Patterning problem, sketch planes..

[Phizinza]

So I've got a problem. I need to rotate a Circular Pattern. See in the picture where the cut outs are (blue highlighted) they need to not sit over the half cut outs in the bottom of the piece, instead the left over "tooth" part needs to sit over them. See the hole to the left, that needs to come through the top of one of the "Teeth". Anyone know how I can do this?
Its because I drew the sketch for the Revolve on the Front Plane. Then used the top surface with the Revolve sketch to define a Plane1 to draw the cut outs on... I also used the Front Plane to draw the half round cut outs under it.

 

[michael3130]

Phizina,


I'm not 100% sure I get what you're trying to do but do you mean you're trying to leave out some of the instances of the pattern, like miss out every 4th one?? If that's what you're trying to do in your pattern featurethere should be a box for skipped instances. When you use the feature tool a preview will appear as a white dot, just click on it and it will turn black so it will be missed out.


I may be way off the mark so let me know if I understood right. It is only 8.35am and I'm never awake till noon

 

[Phizinza]

No. Heres another images to help explain.

What I want is the part in the green circle over the part in the yellow circle instead of the part in the red circle there. I hope I haven't just complicated it more for you.

Basically I'd like to just rotate that top pattern-extrude cut around but I don't think that is possible. I've already gotten the part almost finished (these images have a lot suppressed). So I really would hate the idea of having to start again. :-/

 

[michael3130]

Told you I wasn't awake yet. Let me think about it for a short time and come back to you to see if there's any easy way to do it.

 

[michael3130]

Can you show an underside view? Is your cut-loft feature used for those bottom cutouts?


The problem you have then is just that the cutouts for the teeth at the top are out of sync with the way you want them to be with the bottom circular cutouts. If you have used the standard planes to set up these features then it wont be that easy to sort the issue.


What you're best to do when you're creating this sort of part is to add additional planes which the features are referenced off which can be rotated to allow for changes in your design.

 

[jimshaw]

Phizinza - You need to focus your efforts on the first feature of that pattern. If the original featureis sketched on the front plane (for example), then create a datum plane that is 90* from the right plane (same exact location as the front plane). Slide this new datum plane as high up on the feature tree as it will go. Now edit the sketch plane of the original feature (the one which was patterned) and select the new datum plane, it should regenerate with no issue, since no geometry has moved. Now edit the 90* to 0* or 180* and cross your fingers.


Not sure if this violates your design criteria, but you could also move the half cutouts on the bottom as well...

 

[Phizinza]

micheal3130, Heres the bottom

jigshaw,
I'll give that a go, but instead I might work it on the bottom side features as they are only related to the standard planes where as the top "teeth" features are related to a plane which is related to the first revolve sketch which was drawn on the standard front plane.

I'm slowly learning things. So next time I want to draw up something rounded I will make new planes first, as these can be rotated? I'll report back after trying that datum plane thing on the round cut outs under the part.
Thanks!

 

[jimshaw]

Aren't parent-child relationships awesome! Don't forget to either backup a last known good model, or work on a copy - you know, in case you piss off the CAD gods while regenerating things...

 

[Phizinza]

Its done! I done what you said jimshaw. Took a bit to fix up the extrude cuts on the bottom and the loft cuts down there too but it worked. Here is it fixed.

Thank you people, very helpful yet again!

 

[michael3130]

Nice one Phizina, well done. Jim explained it well


CAD gods....lol.

- you know, in case you piss off the CAD gods while regenerating things...

 

[jimshaw]

Fantastic! Glad it worked out! Can you share with us what this part does? I love hearing about the different applications...

 

[Phizinza]

This is for a Suzuki Differential, it fits in to replace some of the gears that let the differential differentiate speed between left and right wheel. What it does is turns the differential into a ratchet device, in a way locking left and right together but letting them ratchet around if they need to turn more then the slower wheel. It's called a Diff Lock normally. Its mostly used offroad where if you lift a wheel of the car while going over a rock you would normally loose all your engine power to that wheel. With this modification the wheel in the air would be locked to the wheel on the ground and thus you still get drive.

I'm actually just copying this piece from one I have in my hands. The plan is to use this design and modify it to fit a Subaru Differential. I figured it would be easier creating a direct copy and working with that instead of leaving all the sizes and math on paper. Next step is to measure gaps and sizes with it fitted in the Suzuki differential then measure the Subaru differential and hopefully just resize this drawing I have to match the Subaru. If that fails at least I know how to draw one from scratch now that I have already done it!

Thanks again guys!