constant scallop

[gmenzies]

pent III 1 gig // 500 megs ram

allocations set at about 70 % of avalable ram.

.375 Ø ball nose cutter / 10000 rpm / .005"

step over // 80 inches per minute. cut tolarance set to .0002 "

job: 70/75 aluminium ( cutting a 3d cavity )

i sometimes have mastercam hang .

could someone please give me advice if my approch is wrong . being the only programer here .

i sometimes guess or should i say experiment

to get good surface finish results .

thanks

[cadcam]

so is your problem is that some times it hangs or is there some thing i am missing ?

Have you uploaded the file so we can look at it?

i use this path all the time and love it.

in 98% time i get the best finish from this path.

------------------

jay/ aka cadcam

Precision Programming

cnc programming &

Predator & mastercam reseller

email: [email protected]

web: www.ppcadcam.com

[This message has been edited by cadcam (edited 07-03-2001).]

[mopar]

The problem with setting ram allocation that high is that you are also robbing the computer of mathmatical processing power ie; the ability to crunch numbers. Try to relax the cut tolerance to say .0005 or even .001 if part tolerences permit. Also if permitted increase the stepover amount to say .007~.01 and see if this helps.

[cadcam]

I am not seeing the step over being to small i have done this tool path as small as .001 with no problem.

------------------

jay/ aka cadcam

Precision Programming

cnc programming &

Predator & mastercam reseller

email: [email protected]

web: www.ppcadcam.com

[This message has been edited by cadcam (edited 06-30-2001).]

[gmenzies]

clarification-- my computer hangs on constant

scallop , on large multi-surface .

thanks guys for the replys. setting the allocations could be the trick , i will try that .

i cannot set the cut tolarnce's for this application to above .0005" . otherwise i get little facets . and the polishing guys

really don't like that .

i presented this problem to a reletive who is a computer enginer. his first question was-- is it time dependent ? with that in mind -- power managment came up. possibly

scince the toolpath does take about a hour to crunch . my hard drives could be shutting down.

i have not tried the upload thing . it's a holiday on monday in Canada -- happy birthday Canada-- so i will upload the file on tuesday.

[Guest CNC Apps Guy 1]

Just as a matter of personal preference, I turn off all that Power Management Crap 9x out of 10 it's never a problem, but that one time (or several in this case apparently) it is. If you have a company policy regarding Energy Conservation, you may just want to have the monitor go into "Sleep Mode" and leave the computer in "Always On" mode. HDD sleep can have a detrimental effect on mamy applications (including Windows - of all programs) if they are left active(open) when the computer goes into Sleep Mode.

Just my 2 Cents from personal experience.

------------------

James M.

Mastercam Enthusiast

[Tony]

Both My re seller and MC Tech support have told me "You have to use boundries around the part, you cant just wrap a window around the entire core block etc. and say DO IT"

It will choke.(Constant scallop) Some friends of mine locally Run "Batch" all the time, I never tried it

Tony

 

[cadcam]

This does not make sense tony that you have to make a boundry. i do it all the time and just tell it all surfaces no boundry and don't have a problem.

Gmenzies,how big of a part when you say large multi-surface?

Will be looking for this file tommorow.

thanks jay

------------------

jay/ aka cadcam

Precision Programming

cnc programming &

Predator & mastercam reseller

email: [email protected]

web: www.ppcadcam.com

[Guest CNC Apps Guy 1]

Batch works great.

Where scallop tends to choke is where there are vertical surfaces. Why, you ask? Imagine trying to run a toolpath on a razor's edge. That's the way Mastercam sees a vertical surface edge.

Pick all the surfaces except for the vertical ones and you'll have a much better go of things.

------------------

James M.

Mastercam Enthusiast

[mopar]

Here's some thoughts:

1) We really don't know the size of the surfaces yet.

2) The facets you see could be from servo lag on your machine, too fast a feedrate (tool stutters across the part) or poor surface generation tolerences at file importation or from whomever drew it.

3) You don't have to select a outside boundry to surface/scallop. Use a check surface to prevent the tool from diving or overcutting.

4) For the vertical wall problem, use a check surface and scallop from outside to center, or a surface/contour type toolpath with a large gap setting to prevent the tool from hopping to and from refrence point. In a pocket type operation just choosing the floor surfaces will cause the tool to overcut the walls by half it's diameter. Again, set the vertical walls as check surfaces. Cutting from center out will work here.

5) Turn off screen saver, close all other programs, disconnect from any networks, look for coffee and snacks

[Guest CNC Apps Guy 1]

6) Open cup holder, errrrr CD-ROM tray.

7) Sit back and enjoy.

------------------

James M.

Mastercam Enthusiast

[gmenzies]

ftp://mastercam:[email protected]/Mastercam%20forum/

 

i uploaded the file scallop-1.zip

i was going to include the toolpath , but the code was way to big ( were stll stuck at 2400 baud rate).

Mopar-- the facets are cut tolarance . if i run the toolpath through my verify , the facets will show up. outr machine is 1 year old .

we use meta-cut for our optimization - does a real nice job with the code.

instead of using check surfaces. I biuld a boundary and offset the parting line .005"

and have the tool roll the top edge. that way i don,t have to worry about a toolpath that jumps around.

the geometry was biult in solid works

 

[Ambassador]

Gmenzies, I had a look at your file, nice blow mould cavity. There is one bad surface in it, to find the bad surface Analyze, Surfaces, Check Model. This will show you find the "bad surface". I have run a few programs (Scallop) and haven't had any problems. I will tighten up to your settings from the origional post and run it.

Ambassador

[cadcam]

Gmenzies, i took your file ran a .25 ball step .005 with Tol .0002 using your large red boundry took about 14min and at the end it had one extra jump.

i did not check for bad surfaces like the Ambassador did.

but i did put my part backup on the ftp the file is now about 2.7 megs with this path in it as a "EXE" file.

Oh ya i renamed mine scallop-1jay.exe

by the way had no hangups at all.

i was running this on a setup like yours.

1gig pro with 512 meg ram Win2k as the os.

I forgot I do not set my allocations nerly as high as you.

I run 133meg out of my 512meg & it works great.

------------------

jay/ aka cadcam

Precision Programming

cnc programming &

Predator & mastercam reseller

email: [email protected]

web: www.ppcadcam.com

[This message has been edited by cadcam (edited 07-03-2001).]

[This message has been edited by cadcam (edited 07-03-2001).]

[gmenzies]

I guys

appreciate the input - appears to be a combination of allocations and power managment.

i often get the bad surfaces . i model all my work in solidworks and export with the mastercam flavors (iges) i have tried parasold x_t export with the same results.

don't really understand where the bad surface

are created (yet)

i will download the ftp cadcam . and have a look

regards Gord

[This message has been edited by gmenzies (edited 07-03-2001).]

[lynnz]

I also use solidworks. The way I import to Mastercam is through Parasolids. Instead of accepting the default .x_t or .x_b I click on file type and select .prt for original Solidworks format. This works great and usually have a good translation. We do some very complex 3D molds and such.

File,Convert,Parasolid, change file type to .prt

If in Solidworks, you are using configurations in your modeling, this approach won't work unless you are importing the default configuration. If its another configuration other than default then you need to export it as .x_b to bring it into Mastercam.

Good luck

Lynn

[mopar]

Our engineer exports from solid works. Every time I get the files (iges) they are full of holes, cracks, faceted edges, and weird "fins" at surface intersections. I take what I need for the job, fix it and throw away the rest.