The ‘earn your subscription’ scheme rewards calculation uploads with XLC Pro subscriptions and allows ExcelCalcs to:
• Thank users who delight us with their contributions.
• Generate content to enrich the site.
• Open the site to users regardless of their ability to pay (students, retired people, people from poor countries, people from non profit organisations…).
• Incentivise new users to 'learn and earn' their XLC Pro subscription.

 You need to co-ordinate with site administrators via the forum to prevent repetition of calculations and follow our advisory notes so that we have a consistency of quality and style across the Repository. A long standing objective for ExcelCalcs is to create the world’s largest repository of Excel calculations. There is a whole world of mathematical problems out there; we’ll never do it alone and we are only too happy to reward your contributions with XLC Pro subscriptions.

The ‘earn your subscription’ scheme also allows us to eliminate bureaucracy from the ExcelCalcs subscription process. Previously we have differentiated between commercial users and educational users. Difficulties arose in the verification of student ID’s and tracking their transition from educational user to commercial user. Retired engineers complained that they are neither commercial users nor educational users but like to ‘keep their hand in’. So we have decided to stop differentiating altogether and use the ‘earn your subscription’ scheme as the 'open door' to the site. To be a member now you need to actively contribute in some way (either financially or by donating calculations). 

XLC Pro (12m) Discount Coupon

Our new subscription regime means that XLC Ed subscribers will no longer have such extensive access to the repository. To encourage users who wish to pay for an XLC Pro subscription we have issued a discount coupon code “NDNJY2” for a $20 discount on an XLC Pro (12M) subscription – it will expire on the 19th September 2009 so be sure to use it before then.

“How do I use the coupon code?” - Just select the XLC Pro (12M) payment plan and you’ll be prompted to enter your coupon code on the checkout page. You will see the cost reduce from $90 to $70 before you are sent to the Paypal site.

Repository News

viveksood72  submits RETAINING WALL.xls

Eng.filipe submits  Filipe EC3.xls

Astronautic Structures Manual (On-Line)
Abstract: This document (Volume 1, 2, and 3) presents a compilation of industry-wide methods in aerospace strength analysis that can be carried out by hand, that are general enough in scope to cover most structures encountered, and that are sophisticated enough to give accurate estimates of the actual strength expected. It provides analysis techniques for the elastic and inelastic stress ranges. It serves not only as a catalog of methods not usually available, but also as a reference source for the background of the methods themselves.

fastracer20 submits pipe_flow.xls - This is the pipe_flow.xls file that was submitted by John Doyle a long time ago. I found it to be very useful in metric units, but I am in the states in the gasonline (petrol) industry so I took the time to convert everything to English units. I also added a few things such as a line for an orifice plate. Everything is still based on Crane Flow of Fluids except the orifice calc, for which I have no reference for the imperical equation.

JStewart submits  Relative Velocity.xls

AFingle submits  Constant Acceleration Motion Calculations.xls
Excel encoded the HyperPhysics Motion page following the conventions and advisory notes set out on www.excelcalcs.com/earn-your-subscription/.

m4grem submits BTH pinned plate reworked.xls

pneumatic  submits vehicle acceleration calculation.xls