Pages

▼

Tuesday, July 21, 2015

Modifying Estes Engine Hooks? TIP

If ever I run across a engine hook "finger tab", I cut it off and smooth the sharp edges with a metal file. On a model like the Estes Mercury Redstone the standing rocket will rest on the engine hook finger tab. The fin trailing edges won't touch the display shelf!
Finger Tab engine hooks can get caught on clothes pins used to raise the rocket on the launch rod.
In the Odd'l Rocket RAISE Spring instructions I went into detail about how to avoid getting hung up at the launcher.

Last January, Jim (K'Tesh) posted a poll asking how many modify the engine hook finger tabs:


To see the entire forum thead, CLICK HERE

In post #5 David Stribling wrote:
We use clothespins clipped to the rod to keep the rocket off the blast deflector. After having several Estes hooks catch the pin and prevent liftoff, I started whacking them off.

In post #9, Bob Harrington wrote:
I don't actually remove the finger tabs. I just turn it around and install the engine hook with the finger tab at the forward end.

In post #10, Fast Cargo added:
Exactly what I do. By using this method in combination with an engine block results in a hook that is clean looking, and in combination with the 'tabbed' part being hooked around the engine block, minimizes the chance of the hook sliding out of position in either direction.
at

6 comments:

  1. LonnieJuly 22, 2015 at 9:12 PM

    "I just turn it around and install the engine hook with the finger tab at the forward end."

    For the life of me, I can't figure out how Bob can get the finger tab into the slot in the motor mount, and how Fast Cargo can get it "hooked around the engine block." Huh? What is this this magic? I'd like to see how they do it.

    That said, yes, I ALWAYS cut the finger tab off Estes hooks...when I use them. I also take the time to file the edges smooth so they don't cut under my fingernails. Estes hooks are wider than they used to be and I find them cumbersome to use on smaller diameter rockets. I only use Estes hooks on BT-55 and larger rockets. For BT-50 and smaller, I make my own hooks from the thin stainless steel spines in OEM windshield wiper blades.

    ReplyDelete
    Replies
    1. Chris MichielssenJuly 23, 2015 at 8:41 AM

      Hi Lonnie,
      I haven't tried leaving the finger tab on and flipping it over around the engine block. I don't see how that would work either.
      Most of the older builders will cut off the finger tabs, especially on a model (like the new version of the Mercury Redstone) where the model would stand on the hook, not the fins!
      We all used the old style elongated "C" shaped hooks without problems. So it takes an extra second to remove an engine, big deal!
      I'll leave hooks off BT-20 models. Having the hook and Mylar ring outside the tube and visible is ugly.
      I've probably made a hundred of the wiper blade engine hooks. I always replace the kit hooks that aren't made from spring steel.

      Delete
  2. AnonymousJuly 22, 2015 at 10:02 PM

    I always cut off the finger tab and then turn the motor hook around so the clean bend is at the back; saves some filing. I think the finger tab looks goofy, especially for scale or sport scale models.

    ReplyDelete
    Replies
    1. Chris MichielssenJuly 23, 2015 at 8:43 AM

      Hi Eero,
      I agree! Like I mentioned earlier, especially on a model like the Mercury Redstone where the model won't stand up because the hook is longer than the trailing edge of the fins.

      Delete
  3. UnknownAugust 22, 2015 at 12:09 AM

    I've heard a few people mention that the finger tabs may even effect the direction of flight by interfering and deflecting the thrust at an angle. I have never seen or experienced this, but noticed that the finger tabs come pretty close to the nozzles of mini motors. Thoughts on this?

    ReplyDelete
    Replies
    1. Chris MichielssenAugust 22, 2015 at 10:23 AM

      Hi Alpha Co.,
      On the 13mm engines, Estes has redesigned the finger tabs and made them smaller. The older 13mm hooks were too close to the nozzle. I don't think its a problem with the 18mm engine hooks.
      Here's a blog post with pictures from 2013 -
      http://modelrocketbuilding.blogspot.com/2013/08/new-mini-engine-hook-from-estes.html

      Delete