Friday, March 26, 2010

Helix Bow Compass and Staedtler Halfpipe Pen-style compass comparison and early test

While browsing through the clearance section of a big box retailer, I spotted this carded Helix bow compass for 75 cents.
Gotta admit I picked it up mostly because the existence of 2 mm compass leads was still fresh in my mind thanks to a recent post in Pencil Talk.
Got a pen-style compass out of storage for a quick comparison. Coincidentally both compasses were manufactured in China.
The Staedtler Halfpipe pen-style compass could travel well in a sketching kit thanks to its safety cap that protects the lead and needle while keeping it securely closed in its pen-form. Its barrel has a storage container for 3 pieces of spare lead. Sadly these nice features do not amount to much given its performance as shown below.
The Helix bow compass came equipped with a softer graphite lead and held its setting well, so it efficiently drew darker circles with precision at the first try (up to 8" in diameter"). Its center wheel allowed for minute adjustments, and its metal construction felt sturdy enough for its price point (though I would not bet much on its resistance to rust). By contrast, the Halfpipe loaded with a harder lead did not hold its setting during successive passes drawing unwanted lighter ever larger concentric circular outlines (up to 12" in diameter). Thus despite its protective cap and built-in lead container, this Staedtler compass would not be a good choice for use in a Geometry class or any other application that might require it to hold high-precision settings. Still they might be of some use in upcoming cartooning classes.
While I normally prefer to draw 100% freehand, I think both of these compasses might serve some students to lay down the initial construction circles for creating their own Pokemon or Bakugan style monster capsules.

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