Large GAP settings

[MotorCityMinion]

I've had to increase my gap settings on several surfaces up to 6.75" in order to get the tool to stay down. Will this alter the geometry of the surfaces?

[Guest]

IMO,, if you had to make your gap settings THAT large, I would either redo the surface or create surfaces to close your gaps.

 

I have seen large gap values like that cause "unintended" issues.

 

JM2C

[Chris Rizzo]

it shouldn't affect your cut geo. , just induce some funky tool motion occasionally. of course every situation is different. i've used ridiculously large gap settings to force smooth tool motion. now with the hst stuff and surf>fin>blend i really haven't come across the need anymore

[Justin Beebe at Folsom Tool]

Motorcity,

 

I have been using large gap sizes of up to 6.00 inches lately. I set motion< gap size keep tool down to "follow surfaces". These setting have been working good and I have been able to keep the tool down with much success. Occasionally I notice the tool wants to do something weird during backplot so I alter the settings, but for the most part the large gap size has been working out nicely. I have not taken the time to backtrack and see how small I could make the gap size and still keep the tool down. 6.00 inches may be overkill.

[sharles]

Typically I run my gap at 900% for all surface programs. The only time I change that is when I am making a "test" program with a 10.0" stepover and I WANT the tool to pick up between steps.

[MotorCityMinion]

Thanks for the input. Glad to hear that large gap settings don't mess with the geometry.

 

Must have been a glitch. I switched to direct (from smooth), then regen'ed. Looked good so I reset the gap to .50 and it worked, I then reset all my surfaces that way and the tool motion, (retract) came out perfect. This also eliminated some goofy moves at the ends of the surfaces. I have both solids and surfaces in this part. Some of the solids kept giving me an invalid arc error and I ended up re-creating the surfaces, which was a bummer because the original solid surfaces seem to look more accurate (neater / tighter) than anything I create in MC.

[Mr. Dayshift]

I use a containment whenever possible to limit my toolpath. I do not get the gap retracts.

 

Some scenarios will need the check surfaces in place, so excersize caution.

 

Can someone comment on the surface from solids chord setting vs. toolpath tolerance. Is it relevant here?

[MotorCityMinion]

I have no experience with containment boundaries or check surfaces as this is my first real surfacing project but I have found that the more variables I monkey with, the more trouble I create for myself. If I would have just left the default setting at Direct, I could have saved a lot of aggravation. I will have to set up some type of check surface here sooner or later as there are sharp corners in this project that I have to stay away from.

[sharles]

I ALWAYS use a containment boundary for my surface programs. Maybe that's just how I was trained, but I can't even imagine just letting the toolpath go wherever. Wouldn't it typically fall off the part? Not sure since I've never tried it. I know when my containment boundary was slightly too big, my toolpath "fell" down the side of the part.

 

I rarely use check surfaces but they can be very helpful at times.

[crazy^millman]

When doing surfacing if you have everything set up right most times you can just pick the surface and be done and it will not fall off the part. All things have their place and by limiting yourself to one thing you may create extra work and even fall short of the true ability of Mastercam IMHO. Containment has it place not saying it doesn't but only using that or always using that is like saying I can only work in a 10' x 10' area a lot can be done if we do not think we are always contained.

 

HTH

 

[ 04-29-2008, 06:44 PM: Message edited by: Crazy^Millman ]

[Justin Beebe at Folsom Tool]

Ron,

 

Good point! When circumstances allow I try to toolpath the part with the least geometry creation possible. Some times there is no way around it. I'll use boundries if needed but prefer not too.

[MotorCityMinion]

How do you set up a containment with Finish Flowline? I only see check surfaces there.

[Chris Rizzo]

quote:

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When circumstances allow I try to toolpath the part with the least geometry creation possible

---

+10000000 certainly no hard and fast rules but i have found starting with the least amount of geo and see what happens. THEN add check and containment if needed. Also alot is possible with other settings, ie. angle or depth limiting.

 

Motor,

 

Not all surf toolpaths support containment boundry, floline in one of them, therefore the option is greyed out. Just like how surf rough pocket doesn't support check surfaces.

[sharles]

I'm trying to use the surface rough restmill program and the tool is picking up on every stepover and I've got the gap set at 2000%.

 

Does anyone have any suggestions. Is the only way to keep the tool down is to use the newer high feed programs?

 

I've kind of stayed away from them because my computer is getting so old that it's slowing down on even the more simple toolpaths. So I'd appreciate, if possible, a solution to the old surface rough restmill program.

 

Thanks.

[Thad]

It's been a while since I've done any surface toolpaths, but isn't that just the nature of that particular toolpath? IIRC, Surface Rough Restmill is a planer toolpath, kinda like Surface Contour.

 

Thad

[Midwest]

Sharles, what is your step over?

 

I usually start setting the gap the same as my step over amount.

 

example: For a .005 step over I use a .005 gap.

 

works almost every time for me.

 

HTH

 

[sharles]

I'd have to open my current file (and it's a huge one) and see the stepover, but I'll give it a shot to just make the gap the same as the stepover.

 

thanks for the suggestions.