Holverson Designs Tangent

Scratch - Holverson Designs Tangent {Scratch}

Contributed by Bill Eichelberger

Construction Rating: starstarstarstarstar
Flight Rating: starstarstarstarstar
Overall Rating: starstarstarstarstar
Published: 2013-06-17
Manufacturer: Scratch

Brief

The Holverson Designs Tangent is a big, stable sport flier from the second golden age of rocketry.  Designed by renaissance man Doug Holverson, the Tangent was unique in that it was one of the early kits to offer laser cut balsa fins, and eventually became one of the first rockets to offer cheesy foam.  Having built the foam Tangent previously, I'd long wanted to build an original balsa Tangent to be able to compare the two.

Components

  • BT-60 main body tube
  • BNC-60 nose cone
  • 2 CR2060 centering rings
  • 2.75" 18mm motor tube
  • CR520 engine block
  • engine hook
  • launch lug
  • medium screw eye
  • medium snap swivel
  • 18" parachute
  • 36" length of Kevlar
  • 36" length of 1/8" sewing elastic

Construction

My Tangent was a decade + old when I decided that I was a builder, not a collector, and started the project.  Mint in bag though it was, I found that the much vaunted laser cut fins had warped severely during storage, so I cut another set and put the originals under a heavy book for possible later use.  Construction was the same as building an Estes Big Bertha, Quest Big Betty, Semroc Vega or any other big, basic, 18mm-powered small field flyer.  Fins were attached with Elmer's Tacky Craft glue.  Fillets were made using plain old Elmer's white glue, which also was given the responsibility of making sure the motor mount stayed secure, which it performed admirably.  I tied a 36" length of Kevlar around the motor tube, then threaded it out through the front centering ring, attaching it to another 36" length of 1/8" sewing elastic to complete the shock cord.  A medium screw eye was glued into the balsa nose cone base and a medium snap swivel tied the whole recovery system together.

Finishing

I did away with balsa grain and tube spirals using the standard recipe of Valspar primer, thinned Elmer's Fill & Finish, and sanding.  After everything was up to my smoothness standard, or rather, down to it, I sprayed the nose cone and fins with Testor's Italian Red.  The fins were then masked off and the main body tube was sprayed with Valspar gloss white.  The decals that came with the kit were stick ons, but they'd lost much of the adhesive over the years of storage, so I printed off some inkjet decals using a scan at YORS (http://www.oldrocketplans.com/hdi/hdi2001/hdi2001.htm).  Everything looked great when I was finished.

Construction Score: 5

Flight

First flight was the final flight of Opening Day, 2013 at B6-4 Field.  I like the BT-60 birds at B6-4 Field because when loaded with a B6-4, BT-60 birds fly to the level of the field.  Every bit of the flight is visible, the slow takeoff, the flight to treetop level, ejection, and recovery.  Winds sometimes cause some problems, but if one uses his head, one recovers all of his birds, and gets flight pics to boot.  The Tangent flight on this day was probably one too many, and I almost paid for it.  Winds were coming from the southeast, which was causing some windcocking over toward the school, but nothing in the way of recovery issues with the triple threat of the trees, wires and US 27.  The Tangent left the pad and hardly windcocked at all, but at ejection it raced across the field, first missing the trees, then wires.  I had dropped the controller and started running as soon as the breeze took it, but I could see that one way or another it was going to be in trouble.  I crested the hill just as it passed under the wires, but could tell that I was going to be nowhere fast enough to prevent it from landing in US 27, and I could hear traffic as I ran.  It fell out of my sight for just a moment, just as a Hyundai Accent buzzed past in the right lane.  I waited for the crush sounds, but heard nothing, and as I approached the landing area, one of the Little League dads who was packing up to leave darted out to pick the Tangent up from the left lane.  I thanked him profusely, answered his questions; yes I could fly it again, no the motors aren't expensive, yes I often have them land in the trees around the field.  Damage was relegated to achipped fin tip from the landing.  Considering the alternative, I counted myself fortunate indeed.

The second and possibly final flight was another B6-4 Field flight on a B6-4.  The Tangent was the last flight of the day and the previous seven flights had all followed the same flight pattern, windcocking to the left and ejecting at the edge of the field, then recovering somewhere on the infield.  All but two of the flights even used the same chute.  The Tangent flight was nothing like the others.  It left the pad and flew straight and oddly high until catching the breeze just before the treetops.  Ejection occurred just as it was tipping over, and the rocket immediately caught the breeze and began to drift quickly toward US 27.  It was pretty obviously going to clear the road, but it looked like it was going to hit the parking lot or building directly on the other side.  I was half right.  It hit the roof, where the breeze died and left it stranded.  I considered going home for a ladder to make a quick climb and grab, but the local police have a tendency to show up at inopportune times like this and I wasn't sure the situation would be explainable.  I'm hoping we get a decent storm that blows it down in the next few weeks.  All I need is the nose cone.

Flight Rating: 5

Summary

Pros: Classic style.  Great small field performance.  Seldom seen at the pad.

Cons: Gave birth to the cheesy foam revolution.  Viva le balsa!

Overall Rating: 5
 

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