LOC IRIS 3.10 Inch Model Rocket Kit Instructions

LOC IRIS 3.10 Inch Model Rocket Kit

Due to the high thrust motors that can be flown in this rocket, epoxy is recommended!
Before beginning construction, read over instructions to become familiar with the proper construction steps. Check Parts List to make sure you have all the parts.
TEST FIT ALL PARTS! Light sanding may be necessary to obtain proper fit.

ITEMS YOU WILL NEED TO BUILD THIS KIT

Basic Construction FAQ

The major parts involved in each step are shown shaded at the beginning of that step. Areas, where epoxy should be applied, are shown as well.

Prep and Assembly

• Read and understand the instruction steps fully before you begin the step.
• ALWAYS sand the parts to be bonded with 100-120 grit sandpaper.
• We strongly recommend you dry-fit (assemble without gluing) all parts in each step BEFORE epoxying them together. Sand or adjust fit as needed before gluing.
• Most epoxies work fine. Use 5 or 15 minute depending on how quickly you feel you can complete the step. Use longer set-time epoxy if you’re unsure.
• To make internal fillets to the fins deep up into the airframe, “load up” the end of a dowel with a blob of epoxy, then stick the dowel into the airframe and onto the fin joint you’re working on. After depositing enough epoxy in this fashion, you can pull the dowel toward you, making a fillet with the rounded edge of the dowel.

Painting/Finishing

• Before you paint the fins, scuff the entire surface with 220 grit sandpaper. This is easiest to do before mounting the fins.
• Plastic nosecone imperfections can be filled with plastic model kit putty.
• Stay with the same brand of paint throughout the process; primer, base color, accent colors, and clear coat. DO NOT skimp on the “shake the can for at least two minutes after the ball rattles” step! For the best finish, let each coat dry overnight and sand lightly with 320 or 400 grit sandpaper.
• Apply the last color coat as heavy as possible without running or sagging. Let the paint cure for at least 48 hours before handling!

Parts List

Check your parts before you begin your build!

• Pre-slotted main airframe
• Payload airframe
• 38mm motor mount tube
• Airframe to MMT centering ring – (3)
• Airframe coupler tube
• Coupler bulk plate
• Coupler hardware set
• Eyebolt
• Washer
• Nuts – (2)
• Nose cone
• 4 Fins
• Parachute
• Nylon Shock cord
• Linear Launch lugs – (2)
• Decal sheet

Epoxy, paint, and motor not included.

Optional Parts List

This LOC kit will show the following options to make your build even better! Just click on the option below and it will take you directly to the Loc web page!

• Loc Pro 38mm Pro Motor Retainer
• Adjustable Density Expanding Foam.
• Fire Resistant Shock Cord Sleeve
• We recommend a clear coat of some sort to help protect the decals as well as “seal” their edges to help prevent them peeling off. When using any clear coat, put on only VERY thin, light coats, and wait at least 5 minutes between coats. The clear coat can damage your decals or paint if you put it on too heavily or don’t wait long enough between coats!

STEP 1

Pre-assembly Fitting and Sanding

The first few steps are going to involve scuffing, sanding and fitting some of the parts to your kit. The time you spend in the pre-assembly/fitting stage will aid in making assembly smooth when the adhesives come into play. Take your time here to get things right.

Image above shows the:

1. Motor Tube
2. FWD Centering Ring
3. Mid Centering Ring
4. AFT Centering Ring
   • Lightly scuff/sand the motor tube to ensure proper adhesion of epoxy.
   • Dry fit all centering rings into the airframe and over the motor mount tube. The FWD and MID centering rings can be a little snug in the airframe and on the motor tube. If it is too tight, sand the ID and/or OD for a better fit.
   • Use a pencil to mark the AFT centering ring for identification. You do not want to switch the MID and AFT centering rings during assembly! The AFT standard centering ring should be looser in the airframe and over the motor mount tube; you will need to slip the AFT centering off the motor tube while it is in the airframe during a later step. Sand the ID and/or OD for a loose fit if necessary.

STEP 2

Motor Retention – Decision Time!

Your choice of motor retention will determine exactly where the AFT and MID centering rings are placed on the motor tube. Review the two choices below and decide which one you will use.

Choice 1– Standard Motor Retainer Included with this Kit

Loc has sold hundreds of kits using the standard Loc motor retainer system. Composed of two L brackets, bolts and retainer nuts, it’s a simple but effective method of motor retention. This method is included with your kit. Using this method, the AFT centering ring mounts flush to the AFT end of the motor tube.

Choice 2– Optional Loc Pro Motor Retainer

LOC PRO Motor Retainers are CNC machined aluminum and anodized. Install onto aft of motor tube with JB Weld® and easily flip motors in the field quickly! It’s a slicker and quicker way to fly! Using this method requires additional sanding and 3/8” of motor tube to extend beyond the AFT centering ring.

Once you have decided on motor retention, move on to the next step.

NOTE:
You can continue to build if you decide to purchase the optional Loc Pro Motor Retainer. Just leave 3/8 of motor tube extending past the AFT centering ring!

STEP 3

More Pre-assembly Fitting and Sanding

• A-1. If using the Standard Motor Retention – Slip the MID then AFT centering ring over the motor tube. Align the AFT centering ring flush with the end of the motor tube. DO NOT glue the AFT ring in place!

• A-1. If using the Loc Pro 38mm Motor Retention – Make a 3/8” strip of masking tape and apply onto the AFT end of the motor tube. Slip the AFT ring down so it butts up against the tape. DO NOT glue the AFT ring in place!

• B-1 or B-2. Dry fit the fins between the AFT centering ring and the MID centering ring. This gives you an accurate location of where the mid-centering ring should be placed. Using cyanoacrylate glue (super glue), lightly tack the MID centering ring in place.
  DO NOT GLUE THE FINS TO THE TUBE, AND DO NOT GLUE THE AFT RING IN PLACE!

• C. Locate the FWD centering ring 1/2” from the FWD end of the motor tube. Tack in place using cyanoacrylate glue.

STEP 2

Dry Fit Motor Tube Assembly to Airframe

• A. Dry fit (NO EPOXY!) the motor tube/centering ring assembly into the airframe.
• B. Make sure the MID and AFT centering rings do not interfere with the fin slots.
• C. Dry fit a fin into each fin slot to make sure they fit correctly.
• D. Make three or four cellophane tape tabs and apply to the AFT centering ring as shown above to aid in removing this ring at a later step.
• E. Dry fit/test the fit of the aft ring over the motor tube. You need to be able to slip this ring on and off during final motor tube/airframe assembly.

STEP 3

Nylon Tether and Centering Ring Fillets

• A. Install the eye bolt for the nylon tether. The eye faces forward; use a nut/washer/centering ring/washer/nut. Tighten the nut securely. Make sure the eye does not interfere with the airframe – test fit!

• B. Stand the motor tube vertically, AFT side down. Mix a batch of epoxy and make epoxy fillets on the top of the FWD and MID centering ring. Do not get epoxy inside the motor tube!

• C. When the epoxy has cured, flip the motor tube over and apply an epoxy fillet to the backside of the FWD centering ring only.
  DO NOT make an epoxy fillet on the backside of the MID centering ring!
  While the motor tube is upside down, also spread epoxy over the nut and threads of the eye bolt to prevent loosening.

• D. When the epoxy has cured, attach the nylon tether to the eye bolt.

STEP 4

Motor Tube to Airframe Assembly

• A. Coil the nylon tether and shove it into the motor tube to protect it during the next steps. Lay your motor tube alongside the airframe and make a mark where your FWD and MID centering rings will rest when installed. Lightly scuff/sand the inside of the airframe where the centering rings will rest when installed.
• B. You will need a long stick or dowel for applying epoxy in this step. Make two marks on the stick at so you can tell how deep the stick is in the airframe when spreading the epoxy. Using your extended epoxy applicator, spread a bead of epoxy around the inside circumference of the airframe where the FWD and MID centering rings will rest.

DO NOT APPLY EPOXY WHERE THE AFT CENTERING RING WILL REST!!!
You will need to slip the AFT centering ring off the motor tube in a future step! Push the motor tube assembly into the airframe. The MID centering ring should be exactly at the top of the airframe fin slot.

Make sure the MID and AFT centering rings do not interfere with the fin slots. Flip the airframe to a vertical position (FWD end up) and let the epoxy cure.

STEP 5

Fin to Airframe Assembly

• A. Gently pull the AFT centering ring off the end of the rocket by tugging on the tape tabs. Apply a bead of epoxy to the root edge of one fin tab and insert fin into fin slot. Make sure the fin is at a right angle (90˚) to the airframe. Set aside to cure. Keep the airframe in a horizontal position until the epoxy cures. Do one fin at a time, and let cure; then move on to the second fin and repeat the epoxy process. Repeat with the last remaining fin.
• B. Place tape over the end of the motor tube to protect it during the next step. Do not get epoxy inside the motor tube or on the area where the AFT ring will slide onto the motor tube!
• C. Using a stick, apply an epoxy fillet to the fins at the motor mount tube and the inner airframe wall.
• D. Remove the tape tabs from the centering ring and permanently epoxy it in the base of the rocket. If you are using the Loc Pro Motor Retainer, the motor tube must protrude 3/8” from the face of the AFT centering ring!
• E. Apply an outer epoxy fillet to both sides of each fin. Allow the epoxy to set up before rotating the rocket to do the next set of fins. Once the epoxy has fully cured, you should sand the fillet smooth with fine sandpaper.

LOC PRO Build Tip! Adjustable Density Expanding Foam
Two-part expanding foam, great for fin encapsulation, securing lose weight, etc. By combining equal parts of A and B, the foam expands to about 10 times its original liquid volume. The result is a rigid foam that is extremely strong and still relatively lightweight. This is perfect for filling small spaces where the highest strength is required and weight is not a real issue. Go here!

STEP 6

Bulkhead Assembly

• A. Assemble the bulkhead as shown in the drawing.
  • Slip a washer over the eyebolt
  • Push the eye bolt into the hole in the bulkplate.
  • Slip the second washer onto the eye bolt.
  • Thread the nut on to the eye bolt and tighten it with a wrench.
  • Spread epoxy over the nut and washers for a secure connection.
• B. Spread a layer of epoxy around the inside circumference of the coupler to a depth of about 1/2”. Push the bulkhead assembly into the coupler until it is about 1/4” past the edge. Allow the epoxy to set. Then apply an epoxy fillet to both sides of the bulkhead.
• C. Draw a pencil mark at the midpoint of the coupler. Spread a layer of epoxy around the inside circumference of the payload section tube to a depth of 1/2 of the tube diameter. With a slow twisting motion, push the coupler into the payload section tube up to the pencil mark. Allow the epoxy to cure.

STEP 7

Nosecone Payload Bay Assembly

• A. Slip the nosecone into the top of the payload section tube. Secure the nosecone to the payload section with small screws or removable plastic rivets equally spaced around the circumference of the payload section tube about 1 below the nosecone. Be sure to pre-drill holes of the appropriate size when using screws. 1/4 long sheet metal screws work well in this application. If you prefer to use PML Removable Plastic Rivets (RVT-24) , you will need to drill 5/32 diameter holes.
• B. Next drill a 1/8” or 5/32” hole near the base of the payload section tube completely through the coupler. This hole is needed for high-speed, high-altitude flights to bleed off internal air pressure.

STEP 8

Parachute / Recovery System Assembly

Make a parachute loop in the nylon shock cord 1/3 of the way from the nose cone end. Attach the short end of the shock cord to the eye bolt in the payload bay bulkhead. Most builders use a quick link (not included) for this purpose. A quick link makes it easy to change out shock cords if needed.

STEP 9

Rail Guides Installation

• Install the rail guides into the booster with provided screws. Drill a small hole at the location of the forward and aft centering rings, centered between fin set.
• Drop a small amount of epoxy in drilled holes, thread the rail guides and screws in the holes, rotate rocket 180 degrees and let cure.

STEP 10

Paint / Finish

Seal fins and launch lug with sanding sealer using a brush. Sand lightly between coats to fill pores and obtain a smooth finish. Lightly sand plastic nose cone with fine sandpaper to remove the molding seam line. At this time, remove any plastic flash that was molded into the nose cone eyelet.

When you are satisfied with the smooth sanded finish of your model, it is ready to prime and paint.

• Spray rocket with primer, sand, and repeat until a smooth finish is obtained
• Spray the rocket with the paint of your choice, let dry.
• Apply a protective clear coat
• Apply vinyl decals to your liking
• Repeat with a clear coat.

Schools, Clubs, and Other Groups
Loc Precision Multi-Packs are available for this and other Loc Precision Rocket kits. Call or email us for multi-pack pricing.

PREFLIGHT

Sim Your Rocket!
LOC/PML rockets can fly on several impulse motors. Depending on your flying field and finished weight, these are very versatile kits. The Rocksim® file is available on the product page on our website.

Always check stability to ensure stable flight; the Center of Gravity (CG) must be forward of the Center of Pressure (CP) in flight ready condition.

After finishing your rocket, permanently mark the center of pressure on the airframe. After loading the rocket with a motor, make sure that the center of gravity (balancing point) is at least one body diameter forward of the center of pressure mark. The center of gravity can be moved forward by adding weight to the nose cone. Remember to use enough recovery wadding to protect the chute and shock cord from the hot ejection gases.

Always follow motor manufacturer’s instructions for motor use and ignition, and launch this vehicle on calm, windless days to insure safe recovery.

Model Rocket Safety Code

• Materials – I will use only lightweight, non-metal parts for the nose, body, and fins of my rocket.

• Motors – I will use only certified, commercially made model rocket motors, and will not tamper with these motors or use them for any purposes except those recommended by the manufacturer.

• Ignition System – I will launch my rockets with an electrical launch system and electrical motor igniters. My launch system will have a safety interlock in series with the launch switch, and will use a launch switch that returns to the “off” position when released.

• Misfires – If my rocket does not launch when I press the button of my electrical launch system, I will remove the launcher’s safety interlock or disconnect its battery, and will wait 60 seconds after the last launch attempt before allowing anyone to approach the rocket.

• Launch Safety – I will use a countdown before launch, and will ensure that everyone is paying attention and is a safe distance of at least 15 feet away when I launch rockets with D motors or smaller, and 30 feet when I launch larger rockets. If I am uncertain about the safety or stability of an untested rocket, I will check the stability before flight and will fly it only after warning spectators and clearing them away to a safe distance. When conducting a simultaneous launch of more than ten rockets, I will observe a safe distance of 1.5 times the maximum expected altitude of any launched rocket.

• Launcher – I will launch my rocket from a launch rod, tower, or rail that is pointed to within 30 degrees of the vertical to ensure that the rocket flies nearly straight up, and I will use a blast deflector to prevent the motor’s exhaust from hitting the ground. To prevent accidental eye injury, I will place launchers so that the end of the launch rod is above eye level or will cap the end of the rod when it is not in use.

• Size – My model rocket will not weigh more than 1,500 grams (53 ounces) at liftoff and will not contain more than 125 grams (4.4 ounces) of propellant or 320 N-sec (71.9 pound-seconds) of total impulse.

• Flight Safety – I will not launch my rocket at targets, into clouds, or near airplanes, and will not put any flammable or explosive payload in my rocket.

• Launch Site – I will launch my rocket outdoors, in an open area at least as large as shown in the accompanying table, and in safe weather conditions with wind speeds no greater than 20 miles per hour. I will ensure that there is no dry grass close to the launch pad, and that the launch site does not present risk of grass fires.

• Recovery System   I will use a recovery system such as a streamer or parachute
  in my rocket so that it returns safely and undamaged and can be flown again, and I will use only flame-resistant or fireproof recovery system wadding in my rocket.

• Recovery Safety I will not attempt to recover my rocket from power lines, tall trees, or other dangerous places.

Launch Site Dimensions

Installed Total Impulse (N- sec)| Equivalent Motor Type| Minimum Site Dimensions (Ft.)
---|---|---
0.00 – 1.25| 1/4A, 1/2A| 50’
1.26 – 2.50| A| 100’
2.51 – 5.00| B| 200’
5.01 – 10.00| C| 400’
10.01 – 20.00| D| 500’
20.01 – 40.00| E| 1,000’
40.01 – 80.00| F| 1,000’
80.01 – 160.00| G| 1,000’
160.01 – 320.00| Two G’s| 1,500’

E-MAIL: info@locprecision.com
PHONE: 920.892.0557

Since Yank Aeronautics LLC dba LOC PRECISION cannot control the use of its products once sold, the buyer assumes all risks and liabilities therefrom and accepts and
uses LOC Precision products on these conditions. For any questions or issues please contact LOC directly—info@locprecision.com.

© YANK AERONAUTICS LLC. dba LOC PRECISION ALL RIGHTS RESERVED.

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