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View Full Version : Khalid's Madness: Break Through in speed increase in 3D contouring (DIY)



Khalid Khattak
11-21-2008, 12:30 PM
Following is the simple technique u can dramatically increase the speed of ur 3D countouring... I use normally raster machining strategies as shown in attached figure.. I increased my Z-axis and X-axis motor accelerations twice as compare to Y-axis motor..

I got dramatic time reduction from 3 hrs to 45 minutes in one of the 3D carving..


Now What u comments on that???....http://www.cnczone.com/forums/images/smilies/RAINFRO.gif

Bruce Volden
11-23-2008, 6:12 PM
Khalid,

I cannot comment on the speed things (no CNC here), but, do I see a bed in the CNC room???

You must get out more often!!!;)

Bruce

Neville Stewart
11-23-2008, 11:08 PM
Khalid, I have to say you do wonderful things with limited resources. I see your work on here, Vectric & Artccam. Keep it up! Do I understand in this process that you have doubled the speed of the "least" moving axes, namely your X&Z? I had a theory about something like that. I had a "Carvewright" before the one I have now & it would move incredibly fast in those axes. so I wondered if I could "tune" my Shopbot up to move like a Carvewright, but I was always afraid I would bend something :-)

Khalid Khattak
11-24-2008, 8:58 AM
Khalid,

I cannot comment on the speed things (no CNC here), but, do I see a bed in the CNC room???

You must get out more often!!!;)

Bruce

Bruce... U can see very poor housekeeping in my Hobby room... At those days i was cutting the MDF parts from my new MDF CNC router on Steel router.. I was struggling with MDF dust... To avoid dust accumulation i remove the bed sheet from my bed...

Now when I typing this, i amlaying in my bed with keyboard in my lap... this is the most relaxing and ergonomic position while i am using/playing with my home computer...currently my room is very neat and i am enjoying..

Best Regards and thanks for posting

Your freind Khalid

Khalid Khattak
11-24-2008, 9:07 AM
Khalid, I have to say you do wonderful things with limited resources. I see your work on here, Vectric & Artccam. Keep it up! Do I understand in this process that you have doubled the speed of the "least" moving axes, namely your X&Z? I had a theory about something like that. I had a "Carvewright" before the one I have now & it would move incredibly fast in those axes. so I wondered if I could "tune" my Shopbot up to move like a Carvewright, but I was always afraid I would bend something :-)

Stewart:) i hope u have read the explaination of above speed increase in many forums... again i am putting here to read others visiting this thread..


I use Mach3... Now read the following and if it make sense then comments and if somebody is unclear then also please ask the question...

Basically the lengthy axis (Y-axis in my case) is the problem.... U may have various issues along Y-axis side i.e. Leadscrew Binding, heavy Gantry load, resonance... The lengthy axis is always prone to that issues, You can just optimize the cutting strategies to debottleneck this axis....this one axis can be debottleneck as per my above approach..

I experimented it myself and its really working for me..

As Y-axis moving large weight (complete Gantry), its prone to large inertial forces too... All three axis acceleration well be different when u optimized ur motors..

Lets take an example...

My Z-axis can bear accelerations upto 50 @ 100IPM without loosing steps....
My X-axis can bear acceleration upto 45 @ 100IPM without loosing steps..
But My Y-axis can't go more 20 @ 100IPM..

So why not keep the acceleartion values say 43 for z and x axis and keep them 20 for y-axis... Now all u have to do to adopt raster startegies as shown in fig.

Does this makes since???

Regards
Khalid

Now..i don't know what software Shopbot is using to controll stepper/servos.. but i saw a video on youtube MECHMATE doing 3D countouring 300+IPM...

We can do that...TAKING RISK WILL MAKE YOU MOVE HIGHER...

Best of luck

Khalid Khattak
11-24-2008, 9:13 AM
Khalid,

You must get out more often!!!;)

Bruce
LOLZzzzz....can't u see my dedications to CNC.. although i have very lean resources.. i have no top-class cutter bits:( (i can just think of those bits that u using on ur router), my lead screws are full of pitting corrosion...i have cheap chinese plunge router (US32$)...salvage stepper motors....even my CNC bed is not levelled yet...But this is my hobby...and i enjoy the most..;)

Neville Stewart
11-24-2008, 11:47 AM
Thanks Khalid, I will definitly try that. I was after better cut resolution by not sliding thst big X gantry back & forth on a 3D cut, but now it seems I can do that & shorten the time too. Do you have a problem getting bits in Pakistan? Neville

Khalid Khattak
11-24-2008, 11:54 AM
Thanks Khalid, I will definitly try that. I was after better cut resolution by not sliding thst big X gantry back & forth on a 3D cut, but now it seems I can do that & shorten the time too. Do you have a problem getting bits in Pakistan? Neville

Stewart... Bits available in Pakistan..but i can't afford the prices... You know, I am a Hobbiest..The work u see, i created for my self satisfaction and used in my own home..a lot money out no money in:rolleyes:

Khalid Khattak
11-26-2008, 2:34 PM
Following is the post from one of our colleague who debottleneck his cnc as per my above mentioned procedure.

"I changed my machining to very similar configuration, x-raster so the machine 3D cuts in a x-z direction and y come into play only at the end of the cut. Also changed the look ahead in Mach to 100 lines.
My speeds went from 25 ipm to 100 ipm!! http://www.vectric.com/forum/images/smilies/icon_biggrin.gif Its almost a little scary to watch after seeing 25 ipm for so long. A 3d carving in under an hour is a very nice change from 3-4 hours.
Maybe I can make some $.$$ in 3D carving.
Thanks for the tip!!

Mike
_________________
Mike E
"

This post is taken from Vectric Forum, where i posted the thread with the same name.Here is the thread:
http://www.vectric.com/forum/viewtopic.php?f=28&t=4220

Khalid Khattak
12-17-2008, 8:14 AM
Nick also benefitted the above technique.. here are his views http://forum.artcam.com/images/smiles/icon_smile.gif

Well I finally got a chance to try your method!!! It was definatly an improvement on speed. I had to set my acceleration up to about 100 on my X and Z axis in mach. I ended up losing steps on the second try. The first time I did the cut it took 1hour36min the second time I cut the same part I got it down to 1hour 11min. I still need to adjust the acceleration a little more for the 3d work. The DRO read from 24ipm up to 99ipm I would guess it averaged about 50ipm.

Thanks for the info Khalid it will help me cut faster!!!

Nick