3-D-printed digital torque meter
by Don Slusarczyk
don@slusarczyk.com
3-D printers have become quite affordable for everyday consumers and modelers. The printer that I currently use is a Prusa i3X and it costs approximately $300. It can print a part up to 8 x 8 x 8 inches in size. For Indoor Free Flight (FF) modelers, this means we can design and print out jigs, fixtures, tooling, or whatever else we can think of to assist in our hobby.
Jake Palmer recently designed and published files for a digital torque meter that uses 3-D-printed parts. Jake’s version is based on a Bill Gowen design, which uses the internal components from a pocket digital scale. The 3-D print files are located on a website called Thingiverse as item #2441787.
The total print time was approximately 8 to 9 hours for all of the required parts. For those without a 3-D printer, there are 3-D print services that can print the parts for you. Your local library or university might also have a 3-D printing service.
The heart of this torque meter is a load cell and digital display taken from a $10 pocket scale purchased on Amazon. Other items that you will need to build the scale include screws, a AAA battery box, and stop collars. There is a parts list on Thingiverse with the additional items needed. I also did a build thread on the Hip Pocket Aeronautics forum with step-by-step instructions and photos of the entire assembly process.
For those who are not so adventurous to make one of their own, Jake is selling fully assembled torque meters for a limited time. The funds received from the sale of the meters will help the 2018 Junior F1D Indoor team.
T-shirts are also available for purchase to help fund the 2018 F1D Indoor team. Visit www.indoorfreeflight.com for details on how to order shirts, as well as how to contact Jake for a torque meter.
Kent State Contest Update
Last year, we were unable to secure a date for a contest; however, working with the new athletic director, we have obtained dates for a two-day contest. The contest will be Saturday and Sunday, April 28-29, 2018, from 8 a.m. to 8 p.m. each day.
Kent State is a great Category II site and many records have been set there throughout roughly the past 15 years. The fieldhouse has plenty of floor space, a full-size football field with a track around it, and the ceiling is peaked in the middle, which is good for Glider events.
For more detailed information about the contest, see the flyer that is posted on Indoorfreeflight.com, or email me at the address at the top of this column and I will send you a copy of the flyer.
Indoor Record Updates
At the October contest in Hangar #3
at Rantoul National Aviation Center in Rantoul, Illinois, Kurt Krempetz established a new Category II record for
Unlimited Catapult Glider. His record flights were 60.8 and 61.8 seconds for a 2:02.6 total. This is an amazing record because the ceiling is only 44 feet high! Josh Finn recently set the bar high for Category 1 F1R (35cm) in a September contest held at St. Luke’s gym in Dunwoody, Georgia. Josh did a 28:07, surpassing flying buddy Nick Ray’s existing record of 26:35 that was set a month before. However, at the October contest in Rantoul, Nick struck back with a 27:22, besting Josh’s 26:39 record. During Labor Day weekend at the hangar in Lakehurst, Illinois, Brett Sanborn set a new Category IV F1D world record of 32:09! Joseph Szczur (a member of the Junior F1D World team) set the youth Senior Category IV record for F1D at 18:07, which beat the previous record of 17:31 that he established at the F1D Team Finals. Ross Clements (also on the Junior F1D team) set the youth Junior F1D record of 16:14 at the team finals, as well as an A-6 record of 4:38. Congratulations to all of the new record holders!
Fiberglass Propeller Forms
Mike Kirda is now selling fiberglass molded propeller forms in various pitches and cambers. These molds can be used to make built-up propellers for F1D or the cambered molds can be used to make sheet balsa propellers for events such as F1L and Limited Pennyplane. Check out Mike’s website, Propblocks, for information about the current mold sizes he offers, as well as other indoor items he has for sale.
Until next time, keep the weights down and the times up!
SOURCES:
National Free Flight Society (NFFS)
www.freeflight.org
Hip Pocket Aeronautics Builder’s Forum
www.hippocketaeronautics.com/hpa_forum/index.php
Indoorfreeflight.com
www.indoorfreeflight.com
Propblocks
propblocks@gmail.com
www.propblocks.com
Thingiverse
www.thingiverse.com
