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 ^]

 


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