Tips and Technique of the Day Thread

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Tacking down wires:

Contributor: @OverTheTop

CA glue is good for tacking down wires at intervals, but is fairly permanent.

Hot-melt glue works well for wires too and can usually be sheared off when changes are needed. Heat with a heat gun also works but is a little more messy.

 

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Homemade Balsa Filler:

Contributor: @prfesser

If you live where you can work outside with acetone and not be bothered by neighbors, a fast-drying balsa filler can be made by adding acetone or lacquer thinner to glazing/spot putty (ONE part, NOT the two-part body filler) such as Bondo brand. It doesn't take much acetone to thin it to a painting consistency. It can usually be sanded within an hour if not applied too thickly, so you can do half a dozen coats in a day if necessary. And it doesn't clog paper--if you find it's clogging the paper, it's probably not quite dry. And it doesn't warp balsa appreciably. Gloves and a bit of breeze to carry the acetone fumes away are strongly recommended.

 

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Tie your hair up:

Contributor: @dr wogz

Safety tip: Tie up your hair, and remove the loose cuffed shirt, especially around drill presses & other rotating tools.

This is not a problem for @cwbullet , but some of you might need to take it to heart.

 

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Make Space with a Fliptop

Contributor: @Sandy H.

1. If you have more tools than space, look into flip-top designs and build one or more. The attachment is an example of one I did and still use. Sander and scroll saw on one side, small wood lathe on the other. Some tools are more logical than other tools, but I've even seen examples with a miter saw on one side and a mini-drill press, so look at examples that have tools you also have/want to get.
2. If you build a flip-top tool bench, don't randomly place other items on the random flat surfaces. It takes longer to clean-up before flipping to the next tool. . . #DoAsISayNotAsIDo. . .

 

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List of Techniques (Index 3)

Page 1		Link to page 1 index
Page 2		Link to Page 2 Index
61	2 Apr 2023	Overcoming difficult-to-insert couplers:
62	3 Apri 2023	Epoxy and Two Paper Towels
63	4 Apr 2023	Soldier Tip
64	5 Apr 2023	Bang the CA bottle on the table
65	6 April 2023	Longer Epoxy Cure Equal Stronger Bond
66	7 Apr 2023	CA the End of Tubes
67	8 Apr 2023	Tape Method for Fin Can
68	9 Apr 2023	Fix for Broken Tape in Tape Method for Fin Can
69	10 Apr 2023	Make to Avoid Mess
70	11 Apr 2023	Cheap Standoffs
71	12 Apr 2023	Swap Out the Spout
72	13 Apr 2023	Heat will thin epoxy
73	14 Apr 2023	Use Plastic Expansion Inserts
74	15 Apr 2023	Extend your igniters with wire wrapping
75	16 Apr 2023	Use magnets to avoid losing nuts and washers
76	17 Apr 2023	Recycle those N-95
77	18 Apr 2023	Put tape over the piezo.
78	19 Apr 2023	Write your name on your rocket
79	20 Apr 2023	Label your motors
80	21 Apr 2023	CA your tube ends
81	22 Apr 2023	Cut your masking on a mat or glass.
82	23 Apr 2023	Rail Button Location
83	24 Apr 2023	Use Tool Racks
84	25 Apr 2023	Sharpen Those Blades
85	26 Apr 2023	Antizipper or Zipperless Design
86	27 Apr 2023	Prep Before Gluing
87	28 Apr 2023	Keep your propellant dry
88	29 Apr 2023	Use umbrella bags to protect your rockets
89	30 Apr 2023	Yellow or White Glue?
90	1 Apr 2023	Buy an Aluminum Angle
Page 4		Link to the next index

I am asking you each to help me post tips. Send me any ideas, and I will add them to the list.

Comments or suggestions should be posted here:

TRF Tips and Techniques Comments Thread.

Guys, We are going to use this thread for comments and suggestions against the Tip of Day thread in the Techniques forum. This goal is the maximum value and limited side chatter. If you have a comment, post it here and add a link to the post you are commenting about.

www.rocketryforum.com

 

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Overcoming difficult to insert couplers:

Contributor: @prfesser

You've inserted the shock cord and chute, and you're trying to insert the payload section's coupler, but it just doesn't want to get started (especially with smaller tubes). To make it a little easier, sand a very slight bevel on the edge of the coupler and on the inside edge of the booster airframe. 180-220 grit paper is good for thicker-walled mid- and high-power airframes/couplers. For thinner-walled model tubes, 320-400 grit. Wrap the paper around a smaller tube or a finger to do the booster, rotate the tube as you sand, and sand only on the "pull stroke" to avoid a ridge on the inside. Don't press hard, the bevels don't need to be huge. If you use CA on the edges of the tube/coupler, sand after the CA has done its job.

 

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Epoxy and Two Paper Towels

Contributor: @John Kemker

When using epoxy, pull out two paper towels and fold them up and put one under each bottle. After measuring the resin, wipe the tip with the one under the resin bottle, then discard that towel. Measure out the hardener, use the towel under that bottle, then discard the towel. That way, you avoid cross-contaminating the resin and the hardener.

 

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Soldier Tip

Contributor: @John Kemker

Remember that a good mechanical connection is just as important as a good solder joint when soldering wires. Heat the joint and let the solder flow into it.

 

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Bang the CA bottle on the table:

Contributor: @dr wogz

Bang your CA glue on the table as you use it. This helps keep the tip clear (the knock drops any glue in the long neck back into the bottle).

I am unsure how much this works, but I have been doing it for weeks. It sure makes my wife shake her head at me. Then again, it is probably worth it - no clogs.

 

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Longer Epoxy Cure Equals Stronger Bond

Contributor: @dr wogz

The longer the epoxy cure time, the longer it has to work itself into all the cracks, crannies & crevices of the joined parts. Therefore a stronger bond.

True, but it also creates more time to run. Find a middle ground.

 

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CA the End of Tubes:

Contributor: @SolarYellow

CA on the ends of tubes and couplers prevents the ends from getting burred up during handling rocket prep. The burrs create an artificial and variable but very short tight fit, so they are bad.

 

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Tape Method for Fin Can

Contributor: @ep29030



This used to be the standard technique for PML kits. Put two pieces of tape on the forward side of the aft centering ring. Don't glue the ring on the motor or body tube (duh!). Once the whole unit is in place in the airframe, glue the forward side of the first (forward) centering ring to set it in place. Also, tack your TTW fins down on the motor tube. Now, remove that aft centering ring by pulling on the tape tabs, and you will have access to your TTW fin tabs and the aft side of the forward centering ring.

This method will allow access to the fin tabs to apply better internal fillets.

 

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Fix for Broken Tape in Tape Method for Fin Can

Contributor: @KenECoyote

This step is a solution for breaking the tape in Tape Method for Fin Can. It also can be used to remove a stuck centering ring that has not been fully glued in place.

Is a dry fit centering ring stuck in place? Insert screws in the aft cr to be able to pull it out to do internal fillets.

 

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Make to Avoid Mess

Contributor: @KenECoyote

When using a cutoff wheel on bolts that extend out too far in your e-bay, use masking tape to cover areas around it to avoid the mess.

 

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Cheap Standoffs:

Contributor: @KenECoyote

Use aquarium air tubing as standoffs for your altimeters and electronics. You can cut a ton of them for a few bucks.



Pictured is one I had used for an Eggtimer TRS.

 

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Swap Out the Spout:

Contributor: @KenECoyote , @neil_w , @Sooner Boomer



If you like to use Elmer's Carpenter's Wood glue, but dislike the wide spout, simply swap it with one of the Glue-All/School Glue/white glue spouts! It works great as a precision applicator and it's much better suited for rocket building (Edit add: and wood glue fillets!).



This technique is also found at:

Doing fillets with Titebond Quick and Thick

I've had varied experience filleting my LPR models. Initially I used Titebond No Run/No Drip (previously Titebond Molding and Trim), now I have a bottle of Titebond Quick and Thick, which is basically the same stuff, with one key difference. After doing a bunch of fillets last night, I thought...

www.rocketryforum.com

The best part about this tip is that you can save bottle lids and use them for wide or thin applications as needed.

 

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Heat will thin epoxy

Contributor: @dr wogz

Don’t use alcohol to thin epoxy, use heat! Apply, then heat up with a hair dryer. (This also speeds up the cure time though..)

Heat can also be used to thin aged hardener (firmed).

 

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Use Plastic Expansion Inserts

Contributor: @ep29030

Cardboard Airframes: IF you want to install motor retention clips in a rocket with balsa or thin plywood centering rings, try using those plastic drywall screw expanders (MolIies?) to improve the screw's grip. I've used them successfully in the past on LOC kits where I added homemade motor clips after the kit was built. And if you want to replace them, they come right out again.

 

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Extend your igniters with wire wrapping

Contributor: @caveduck

Wire-wrap extensions onto Estes igniters with a manual wire wrap tool and some pre-cut and pre-stripped #30 wires 4-6” long. Only takes 30 seconds and protects your clips from getting trashed in the motor exhaust. Even though the igniter wires aren’t square like header pins, the connection is pretty secure.

 

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Use magnets to avoid losing nuts and washers.

Contributor: @KenECoyote

Ever get annoyed with losing some wing nut or washer while opening or closing your dd bay (especially in the field)? Try epoxying a magnet to the bay lid they go onto.



This is also a visual reminder that the nuts aren't on.

*****Note that magnets should not be too close to electronics.******

 

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Recycle those N-95s.

Contributor: @dr wogz

Recycle those N-95 masks! Wear them when sanding & painting!! There is no reason to throw them away after using protection against COVID. They work for a much longer time, protecting against dust.

 

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Put tape over the piezo.

Contributor: @KenECoyote

If you are testing an altimeter with a piezo speaker (little round black ones like those on SLCF & Eggtimers) and don't want to disturb or alarm others, put a small piece of masking tape over it, and it cuts the sound down considerably.

View attachment 492670-2074371bd8a5f0e426180ac139f5bfe5.mp4

Just remember to remove it before launching!

 

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Write your name on your rocket

Contributor: @DabCat

Putting your name and phone number/contact details on your rocket. In more than one place, in case of separation, motor getting ejected unintentionally, etc. I write my name on my altimeter sled or av bay bulkheads and motor casings. Often I'll run a thin strip of masking tape along a motor casing with my name and phone number. I'll write it somewhere else for rockets without av sleds or motor casings, such as the nosecone shoulder, coupler shoulder, parachute, streamer, etc. It acts as extra insurance in multiple scenarios and never hurts to add. This last ROCstock, I could return two rockets to their owners because the owners had written their names on them.

 

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Label your motors:

Contributor: @DabCat

I like to build a bunch of motor before a launch, so to avoid mixing them up, or forgetting what's loaded in casings if I don't end up launching them, I like to write on a piece of masking tape what the motor is, what the delay is cut to, and what rocket it was intended for. Sometimes I'll also write the date on it in case it ends up being a while before I fly it.

 

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CA Your Body Tube Ends:

Contributor: @cwbullet

This tip works for cardboard body tubes used in high and low power. The cut ends of the body tubes are the weakest parts of the tubing. The body tube ends can be strengthened, and this tip is just one means to do so.

1. My tools of choice are cotton tip applicators or Q-tips, thin or medium consistency CA glue, scrap of cardboard, and 400 Grit Sandpaper.
2. Like an artist, I use a scrap peice of cardboard as a CA palate to maintain control of how much I add and to prevent running. Squeeze out a small pool of CA glue onto the piece of cardboard. *****Warning: I recomment you not apply CA directly to the tube and keep the cardboard flat. This tends to run and increase the risk of gluing parts to the tube or feet to the floor (Sorry, Bridgett). ******
3. Hold the body tubing with your non-dominant hand. The tube is parallel to the floor, the open end facing your dominant hand. Keeping it parallel will prevent running.
4. Dip the Q-tip into the CA glue drop and allow a small amount to soak into the cotton tip. Spread the glue around the inside end of the body tube (1/4" approximately). The CA coating will darken the tube to show where you have already treated it.
5. Once dry, you can apply it to the other end of the tube (if desired).
6. After the CA coat dries on both sides, smooth out the rough glued surface with 400 grit sandpaper. I use my finger as a sanding block by wrapping the sandpaper around my finger.

Your motor or body tube is now strengthened and ready to use. It will reduce delamination but will probably not prevent a zipper. Next, we will discuss how to prevent zippers. Technique adapted from Chris Michielssen.

 

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Cut your masking on a mat or glass.

Contributor: @russell_t

Applying tape edge masks to model rockets for paint detailing (Saturn V and Saturn 1B are examples) can be difficult with stock masking tape. It is helpful to trim it down to size.

Steps:

1. Place the section of tape on the mat, glass, etc. (If going the whole diameter of the tube, multiply the diameter by 3.14 plus a little for overlap and it will be the right length from the start).
2. Use a straight edge and a sharp (new) blade to cut the length of tape down the middle.
3. Apply to the desired area.

When feasible to do this where masks are concerned, it can reduce waste and make your masks more precise.

 

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Rail Button Location:

Contributor: @cwbullet

This topic is going to be a little controversial. Almost everyone has an opinion. My opinion I based on experience and observation. I hope this tip stokes some discussion. The images I am using are off Tinkercad and from blacksky.


Round Rail Guide



Conformal Rail Guide

Rail buttons serve as the primary means to control the flight while the rocket is mounted to the rail and maintain a controlled flight until the rocket accelerate to enough speed to be stable. You can launch without rail guides if you use a tower, but without a special method to maintain stability, you need at least two rail buttons (round) if they are round and allow the rocket to rotate. If you use Conformal rail guides, you may get away with a single one.

It you do plan to use a single conformal rail guide, I high recommend that you place it as low on the rocket as possible to acquire the maximum speed prior to release from the rail's control. If you use two rails, I usually follow the blacksky method (below) and go about 1-2 body diameters below the center of gravity. The key is to make sure the button is not too high. Too high and the rocket may rotate on the rail before the bottom button is released from the rail. Higher on the rocket also make getting the rocket on the rail more difficult.




I have seen people put a button on the AV Bay switch band. I would not do this unless you plan to place three rail buttons.

Do you have another opinion? Let's discuss it in the comments thread. I have no problem with editing this post if there is a consensus on a better way to do it.

Comments:

TRF Tips and Techniques Comments Thread.

That wire wrap tool in my photo is about 30 years old. Yup. I use two—one from Radioshack and one from Ok Industries. Both are over 20-30 years old. I used them on electronic projects before I joined the military. Someone told me they old work with square pegs also. I have found them quite...

www.rocketryforum.com

 

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Use Tool Racks:

Contributor: @caveduck

The Adam Savage theory of tool organization - "drawers are where tools go to die" - he likes vertical slanted racks with holes that you can drop your tools into so they are always instantly accessible.



I haven't gotten serious about this, having made a bunch of custom drawer racks, but I have a bunch of skinny pointy stuff, pliers, etc. that could benefit.

 

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Sharpen Those Blades:

Contributor: @Sooner Boomer

Use a whetstone to sharpen the *back* of a #11 Xacto blade to a point. I've noticed that many don't come to a sharp point. Having a sharp point makes it easier to make a piercing cut. I also use the knife tip to mark or start a hole in soft material. Having a fine point makes this more accurate.

 

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Antizipper or Zipperless Design:

Contributor: @cwbullet

On this topic, I am more of the gatherer than the writer.

Zippers can ruin your rocket weekend. Designs meant to reduce zippers are all over the place. Zippers happen when parachute deployment occurs at a high rate of speed or when your shock cord is too stiff to absorb the shock of deployment. If the rocket is designed using traditional methods, the shock cord can rip a good slice down the side of the body tube.


The photo above was posted by @tim cubbedge and is a great example of a zippered tube.

This high-speed deployment has happened due to early or late ejection with a ballistic trajectory. Either case is a deployment at a higher-than-desirable speed. The main problem is a whipping effect with a long piece of shock cord against the side of the body tube. The stress on the shock cord is imparted on the body tube, resulting in a zipper.

So how do we prevent them? The best method I have seen is a "zipperless" design. The best article I have ever seen on the topic was by Stu Barret. It can be found on the Info-Central:

Info Central - Presented by Rocketry Online

I also attached a PDF copy.

Another good read is the Peak of Flight 290:

https://www.apogeerockets.com/education/downloads/Newsletter290.pdf

Another thread:

What does “Zipper-proof” design mean?

I know what a zipper is, in regards to rocket damage, but I’m wondering how this zipper proof design is achieved.

www.rocketryforum.com

The best solution is to avoid zippers, but you can also repair them,
but that is a topic for another day.

If you have a better solution, please post it in the comments thread.