Side Scan Sonar Tow Cable Sheave

Deigned by:  Dan Scoville

Machined by:  Dan Scoville

Goal:  Make a sheave to hold a 0.1875 inch diameter steel cable for towing the side scan sonar.

I can not take full credit for the design of this sheave.  I patterned it off of a sheave I saw online somewhere but did my own design work after that.  As you can see from the CAD files the sheave can be opened by pulling a couple pins and pivoting the side plate around.

I stated with two 1/2 in thick pieces of aluminum rough cut into circle to make the sheave wheel out of.  I do not have a lathe big enough to turn the sheave wheel on so making it in halfs was the next best choice.  I cut the outside diameter of each part and then angled the head of the mill over to profile the area where the cable would lay.

Finally I cut the center hole in the wheel where the axel and bushing will go.  

Next I flipped over the side plate and machined out some material to lighten the part up.   The side plates were bolted together and I machined in 4 holes to further lighten the part and make it look better.