I have found that works fine for TBII but not for Quick and Thick, which clogs up the nozzle pretty quickly.
TRF Tips and Techniques Comments Thread.
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For keeping shock cords bundled nicely and quickly, I use the small rubber bands used to make bracelets. You can get a pack of 600 for about $5.
It fits well over small and large bundles, it's quicker than tape or crochet and it provides some shock absorption too.
Double it up on small cords. For big cords, it stretches plenty enough for bundles; however, you can double it on smaller bundles to keep it tighter and for more shock absorption.
It fits well over small and large bundles, it's quicker than tape or crochet and it provides some shock absorption too.
Double it up on small cords. For big cords, it stretches plenty enough for bundles; however, you can double it on smaller bundles to keep it tighter and for more shock absorption.
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You can also use dental rubber bands (smaller version of the above) for thinner aramid lines with your LPR & MPR recovery rigging.
Knots:
I've been using the "Perfection Loop" (posted a thread around here somewhere with a better method for tying it than illustrated at animatedknots.com) in place of a bowline, but have been thinking I should take another look at the figure 8.
At what point in flatness of cord do you transition from other knots to the "tape knot?" The heavier weights of aramid cord, as seen in the previous post, tend to get oval. Is there a threshold like 1.5:1, 2:1, etc?
Gluing prints:
Having digested the "Properly bonding composites and what your government doesn't want you to know" thread again earlier this week, I wonder whether there might be value in sanding prints in order to "activate" the surfaces and promote chemical adhesion of the glue. Also, I would be amazed if it didn't make a big difference to match adhesive to printing polymer, at least for some materials. For instance, it seems logical that more hygroscopic materials might interact and attain optimum bond strength with different types of adhesives than less hygroscopic materials.
I suspect resin printing is likely to be a whole different situation, since it's thermoset and not thermoplastic. Mechanical activation of the surface may make a bigger difference due to the lower porosity, and the different types of resins may work quite differently with different adhesive types. As well as how well cured the parts are in the first place, etc. I've seen some discussion of leaving resin printed parts without final cure, "gluing" them together with raw resin, and UV-curing the whole assembly at once. Might be worth looking into whether that approach could be used to adhere prints to other materials.
Knots:
I've been using the "Perfection Loop" (posted a thread around here somewhere with a better method for tying it than illustrated at animatedknots.com) in place of a bowline, but have been thinking I should take another look at the figure 8.
At what point in flatness of cord do you transition from other knots to the "tape knot?" The heavier weights of aramid cord, as seen in the previous post, tend to get oval. Is there a threshold like 1.5:1, 2:1, etc?
Gluing prints:
Having digested the "Properly bonding composites and what your government doesn't want you to know" thread again earlier this week, I wonder whether there might be value in sanding prints in order to "activate" the surfaces and promote chemical adhesion of the glue. Also, I would be amazed if it didn't make a big difference to match adhesive to printing polymer, at least for some materials. For instance, it seems logical that more hygroscopic materials might interact and attain optimum bond strength with different types of adhesives than less hygroscopic materials.
I suspect resin printing is likely to be a whole different situation, since it's thermoset and not thermoplastic. Mechanical activation of the surface may make a bigger difference due to the lower porosity, and the different types of resins may work quite differently with different adhesive types. As well as how well cured the parts are in the first place, etc. I've seen some discussion of leaving resin printed parts without final cure, "gluing" them together with raw resin, and UV-curing the whole assembly at once. Might be worth looking into whether that approach could be used to adhere prints to other materials.
I have tried surface-activating ABS prints using flame treatment. I found it to be very process dependent so I abandoned using that method. When it worked it was good, but too hit and miss.
Added today.
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Instead of buying Rapid Tac for cut vinyl decal application, you can make a less-expensive solution yourself by mixing distilled water with a surfacant, such as Ilfotol, Jet-Dry, etc. You only need a few drops per liter of water in order to be effective. If you'd like to add cleaning power, add some 90% Isopropyl Alcohol, about 10% by volume.
I use this solution to clean vinyl records with my vacuum system and to apply decals:
https://londonjazzcollector.wordpress.com/for-audiophiles/home-brew-cleaner-for-vacuum-rcms/
I use this solution to clean vinyl records with my vacuum system and to apply decals:
https://londonjazzcollector.wordpress.com/for-audiophiles/home-brew-cleaner-for-vacuum-rcms/
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@cwbullet,
Thanks for the mention. You might add a link to my post on an alternative method of tying it.
https://www.rocketryforum.com/threads/perfection-loop-knot-another-way-to-tie-it.177792/
The advantage of my method is you can end up with the loop actually passing through something without having to pass that thing through other portions of the knot.
Thanks for the mention. You might add a link to my post on an alternative method of tying it.
https://www.rocketryforum.com/threads/perfection-loop-knot-another-way-to-tie-it.177792/
The advantage of my method is you can end up with the loop actually passing through something without having to pass that thing through other portions of the knot.
I missed a few days due to illness. I am trying to get caught up.
Use the reflection from your overhead light as an alignment tool. Here I used it to assist with decal positioning, to keep things aligned with the vertical stabilizer at left (you have to adjust your head position to make sure you keep the reflection in the correct spot; it's a little bit off in this picture, slightly above the vertical stab.)
Added for today. Thanks, we are up to date.
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Paint with a brush.
I did my routine of white primer, grey filler-primer sanded, then white primer, then sanded. There were several little spots scattered around the rocket that needed a bit more filling, but smaller than anything you'd use "filler" or putty on. I really didn't want to sand off another full layer of filler-primer, so I decanted some into a red plastic cup and painted it onto the small spots that needed it with an old hobby/model brush.
It made for a LOT less sanding to knock those spots down to level after it dried overnight and will need to add less white primer (weight and cost - I need to reorder white primer) to cover the grey and get a uniform base for a light color coat.
I did my routine of white primer, grey filler-primer sanded, then white primer, then sanded. There were several little spots scattered around the rocket that needed a bit more filling, but smaller than anything you'd use "filler" or putty on. I really didn't want to sand off another full layer of filler-primer, so I decanted some into a red plastic cup and painted it onto the small spots that needed it with an old hobby/model brush.
It made for a LOT less sanding to knock those spots down to level after it dried overnight and will need to add less white primer (weight and cost - I need to reorder white primer) to cover the grey and get a uniform base for a light color coat.
Thanks - I added it today
Cutting body tubes:
Holding the knife at a fairly high angle, so that the tip does the work, seems to work much better for me than a low angle, where the body of the blade cuts. It may make a slightly rougher cut but that's why the Flying Spaghetti Monster created sandpaper.
Also, I use those big advertising cardstock "postcards" (junk mail) wrapped around the tube as a guide. With several turns around a body tube they provide a thick edge against which the blade can rest. With my shaky hands I need all the help I can get...
Holding the knife at a fairly high angle, so that the tip does the work, seems to work much better for me than a low angle, where the body of the blade cuts. It may make a slightly rougher cut but that's why the Flying Spaghetti Monster created sandpaper.
Also, I use those big advertising cardstock "postcards" (junk mail) wrapped around the tube as a guide. With several turns around a body tube they provide a thick edge against which the blade can rest. With my shaky hands I need all the help I can get...
I use the Estes tube cutting guides. One of their best products, IMHO.
Great for standard-sized body tubes. Unfortunately my tube collection has a lot more non-standard sizes than it does Estes sizes. I've often meant to make a Kuhn tube cutting jig but never got a round tuit.
Gluing-technique tips:
For the strongest possible bond, especially with epoxy and porous surfaces (balsa, plywood, some 3D prints), consider adding a thin scrim of glue to both surfaces when practical. It's common to apply glue to one surface and expect it to wet the second surface adequately when assembled but that doesn't always occur.
As many others have pointed out...how often have you had the glue grab too quickly, leaving the coupler/engine block only partly inserted? Epoxy is slower but doesn't grab the way that most wood glues do, so gluing couplers, motor mounts etc. can be easier with epoxy than with wood glue. And with very thin body tubes (e.g. my Saturn V Skylab) epoxy may be heavier, but there's no solvent to evaporate so epoxy avoids distortions in the tube that can occur from water evaporation with wood glues.
(Yes, I'm an epoxy fan.)
For the strongest possible bond, especially with epoxy and porous surfaces (balsa, plywood, some 3D prints), consider adding a thin scrim of glue to both surfaces when practical. It's common to apply glue to one surface and expect it to wet the second surface adequately when assembled but that doesn't always occur.
As many others have pointed out...how often have you had the glue grab too quickly, leaving the coupler/engine block only partly inserted? Epoxy is slower but doesn't grab the way that most wood glues do, so gluing couplers, motor mounts etc. can be easier with epoxy than with wood glue. And with very thin body tubes (e.g. my Saturn V Skylab) epoxy may be heavier, but there's no solvent to evaporate so epoxy avoids distortions in the tube that can occur from water evaporation with wood glues.
(Yes, I'm an epoxy fan.)
Cutting body tubes:
Holding the knife at a fairly high angle, so that the tip does the work, seems to work much better for me than a low angle, where the body of the blade cuts. It may make a slightly rougher cut but that's why the Flying Spaghetti Monster created sandpaper.
Also, I use those big advertising cardstock "postcards" (junk mail) wrapped around the tube as a guide. With several turns around a body tube they provide a thick edge against which the blade can rest. With my shaky hands I need all the help I can get...
Added for yesterday.
I added it for today. Thanks for helping me come up with ideas while I was launching rockets.
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To prevent paint from getting into the launch lug, I cut chunks of the paper stick from a cotton swab and wrapped them in blue masking tape to fit the ID. I leave them in place as plugs from the first primer layer until the last sanding before color coats, when I punch them out and clean up the excess primer buildup around the ends of the lug with 400 dry. This has worked well on several rockets now, and the plugs are reusable for several rockets if you clean up the ends.
In the processing of adding today.
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When assembling a snap-ring motor, make sure the snap ring is in the groove by grabbing the "ears" of the snap ring with your snap-ring pliers and slightly compressing the snap ring. Give a gentle rotation to see if it moves freely and smoothly. If it does, the snap ring is properly seated. If you feel grit or resistance, you either have a grain of sand or are not properly seated.
(This is from a conversation with Scott Koremeier of Loki Research this afternoon.)
(This is from a conversation with Scott Koremeier of Loki Research this afternoon.)
added today
That's why they're gold plated.
Thank guys. I am running out of ideas. If you have another way to do something, Please share it.
The number one, single most important tip for getting rocket stuff done: get off the couch.
Wait, is that an accusation? I resemble that remark every evening.
Only a self-accuasation.
Re: Ejection charge canisters.
Haven't used this for a long time but I found that the soda straws in my cupboard were a perfect snug fit for the plastic e-match protective shield. Cut a piece of soda straw, slide match head/shield in one end, wrap of tape to hold it in place. Scoop BP into the straw---if memory serves, a bit over 1" of BP was one gram, but test to make sure. Trim straw to length if necessary. Wrap of tape around other end, pinch the tape closed.
Haven't used this for a long time but I found that the soda straws in my cupboard were a perfect snug fit for the plastic e-match protective shield. Cut a piece of soda straw, slide match head/shield in one end, wrap of tape to hold it in place. Scoop BP into the straw---if memory serves, a bit over 1" of BP was one gram, but test to make sure. Trim straw to length if necessary. Wrap of tape around other end, pinch the tape closed.
Can you take a camera photo of the end result? I would just like a photo of this addition.
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