Parachute with spill hole question

Discussion in 'The Watering Hole' started by noffie79, Sep 2, 2015.

Help Support The Rocketry Forum by donating:

  1. Sep 2, 2015 #1

    noffie79

    noffie79

    noffie79

    Well-Known Member

    Joined:
    Jul 25, 2015
    Messages:
    1,287
    Likes Received:
    1
    I primarily fly Estes PS II kits and have up till now used the cheap 24" nylon chutes that come with them. I wanted to find a better chute, so I ordered a 15" Fruity Chute. I understand that the spill hole reduces oscillation, but does that also result in a faster decent or less drift?
     
  2. Sep 2, 2015 #2

    noffie79

    noffie79

    noffie79

    Well-Known Member

    Joined:
    Jul 25, 2015
    Messages:
    1,287
    Likes Received:
    1
    Also, the 15" Fruity was rated as 0.9 pounds (14.4 oz) at 20 ft/sec. I have a 20 oz Leviathan. Wondering if I should've went with the 18" instead? Of course, not all of my rockets are that heavy. Any input would be greatly appreciated!
     
  3. Sep 2, 2015 #3

    Darian Rachal

    Darian Rachal

    Darian Rachal

    Well-Known Member

    Joined:
    Jan 19, 2009
    Messages:
    628
    Likes Received:
    0
    A 15" chute does seem rather small for a rocket the size of a Leviathan, unless the rocket is going to land in some fairly high, soft grass. My thinking is to have the rocket come down as quickly as possible without damage. I believe the 18" would be a better choice.
     
  4. Sep 2, 2015 #4

    noffie79

    noffie79

    noffie79

    Well-Known Member

    Joined:
    Jul 25, 2015
    Messages:
    1,287
    Likes Received:
    1
    Well, my flying field is primarily a soybean field. It's a little patchy, but my main concern is staying out of the TREES, about 800-1000 feet away. Thought I'd risk a little damage over completely losing my rockets. But I think I'll pick up the 18" for the Leviathan, Partizon, Argent and Scion. I'll use the 14" for my Ventris and Sahara.
     
  5. Sep 2, 2015 #5

    mpitfield

    mpitfield

    mpitfield

    Moderator Staff Member TRF Lifetime Supporter Global Mod

    Joined:
    Jul 7, 2013
    Messages:
    4,677
    Likes Received:
    318
    Gender:
    Male
    Location:
    Toronto, Ontario
    Fruity chute have a theoretical 1.5-1.6 CD, so they are typically more effective than an equivalent sized chute. The spill hole does mitigate oscillation however it represents about 20% of the canopy for the classic elliptical and 10% for the TARC, which is roughly 4%/2% of the area. So technically a 15" chute is slightly smaller, however the effectiveness of the design will more than make up for the reduced area due to the spill hole.

    I would say the 18 would be more on par with the 24", but if you want to bring it down a bit faster then you're doing the right thing. Keeping in mind as Darian said, a soft surface would help.

    One of the issues with the smaller sized Fruity Chutes is the bridle can take up quite a bit of space, due to it’s rigidity, so packing them into smaller tubes can more challenging.
     
    Last edited: Sep 2, 2015
  6. Sep 2, 2015 #6

    noffie79

    noffie79

    noffie79

    Well-Known Member

    Joined:
    Jul 25, 2015
    Messages:
    1,287
    Likes Received:
    1
    Thanks for the info guys. I did just order an 18", so I'll try both and see which one I like better. Of course I'll keep both and for the days you could feel a fly sneeze, I'll use the bigger of the two. For a little wind, I'll use the smaller.
     
  7. Sep 2, 2015 #7

    mpitfield

    mpitfield

    mpitfield

    Moderator Staff Member TRF Lifetime Supporter Global Mod

    Joined:
    Jul 7, 2013
    Messages:
    4,677
    Likes Received:
    318
    Gender:
    Male
    Location:
    Toronto, Ontario
    Sounds like a good plan...good luck with it.

    You will love Fruity Chutes, I have many of them. They may be a premium priced chute, however the quality is obvious and the performance is first rate.
     
  8. Sep 2, 2015 #8

    noffie79

    noffie79

    noffie79

    Well-Known Member

    Joined:
    Jul 25, 2015
    Messages:
    1,287
    Likes Received:
    1
    I can't wait to get it in the mail and see how well it works! Once I seen them, I knew I had to have one (or two). When you say that the bridle can be a bit challenging to put in a smaller BT, what size are you referring to? The smallest I'll be putting it in is a 2" Estes Ventris.
     
  9. Sep 2, 2015 #9

    mpitfield

    mpitfield

    mpitfield

    Moderator Staff Member TRF Lifetime Supporter Global Mod

    Joined:
    Jul 7, 2013
    Messages:
    4,677
    Likes Received:
    318
    Gender:
    Male
    Location:
    Toronto, Ontario
    With a typical nylon chute the shroud lines are usually just sewn from one corner to the other, in most cased a single line, 6 shroud lines, 3 single lines. In this case it is up to you to center the lines, using whatever method you prefer. With Fruity Chutes Gene sews a bridle onto the end of the shroud lines, no guessing where the center is and you just add your quick link to the loop sewn into that bridle.

    The challenge can be that the bridle may extend more than you have room for and compacting it down is not an option due to the rigidity of the chute. Realistically there are few cases where this would be an issue. I had Gene make me a custom 24" classic elliptical using the spectra compact lines as a replacement for the cheap nylon 24" chute that comes with the Mariah 38, however this was one of those cases where the chute would not fit due to the bridle.

    I only have the classic elliptical and iris ultra chutes so I am not 100% sure if the construction of the shroud lines and bridle is the same for the TARC series or not. According to the web store it is...did you order the TARC or classic elliptical?
     
  10. Sep 2, 2015 #10

    noffie79

    noffie79

    noffie79

    Well-Known Member

    Joined:
    Jul 25, 2015
    Messages:
    1,287
    Likes Received:
    1
    I ordered the classic elliptical
     
  11. Sep 2, 2015 #11

    mpitfield

    mpitfield

    mpitfield

    Moderator Staff Member TRF Lifetime Supporter Global Mod

    Joined:
    Jul 7, 2013
    Messages:
    4,677
    Likes Received:
    318
    Gender:
    Male
    Location:
    Toronto, Ontario
    I was just packing my chutes away from the URRG weekend launch so I just snapped this pic showing the following, from top to bottom:

    18" classic elliptical, shroud lines off to the left coming into the bridle and a sewn in swivel, standard lines
    15" classic elliptical, shroud lines off to the left coming into the bridle and a sewn in swivel, standard lines
    24" typical nylon chute with a swivel added at the center mark of the shroud lines
    12" classic elliptical, shroud lines off to the left coming into the bridle and a sewn in swivel, compact spectra lines (this was a custom order)


    View attachment 271138

    One thing about dealing with Gene, is that he can make you anything you want, outside of the standard items on the web...within reason. You just need to wait for the custom stuff, which can take some time but if you plan ahead then you can get exactly what you need.
     
  12. Sep 2, 2015 #12

    noffie79

    noffie79

    noffie79

    Well-Known Member

    Joined:
    Jul 25, 2015
    Messages:
    1,287
    Likes Received:
    1
    I really do appreciate all of your input. I haven't been into MPR long, but I knew right away I wanted to use swivels. I've been using the same chute for all of my rockets, and since each kit comes with one, I have LOTS of spares. I attached a swivel at the center of the lines, like your third down in the photo. The main reason I wanted an elliptical with a spill hole was to mitigate the oscillating and hopefully bring them down not necessarily faster, but without drifting as much. I know you can never exactly predict where it's going to go due to updrafts and such, but I was sold when I seen the bridle and sewn in swivel. By the sounds of things, these chutes should bring them down perfectly and with less drift. Like I said, bigger on calm days, smaller with more breeze to stay away from the trees!
     

Share This Page

Group Builder