tent completed

The tent is complete with 17 hours to spare before departure to South America (Aconcagua). Time to eat, sleep and prepare for the next phase of work to be done.

Photo Source: Andrew McCarthy / Date: 2.11.2012 : 2102 / Location: Ann Arbor, MI

inner tent complete

The inner tent was completed February 9. This was a large hurdle in the work and now I am moving quickly into the completion of the fly, and then into final waterproofing sealants and touch ups.

Photo Source: Andrew McCarthy / Date: 2.9.2012 : 1743 / Location: Ann Arbor, MI

the art of sewing

Over the past few weeks sewing has become a major mode of the fabrication process. The methodology for working has allowed for a blend between the digital and analog. It has not been a linear process, but an integrated one that incorporates highly articulated digital modeling software and analog means for construction using hand measurements and adjustments. Sewing is at the forefront of the hands on process, where it enables a high sense of craft and deliberate control over each piece of material. Every stitch has its own ability to generate the fabric form of the tent.

Photo Source: Andrew McCarthy / Date: 2.8.2012 : 0904 / Location: Ann Arbor, MI

test fitting the fly

The initial test fit of the fly (which covers the inner tent) was successful. The proper fitting confirms that the double curvature was calculated correctly. Next step is to complete the inner tent, attach it to the base, and then complete the fly. Flight leaves at 3pm on Sunday Feb. 12, so no time to waste.

Photo Source: Andrew McCarthy / Date: 2.9.2012 : 1238 / Location: Ann Arbor, MI

shifting to full scale

Shifting to full scale requires careful consideration for tolerances, especially with regards to the sewing offset for the ripstop nylon fabric. Currently the base with the reinforcements is complete, and now beginning to work on the inner tent construction.

Photo Source: Andrew McCarthy / Date: 2.6.2012 : 2204 / Location: Ann Arbor, MI

when the dust settles

The test has informed the next iteration of design about several modifications that need to be implemented. This includes widening the rear cross member, creating areas of ventilation on the top middle panel near the rear, inserting vents along the lower corner panels for exhaust ventilation, and change in seam length. These changes are being integrated into the final design and fabrication which is already under construction for the February 12 departure to Aconcagua where it will be tested in extreme conditions for 24 days.

Photo Source: Andrew McCarthy / Date: 2.2.2012 : 1302 / Location: Ann Arbor, MI

wind tunnel testing

Aconcagua is known for its extreme winds, and therefore a wind tunnel test was imperative to simulate these conditions and understand the accountability of the structure. The tent was able to sustain wind speeds ranging from 60-80 mph before minor tears occurred. The last test of the day challenged the efficacy of the design with wind speeds up to 122 mph which put the tent in complete failure, blowing out the back door and tearing apart both sides.

The video below records the last test of the day. The numbers being read off are referencing air velocity in feet per minute to an engineer that is reading back the wind speed in miles per hour. This is a rough cut, and the final video will be posted in late march

 

Photo Source: Andrew McCarthy / Video Source: Andrew McCarthy / Date: 2.2.2012 : 1158 / Location: Ann Arbor, MI

wind tunnel preparation

To ensure that the wind tunnel produces accurate testing results, the preparation is critical. The initial phase of preparation involves working with Aerospace engineers place bolts into model which secure it to the tunnel, and then review various tests that are going to be run so that the results desired are tested.

Photo Source: Andrew McCarthy / Photographed (lf /rt): Andrew McCarthy, Chris Chartier, Nate Anderson / Date: 2.2.2012 : 1241 / Location: Ann Arbor, MI

pole fabrication submitted

The pole design for this tent requires pre-bent rods creating curvature that can match with the digital model. This will enable the fabric to respond accurately, and with tension when it is set into the structure. The pole design was generated by the space required for interior movement of my body. Vertical height is given when sitting up is required and slope occurs near the feet. This creates an aerodynamic nose to orient into the high speed winds on Aconcagua.

Drawing Source: Andrew McCarthy / Date: 1.29.2012 : 1014 / Location: Ann Arbor, MI

nearly complete scaled prototype

The first design prototype (1/2″ = 1′ 0″ scale) is nearly 90% complete. The final touches will include guy line tension cords and stakes that will keep the fabric taught, and assist in keeping the tent rigid in high winds and extreme weather conditions. This is the model that will be tested in the Aerospace engineering wind tunnels on Thursday Feb. 2. A little work left to do and it will be ready for testing.

Photo Source: Andrew McCarthy / Photographed: Andrew McCarthy / Date: 2.1.2012 : 2358 / Location: Ann Arbor, MI

testing the efficacy of the digital

The use of digital modeling software and scripting to create accurate double curvature needs to constantly be reviewed and tested with regards to the fabrication and material constraints. These are conversations that occur daily, enabling the project to continue its fast track pace, and see fruition in the next week.

Photo Source: Andrew McCarthy / Photographed (lf /rt): Prof. Shaun Jackson, Andrew McCarthy / Date: 1.30.2012 : 1506 / Location: Ann Arbor, MI

the power of the zund knife cutter

Working late into the night to study the double curvature in digital software and then cut out the fabric (zund knife cutter) for the final 1/2 scale prototype model that will be tested in the wind tunnel Thursday Feb. 2 at speeds up to 90 mph.

Photo Source: Andrew McCarthy / Photographed (lf /rt): Nate Anderson, Andrew McCarthy / Date: 1.29.2012 : 0522 / Location: Ann Arbor, MI

taking measurements

The design for the tent is generated from the scale and movement of my body, area of my pack, and size of my boots. The first step was to take simple measurements, and this was a revision of those measurements to ensure the proper interior dimensions before submitting poles for fabrication.

Photo Source: Andrew McCarthy /Photographed: Andrew McCarthy / Date: 1.26.2012 : 2241 / Location: Ann Arbor, MI