facetted tollpaths

[Bruce McPherson]

First of all I am running version 7.2, with hopes of upgrading to 9.My problem is, when I try to toolpath using surface contour I get a facetted path around the arcs.I've tried changing parameters and the different gap and edge settings.Sometimes it does work but never the same twice.I am using iges models from SDRC brought out with using bspline flavour.If anybody has any ideas please help.If version 9 fixes this that would really push my upgrade,Thanks

[gms1]

Ive never used 7.x but I do know that if your geometry is a spline, MC will make small x y moves instead of arcs. Creating the faceted look.

I dont know if filtering is available in 7.2, but if it is, that will correct your problem.

 

Greg

[BernieT]

Welcome to the forum!

 

This previous thread covers your problem pretty well:

http://www.emastercam.com/cgi-bin/ultimate...ic;f=1;t=000749

 

HTH BerTau

[Bruce McPherson]

Thanks guys I'll try these out.

[Jim Whipple]

quote:

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but I do know that if your geometry is a spline, MC will make small x y moves instead of arcs.

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Bingo!!!

 

The filtering , I think, may worsen the problem by making the lines longer. Can you check the output settings on the cad system where the Iguess file came from? That may be the source of your troubles

Hope this helps

Jim

[Bruce McPherson]

Well nothing but bad luck so far.Does anybody think version 9 will help?

[Jim Whipple]

Well nothing but bad luck so far.Does anybody think version 9 will help?

 

It's not a Mastercam issue...the problem comes from the file you imported....the Iges out settings need to be tightened up

What porgram sent you the files?

Jim

[Bruce McPherson]

We've tried SDRC and played with the tolerances and flavours and also UG for iges and even a VDA from SDRC all with the same result.It looks like its coming down to needing a step translater.

[Scott Bond]

Hi Bruce Welcome to the forum.

 

Can you post your GEO on the FTP ?

 

Scott

[TODD_P]

We have been using the parasolid translater in SDRC Ideas and its been working great.

 

[ 01-08-2003, 11:35 AM: Message edited by: TODD_P ]

[Bruce McPherson]

Ok the file is in the MC7 folder under "bruce_facet.iges"

[P_Scott]

Bruce,

 

Filtering should help as long as you know how to set it up properly. The disadvantage with V7 is that it doesn't have nearly the amount of control with Filter as V9 or even V8 has. The Filter button is on at the bottom of the same page as the Clearance, Feed Height, TOS values. I usually set my Filter tolerance to an amount that's twice as large as the Cut tolerance and try to look ahead by as many entities as possible (typically around 1000 in V7). The IGES file appears to be OK. I've made a couple of toolpaths with the use of Filter for your IGES file and downloaded it to the FTP (Bruce_Facet_SFA.MC7). Unfortunately in V7 you have to "Redo" the toolpath to even see any of the parameters, let alone make any changes. In V9 you can review the parameters and make changes to minor things without even the need to regenerate the toolpaths. Changing a tool dia. or stepover distance will require a regen but it's faster than selecting "Redo" and trying to remember what it is you wanted to change. HTH

[Scott Bond]

Hi Bruce

I agree with Peter Scott that the surfs and splines are good . V7 will not be able to understand the v9 that Peter Scott talking

about.

Chang your v7 surf tolerance from

the defalt of .001 to .0003 .

[Bruce McPherson]

I brought in the new mc7 file from the ftp and was able to look at the toolpath.I wasn't able to change the look ahead to 1000.It will only let me change between 3 and 100.Is there in a setting in the config that I'm not seeing.I changed the tollerances like Peter said and the facets got worse.Also was Scott talking about changing the surface tolerance in the filter or in the config?

Thanks for all your help guys.

[Tony]

Convert your Splines to Arc's (Modify/convert to arcs)Start off with a .0005 tolerence and keep going up until you get them all.

Remanufacture the Surfaces.

[Trevor Bailey]

I had the same problem when I used V7x.... The IGES files came from Ideas and UG. I always had to recreate some of the easier surfaces because of facets on the finished product/part. Even the filtering method is not going to help you very much. It will only make the facets smaller.

[Bruce McPherson]

FINALLY!!!! I finally found the right combination that works.I turned the filter completly off and kept shrinking my cut tolerance till I got my desired cut.Thanks everybody for your input.BTW There going to upgrade me to version 9 within the next week.

[Toolfab]

quote:

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There going to upgrade me to version 9 within the next week

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Well than you got why more than you expected out of this......good for you!

 

[P_Scott]

Bruce,

 

quote:

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There going to upgrade me to version 9 within the next week.

---

That's great news. I want to caution you that the Filter in V7 was rather new and didn't work quite the way it should. Don't automatically assume that if a function didn't work right in a previous version that it will work the same way in V9. What I said before about making the Filter tolerance about twice the cut tolerance works for a majority of toolpaths in V9 but there are other ratios to use if you want to experiment. The Filter settings are also in a different location in V9. They are found in the "Total tolerance..." button on the third tab of most surface toolpaths. Enjoy your V9 as I'm sure you will find it much more efficient and easier to work with. If just for the full toolpath associativity alone. No More REDO.

 

[ 01-10-2003, 08:43 AM: Message edited by: Peter Scott ]