
I know that the complexities & compatability issues of programs will always play a part towards the success of any project, so with alittle help along the way a person will just have to live with some short-comings within the technolgies.
Thanks again. All your comments were greatly appreciated.
Rusty
-
I have the same problem with spirals generated in mastercam. Also it stops in each of the 4 quadrants when cutting a circle.
-
Could you guys please post files that are giving you trouble? and please put in a note on the lines so I can find them :)
thank you
Brian
-
Brian:
This is the file that seems to be the worst. Cuts not bad at 10 inches/min & starts to get bad at 30 inches/min & vilantly jerky at 100. Still cuts & doesn't miss a beat, but is hard on the machine.
Try it for yourself & let me know how it cuts on your machine.
( Outside Chamfer )
( Mach2/3 Postprocessor )
N20G00G21G17G90G40G49G80
N30G70
N40T1M06
N50G00G43Z1.0000H1
N60S12000M03
N70G94
N80X0.0000Y0.0000F30.0
N90G00X1.8767Y1.4232Z0.2500
N100G01Z-0.2500F20.0
N110G01X0.6186Y3.6682F30.0
N120X0.5271Y3.8583
N130X0.4584Y4.0633
N140X0.4158Y4.2790
N150X0.4014Y4.5002
N160X0.4158Y4.7215
N170X0.4584Y4.9372
N180X0.5271Y5.1422
N190X0.6186Y5.3323
N200X1.8765Y7.5770
N210X1.9744Y7.7308
N220X2.0965Y7.8808
N230X2.2438Y8.0222
N240X2.4159Y8.1493
N250X2.6111Y8.2562
N260X2.8257Y8.3375
N270X3.0544Y8.3883
N280X3.2906Y8.4056
N290X3.5268Y8.3883
N300X3.7555Y8.3375
N310X3.9701Y8.2562
N320X4.1653Y8.1493
N330X4.3375Y8.0222
N340X4.4847Y7.8808
N350X4.6068Y7.7308
N360X4.7047Y7.5770
N370X5.4377Y6.2689
N380X5.4483Y6.2530
N390X5.4614Y6.2384
N400X5.4769Y6.2257
N410X5.4943Y6.2155
N420X5.5129Y6.2082
N430X5.5321Y6.2039
N440X5.5511Y6.2025
N450X10.1131
N460X10.2919Y6.1917
N470X10.4756Y6.1575
N480X10.6599Y6.0982
N490X10.8396Y6.0127
N500X11.0092Y5.9017
N510X11.1635Y5.7674
N520X11.2979Y5.6131
N530X11.4088Y5.4434
N540X11.4943Y5.2638
N550X11.5537Y5.0795
N560X11.5878Y4.8958
N570X11.5986Y4.7170
N580Y2.0800
N590X11.5876Y1.8996
N600X11.5528Y1.7141
N610X11.4923Y1.5281
N620X11.4051Y1.3468
N630X11.2918Y1.1759
N640X11.1546Y1.0208
N650X10.9973Y0.8862
N660X10.8244Y0.7759
N670X10.6417Y0.6917
N680X10.4547Y0.6343
N690X10.2687Y0.6026
N700X10.0881Y0.5947
N710X10.0876Y0.5947
N720X10.0865Y0.5947
N730X10.0859Y0.5947
N740X3.2906
N750X3.0830Y0.6080
N760X2.8735Y0.6493
N770X2.6676Y0.7192
N780X2.4712Y0.8171
N790X2.2899Y0.9406
N800X2.1282Y1.0860
N810X1.9898Y1.2486
N820X1.8767Y1.4232
N830G01Z-0.5000F20.0
N840G01X0.6186Y3.6682F30.0
N850X0.5271Y3.8583
N860X0.4584Y4.0633
N870X0.4158Y4.2790
N880X0.4014Y4.5002
N890X0.4158Y4.7215
N900X0.4584Y4.9372
N910X0.5271Y5.1422
N920X0.6186Y5.3323
N930X1.8765Y7.5770
N940X1.9744Y7.7308
N950X2.0965Y7.8808
N960X2.2438Y8.0222
N970X2.4159Y8.1493
N980X2.6111Y8.2562
N990X2.8257Y8.3375
N1000X3.0544Y8.3883
N1010X3.2906Y8.4056
N1020X3.5268Y8.3883
N1030X3.7555Y8.3375
N1040X3.9701Y8.2562
N1050X4.1653Y8.1493
N1060X4.3375Y8.0222
N1070X4.4847Y7.8808
N1080X4.6068Y7.7308
N1090X4.7047Y7.5770
N1100X5.4377Y6.2689
N1110X5.4483Y6.2530
N1120X5.4614Y6.2384
N1130X5.4769Y6.2257
N1140X5.4943Y6.2155
N1150X5.5129Y6.2082
N1160X5.5321Y6.2039
N1170X5.5511Y6.2025
N1180X10.1131
N1190X10.2919Y6.1917
N1200X10.4756Y6.1575
N1210X10.6599Y6.0982
N1220X10.8396Y6.0127
N1230X11.0092Y5.9017
N1240X11.1635Y5.7674
N1250X11.2979Y5.6131
N1260X11.4088Y5.4434
N1270X11.4943Y5.2638
N1280X11.5537Y5.0795
N1290X11.5878Y4.8958
N1300X11.5986Y4.7170
N1310Y2.0800
N1320X11.5876Y1.8996
N1330X11.5528Y1.7141
N1340X11.4923Y1.5281
N1350X11.4051Y1.3468
N1360X11.2918Y1.1759
N1370X11.1546Y1.0208
N1380X10.9973Y0.8862
N1390X10.8244Y0.7759
N1400X10.6417Y0.6917
N1410X10.4547Y0.6343
N1420X10.2687Y0.6026
N1430X10.0881Y0.5947
N1440X10.0876Y0.5947
N1450X10.0865Y0.5947
N1460X10.0859Y0.5947
N1470X3.2906
N1480X3.0830Y0.6080
N1490X2.8735Y0.6493
N1500X2.6676Y0.7192
N1510X2.4712Y0.8171
N1520X2.2899Y0.9406
N1530X2.1282Y1.0860
N1540X1.9898Y1.2486
N1550X1.8767Y1.4232
N1560G00Z0.2500
N1570G00Z1.0000
N1580G00X0.0000Y0.0000
N1590M09
N1600M30
%
Not sure how to send an attachment.
Thanks.
Rusty
-
Ran good here... Could you send me your XML and I will see if I can find a problem in the settings
Thank you
Brian
-
Thanks Brian:
What feedrate did you use? Was it real smooth?
I do not know where to find the XML file & how do I send it.
Talk to you later.
Rusty
-
Send it to brianb (at )newfangledsolutions.com
It is in your Mach3 directory and in called Mach3Mill.XML
I ran it at 100IPM :)