rotating mechanism - help and advice needed.

[Brandlin]

Hi guys

I'm responsible for this
http://brandlin.blogspot.com/search/label/Dropship
I know a few of you have commented on another thread and voted on the blog.

I'm need some inspiration.

I want the 4 engine pods to be able to rotate to enable verticle take-off and forward propulsion. I dont want anythign as sophisticated as a motorised movement, I just want to be able to pose the model (for wargaming) in a number of different configurations with all the engines aligned.

I intend to cast this item in resin fo i have half a dozen or so for my own use and who knows someone else might like one or two!

My thoughts so far have been to locate magnets in the centres of the 'joint' so as to hold the engine pods to the body. I could then cast the pieces with a recess ready made for the magnets to be glued in.

The requirements of the joint are:

1. Positively locate the engine so that it doesn't swivel.
2. Allow all four engines to be identically positioned.
3. Allow all four engines to be individually positioned.
4. Range of movement of 180 degrees
5. Minimum step of say 15 degrees - say 12 positions.
6. Must be something that can be cast onto the body of the hull or the side of the engine in resin

I have looked (on the net) at a number of the aftermarket joint parts for gundam models, but these don't seem to have the positive step locations i'm looking for, they also seem to reply on the soft plastic/rubber qualities of the material they are cast in to ensure a tight non slipping fit which i couldn't recreate in resin.

I have bought some ABS plastic rings which fit snuggly into each other. I'd then place one ring inside the other, mark out the locations and drill through the join between the rings. Then by glueing say a piece of brass rod (with a slightly smaller diameter than the drill used) into one of the mating sides the two rings could be located one inside the other in any position where the brass rod alignes to a half hole in the other ring.

like this (but with more holes)
http://kolvyr.wikispaces.com/space/show ... ocator.gif

Alas I have been unable to drill the holes accurately wnough to allow this approach to work.

Can anyone think of any other mechanism, along with ready made components that would give me the joint i need?

[Kylwell]

Well... you could steal some click joints from Lego kits. If the resin is tough enough it'll handle it.

[Chacal]

Ribbed conical bottle/tube caps.

Take the cap of a toothpaste tube, for instance. It is conical, and the knurls are regular. If you make an indentation on the fuselage using that shape as a pattern, and a corresponding male on the engines, and if you go with the idea of using the magnets, just pulling the engines a little bit out and rotating them a few degrees will make them 'click' into a new position.

By the size of the contact lens thingie, I think a toothpaste cap will be okay, but you might look into something smaller.


[I haven't read all the posts on the blog, but the fuselage—is it a Listerine bottle? BTW, why not enter it in the 'pick-a-part' 'contest'?]

[Umi_Ryuzuki]

If you want easily obtainable, and repeatable pieces, then
the KS brass tube will work as a socket. the pin can just be cast resin.

[Brandlin]

Thanks for the ideas guys....

I think i have solved it though! Update on blog.

Brandlin
http://brandlin.blogspot.com/