Responsible Engineers: Dave, Trevor, Abraheim, Adam

Overview:

• Can't put a huge aluminum cylinder on the lathe. 

• Can't assume the cots cylinder is perfectly smooth/uniform... it will have some imperfections and be warped.

Problem: 

Screw holes are not radially symmetric (run-out tolerance is too high)

Proposed Solutions:

Get inside circular (using cylinder hone)

Cylinder Hone:

[As seen on mscdirect ^]

• Allows us to clamp chuck from inside of the cylinder when radially indexing (?)

• Cylinder hone extension (allows us to reach deeper into the rocket): here

• Change stones on cylinder hone to 320-grit sandpaper: here.

Find a way to make the outside circular, then radially index how we have been

• Build a new tool to attach to drill?

• Use homemade woodturner to slowly turn and sand the outside?

Next Steps:

• Order cylinder hone online

• Replace stones with 80 grit sandpaper.

• Look at homemade turning tool

• Research industry solutions

• Ask around about any bigger lathes on campus

Max Height: 8 feetz

Big Cylinder:

6’’ Diameter

7’ height (upper end)

Small Cylinder:

4’’ Diameter

4’ height (upper end)

Tools:

• Engine Cylinder Hone 

• Homemade wood turner

Resources:

https://www.sandvik.coromant.com/en-us/knowledge/drilling/radial-adjusted-drilling

https://www.keyence.com/ss/products/measure-sys/gd-and-t/type/run-out-tolerance.jsp

https://www.gdandtbasics.com/circularity/

Information:

• Runout tolerance = Axis offset + Total circularity

(a.k.a. how much it wobbles and how far from a perfect circle it is)

• Proposed solution online: Straight surface + diameter gauge?

Gameplan:

Circularize interior using an engine hone

• Attaches to a drill and rotates three spring loaded grindstones that remove more or less material based on their spring pressure.
  
  

Circularize exterior using an improvised lathe

• Attach cylinder to a motor after the interior has been circularized (friction fit with laser cut wood circle?)
• Attach other end to a bearing so it can rotate (also friction fit with laser cut wood circle?)
• Fix a piece of sandpaper at a set diameter and move it up and down the cylinder until the entire thing matches that diameter (check tolerance at multiple locations to reduce error).

       Backup method: Use a centerless grinder (more work but potentially better results)

• Cylinder sits on a rest while a grinder is rotated next to it
• A second regulating wheel is moved in to apply pressure and rotates without slipping with the cylinder

[As seen on Wikipedia ^]