Parallel finishing with hiccups

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sergio
Posts: 2
Joined: Wed Aug 01, 2007 4:15 pm
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Parallel finishing with hiccups

Post by sergio »

Hello all

Robert thanks for the post.
My parallel finishing is very very slow I don't know if is due to the machine or due to any configuration in VM.

Please look at the pttached images,they show all the other config.

1-The machine seems to have hiccups when is cutting the smooth surface on the top and also the radius on the side.

my configurations are:
0.01 intool
0.01 outool
0.01 stook
angle cut 90
step over 0.3

0.005 Chordal deviation

I know I can try to optimize the program with "fit arcs to toolpath" but although the final result is a little better it is still slow in asome areas and fast in others.

The goal is of course to have a program running more smooth and fast.

thanks to all

sergio
[email protected]
Rui
Posts: 31
Joined: Wed Aug 01, 2007 4:15 pm

Parallel finishing with hiccups

Post by Rui »

really don't what kind geometry you're trying to apply parallel finish, but with these toolpath's parameters it may look a bit strange even with other software.
with my computer I had to turn off some applications like anti-virus, and all *.exe files related with webcam, modem, scanner...
I am used to do it with other software, and to see the results.


saudações dum conterrâneo que também usa Visualmill,e a ver vamos se posso participar numa futura sessão de apresentação para ver se há novidades.
se precisar de algo apite.

[Edited by Rui on 10-Jul-05 15:55]
jake
Posts: 74
Joined: Wed Aug 01, 2007 4:15 pm
Location: Dayton, Ohio

Parallel finishing with hiccups

Post by jake »

are your units inches or mm?

in inches, I would have the intol, outtol at .001 - .0005 for finishing.

same for chordal tolerance (when importing data) - I would set to less than .001" (.005 is ok if it is metric). (depending upon the size of the part and the required tolerance, of course)

if you are in metric units your values should be OK. I would suspect a control and/or post processor problem. What control are you running? Are you loading the files into the control or "drip feeding" through a serial line?

Areas to look at: - data starvation, especially if you are drip feeding over a serial line.
block transition mode - (sometimes in the G27, 28, 29 area) - if you are in a mode that requires getting completely in position before progressing to the next block and the point density is high, you will progress slowly if you are not in the right mode. There should be some mode where the block transitions occur in a blended way (not waiting for feedrate to slow down, or following error to go below some value)
feed mode - make sure you are not posting in G00 (instead of G01). This is not likely, but make sure your post is putting the feedrate stuff out properly, including the G01. - if the point density is high you may not notice that you are in G00, and you may be feeding very slowly, because G00 (in most controls) will wait for the following error go get to some low value before transitioning to the next block, and the acceleration rate is usually lower than in feed mode, thus on short blocks not much speed is achieved.

Many controls are not well suited for 3d finishing work. The block processing time (throughput) is too slow in many controls. Most Italian controls (Fidia, Osai, Selca, for example) are well suited for 3d work. Siemens 840 controls, some Heidenhain controls are also strong at 3d work.(anything with nurbs interpolation is most likely going to do a good job at high speed 3d) Most Fanuc controls are generally not well suited for high speed 3d milling. AB 9 series, or anything else AB not made by Osai (8600 or 10 series) not well suited. (8600 or 10 series were made by Osai, sold by AB, and are much better suited for high speed 3d work)

Most controls on small machines like Fadal, Haas, Miltronics, etc, are also usually not well suited for high speed 3d work.

Any CNC control will work to some degree, but the majority of controls are ideally suited to point to point milling and drilling type operations. The block processing time is not fast enough for high point density work.


[Edited by jake on 18-Jul-05 06:39]
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