Calculating warp for the rigid heddle loom

At a request from a student, I have put together a warp calculations sheet and a companion video. Both are available here. You do need to sign in to access the materials, but I have made these completely free for your benefit. The video can be viewed on Youtube if you prefer. 
The printable PDF includes a sample sheet and in the video I take you through another sample, just to make sure you "get it"!
I have already had a huge amount of positive feedback from students who have found these useful, so please take a look if it's of interest to you.
Happy Weaving!