Another good tool for burnishing is a regular teaspoon. Just push with your thumb in the bowl of the spoon and let the back do the burnishing.
TRF Tips and Techniques Comments Thread.
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I am going to move this from daily to twice a week. It is getting difficult to find tips now.
Posted for Tuesday!
added for today.
A tip when dispensing pigments, fillers, thickeners, microballoons, chemicals of any sort including fertilizer and foodstuffs in the home. Most people tend to shake or jiggle the container to help the solid come out. Which usually leads to solid flooping out and into the desired container. And everywhere else as well. The finer the powder, the greater the floop and the larger "everywhere else" becomes.
Instead, tilt the container slightly and rotate it gently back and forth on its axis. You'll have much better control. Bigger back-and-forth arcs to dump larger quantities. And if practical, place a wide "powder funnel" (e.g., gallon milk jug with the bottom cut off; wide exit needed for solids) on the receiving vessel, to minimize escape of solids.
Instead, tilt the container slightly and rotate it gently back and forth on its axis. You'll have much better control. Bigger back-and-forth arcs to dump larger quantities. And if practical, place a wide "powder funnel" (e.g., gallon milk jug with the bottom cut off; wide exit needed for solids) on the receiving vessel, to minimize escape of solids.
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Non-Range Safety Tips
Of course, I encourage everyone to follow the TRA/NAR safety codes at all times. However, here's some general rocketry-related safety tips for when you're building and finishing your rocket:
Of course, I encourage everyone to follow the TRA/NAR safety codes at all times. However, here's some general rocketry-related safety tips for when you're building and finishing your rocket:
- All spray paints require a mask. I use waterborne Createx for most of my paint jobs. It still requires a mask that can handle VOCs (volatile organic compounds), as there are acrylics, polyurethanes, acetone, and other nasties in the paints, the reducer I use (humidity issues in Georgia), etc.
- Wear a mask when sanding! Doesn't matter what you're sanding, whether it's balsa (sorry, Marty!), plywood, epoxy fillets, paint or anything else. Fine particulates will get in your lungs if you don't wear a mask. It's not fun. Besides, who wants to blow colored snot after a sanding session?
- Wear a mask (sense a theme?) when using epoxies. Make sure it's as good as the one you use when painting and can handle VOCs. Epoxy resin is a nasty chemical when uncured, often containing BPA (BisPhenol-A) and other things that can cause sensitivity after use. Sometimes right away, sometimes only after years of exposure.
- Wear gloves and long sleeves when using epoxies. See reasons above. It can get through your skin very easily. If you get any on you, immediately wash with soap and water! Do not use alcohol to clean it off your skin. The alcohol can dilute the resin and help it soak into your skin.
- Keep your work area clean and clear of clutter. You're less likely to knock over a container of something nasty if your work area is uncluttered.
- Do not eat or drink while handling adhesives or other chemicals.
- When cutting something with a knife (box-cutter, utility blade, hobby knife, etc.) always cut away from yourself and others. That way, a slip is less likely to injure anyone.
- When soldering electronics, make sure to work away from flammable substances. A silicon mat, such as a 'slap mat' for resin printing, or a SilPat for baking, makes a great surface to work on. Use as short a cord as possible for your soldering iron. Longer cords increase resistance, possibly causing heating in the cord.
- Speaking of soldering, use a fume extractor fan when soldering, especially, but not limited to, when you're using solder that contains lead.
- Pace yourself and work while rested and alert. A rushed job when you're tired and impaired can lead to injury and a crappy-looking rocket.
- Plan your work. If it helps, write down the steps, in your own words, that you are going to follow. Then follow them! Take notes as you go, so you can revise them for the next build. Note what worked and what didn't.
- Wear an apron or old shirt when using adhesives or paints. That way, you won't have epoxy, Titebond, CA, or any other goop on your good clothes. Since you won't care if it gets junk on it, you won't be jumping up and possibly knocking something else over because you just got epoxy on your favorite shirt.
- Have fun. If you get frustrated or stop having fun, take a break. You're more likely to make a mistake when you're upset.
I was with you up until this point.
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Label Your Motors!
If you preassemble motors prior to the launch, make sure to label them. I like to wrap the instructions from the motor around the casing.
If you preassemble motors prior to the launch, make sure to label them. I like to wrap the instructions from the motor around the casing.
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How to install a flanged motor retainer to a flush-mount MMT
Installing a motor retainer, like the Aeropak, it can be difficult to get the retainer ID to match the MMT ID smoothly. If you have an adapter to let you use a smaller diameter motor in the MMT you're trying to mate to, tape up below the flange of the adapter so it matches the ID of the MMT. Then, you can fit the adapter into the retainer and the MMT and mark and drill the holes for the flanged retainer.
After the flanged retainer is installed, you can remove the tape.
Installing a motor retainer, like the Aeropak, it can be difficult to get the retainer ID to match the MMT ID smoothly. If you have an adapter to let you use a smaller diameter motor in the MMT you're trying to mate to, tape up below the flange of the adapter so it matches the ID of the MMT. Then, you can fit the adapter into the retainer and the MMT and mark and drill the holes for the flanged retainer.
After the flanged retainer is installed, you can remove the tape.
Regarding #9: Using an extractor fan is a good idea when soldering. It doesn't matter whether it is leaded or lead-free. The flux fumes are bad for your health. Mostly at home I just hold my breath when making the joints, but an extraction fan (even just a usb-powered desk fan) facing away from you makes life easier.
Another tip: After soldering always wash your hands to remove any residues from the metals or the flux.
If the motor is already installed in the rocket, a masking-tape label around the plastic cap that fits over the nozzle (on AT motors at least) with the motor info works, too. Or even around the nozzle itself. Write small.
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Thank you for clarifying, @OverTheTop. That's why I said "especially, but not limited to, when you're using solder that contains lead."
Always great that your head gives off enough heat to cause convection of the air around that draws the fumes straight at it.
If the motor is already in the rocket, you can put that label anywhere on the rocket. I do that even with LPRs that I prep in advance.
added for Tuesday. I like this tip. It might save me a few disasters.
@John Kemker
- All spray paints require a mask. I use waterborne Createx for most of my paint jobs. It still requires a mask that can handle VOCs (volatile organic compounds), as there are acrylics, polyurethanes, acetone, and other nasties in the paints, the reducer I use (humidity issues in Georgia), etc.
Added for Tuesday.
If anyone has a tip I can use, post it. I am a little under the weather after an injury and am medicated. I could use the help.
Regarding today’s tip (https://www.rocketryforum.com/threa...he-day-thread-twice-a-week.177679/post-249089):
I do this all the time twisting CAN pairs for harnesses at work. If you haven’t secured it to anything yet, put one end in a vise and you can get a real nice twist. If you pull the drill up and back once you’re done twisting, it helps set the twist and it will untwist less when you release the pressure.
I do this all the time twisting CAN pairs for harnesses at work. If you haven’t secured it to anything yet, put one end in a vise and you can get a real nice twist. If you pull the drill up and back once you’re done twisting, it helps set the twist and it will untwist less when you release the pressure.
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There's literature that indicates the optimum taper for a straight-taper transition is 4.5 degrees per side. Working through the trig, that means the length of a taper should be 12.7 times the thickness (per side) being tapered. Easy enough to remember, because it's the same as the conversion from mm to 0.5 inch.
For example, if you're just tapering the thickness of a 0.013-inch wall tube, the taper should ideally be 0.165 inches long. That's right about in the middle between 5/32 in (0.156 in) and 11/64 (0.172 in), both of which are probably close enough for my model rocket building skills.
If you're tapering the LE/TE of a fin, and want the taper to be 1/32 thick per side (e.g., leaving 1/32 thickness out of 3/32 stock), that ends up being 0.396 inch, or 10.1mm. I'd probably just mark 10mm, since my skinniest pencil lead is 0.2mm.
If you're doing a boat tail or other transition from BT-50 to BT-20, it ends up being 1.5(24) inches long.
For example, if you're just tapering the thickness of a 0.013-inch wall tube, the taper should ideally be 0.165 inches long. That's right about in the middle between 5/32 in (0.156 in) and 11/64 (0.172 in), both of which are probably close enough for my model rocket building skills.
If you're tapering the LE/TE of a fin, and want the taper to be 1/32 thick per side (e.g., leaving 1/32 thickness out of 3/32 stock), that ends up being 0.396 inch, or 10.1mm. I'd probably just mark 10mm, since my skinniest pencil lead is 0.2mm.
If you're doing a boat tail or other transition from BT-50 to BT-20, it ends up being 1.5(24) inches long.
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On removing masking early, I've wondered about that in context of multi-layer masking strategies as practiced by @James Duffy and others to get more complex graphic schemes. Seems like just stacking it up and then hoping for the best/no/few problems when you take it all apart is all you can do that way.
Yes, and the arms block air coming from the sides which accentuates the problem. Without arms, the solder doesn't go into the face, because air can be drawn from either side of the body.
Cut the arms off anyone that's going to solder without extraction. That'll partially solve the problem. Or remove their heart to promote airflow from one side of the body to the soldering area.
On masking: in one of his books Peter Alway suggests aluminum foil rather than newspaper/kraft paper/etc for covering large areas. It's a great idea. Easier (than paper) to make it conform, especially to fins and complex shapes. A little care is needed to avoid puncturing the foil, but if it does puncture just tape more foil over the puncture.
(Not-pro tip: Go to Sam's Club or Costco and get the 1000 foot roll. We use a lot but it still hasn't run out, nearly two years later.)
(Not-pro tip: Go to Sam's Club or Costco and get the 1000 foot roll. We use a lot but it still hasn't run out, nearly two years later.)
Interesting. If the foil develops a small puncture or tear, it would not be over a large area, so I should think that a piece of tape there would be OK, unless it's riche in the middle of a compound curve.
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If you use plastic grocery bags, be sure any of the marketing ink is away from the paint. I had to sand blue ink transfer off orange paint once.
I appreciate all the help keeping this thread going.
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