Thicken range, change the minimum

[mcvueiadh]

Hi everybody,

I have to thicken a huge surface (however it is as simple one) roughly 500 by 2500 mm. I would like to thicken it on 3 mm but I can't the minimum value possible of the range is around 5.5mm. I made different tests and I guess the thickening range is calculated based on the dimensions of the surface. Am I right ? Is there a way to change it ?

Because even if I thicken this surface on 3 mm there will be no collision. I tried with a mere plane surface, a simple rectangle of 500 by 5000 mm but it wouldn't thicken it with 3mm.

I'm using Creo 3.0

Thank you for your help and sorry for my broken english.

[bgruman]

Set your model to absolute accuracy.

File - Prepare - Model Properties - Accuracy - Change...

Choose "Absolute" and set a value.  (I typically use 0.05 for metric parts)

Good Luck

Bernie

Bernie Gruman

Owner / Designer / Builder

www.GrumanCreations.com

[bgruman]

BTW,  the steps listed are for Creo2.   Don't know if they are the same for Creo3...

[danderson]

Most likely you have a surface with a radius or curve  that when offset approaches 0mm or trys to go inverted or negitive. Try creeping up on it and have shade with edges turned on. Look for features that get smaller as you gradually increase the thickness. Hope this helps, Don Anderson

[MartinHanak · Accepted solution]

Matthieu,

I did this test:

• I created new parts (millimeters, default relative accuracy 0.0012)
• I created Fill surface - rectangle 500x5000
• I tried Thicken feature - it refuses thickness smaller than 6 mm
• File - Prepare - Model Properties - Accuracy - Change ... I changed relative accuracy from 0.0012 to 0.0001
• now I can create Thicken feature with thickness equal to 3 or 5 or 5.5 mm

So it is evident that the problem is related to model accuracy. There is huge difference between thickness and other dimensions.

Martin Hanak

[mcvueiadh]

Thank you guys for your help !

The accuracy did worked.

[dgschaefer]

FYI - Relative accuracy drives the smallest allowable edge by the model size, as you've discovered.  It's a ratio. 

Absolute accuracy sets the actual dimension of the smallest allowable edge.  It is unit dependent, so in a MM based part setting your absolute accuracy to 0.0001 means Creo will be allowed to create edges as small as 0.0001mm.  0.0001 is a good value for inch parts, 0.002 is fine for metric parts.

[JonathanHodgson]

Depending on the type of component you're modelling, you may be able to get away with much larger accuracy settings - I think ours is 0.01 mm (do you ever need to model a 10 micron step?).