Flexible Sight Glass Installation 

Another informative video. Thanks again.

First time I have ever seen the grinder wheel installed upside down...but hey, if it works, it works...

Where did you buy the flexible sight tube and fittings? Also, side note about the drilling, if you use an oil or lubricant it helps keep the metal cool and should make it a lot easier to cut with the step bit.

5:28 Your grinding disc is upside down.