Sunday, April 30, 2017

New Rotary Punch? Tools - TIP

I use a rotary punch (leather punch) on almost every rocket build.
Holes are punched in centering rings, these are some hand cut rings so the center holes are a little rough.
Instead of punching holes in parachutes with a pencil I make shroud line holes with the rotary punch.
TIP: When punching small shroud line holes in a parachute, always place thin cardboard underneath the plastic sheet for a cleaner punch.
On the right are holes punched for an altimeter payload. Punched holes are much cleaner than a hole drilled with a knife blade tip.

After a few thousand punches my old rotary punch was getting dull. I bought a new one at Home Depot, The name brand was "GENERAL", it has black handles. I can't recommend this brand.
Look close at the punch tubes. The tubes on the right have a slight taper at the cutting edges as if they are sharpened. The General brand punch certainly works but the tube ends aren't sharpened.
The two holes on the left were punched by the Home Depot General brand punch.
The two holes on the right were punched using the tool I bought today at Michael's crafts. This new punch has red handles. You can easily see the difference in the cut.

On a recent purchase at Michael's crafts I signed up for their emails. About twice a month I get an online coupon for 60% one item! With that coupon my new, better punch was only about $4.00.
My local Michael's doesn't have a great selection of rockets, but I'll use the coupons for other supplies.


  1. That tip is very useful! I've tried using a rotary punch for shroud line holes, and got so frustrated, because I wasn't getting a clean cut. It never occurred to me to put a bit of cardboard underneath!

    1. Hey Daniel,
      Use the thin, single layer cardboard like cereal box board.