Making cluster centering rings in OpenRocket

Is it possible to make centering rings for a motor cluster mount in OpenRocket? I've tried, and either it creates a ring with a single opening (which doesn't accommodate the three - in this case - motor tubes), or it creates a weird, multi-ring shape which pokes through the body tube. Seems like this should be a basic design element.

lcorinth said:

Is it possible to make centering rings for a motor cluster mount in OpenRocket? I've tried, and either it creates a ring with a single opening (which doesn't accommodate the three - in this case - motor tubes), or it creates a weird, multi-ring shape which pokes through the body tube. Seems like this should be a basic design element.

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Can't answer your question concerning Open Rocket. I can't seem to get this program to work on any of my computers. Must be something i'm doing wrong but that's beside the point.
You don't need Open Rocket or any other sim's program. you can layout cluster centering rings with just about any drawing program or with compass and ruler long hand. All you need is the OD and ID diameters of your airframe and motor tubes.
I've done this for years in Corel Draw. We're Up to CorelDraw x7 but one can purchase much earlier versions for next to nothing or it's possible to layout cluster mounts in Window Paint.
I stack cut Cluster Centering rings on a scroll saw simply by drilling holes in the openings and cutting out the centers. Then use a drum sander to smooth out the ID's. OD is sanded to fit on a belt sander.
The Trick to stack cutting 2 to 10 centering rings is to use double faced masking tape between each layer. This makes it easy to cut many rings at the same time and all exactly the same.
Hope this helps

Yes. Check out my SA-3 Goa build over in the LPR section, its booster is a 3 inch with a 5 tube cluster, the rings were printed on cardstock then cut from 1/8inch aircraft ply. Sorry I dont currently have the ability to go into further depth

The secret with Open Rocket would appear to be:

1. Only add ONE inner tube.
2. Select the CLUSTER tab from the edit dialog for the part.
3. Select the Cluster configuration wanted.

Open Rocket will take care of multiplying the tubes for you.

4. Should you need to make changes to one tube only (IE make a larger center engine), select SPLIT cluster.

Add your centering rings to the MAIN tube (not engine tube) after you are all done tweaking the cluster.

Thanks RWW: adding the centering rings to the main tube after finished tweaking the cluster.

Unfortunately in OR, you will still see the unwanted center hole in Rocket Design view. In this view, the 6 motor tubes are seen slightly protruding the centering ring, but those aren't actual holes in the centering ring:


...but when printing/exporting the design to PDF, the centering ring looks as it should, i.e. holes for 6 motors and no center hole.