Looking for engineering input

[ToolFool360]

Howdy! I’m building a launch tower for a rocket and looking for some engineering ideas.

The main goals for the design are to accommodate rockets with different airframe diameters while keeping the tower easy to assemble, adjust, and use.

I’m currently trying to figure out a mechanism that allows the three inner rails to move in sync. Ideally, moving one rail would cause the other two to move with it, keeping them evenly spaced around the center axis of the tower. I’d also like a way to lock the rails securely in place once the desired diameter is set.

Does anyone have ideas for mechanisms that could achieve this? I’d appreciate any suggestions, examples, or design inspiration!

Thanks!

[ToolFool360]

Forgot to attached file

[davebYYPCU]

Easy in fusion, choose a revolute Joint on one arm, and Motion Link the same joint on a second arm.  Lock movement to the 1:1 ratio.  Repeat for the 3rd arm.

Real life, would need the rocket centered, the arms tightened in place with bolt or wing nut system.  (Removable cone shaped Jig)

Might help...

[Drewpan]

Hi,

How you work out this engineering problem will depend upon the usual

Constraints. How much do you want to spend and how much work you

want to do. If I were creating this design then I would consider a simple

screw system where each "leg" was on a screw and you adjusted the screw

to get the correct distance from the centre. Think like a 3D Printer moves

the print head around, screws and cable drives. In this instance I would

use a small motor screw drive to turn the screws and simply sync them

up until they all worked at the same time.

Here is your issue. Cheaper motor drives may not necessarily all drive at the

same speed. One motor may be say a 1/4 turn slower per minute than another

drive unit. This is not so much of a problem with small threads and small

distances but the more precision you need the tighter the threads and the

more control you will need on your motors. This is one of the reasons that a

Stepper motor is much more expensive than a simpler system. With a stepper

motor you can control exactly how many steps the motor will move. With fine

thread screws you can have very precise accuracy.

I would have a look for basic robot or 3D Printer designs out there and see

what affordable Off The Shelf hardware they use and go from there. Also

remember that you are firing a Rocket so heat shielding will be important

unless you want to rewire and change the system every time you launch.

I would also have a look at the Stiffness of the rail assembly you are using.

It looks a little flimsy to me and may need one or two extra reinforcements.

If a Rocket vibrated enough it may be possible to shake out of the clamps

and get jammed within the rails. This would look fairly impressive until just

after everything goes Boom and you realise that Rocketry is an expensive

hobby. Look at Uncle Elon and how much he spends on his Hobby.

I would probably use a similar design but to reduce vibrations I would use

four triangle sets, at least for the bottom section and three if you joined a

second section to that. You shouldn't need more than that unless it is a

really BIG Rocket. In that case you may consider a Free Standing launch

with drop away stabilisers.

Cheers

Andrew

[BetterWithTools]

Just a bare bones basic example but something like this top and bottom could be linked and held in place wth wingnuts on studs from the top Rail/clamp.

[ToolFool360]

this is a similar idea to what lathe chucks use to bore them. I didnt think of that. IM not sure how id integrate it into the design but it could possibly be used as a blast plate too.