Model rocket shock cord length.

Model rocket shock cord length Selection of shock cord length and width is the same as for single-event recovery. Mine is the Lariat loop around the aft of the motor tube. Aug 7, 2015 · I Z fold my shock cord about 6 to 8 inches long and lightly wrap it with masking tape. test round Kevlar cord which will run from top centering ring …. As previously mentioned, the two primary things you need to keep in mind when constructing your shock cord are the two forces it is built to withstand: the force of the components Apogee Rockets : Shock Cord - Model Rocket Kits Rocket Motors Launch Accessories Rocket Software Rocket Books & Videos Building Supplies Electronics & Payloads Wearables Gift Certificate Rocket Novelties and Gifts Garage Sale Ejection Systems Display Stands Customization ARC Supplies Advertising Rocket Building Supplies, T. It won't be bothered by hot ejection gases. 1" rocket = 5ft -- 4 Apr 16, 2022 · Whether the attachment point is the baffle or the engine mount, with a shock cord recommendation length range of 3-4 times the length of the rocket's body, the difference will be negligible. The main reason to go longer with shock cords is for shock absorption. 25x or 1. Short heavy rockets are going to need a much longer cord, long light rockets will need a much shorter cord. Crafted with precision, this braided cord boasts an impressive 100-300 pound test strength, ensuring the utmost durability for your high-flying ventures. R. Usually when I build a rocket I make sure the shock cord is longer than the overall length of the rocket but the shock cords included with the Pro Series are much longer than that. If you added nose weight and the NC is heavy, I would attach the drogue to the NC anchor with a 2-3x length of shock cord and it should have its own blanket. Model Rockets & How-To Rocketry Information Contains two 1/8 in. Thanks Mike Mar 26, 2013 · I always use a length of 100# kevlar about twice the length of the rocket as the primary shock cord, usually with the OE cord tied to one end. Made of 100% Dupont Kevlar Fiber, braided, 550 pound high strength, high toughness, excellent abrasion resistance, with high thermal stability. 2. With nylon and particularly Kevlar having less give, you need lots of length to make up for it. 5" in diamter and about 6' tall. Elastic I make normally 2 times the model length, just for safetytoo long and it can tangle. 1. - what length shock cord from the pilot/drogue to the deployment bag Mar 26, 2013 · A long shock cord is good because, as mentioned, it allows the parts of the rocket time to slow down relative to each other before the limit of the cord's length is reached. Now you can hold the rocket in the air by the shock cord and see if your suspension lines are all even. Users liked: Kevlar cord is durable and heat resistant (backed by 2 comments) Kevlar cord is strong and abrasion resistant (backed by 3 comments) Kevlar cord has minimal stretch (backed by 2 comments) Aug 27, 2011 · Figured we'd gotten the shock cord question answered. Middle or high power rockets should use tubular nylon at least 5 times the rocket length. Also with longer lengths aerodynamic drag should become a factor in absorbing the deployment shock. If the rocket is going fast enough during deployment, zippers can happen. I would use about 25 to 30 feet of shock cord. Make shock cords for model rockets a minimum of 2 to 3 times the overall length of the rocket. I have 1500 lb. 5 - 3 lb length 48" chute 36" 1/4 round (umbrella) shock cord used is 1/8" kevlar bungee attached at the motor mount. to Load line length, ie 24" chute = 30" or 36" line length to the supported load connection. A "general rule of thumb" stating 3-5 x the total rocket length is followed by many of you because "it Oct 15, 2011 · I view it this way- if 3X is good then lets say that it applies best to the 10:1 or longer rockets, so pick an average 10:1 or longer rocket of the diameter in question, provide 3X the length, and use that in your short stubby rocket of similar diameter. Works very well with 1/4" and larger shock cord. The NC is tied about 1/3 the way down the OE cord. Jul 27, 2010 · Hey folks agian. This shock cord provides a secur Model Rockets & How-To Rocketry Information rocket assembly your single shock cord (2-3x the rocket length) is tied to the other end of the swivel to complete the harness. and High Powered Rocketry. Aug 2, 2009 · After an exhaustive search on line, including this forum, I am unable to find any formulas for calculating shock cord sizes, lengths, etc. A. Braided Kevlar cord is perfect for any Vander-Burn plywood upgrade kit, or for replacing your old shock cords in heavier model rockets. This is the paper-like piece in the picture to the right. As previously mentioned, the two primary things you need to keep in mind when constructing your shock cord are the two forces it is built to withstand: the force of the components Feb 5, 2025 · - For larger rockets (over 5 lb/2. Oct 9, 2022 · I understand that deciding on a shock cord length is pretty subjective but I would still appreciate any thoughts. Other end of OE cord tied in a loop for recovery attachment. From elastic to Kevlar to Tubular Nylon. It has 3 inch tube, 29 mm motor mount, and all in is about 42 inches long. Corner to corner line length 60" or 72". The tensile strength for this shock cord is 1500 lbs, sufficient for any mid and high-power model rocket. You'll notice that model rockets sometimes get damaged when the nose cone hits the body tube (leaving an "Estes Smile" or "Estes Dent"). Since the nose cone, when ejected by the model rocket engine ejection charge, is held to the rocket by the shock cord there can be significant forces on the shock cord mount. 27 kg), use a shock cord length of 5-7 times the rocket's length. Keep it separate from the main and it's shock cord to avoid tangling. Kevlar (for 1-24oz rockets) has 220# tensile strength and is a great alternate choice for elastic. (actually, since I cut 4 lines for my 8 hole chute, each line goes to two holes, so it is really 4X diameter of chute, but counting each line individually (chute to snap swivel) it is 2X diameter. ApogeeRockets. This will allow excess material to tie the knots with. C. Pricing is per foot. 6 ounces : Number of Pieces : 1 : Model Name : 2278 Shock Cords and Mount Pack, for Model Rockets : Art Craft Kit Type : Model Rockets : UPC : 047776022782 Sep 11, 2017 · Some have said that 1/8'' is okay then others say no less than 1/4'' kevlar on a rocket that size. rubber shock cords and four shock cord mounts. and here is the question: how long should Kevlar shock cord be Apr 6, 2005 · What length of shock cord would I need for this rocket? Is there a formula for this? approx. Recommended for high-power rockets. Thirty minute epoxy works best for this. Low power rockets can use 100 lb. Apr 17, 2003 · Nylon and Kevlar shockcord should normally be 3-5 times the total length of the rocket. But remember, just like stability measurements this is based on rockets of standard fineness ratio, and standard weight per length. You mount the Kevlar to the motor mount your favorite way. Too short of a shock cord and your parachute won't deploy. May 31, 2018 · As long as you NC isn't heavier than your airframe, you can go drouge-less. Jan 1, 2018 · Model Rocket : Item dimensions L x W x H : 10 x 4 x 6 inches : Material : Plastic : Included Components : Estes Rockets 2278 Shock Cords and Mount Pack, for Model Rockets : Item Weight : 1. UFO's, fun & random Brand LOC Precision Diameter 3mm Dimensions 3 x 2430mm Length 2430mm Type Shock cord. The consensus on determining the length of the shock cord for your model rocket is that it should be three times as long as the body tube of the rocket itself. This shock cord provides a secur Nov 9, 2014 · I know the general rule-of-thumb that a shock cord should generally be 2-3x the BT length, is just a rule of thumb, but does it mean the entire shock cord should be that or just the part that extends past the top of the BT? BTW, I NEVER attach my chutes directly to a nose cone. You then attach a fabric elastic cord to the Kevlar cord outside of the body tube. . Any more is probably overkill. minimum) - then multiply that number by the *diameter* of the rocket in inches -- i. Model Rocketry: America’s Hobby in the Cold War 1960–1980 Amazon. 1" and 2. Jan 17, 2019 · For a foot-long model rocket like the Crossfire, use a 3 foot section of Kevlar shock cord. Is it generally longer=better? I'm building a Quest Totally Tubular and was thinking of cutting the 12in shock cord down. Our Kevlar Braided Shock cords are the strongest, most compact, and highest quality in Low, Mid, and High-Powered Rocketry. Cut a piece of your favorite cord material two inches longer than the mea-surement you just took. Aug 6, 2006 · What is the basis for the "rule of thumb" that state the shock cord should be 2 to 5 times the length of the rocket? What, exactly is the connection I researched the Emma Kites 100 Kevlar Braided String Utility Cord 100Ft 100Lb and I thought you might find the following analysis helpful. I recommend Kevlar® (www. Reply. x 18 in and one 1/4 in x 36 in. Keep in mind that these are rough estimates. It's essential to consult with experienced rocketeers, simulate deployments, or conduct test flights to determine the optimal shock cord length for your specific rocket and recovery system. What is the best length of tubular nylon I should use for this rocket and the width of the tubular nylon? By the way it will fly on a K motor. Jan 10, 2003 · Shroud line length, was one of the discussion topics. 12 feet is a good length to order for a Vander-Burn upgrade kit. Elastic is great for light weight (for 1-24oz weight rockets) applications and can stretch to 175% of length. e. What I have found are opinions about cord lengths. Use enough wadding to fill 2 x the diameter of your BT. 6" in diameter (roughly, ST-11/BT-52 to BT-80), bungee cord material ranging in diameter from 1/8" to 3/16" (depending on the rocket's recovery weight) might be a better alternative to wide sewing elastic for use as a shock cord material. Jun 30, 2022 · I am designing and scratch building a Level 1 cert. thats my thinking atleast. Most people refer to their shock cord as one continuous piece when referencing the 3-5x body length standard for a shock cord, even when talking about dual deployment. You generally want your shock cord to be a multiple of your entire rocket's length, usually 3-5x. Any opinions on optimal length of shroud lines? I have been using twice diameter of chute. Your rocket appears to be 5. Introducing our Aramid Shock Cord The ultimate solution for model rocketry enthusiasts seeking unparalleled strength and reliability. Epoxy the shock cord mount to the inside of the body tube rather than using white or yellow glue. Oct 25, 2020 · Length of model rocket shock cord. Kevlar is very heat-resistant, which makes it an excellent candidate for model rocket shock cord material. Wadding Use enough wadding to fill 2 x the diameter of your BT. High power rockets do best with 1500 lb tensile strength. The “rule of thumb” I’ve heard in high power rocketry is to design your recovery hardware and related structures to handle 25-50 Gs of acceleration at recovery snatch loads. Here are my questions. Feb 15, 2025 · If you want to protect from Zippers, you use the Quest model rocket method of Kevlar cord and shock cord. ) put the shock cord in then the chute on top of that. Adjust them as necessary to make the rocket hang level then set the knot at the swivel with some white glue. But it is a little vague on dual deployment; so is the 3X(Length of rocket) to be yet divided again for each deploy event, or does each deploy event get a 3X length of cord? In other words: (3X 11)/2=16. Thanks! Scale model rockets . I always have a small piece of shock cord on it, either by attaching the chute a few inches from the nose cone right to the shock cord for a smaller rocket, or for a dual chute model, I'll actually put a small shock cord onto the cone before attaching the chute to it. the point you are anchoring your shock cord. 5 or 2X(3X 11)= 66 at least twice the length of the model. Too long A common dual-event recovery design is to split a rocket into three sections, with the sections connected by shock cords. I hold both cords side by side and tie a Jan 31, 2022 · In my search, 3X the length of your rocket is an accepted 'rule-of-thumb' length for shock cord design. What is the diameter of the rocket? What is the length? What is the weight? Judging from the picture of your rocket, I would say that 4 yards of tubular kevlar is not enough. Braided Kevlar shock cord is incredibly strong for its weight and is heat resistant, so it makes a great shock cord in model rockets. com : 9KM DWLIFE Braided Kevlar Cord, 100lb~2000lb, High Tensile Strength, Abrasion, Flame Retardant, Kite String, Fishing Line, Model Rocket Shock, Hammock Tarp Ridgeline, Tactical Survival Paracord : Sports & Outdoors Feb 2, 2017 · I expected the shock cords for the Pro Series rockets to be longer than LPR/E2X rockets but they are even longer than I expected. As an added bonus, it is long-lasting. It is not finished yet but the final weight may between 4 and 6 lbs. Wadding. Aug 2, 2009 · The trick is in the terminology -- from the model rocket world, we have "shock cord" which is elastic, and absorbs ejection load. Those of you who have flown this size rocket, what size shock cord did you use? How long? In my "I", "J" and "K" rockets I have used 5/8" shock cord, but lots of it and I have not had a problem. If the rocket is going to go higher than 2000 feet (609 m), then a streamer might be a good choice, as the rocket will probably drift too far if there is any wind. 65. attempt rocket. The parachute folding has been used on chutes from 6" plastic to 24" nylon. I am building a 80 inches long, 4 inches diameter blue tube rocket. Aug 2, 2009 · possible answer 1, the shock cord should be 2-3X your complete rocket length for nylon and Kevlar shock cords possible answer 2, use 100 LB test for rockets powered A-D use 300 LB test for D-g and use 1500+ for H-onward Jul 31, 2008 · But for large model rockets and mid-power rockets with airframes between 1. com/shock_cord. weight 2. Jun 3, 2008 · Hey guys, I was just wondering what a good shock cord length would be for a rocket. The consensus on determining the length of the shock cord for your model rocket is that it should be three times as long as the body tube of the rocket itself. Put the deployment protection in (dog barf, wadding, Nomex, ect. It will easily out-live nylon or elastic shock The shock cord is very critical since the recover system, say a parachute, is actually connected to the nose cone so when the nose cone is blown off the rocket by the model rocket engine ejection charge, the parachute is pulled out of the rocket and can open for a safe recovery. new generation with industry-leading model rocketry products May 3, 2019 · Amazon. Many high power rockets use dual-deployment techniques, where a streamer is ejected at apogee so that the rocket falls quickly and doesn’t drift far. Our model rocket shock cords come in a wide variety for just about any application. Dec 7, 2013 · Model Rocketry: America’s Hobby in the Cold War 1960–1980 Amazon. Braided Kevlar is widely used in model rocketry for several reasons: Shock Cord Replacement: It serves as a replacement for traditional rubber shock cords, providing a more durable and heat-resistant option. $17. The 4 Our model rocket shock cords come in a wide variety for just about any application. Be sure and lightly sand the inside of the tube where the Apr 20, 2005 · When one gets into the full "L" and baby "M" motors strength must be added to rocket design by 10-fold. While not visible while the rocket is assembled, it plays a key role in the recovery of the flight. All the Nat's competitors, and according to Mark, every Chute he observed, use a 1. 1mm Braided Kevlar Cord Camo Green 200Lb 120Ft Abrasion/Flame Resistant Tactical Paracord, Trip Line, Cord Friction-Saw, Boot Laces, Camera Strap, Survival Cord, Model Rocket Shock Cord EMMAKITES Here's a simple way to calculate the proper minimum length for your parachute shock cord. Oct 10, 2016 · Typical shock cord length is 2x-5x rocket length beyond the top of the tube. Jul 5, 2006 · a longer shock cord allows the nosecone to slow down before jerking so It probably has nothing to do with the length of the rocket but rather the weight of the cone and the force of the ejection charge. This is particularly useful for heavier rockets or those that experience high stress during flight. Length of model rocket shock cord Make shock cords for model rockets a minimum of 2 to 3 times the overall length of the rocket. Model Rocket Shock Cord (Length, Material, How to Attach) The shock cord is an extremely important component of your model rocket. tensile strength, while mid power rockets will do better with 250 to 750 lb tensile strength. asp) because it is fireproof, super strong, and fairly inexpensive. How long should a shock cord be for a high power rocket? 3''? 4''? Jul 24, 2013 · As far as 'rules of thumb' (as much as I don't like it), I would say, select a cord with a tensile strength somewhere between 50 and 100 times the weight of the rocket -- and (this simply recent thinking) use 5' as a 'unit length' (i. Shock cords - Tubular kevlar - Loc model touches down. I have built a lot of rockets and I always feel uneasy about the shock cord length and size, so let's start a discussion and agree on a standard. Not only are they stronger than steel, strength vs weight, but they’re designed at a fair price, we have Kevlar Shock Cords rated for 950, 1200, 2,800, 5,300 and 8,600lbs! Mar 24, 2025 · emma kites 1. Though the 3 foot length appears to be a bit excessive, it allows the Kevlar cord to stretch slightly to help absorb the shock of the nose cone ejecting from the rocket body. In high power rocketry, it's imperative to think of it as what it is -- a harness . From elastic to Kevlar to tubular nylon. So here are the questions. 5x canopy dia. The model rocket shock cord mount is a means for attaching the shock cord to the body tube of a model rocket. com. The other end of the kevlar runs down the inside of the body tube and out the bottom. A good rule-of-thumb for shock cord length is three times the length of the rocket. 1500 lb test strength braided cord (not tubular, but it does have a hollow core). This will help to avoid tube zippering or ripped out shock cord mounts when you have a 'hard' ejection. 50-100 Gs to be really conservative. Supplies. The shock cord is connected to the nose cone by simply tying it to Applications in Model Rocketry. lujqga swhwz gczw ixthsw xven knzhge wgc rnao bxsbv cov spcqi ywcvga txyw sqgp ntc