D.I.Y. Couplers - Tip

I needed a coupler "sleeve" to fit a Centuri sized ST-18 (1.8" diameter) tube.

This is for a second prototype of a possible Odd'l Rockets ROBOT kit.

You can't find couplers in this size so I'll have to make one using a 1" length of the ST-18 tubing

Cut the coupler in a straight line using scissors.

Slip the cut coupler and mark the overlap with pencil.

On the left, you can see the pencil line.

Cut off the overlap, not directly on the line, but a little large.

Test the fit in the outside tube. 

Is it is too tight, you can sand to fit with some 220 grit on a block. 

Enlarge the right side picture to see a perfect fit in the tube.