Tips and Technique of the Day Thread

[cwbullet]

This is the tip-of-the-day thread. If you have one for today, post it here.

List of Techniques:

Number:	Date	Technique or Tip:
1	31 Jan 2023	Consider Adhesive Sandpaper
2	1 Feb 2023	Bending Wood / Blasa
3	2 Feb 2023	Use a Syringe for Internal Filets
4	3 Feb 2023	Near Bullet Proof Fins
5	4 Feb 2023	Keeping Paint Out of Tubes
6	5 Feb 2023	Use Sryringes to measure liquids.
7	6 Feb 2023	Use Tweezers with Decals.
8	7 Feb 2023	Shock Cord Mount Repair
9	8 Feb 2023	Prevent X-Acto Rolls
10	9 Feb 2023	Recycle that N-95
11	10 Feb 2023	Protect Your CA Glue
12	11 Feb 2023	Easy Fillets
13	12 Feb 2023	Foam your nose cone.
14	13 Feb 2023	Use Waxed Paper
15	14 Feb 2023	Syringe Style Matters
16	15 Feb 2023	Small Condiment Containers
17	16 Feb 2023	Remember CA Accelerator
18	17 Feb 2023	Get a good Mechanical Pencil
19	18 Feb 2023	Keep it simple stupid
20	19 Feb 2023	Use Aluminum Angles
21	20 Feb 2023	Label Your Motors
22	21 Feb 2023	Instant Launch Lug
23	22 Feb 2023	Straightly Drilled Holes
24	23 Feb 2023	Measure Epoxy with a Scale
25	24 Feb 2023	Use a Rocket Stand
26	25 Feb 2023	Inserting Clay Nose Weight
27	26 Feb 2023	Balsa Dust Filler
28	27 Feb 2023	Hollow Nose Cones in TinkerCad
29	28 Feb 2023	Strengthen your Fillets and Joints
30	1 Mar 2023	Tape that Cone
Page 2		Link to the page 2 index
Page 3		Link to page 3 index
Page 4		Link to page 4 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

 

[cwbullet]

Consider Adhesive Sandpaper:

Contributor: @cwbullet

Adhesive sandpaper can really help your build. It is a great tool to get that sanding shape you want. I love to use it on PVC pipes and dowels to sand in tight nooks and crannies. I also use it on 3D-printed angles to get the custom sanding tool.

Dura-Gold is one example, and although it is a premium product, it is worth the cost.

There are other brands, so just find one that matches your budget.

Examples:

1. https://www.familyhandyman.com/article/pvc-hack-curvy-sanding-tools/
2. 

 

[Funkworks]

Bending Wood / Blasa

Contributor: @Funkworks

My favorite trick I learned here, based on a few TRF threads from a few different people, and with which I tried pushing the limits, was to curve a 1/8” thick balsa board (1" wide) along the grains. This is what worked.

With eye protection and air ventilation:

- Fill a saucepan halfway with water and “ammonia”. The “ammonia” was actually a 5-25% ammonia solution as sold in retail stores. A ratio of 50:50 for water and the ammonia solution was used.​

​

- Heat to a gentle boil.​

​

- Soak in the end of the 1/8” balsa board.​

​

- With pliers, slowly curve the board to satisfaction or until it completely fits in the saucepan. Diameter can reach less than 6 inches.​

​

- Clamp, remove and let dry.​

​

​

 

[conneryc]

Use a Syringe for Internal Filets

Contributor: @conneryc

When doing internal epoxy fillets, use a syringe with a length of tubing stuck on the end to inject the epoxy where needed. You can easily suck the epoxy out of your mixing cup into the syringe to load it up. I usually clean mine with acetone after I'm done so I can reuse it over and over.

 

[cwbullet]

If you have a recommentded post, send it to me, and I will post it.

 

[cwbullet]

Near Bullet Proof Fins

Contributor: @prfesser

For a near-bulletproof fin unit: Bolt TTW fins together using holes drilled in the tabs. After sanding to shape and removing the bolts, sand the sides of the tabs and clean them up. Epoxy the fins to the MMT and fill the spaces with two-part expanding foam before gluing in the aft centering ring. (Denser foam is stronger than low-density. Don't use single-can expanding foam ("Great Stuff"). It can expand and contract significantly with temperature changes. Lumpy rockets are unattractive and can cause other problems. DAMHIKT)

Expanding foam contains an isocyanate, similar to Gorilla Glue, and will stick tenaciously to the tabs. The holes provide a little more surface area. (These are for a fiberglass Super Vega, and no they aren't done yet.)

My L3 rocket was destroyed by a CATO. The fins I found were still glued to the MMT and had foam attached.

 

[cwbullet]

Keeping Paint Our of Your Tubes

Contributor: @KenECoyote

When spray painting 4" diameter rockets, a plastic Chinese takeout soup container fits right into the body tube as a quick way to prevent paint spray from going inside.

Either Quart or Pint fits; however, the Quart size stays put better.





Smaller cups can be used for other size body tubes!

Brown paper will work also, but the containers are more reusable.



Addition added by @prfesser: "the containers should be either polypropylene (PP) or high-density polyethylene (HDPE); recycling #2 or #5. Paint won't stick well to them so that they won't get paint-glued to the tube."

 

[cwbullet]

Use Syringes to Measure Liquids such as Resin and Hardener.

Contributor: @cwbullet

About a month ago, I had an epiphany after struggling with pumps and spills, and messes with West Systems Epoxy. I started putting it in smaller bottles similar to glue bottles. I found the 4-ounce bottle ideal for making igniters and small amounts of epoxy, but they come in different sizes if this size does not meet your needs.



That worked great at avoiding some messes but was precise at getting the mixture at the right ratio. So I started using 1, 3, 5, and 10 ml syringes. That helped the precision by reintroducing mess on the outside of the syringes. A search on the internet suggested oral medication adaptors used for babies.


Now, I have precision and much less mess.



If you have a better idea or another suggestion, please post them in the comments thread.

 

[cwbullet]

Use Decal or Sticker Tweezers.

Contributor: @Huxter

When laying down decals on your rocket, use tweezers to fine-tune the decal's position and avoid clumsy finger errors. The finger has the habit of making the decal stick before it's in the final resting place.

Tweezers are more precise and will keep those nasty finger oils off the decal and stickers. Thank @Huxter for the tip.

I found these interesting decal tweezers on Amazon by Tamiya. I ordered a set to try and review.

If you have a better idea or another suggestion, please post them in the comments thread.

 

[cwbullet]

Shock Cord Mount Repair:

Contibutor: @blackjack2564

This is a blast from the past pulled from the deepest depths of the TRF dungeon. The original posts is:

Is kevlar really THAT much better than nylon?

Working on a 5.5" LOC Goblin and everyone I've talked to swears up and down that tubular nylon is the worst possible thing to use in high power as a shock cord and to use kevlar. If it's THAT bad, why do companies still put nylon in the kits and not kevlar? I'm using 5/8" climbing grade tubular...

www.rocketryforum.com

Simply use few inches of coupler and another small section coupler with slice removed so it fits inside.

Place new Y-harness between the 2 and glue.
when cured slide down fincan to top CR and epoxy into place.
U can drill small hole above assembly and inject glue or Attach syringe to dowel slide down ...use another dowel to push plunger. etc. etc

To remove any remaining damaged original cordage. push it through MM out the back. Use X-acto, razor blade etc. to cut off flush at edge of tube, where its bending into mm tube. I attach blade to my angle iron used to mark lines on airframes, fits right into angle. easy peasy!

View attachment 438218 View attachment 438219 View attachment 438222View attachment 438220

A blast from the past - Thank you, @blackjack2564, for your many sage posts and common sense solutions.

 

[cwbullet]

Prevent X-Acto Rolls

Contributor: @dr wogz

This is both a safety tip and an organization tip. It is hard to find the knife when it is on the floor. Put a tie wrap/cable tie on the [round] handle of your X-Acto knife. So then it won’t roll onto the floor (or into your foot!).

Thanks to @dr wogz for this tip.

If you have a better idea or another suggestion, please post them in the comments thread.

 

[cwbullet]

Recycle Your N-95s.

Contributor: @dr wogz

N-95s are excellent for protection against workshop particulates. They can be the difference in keeping wood, fiberglass, and carbon fiber dust out of those lungs. Protect yourself with that slightly used N-95 from your COVID days.



Thanks to @dr wogz for this tip.

If you have a better idea or another suggestion, please post them in the comments thread.

 

[cwbullet]

Protect Your CA Glue.

Contributor: @dr wogz

Humidity is the villain that will destroy your CA glue. Keep your CA glues in the refrigerator. They are activated by humidity, and a fridge has a low RH. CA solidifies when it contacts humidity or water.

Thanks, @dr wogz for another tip.

One tip that I will add to keep your marriage healthy: If the food and glue together are too much for your spouse or roommates, you can also keep it in an air-tight container with water-absorbing silica pouches. I have also seen folks store them in a sealed glass jar with some of those desiccant packs that are found in all sorts of things.

If you have a better idea or another suggestion, please post them in the comments thread.

 

[cwbullet]

Easy Fillets the Crazy Jim Way

Contributor: @blackjack2564

I have learned so much from Jim or @blackjack2564 on the forum and at our launches. I really appreciate everything he has done for our community. This post is just one more homage to what he has done for our hobby.

Jim uses a shot piece of PVC to mark the tube and shape his fillets. A simple sharpie on the edge of the PVC pulled on the airframe will create the marks, and then tape it off along the marks. Mix the epoxy and use the PVC to pull your fillets.

Tip:

To get perfect fillets, with no edges that stick up & need sanding.
Use your smoothing tool for guide to place masking tape.
Coat edge with Sharpie/marker & rub/roll along V-groove between fin and airframe.
It will leave a line you place masking tape on.

View attachment 336467

When pulling glue smooth, all excess will be on the tape, leaving a perfect fillet & all remaining glue will be removed with the tape.

This is a 1 in. diameter section of PVC pipe, which I use to smooth fillets.
Now is when you tape off each fillet to shape desired.
Remove tape about 15-20 minutes after pulling smooth.

View attachment 336468

Depending on glue used, I sometimes wait as long as 45 minutes after mixing to allow epoxy time to thicken, so it does not sag after pulling to shape. Then I put it in place & smooth.
This is all temperature dependent .

More links:

Crazy Jim's "Punisher-4" new flight video with 4in Fly-away-guides

I'm curious to see how much nose weight is required. I thought it'd need 24-32oz.

www.rocketryforum.com

New Wildman 38mm BlackHawk prototype....first look !

I'm resurrecting this thread. Due to a resurgence in the Blackhawk 38: There have been numerous questions asked about this kit, so I searched back & found this. Lo & Behold I never finished it! [Here anyways....I did the main build on the Australian Rocketry Forum for my mates down under] So...

www.rocketryforum.com

This technique will give you perfect fillets every time.

If you have a better idea or another suggestion, please post them in the comments thread or send me a PM.

 

[cwbullet]

Foam Your Nose Cone

Contributor: @cwbullet

I have done this in both low and high power, but if you are doing it with a thin plastic nose cone, I suggest you put it in ice water to absorb the heat.

Foam the nose cone can create a light weight nose cone that is stronger. It will add a little weight forward to help improve stability. You can also use the foam and small containers such as a film canister to bottle to create smaller cavity for your tracker. I have found it extremely useful.

Four pounds of 2-part foam (2 pounds per square foot density) was added to the tip of the nose cone to increase strength and add some nose weight to the forward section. This would allow for a larger motor such as an "N".


A garbage can filled with water was used to hold the nose cone upright and to cool the foam as it reacted.

View attachment 52944

View attachment 52945

View attachment 52946

 

[cwbullet]

Use Waxed Paper:

Contributor: @dr wogz

Waxed paper has many uses. Glue generally doesn’t stick to it well, so use it as a liner for butt/edge gluing parts, as a liner between stacked books (on the fin), against the dowel for fillets, etc.

It is also good to put down to protect your desk from glue drips.

 

[cwbullet]

Syringe Style Matters:

Contributor: @prfesser

This style of syringe--Neomed is one brand--seems to have been designed with us rocketnutz in mind. Most who have used them agree.

• An o-ring instead of a solid rubber plunger. Solid plungers swell from long contact with epoxy, solvents, etc. Usually renders the syringe and its contents useless. By contrast I've stored epoxy in these literally for months without any problem. The o-ring is a "quattro seal" type so even if a little swelling occurs, it doesn't affect use at all.
• The cap seems liquid-tight, and it snaps on, not just a friction fit. Syringes filled with epoxy & curative are stored (in a plastic bag JIC) in my range box. No leakage seen after months. And when the cap is dropped on the workbench it tends to roll about until the sticky end is up. (Don't know if that's by design...but it's a neat attribute.)
• With a little care large syringes can be filled quickly by pouring liquid into the syringe rather than drawing it in through the tip. Cap the tip, pour liquid to fill, hold cap in place, insert plunger just far enough to seal, turn tip-up, wait for the bubble to reach the tip, remove cap, push plunger in to expel air, re-cap. Especially convenient for thick liquids.
• The tip is offset rather than centered. Less trouble with drips during dispensing.
• Although I weigh epoxy and curative, the graduations are pretty accurate for volume dispensing. Not hard to dispense 1 mL at a time---from a 60 mL syringe.
• A bit more than a buck each, in bulk. Cheap enough to discard when they get messy or the graduations wear off. Need epoxy in a tight space? Mix batch, fill syringe, inject where it'll do the most good, throw it away afterward.

Thanks @prfesser for this tip. I tried the Neomed Offset syringes this week and they are fantastic for for both injecting epoxy and measuring the components.

 

[cwbullet]

Small Condiment Containers

Contributor: @dr wogz

Save the soy sauce or condiment containers from your take-out. They can be used as small parts dishes, epoxy missing cup, etc. Your imagination is the only limit. You can scout out your local burger joint for ‘ketchup cups’ (5 Guys!). I am not recommending that you fill your pockets on the way out, but they are very useful.

Thanks @dr wogz for the tip.

 

[cwbullet]

Remember CA Accelerator

Contributor: @cwbullet

One of the most forgotten items is using an accelerator or bonding agent. CA glue accelerators are an effective tool for making super glue applications more convenient and more straightforward with predictable and repeatable performance results. The primary function of an accelerator (also called cyanoacrylate setter, kicker, boost, blast, or bonding agent) is to facilitate extremely fast setting (curing) and bond times. However, it can be utilized to “build” or “mound” a surface to fill gaps and create a “fillet,” improve bonding on porous surfaces like wood, ceramic, or foam rubber, and used to help mitigate blooming or frosting on your finished assembled item.

Proper Use & Application Methods of Super Glue Accelerator Chemistry​

Super glue's bonding reaction is caused by condensed water vapors (think humidity) and weak base chemistry on the bonding surface (think materials you are bonding together). This means that the more latent moisture a substrate has, the more quickly the glue will cure. Super glue curing begins at the surface level and slowly develops from the outside to the inside, causing thick applications to harden (polymerize) slowly or not at all. Using accelerators in your bonding processes ensures solid bonds, even in challenging environments.

CA glue accelerators rely on an evaporating agent, such as acetone, heptane, or another solvent, to act as a carrier for the active accelerator ingredient. After application, the evaporating agent dissipates, leaving the accelerator chemistry on the bonding surface. Before you begin any bonding, make sure that the components you're working with are clean and dry so that the glue and accelerator can perform optimally.

Do you apply the accelerator before or after CA? Both will work.

1. Before CA Glue: Apply the accelerator directly onto one side of the two bonding surfaces by spraying, brushing, or wiping with an accelerator-soaked cotton swab or towel. Apply super glue to the non-activated (accelerator) substrate. Mate the two surfaces together to initiate rapid cure and provide intimate contact between mating surfaces.
2. After CA Glue: Apply super glue to the bonding surface, mate materials to be joined, and add pressure to help initiate cure and minimize gaps; apply accelerator by spraying over the glue line of mating surfaces.

 

[cwbullet]

Use a Good Mechanical Pencil

Contributor: @SolarYellow

This one comes from @SolarYellow. The right mechanical pencil can make all the difference in marking that perfect cut. He picked up a 0.2mm-lead mechanical pencil. It's a game changer for making precise marks on parts, like alignment marks on the body tubes, etc. The best part about a good mechanical pencil is that you go not need to sharpen it.

https://www.amazon.com/dp/B07KCG3XYS

Thanks @SolarYellow .

If you have an idea or suggestion, please post them in the comments thread or send me a PM.

 

[cwbullet]

Keep It Simple Stupid

Contributor: @cwbullet

This is not meant to be offensive, but most failures in rocketry are caused by overcomplicating the process. Building rockets is already tricky enough, so there’s no reason for you to add complications to the process. Read the directions carefully and then follow the instructions. The guidance in those words and pictures will lead you to success. Shortcuts may sound great but often lead to heartache and failure.

Some new-fangled recovery systems may sound great when you think about it but remember that often any additional complexity just adds another issue that can and often will go wrong.

 

[cwbullet]

Aluminum Angle:

Contributor: @cwbullet

A small piece of steel or aluminum angle can be essential in your build press. I keep several beside my workbench. They are quick and easy tools to create a straight line on the body tube or as guides to keep fins or rail guides straight. Handing multiple sizes gives you the right size tool for multiple sizes of rockets.

 

[cwbullet]

Label Your Motors:

Contributor: @cwbullet

Several of our members suggested that fliers start assembling motors the night before the launch. It makes sense. I often do it myself. One flyer who will remain unnamed planned to fly a 5.5-inch Big Bertha and the Broken Arrow. Both had flown multiple times and were battle worn. One would fly on a K550 and the other A K2050.

Everything went perfectly till the button was pushed to launch the Bertha. Its long fins began to flutter and litter the field with fin parts. You could see the look of horror in the flier's eyes. Instead of Bertha fins, the rocket now has Big Nuke fins. It is still stable, but it is not a Bertha anymore.

Few Berthas can handle that high a thrust motor. Label the motors and prevent this mix-up.

 

[cwbullet]

Cheap Launch Lugs:

Contributor: @Cape Byron

Plastic straws have been banned in Australia, so local supermarkets have packs of 30 paper straws for around $2. You can also find them in the United States. They are available at Hobby Lobby, the supermarket, and Amazon.

Cut one in half and test it on your launch rod—instant Launch Guide.

To Americans, You can use a plastic straw, but cardboard or paper straws stick better.

Thanks @Cape Byron for this suggestions.

 

[cwbullet]

Straightly Drilled Holes

Contributor: @KenECoyote

Have you ever drilled a rail buttonhole crooked?

An Estes Tube marking guide can also be used as a rail button drill guide to ensure you drill holes straight. The pencil holder is just the right diameter for the standard hex shanks. Just use the proper length drill bit.



If it's just the bt, you can even use finger pressure to drill a hole; otherwise, a cordless screwdriver or very small drill is usually better than a large drill.

As always, when making extra holes in your rocket, ensure it's correct before drilling and going slow.

This tool works very similarly to the Milescraft drill jig that can be used for dowels and pipes.

Thanks to @KenECoyote for this tip.

 

[cwbullet]

Measure Epoxy with A Scale

Contributor: @Huxter

Measure epoxy on a postal scale. Most epoxy I use is a 50/50 mix. This also helps keep the two bottles level/equally used. I mix more than I need to ensure I do not run out and help rotate supplies. This 15-minute epoxy is over a year old. The mighty toothpick is one of my favorite mixer and applicator tool!



This suggestion is very similar to the one above to use syringes. The bottom line is that measuring and getting the mixture right is better.

Thanks, @Huxter, for the suggestion.

 

[cwbullet]

Use Rocket Stand

Contributor: @cwbullet

A good build stand is worth its weight in gold. You can use it to build the rocket and to do on-the-field maintenance. I use PVC racks, but there are so many options out there that our RC plane brothers have developed for us.



Above is one of the best ones I have seen by @AlexBruccoleri .

There are two threads I would recommend:

Range Box and Stands

Cases like this one from Harbor Freight are nice because it is easy to design and 3D/FDM print inserts that specifically meet your needs. I find stands annoying and just lay the rocket on the table top. https://www.harborfreight.com/8-bin-portable-parts-storage-case-93927.html

www.rocketryforum.com

I need photos of PVC racks

I need photos of rocket racks made from PVC pipe. I want to build one, and need ideas. Thanks guys!

www.rocketryforum.com

 

[cwbullet]

Inserting Clay Nose Weight:

Contributor: @jqavins

For setting clay nose weight in LP nose cones:

1. Put the clay in and tamp it down with a dowel pretty well, but don't try to perfect it.
2. Place the cone's pointy end down in a drinking glass that's as small in diameter as it will hold it. I like to use glasses that come with shrimp cocktails or chocolate moles in them.
3. Add boiling water to the glass. The clay will soften enough to flow into the tip and self-level.

Not all plasticine clays are the same, so this will not work in every case. But it sure comes out nice when it works.

Thanks to @jqavins for this tip.

 

[cwbullet]

Use Balsa Dust As Filler.

Contributor: @dr wogz

This is a great tip for those of us that are frugal. Save the balsa dust from sanding. You can use just about any fine saw dust. This can be added to epoxy to thicken it up, to be used as fillets.. Sands easily!

Thanks @dr wogz for this tip.

 

[cwbullet]

Hollow Nose Cones in TinkerCad

Contributor: @cwbullet

I have found a quick and easy method to make a nose cone from Rocksim and TinkerCad.

1. Open the file with the nose cone desired in RockSim.
2. In the Components, choose the nosecone and open the nosecone to the edit screen.
3. Click on export and choose to save it as an STL file. I save the file under very high resolution.
4. Import the STL file into TinkerCad.
5. Make a copy of the nose cone. Make the copy a hole (invisible or subtractive).
6. Make the "hole copy smaller than your original copy.
7. Center the copy on the X and Y Axis but keep it at the bottom of your Z axis.
8. Merge the two copies.

Now you have a hollow nose cone.