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Yeah...as we get older that nozzle erosion can get to be a real problem. But no need to feel shame or face it alone. There is hope. Talk to your dr. They have options. :)
I highly recommend crushing up some old grey ie kiln brick or old red brick ! I am going to try some fire proofing rock wool mixed into my nozzle clay/nozzle stuff , I think the fibrous material will hold everything better
I made a girl cry once by telling her "her jaws weren't too gentle on the shaft." That was the second sign I knew I was dealing with crazy. The first sign was that she wanted anything to do with me.
I tried many different types of nozzles back when I was into rocket engines. The best nozzle in my view, much better than graphite, was glass. I made a mold with kiln clay and used melted glass to make a nozzle. Of course, as is the usual case, its not as simple as just melting some glass and pouring it into the mold. I found that first heating the mold to about 500 degrees and then letting it cool slowly after the pour, prevented cracking. The results were excellent, no nozzle erosion.
We used to do glass casting at our 3D printing lab in university. We used casting plaster to make the molds from 3D printed parts, put the biscuits of glass in a flower pot (the ceramic kind with a hole in the bottom) over the mold, and put the whole thing in a kiln. Everything preheats together, and cools together, and the glass will flow out the bottom of the flower pot into the mold once it's hot enough. Mostly made artistic things, though, not rocket nozzles, not not sure what kind of residual mechanical stresses might have been left. The slow cooling is probably a best case scenario for stress relief, I would think, but I'm not a glass blower.
Great results! I think dry mixing the ingredients inherently introduces some unpredictable behaviour. Cracks might occur if the motors are stored for longer. I've heard good things about heating the dry mixture slightly above the melting point of sucrose to allow the sugar to coat the oxidizer, without caramelizing the sugar. You could also dissolve both ingredients in water and boil the water off for an intimate mixture, though I'm sure you're familiar with both these methods already.
I'm curious to know what control is done on particle size of the sugar and oxidizer. Do they come milled or do you mill them yourself? How do you effect complete mixing of the two? These factors will significantly influence burn rate, chamber pressure, etc.
Try making flexi fuel. It uses powdered sugar and Karo syrup. It won't crack over time but you need to put in a thin wax seal over both ends of the motor to keep the oxidizer from absorbing moisture.
Wow. This channel is so incredibly underrated, and with the amount of time it takes to develop a functional, characteristic sugar motor such as this you deserve far more exposure. I’ll be sure to try this out myself!
I wonder if high-temp JB weld epoxy which is silicone release molded with a slight oversize to ensure it doesn't come out when being press-fit into the PVC would work? Thinking of how some things like brake pads are more or less a type of thermoplastic resin (which is a similar material to the ablative heat shields on some rockets), so that might be close as one could cheaply get for the home project version. And a hard material that resists erosion is more likely to be important than heat resistance given the short burn time of the solid fuel.
I used old builders plaster, works great. The older the plaster the quicker it cures and the 4mm nozzle hole holds out fine. I often re-use the canasters many times.
I think hydraulic cement is best for nozzles. You have a lathe, make up a wooden divergent form about 25mm high with a port the size of the hole of a washer that fits inside the motor body, make the form parabolic in shape. Fill to the port, place a galvanized steel washer in, then pour in some more cement and use another convergent form that is about 12mm high and parabolic shape as well. The washer helps prevent the port from eroding and pulls heat into the cement. Hydraulic cement hardens in minutes and is fully cured for use over night.
I've had success making quick easy nozzles out of cardboard rolled up tight an saturated with a high temp super glue and then coating the internal cone and funnel with ash or powdered graphite while the glue is still wet. Goes super hard and stands up to the heat well. Edit.. probably should mention I wouldnt static fire them by your house though heating super glue that hot can make cyanide gas 😂
Yup! My thoughts exactly! I make black powder (BP) rockets and dry press the clay/grog mixture using my rocket tooling (stainless). Works great, the rockets fly high, and I don't have erosion of the nozzles!
Elementalmaker seems to aim for the simple, household ingredients "You Can do It" approach. These comments read like a "competition of complex minds" Ummm... Dude. NASA uses this stuff called: S.P.N.S. (SpaceX Proprietary Nozzle Stuff)
@@timothypirnat3754 Now I've read where some pyrotechnicians wax the inside of their (paper) tubes. But since EM is using PVC, I wouldn't suspect any advantage in doing so.
when i was making sugar rocket motors the best nozzle i got was like this: get the finest steel wool you can find, blend it in a coffee grinder to get small strands of 0.5-1mm long, mix that with plaster of paris and then use this mix to make the nozzle with little water... it was working perfectly and was not deteriorating that much...
I think it would be cool to try to make a coffee and sugar or non-dairy coffee creamer propellant you can put the coffee grounds in the grinder and grind it up to a powder and mix it with potassium nitrates
I tamp the bent-clay in layers. Each layer I'll use a syringe to put a few drops of water on the clay, add a little clay on top, tamp. Then, after the clay is fully dried, I smear some construction adhesive on the outside of the nozzle. The water activates the clay, bonding it together. I haven't had any issues with nozzle erosion at all. In fact I actually was able to make the nozzle thinner saving weight and gaining propellant.
EM, I make BP rockets and NEVER use wax in the clay mixture. I use a bentonite clay/kitty litter/grog mixture and press the mixture in my modified arbor press. I use BP rocket tooling which is stainless. Works pretty well. I haven't done sugar rockets but I'd say they are similar. Your videos show a lot of crud coming out of the nozzle and I suspect the wax is melting and the nozzle is spalling and widening along the way.
When I used to make them I used "Durham's rock hard water putty". The hole needs to be between 1/4 and 1/3 of the ID. When I ignited them I used an e-match shoved up to the top end, that way when the engine started it would light the whole length of the core.
This fireclay stuff looks pretty cool, but if you really want to nip the nozzle erosion problem (especially as you move into larger motor sizes) I'd recommend you check out Rockite cement! I used to cast the cement into a PVC end cap, drill a nozzle through the endcap and the cement, and then PVC glue the endcap onto the motor.
Nice video. 45 degree convergence (not critical) and 15 degree divergence nozzle. Maybe use a tapered center punch for divergence. I still have not found anything I really like that is cheap and easy for nozzles that work good. I have been using plaster that works well but you can't pack it. Put it in and add a tiny bit of water and let it sit for a few days. 2.5 tsp plaster and .5 tsp water seems ok. I make an electric match using a piece of the fuse you use and a tiny wire and I only insert it just past the nozzle into the fuel like the Estes black powder motors. Would be nice to see tests with the igniter at different positions into the motor.
eehhhhhh Not Horrific........hahahahahahaha brilliant. This is why building rockets is a lot more difficult that the average person gives credit for. I really appreciate you showing all the progress along the way and all the awesome data points you pulled from each version. This was super cool to learn step by step.
the reason for paraffin wax is to make the nozzles better storeable and reduce the chance of the nozzle getting separated due to moisture but it makes the nozzle much weaker to erosion.
I place a washer, with the same ID as the throat, where the combustion chamber meets the throat. I also cast the nozzle and end plug with Rockite expansion cement as I did not have great luck with the clays. When I make the cast of the nozzle , I cast the washer in with it. Give it a try if you haven't already.
I think the problems with nozzle erosion are caused by the wax melting... You can try with a few drops of water to slightly moisten the fireclay. This should also work as a binder instead of wax. The best option is to turn a nozzle out of graphite and glue it in with some epoxy.
you need to attach a large bolt or screw with a tapered head to a board grind off the threads and put the pvc over it so the screw is centered. Take 2 tampers and drill a hole down the center of 1. Now throw in a spoon or 2 of cat litter and a few drops off water. Tamp down with the tamper with the hole. throw in your mix and tamp again until 1/2 to 3/4 inch from the top. put in more cat litter and a few more drops of water and tamp some more with the tamper with no hole. When you pull the pipe off the bolt you already have a perfect hole with a tapered nozzle molded into it. It will give better thrust because of the taper.
I make my rockets out of pvc with a bentonite clay nozzle, it works great without a binder but needs a little more pressure. I also use a pvc end cap to prevent the propellant from taking up moisture.
Clay plugs that don't deteriorate or lose their shape 75% unscented cat litter blend down using a coffee grinder or blender 8% pottery clay leaving the Sun for a few days to dry out most mixtures are soft and 17% Elmer's glue these plugs do not melt deteriorate loose form or shape they are extra hard when pressed or ram fire makes them harder and stiffer so even if it's soft when applied the rocket motor fountain or any other device you use hardens it as it's being used
Helloo man im a fan of ur content... all the way from Lebanon!!! I would advise you to use poliester putty .. we call it here iron putty .. its a past used for fill dents in a car before paint ... anyways .. it comes as a putty and there is a curing stuf in a tube that u mix to harden ... i use the same diameter tube (same as engines) as a mold then insert a metal spacer inside to be drilled after as the opening of the nozzle .. also u can carve the two ends of the made nozzle in cone shaped to have the desired bell nozzle ... it works perfectly .. regards!
Heres a bit of advice on why you have so much nozzle erosion, ive had this issue myself and a simple fix is to wither make your clay plug thicker or to make your nozzle hole wider, The wider nozzle hole will cause less power but will fix your erosion issue.
Be careful cutting fuse with scissors! An incredible amount of pressure it placed on the fuse which could possibly cause ignition. I'd recommend using "anvil cutters" for safely cutting fuse.
Just an idea that you may have zero need for, but i've been using node-red to help with automation for stuff like this. You could use it to create a launch control dashboard, have it trigger your ematch and then collect all of the sensor data and dump it into something like influxdb. Then you can graph it super easily with Graphana. The whole thing runs easily on a raspberry pi.
I enjoy your videos. I have a suggestion. You have a lathe, why not machine a reusable nozzle that won't erode and will have both convergent/ divergent for maximum thrust. You'll need to start with an opening slightly smaller than 4mm and open it from there untill the PVC can handle the pressures. One more suggestion. Substitute a small percentage of the fuel mixture with iron oxide powder. I'm guessing at 7% to start with. It gives it a little extra punch to increase your pressure. If I had a lathe I would do what I've suggested. Good luck brother.
I like to keep the projects replicable for folks trying to learn at home. I definitely could just machine a graphite or steel nozzle on my lathe, but that's not something most people can do
You want your fuse to only ignite the far side of your grain (furthest away from nozzle). Do so by electrical taping like of the fuse besides the last quarter inch and inserting it all the way in the grain (giggity)
This was exactly what I was curious about. I would think it should have excellent thermal resistance and the heat from the rocket would actually make the nozzle harder as it fired. I would probably 3D print some sort of cap with the negative of the nozzle shape built in. Pour the plaster, pop the cap/nozzle form on, let it harden, then pop it off with an already perfectly formed nozzle. 🤔 Now I want to try it!
Pumice might be something to make disposable nozzles with. Pumice and high temp epoxy. You mentioned grog, do you know anyone that could form and fire some solid ceramic nozzles for you? Love your videos. Wish I had neighbors that were half as interesting .
Mate, always entertaining, and this just feeds my interest in "you-can't-play-with-anything-burny-or-bangy" Australia. 😁😁 For a man with a lathe, I wonder if you could turn up a metal nozzle or two to preserve the clay nozzle. Something like a tube up through the clay and topped with a disc sitting on the top surface of the clay to prevent the tube being spat out. Mind you, if you go this far, it would be a shame not to make an all-metal compression/decompression screw-in metal nozzle doover. Keep up the fun mate!!
You might be surprised at what you can legally buy here. I have made almost identical rockets with items from Bunnings, Coles and one of several local online suppliers. There's also a whole heap of other fun things you can make. Let's just keep it between us though, lest idiots get stuff banned
Woah.... can you still get Estes motors? ... ... ... that takes me back a couple'a decades. I love your test-stand! Kinda reverse-engineerable in seconds too! ..... oh.... didn't know you had a vid about it.... I shall go watch.
I believe you want to use Satanite clay for the nozzle. Also thin wall pvc would work at half the weight of scl 40. More room for more boom. Likewise if your using a potassium/sugar fuel you need to melt it, blend it then pour it in the engine tube to harden. It's like a 60/40 blend.
Try a different binder for the nozzle.. Look at the STI Firestop website.. They have both silicone and elastomer based caulking compounds. They also have a fireproofing mortar.. A good electrical or construction supply should have many of the compounds on the shelf (avoid the intumescent and exothermic compounds.. You want to look at the plain sealants)
Love watching the videos man! I would love to play around with making rockets with my kids but there aren't a whole lot of places to launch them where I live. I was wondering if you ever considered making nozzles out of something like JB Weld or maybe even better, something like Quick Steel. You could make a 3d printed mold for the nozzle shape... Perhaps cut a few internal notches in the motor housing and press the Quick Steel right into the motor housing with the nozzle mold in the bottom. I have seen some 3d print filament that is water soluble, so you could make an intricate shaped nozzle too.
what if you mix 5 minute epoxy with that clay? that way you got a fairly resilient matrix thats holding the clay together? i have no idea if that would work, but epoxy mixed with minerals is often used in high stress scenarios (not really for hot applications) but maybe still worth a try since its simple and inexpensive
Just wondering - why the insistence on clay nozzles? A washer, or better yet, countersunk washer, would probably hold up a lot better to the force. Plus you can shrink the throat and get better specific impulse, though don't go too crazy with it or your PVC will explode ;)
There might be some cheap steel hardware component that could be pressed in place to serve as the throat of the nozzle. Like a stack of washers? Or a nut? Based on the ISP you could be getting double the performance with a better nozzle.
A bolt with tapered head works too. Grind the threads off and then you don't need to drill a hole either. I put cat litter and a few drops of water to bind it together. I then use a tamper with a hole to press it around the bolt. Sometimes it helps to rub wax on the bolt as a release agent.
Love your videos. I never made a rocket before. My buddy Alex did though when we were kids. His dad made little ceramic washers for his nozzles out of tiles from the hardware store. They got pressed down into the rocket over the clay plug in the bottom. It might be worth a try.?.🤔
@@ElementalMaker I just spoke with Alex. He said they used two washers. One before the clay plug and one after. The inner washer having a smaller hole in the center than the outer.to make the shape of the forcing cone, like a bell rocket engine.
You need the clay they put in a kiln that stuff will work perfectly for that type of heat or you could have a threaded end with an aluminum nozzle that screws on
can the spikes be a result resonance? If the nozzle slowly deteriorates due to a high temperature it might get the geometrical shape that has the acoustic properties to make the outgoing material resonate at its resonant frequency, hitting the nozzle even harder until its shape is such that it eventually drops in efficiency? And I was wondering why cement is mainly used in this area of rocket design, why not some light weight metal? I was also wondering what the mass will be of the rocket as a whole. This video was amazing, thank you very much!
Instead of using bentonite clay and WAX, use glue or epoxy. That would be MUCH more heat-resistant and erosion resistant. Another thing you could try is restrict the opening with a washer. Tamp in the propellant, apply the washer and hold it in place with the clay/epoxy
I wonder if you could substitute smashed-up carbon electrode for the grog, as it was too hard for gunpowder, and carbon can handle mega-heat, while it also doesn't conduct heat very well. If you can keep the heat from propagating through your wax as long as possible, that will likely increase the lifespan from 'momentary' to 'brief'. Also, there are many paraffin wax formulations, so you can select one with a higher melting point, but I think Bee's wax was demonstrated to have a significantly higher heat capacity to change phases (melt) than synthetic waxes (per Cody's Lab). I've also heard that it's more sticky than paraffin, so it's got that going for it.
Ever hear of Satanite? It's an insulating coating for forges and such. If you keep having problems with nozzle erosion, you might try adding that to your mix instead of fire clay
I wonder if hydraulic cement would work as a nozzle material. It can be made into a thick putty-like material. The dry time is quite short too. It's hard as a rock.
Thanks for watching! Parts list in description. Please help keep the channel sponsor free at www.patreon.com/elementalmaker. Every patron gets a virtual hug and my unending appreciation. I will also build a small shrine to worship you. One of these is a lie.
So when will my shrine be constructed?
@@tenchi20229 I would Estimate when you have subscribed at the Ulra pure Diamond level.. let's say 5K a month :) lol
@@tenchi20229 already working on the playdoh bust of your face and the voodoo doll
@@ElementalMaker Awesome!
Yeah...as we get older that nozzle erosion can get to be a real problem. But no need to feel shame or face it alone. There is hope. Talk to your dr. They have options. :)
Glad you found a good formula and nozzle setup. I can't wait to see this rocket fly.
I highly recommend crushing up some old grey ie kiln brick or old red brick !
I am going to try some fire proofing rock wool mixed into my nozzle clay/nozzle stuff ,
I think the fibrous material will hold everything better
I made a girl cry once by telling her "her jaws weren't too gentle on the shaft." That was the second sign I knew I was dealing with crazy. The first sign was that she wanted anything to do with me.
I tried many different types of nozzles back when I was into rocket engines. The best nozzle in my view, much better than graphite, was glass. I made a mold with kiln clay and used melted glass to make a nozzle. Of course, as is the usual case, its not as simple as just melting some glass and pouring it into the mold. I found that first heating the mold to about 500 degrees and then letting it cool slowly after the pour, prevented cracking. The results were excellent, no nozzle erosion.
Now that's awesome!
We used to do glass casting at our 3D printing lab in university. We used casting plaster to make the molds from 3D printed parts, put the biscuits of glass in a flower pot (the ceramic kind with a hole in the bottom) over the mold, and put the whole thing in a kiln. Everything preheats together, and cools together, and the glass will flow out the bottom of the flower pot into the mold once it's hot enough. Mostly made artistic things, though, not rocket nozzles, not not sure what kind of residual mechanical stresses might have been left. The slow cooling is probably a best case scenario for stress relief, I would think, but I'm not a glass blower.
Dude we need a daily 5 minute dose of rocketry from you.
We need your content right now!!
You never cease to amaze me the with the amount of dirty jokes you fit into your videos
I am shocked by the abject lack of d*cks in vises, however.
I agree, Super funny guy AYE!.. Makes me laugh while I learn! I mean what else could a person ask for, Welp back to my "missed-shaft erosion".
Great results! I think dry mixing the ingredients inherently introduces some unpredictable behaviour. Cracks might occur if the motors are stored for longer. I've heard good things about heating the dry mixture slightly above the melting point of sucrose to allow the sugar to coat the oxidizer, without caramelizing the sugar. You could also dissolve both ingredients in water and boil the water off for an intimate mixture, though I'm sure you're familiar with both these methods already.
I'm curious to know what control is done on particle size of the sugar and oxidizer. Do they come milled or do you mill them yourself? How do you effect complete mixing of the two? These factors will significantly influence burn rate, chamber pressure, etc.
Try making flexi fuel. It uses powdered sugar and Karo syrup. It won't crack over time but you need to put in a thin wax seal over both ends of the motor to keep the oxidizer from absorbing moisture.
Wow. This channel is so incredibly underrated, and with the amount of time it takes to develop a functional, characteristic sugar motor such as this you deserve far more exposure. I’ll be sure to try this out myself!
Try Durham's Rock Hard Water Putty for nozzles. You can get it at Home Depot and Lowes as well as most other hardware stores for the last 80 years.
Plaster of Paris would work well. Have used it casting silver so I am sure it would hold up.
I wonder if high-temp JB weld epoxy which is silicone release molded with a slight oversize to ensure it doesn't come out when being press-fit into the PVC would work? Thinking of how some things like brake pads are more or less a type of thermoplastic resin (which is a similar material to the ablative heat shields on some rockets), so that might be close as one could cheaply get for the home project version. And a hard material that resists erosion is more likely to be important than heat resistance given the short burn time of the solid fuel.
th-cam.com/video/BfAZx4FPNkA/w-d-xo.html Yep Durhams's....... I did this and had amazing results for an erosion proof nozzle.
Durhams is much stronger than plaster of Paris, and won't burn like the epoxy+steel in JB Weld.
Bro you're the funniest science channel I've seen on TH-cam.
You clearly haven't watched @explosions&fire, his humor is next level 😁
But I do appreciate it, thank you 👍
I'm so glad you're revisiting rocket motors! I haven't made one in a while. Started running into issues with mix and put it down for a while.
I used old builders plaster, works great. The older the plaster the quicker it cures and the 4mm nozzle hole holds out fine. I often re-use the canasters many times.
Great video! I made some too, i found out that the best nozzle mix is wet plaster with a little bit of vinyl glue. Becomes rock hard!
That would work too. But I press my BP rockets dry and NO wax!
@@htmagic yup, i agree. I bet that the no wax is key. I try to ram my nozzles just slightly damp, not to ruin the fuel
I think hydraulic cement is best for nozzles. You have a lathe, make up a wooden divergent form about 25mm high with a port the size of the hole of a washer that fits inside the motor body, make the form parabolic in shape. Fill to the port, place a galvanized steel washer in, then pour in some more cement and use another convergent form that is about 12mm high and parabolic shape as well. The washer helps prevent the port from eroding and pulls heat into the cement. Hydraulic cement hardens in minutes and is fully cured for use over night.
I've had success making quick easy nozzles out of cardboard rolled up tight an saturated with a high temp super glue and then coating the internal cone and funnel with ash or powdered graphite while the glue is still wet. Goes super hard and stands up to the heat well.
Edit.. probably should mention I wouldnt static fire them by your house though heating super glue that hot can make cyanide gas 😂
congrats on everything you've made. I've been with your channel since the test stand and have always loved your vids
Should use some other binder then paraffin wax. I have a feeling the paraffin wax is what's creating the failure.
Yup! My thoughts exactly! I make black powder (BP) rockets and dry press the clay/grog mixture using my rocket tooling (stainless). Works great, the rockets fly high, and I don't have erosion of the nozzles!
Elementalmaker seems to aim for the simple, household ingredients "You Can do It" approach.
These comments read like a "competition of complex minds"
Ummm... Dude. NASA uses this stuff called: S.P.N.S.
(SpaceX Proprietary Nozzle Stuff)
No binder. Just rammed bentonite. Groove the inner wall of the tube to hold the clay.
@@timothypirnat3754 Agreed! No binder at all.
@@timothypirnat3754 Now I've read where some pyrotechnicians wax the inside of their (paper) tubes. But since EM is using PVC, I wouldn't suspect any advantage in doing so.
I used epoxy putty topped with bentonite clay for the nozzles on my last batch of sugar rockets. Worked well, no erosion.
Have you considered using epoxy adhesive as binder for the fire clay, it might prove more stable than paraffin wax.
when i was making sugar rocket motors the best nozzle i got was like this: get the finest steel wool you can find, blend it in a coffee grinder to get small strands of 0.5-1mm long, mix that with plaster of paris and then use this mix to make the nozzle with little water... it was working perfectly and was not deteriorating that much...
like tiny rebar :D
@@excitedbox5705 yeah :) got the idea from a friend who was trying to make a bullet proof plates this way...
I love the content of your channel, but I love the rocket stuff the best.
Can't wait to see the new rocket fly
I was watching this vid while taking a dump. Then I noticed the tiles in the bathroom and wondered how tile grout would make for a nozzle.
As promised, you have made more pyro videos, and therefore you now have a new top tier patreon. Keep up the good work!
Thank you so much Ryan! I appreciate it hugely!
I see you’ve picked up on AVE’s formula, love to see it, we need more channels like that...
I think it would be cool to try to make a coffee and sugar or non-dairy coffee creamer propellant you can put the coffee grounds in the grinder and grind it up to a powder and mix it with potassium nitrates
I tamp the bent-clay in layers. Each layer I'll use a syringe to put a few drops of water on the clay, add a little clay on top, tamp. Then, after the clay is fully dried, I smear some construction adhesive on the outside of the nozzle. The water activates the clay, bonding it together. I haven't had any issues with nozzle erosion at all. In fact I actually was able to make the nozzle thinner saving weight and gaining propellant.
EM, I make BP rockets and NEVER use wax in the clay mixture. I use a bentonite clay/kitty litter/grog mixture and press the mixture in my modified arbor press. I use BP rocket tooling which is stainless. Works pretty well. I haven't done sugar rockets but I'd say they are similar. Your videos show a lot of crud coming out of the nozzle and I suspect the wax is melting and the nozzle is spalling and widening along the way.
IT'S ABOUT TIME! Been wondering when we were gonna hear from you again. Haha!
Awesome job 👏 there must be some terrific heat and pressure at that/ those nozzles well done. Looking forward to the next stage 👍
When I used to make them I used "Durham's rock hard water putty". The hole needs to be between 1/4 and 1/3 of the ID. When I ignited them I used an e-match shoved up to the top end, that way when the engine started it would light the whole length of the core.
Would have liked to see the failures as well. Our failings and those of others often teach us more than a successful outcome.
This fireclay stuff looks pretty cool, but if you really want to nip the nozzle erosion problem (especially as you move into larger motor sizes) I'd recommend you check out Rockite cement! I used to cast the cement into a PVC end cap, drill a nozzle through the endcap and the cement, and then PVC glue the endcap onto the motor.
Nice video. 45 degree convergence (not critical) and 15 degree divergence nozzle. Maybe use a tapered center punch for divergence. I still have not found anything I really like that is cheap and easy for nozzles that work good. I have been using plaster that works well but you can't pack it. Put it in and add a tiny bit of water and let it sit for a few days. 2.5 tsp plaster and .5 tsp water seems ok. I make an electric match using a piece of the fuse you use and a tiny wire and I only insert it just past the nozzle into the fuel like the Estes black powder motors. Would be nice to see tests with the igniter at different positions into the motor.
eehhhhhh Not Horrific........hahahahahahaha brilliant. This is why building rockets is a lot more difficult that the average person gives credit for. I really appreciate you showing all the progress along the way and all the awesome data points you pulled from each version. This was super cool to learn step by step.
Awesome work man. Can't wait to see that puppy fly!
the reason for paraffin wax is to make the nozzles better storeable and reduce the chance of the nozzle getting separated due to moisture but it makes the nozzle much weaker to erosion.
Good vid, looking forward to seeing it actually fly!
I place a washer, with the same ID as the throat, where the combustion chamber meets the throat. I also cast the nozzle and end plug with Rockite expansion cement as I did not have great luck with the clays. When I make the cast of the nozzle , I cast the washer in with it. Give it a try if you haven't already.
I just discovered the channel and thought "just another guy making shitty rockets" but actually no, he's the AvE of rocketry
Very good
Bentonite on it's own is a good nozzle material, maybe the wax is introducing unnecessary heat sensitivity
IT's likely vaporizing at those temperatures, which could cause the nozzle material to flake right off.
I think the problems with nozzle erosion are caused by the wax melting... You can try with a few drops of water to slightly moisten the fireclay. This should also work as a binder instead of wax.
The best option is to turn a nozzle out of graphite and glue it in with some epoxy.
you need to attach a large bolt or screw with a tapered head to a board grind off the threads and put the pvc over it so the screw is centered. Take 2 tampers and drill a hole down the center of 1. Now throw in a spoon or 2 of cat litter and a few drops off water. Tamp down with the tamper with the hole. throw in your mix and tamp again until 1/2 to 3/4 inch from the top. put in more cat litter and a few more drops of water and tamp some more with the tamper with no hole. When you pull the pipe off the bolt you already have a perfect hole with a tapered nozzle molded into it. It will give better thrust because of the taper.
I got notified this time but I'll have to watch this a few days later because frigging distant learning.
I make my rockets out of pvc with a bentonite clay nozzle, it works great without a binder but needs a little more pressure.
I also use a pvc end cap to prevent the propellant from taking up moisture.
Sugar rockets!!! These are fun to make.
Clay plugs that don't deteriorate or lose their shape 75% unscented cat litter blend down using a coffee grinder or blender 8% pottery clay leaving the Sun for a few days to dry out most mixtures are soft and 17% Elmer's glue these plugs do not melt deteriorate loose form or shape they are extra hard when pressed or ram fire makes them harder and stiffer so even if it's soft when applied the rocket motor fountain or any other device you use hardens it as it's being used
Nice work. Looking forward to the launch.
Helloo man im a fan of ur content... all the way from Lebanon!!! I would advise you to use poliester putty .. we call it here iron putty .. its a past used for fill dents in a car before paint ... anyways .. it comes as a putty and there is a curing stuf in a tube that u mix to harden ... i use the same diameter tube (same as engines) as a mold then insert a metal spacer inside to be drilled after as the opening of the nozzle .. also u can carve the two ends of the made nozzle in cone shaped to have the desired bell nozzle ... it works perfectly .. regards!
Heres a bit of advice on why you have so much nozzle erosion, ive had this issue myself and a simple fix is to wither make your clay plug thicker or to make your nozzle hole wider, The wider nozzle hole will cause less power but will fix your erosion issue.
Excellent vid! Would like to see you work on the composite props again - and yes in details pls.
Be careful cutting fuse with scissors! An incredible amount of pressure it placed on the fuse which could possibly cause ignition. I'd recommend using "anvil cutters" for safely cutting fuse.
Use fire clay and grog and paraffin which helps reduce nozzle erosion. What makes the difference is pressing it in with a five ton press.
Need to replace the wax from nozzle mix, tried using plaster or something?
Just an idea that you may have zero need for, but i've been using node-red to help with automation for stuff like this. You could use it to create a launch control dashboard, have it trigger your ematch and then collect all of the sensor data and dump it into something like influxdb. Then you can graph it super easily with Graphana. The whole thing runs easily on a raspberry pi.
I enjoy your videos. I have a suggestion. You have a lathe, why not machine a reusable nozzle that won't erode and will have both convergent/ divergent for maximum thrust. You'll need to start with an opening slightly smaller than 4mm and open it from there untill the PVC can handle the pressures. One more suggestion. Substitute a small percentage of the fuel mixture with iron oxide powder. I'm guessing at 7% to start with. It gives it a little extra punch to increase your pressure. If I had a lathe I would do what I've suggested. Good luck brother.
I like to keep the projects replicable for folks trying to learn at home. I definitely could just machine a graphite or steel nozzle on my lathe, but that's not something most people can do
Suggestion maybe make some circumferential scratches near one end of the pvc tube for better nozzle plug biting.
You want your fuse to only ignite the far side of your grain (furthest away from nozzle). Do so by electrical taping like of the fuse besides the last quarter inch and inserting it all the way in the grain (giggity)
Why no sodium silicate? Fireworks people handled erosion some time ago.
Out of curiosity, why not use plaster of Paris? It has to be harder than compacted bentonite.
This was exactly what I was curious about. I would think it should have excellent thermal resistance and the heat from the rocket would actually make the nozzle harder as it fired.
I would probably 3D print some sort of cap with the negative of the nozzle shape built in. Pour the plaster, pop the cap/nozzle form on, let it harden, then pop it off with an already perfectly formed nozzle. 🤔
Now I want to try it!
@@BRUXXUS Let us know how it works.
I got your ping pong joke, you must've been to Thailand?
Thanks. Suggestion maybe use a metal cap for the end nozzle?
You're back!!
Honestly, for the parachute, look at “The King Of Random’s” parachute video. It’s super cheap, super simple, and super effective! Easy to make too!
Pumice might be something to make disposable nozzles with. Pumice and high temp epoxy. You mentioned grog, do you know anyone that could form and fire some solid ceramic nozzles for you? Love your videos. Wish I had neighbors that were half as interesting .
Mate, always entertaining, and this just feeds my interest in "you-can't-play-with-anything-burny-or-bangy" Australia. 😁😁 For a man with a lathe, I wonder if you could turn up a metal nozzle or two to preserve the clay nozzle. Something like a tube up through the clay and topped with a disc sitting on the top surface of the clay to prevent the tube being spat out. Mind you, if you go this far, it would be a shame not to make an all-metal compression/decompression screw-in metal nozzle doover. Keep up the fun mate!!
You might be surprised at what you can legally buy here. I have made almost identical rockets with items from Bunnings, Coles and one of several local online suppliers. There's also a whole heap of other fun things you can make. Let's just keep it between us though, lest idiots get stuff banned
@@kirkc9643 Oh I'm sure - if you know your chemistry. Which is where I fear I would end up doing something ...um, unexpected. 🙄
Woah.... can you still get Estes motors? ... ... ... that takes me back a couple'a decades.
I love your test-stand! Kinda reverse-engineerable in seconds too!
..... oh.... didn't know you had a vid about it.... I shall go watch.
@ElementalMaker have you tried 'Fired' fire clay? will be lighter and hold up better.
Throw a beer cap on the end and call it good
Very clean 3d print. What material did you use?
I believe you want to use Satanite clay for the nozzle. Also thin wall pvc would work at half the weight of scl 40. More room for more boom. Likewise if your using a potassium/sugar fuel you need to melt it, blend it then pour it in the engine tube to harden. It's like a 60/40 blend.
That would work great I'm sure but that stuff is pretty pricy for use in nozzles
Try a different binder for the nozzle.. Look at the STI Firestop website.. They have both silicone and elastomer based caulking compounds. They also have a fireproofing mortar.. A good electrical or construction supply should have many of the compounds on the shelf (avoid the intumescent and exothermic compounds.. You want to look at the plain sealants)
Ive seen some using dies to form the nozzles and propellant cores and compact using a press, they also use fire clay powder with paraffin as a binder
Love watching the videos man! I would love to play around with making rockets with my kids but there aren't a whole lot of places to launch them where I live.
I was wondering if you ever considered making nozzles out of something like JB Weld or maybe even better, something like Quick Steel. You could make a 3d printed mold for the nozzle shape... Perhaps cut a few internal notches in the motor housing and press the Quick Steel right into the motor housing with the nozzle mold in the bottom. I have seen some 3d print filament that is water soluble, so you could make an intricate shaped nozzle too.
what if you mix 5 minute epoxy with that clay? that way you got a fairly resilient matrix thats holding the clay together? i have no idea if that would work, but epoxy mixed with minerals is often used in high stress scenarios (not really for hot applications) but maybe still worth a try since its simple and inexpensive
I don't feel good about wax in the nozzle brew. Just take it out altogether.
Just wondering - why the insistence on clay nozzles? A washer, or better yet, countersunk washer, would probably hold up a lot better to the force. Plus you can shrink the throat and get better specific impulse, though don't go too crazy with it or your PVC will explode ;)
There might be some cheap steel hardware component that could be pressed in place to serve as the throat of the nozzle. Like a stack of washers? Or a nut? Based on the ISP you could be getting double the performance with a better nozzle.
A bolt with tapered head works too. Grind the threads off and then you don't need to drill a hole either. I put cat litter and a few drops of water to bind it together. I then use a tamper with a hole to press it around the bolt. Sometimes it helps to rub wax on the bolt as a release agent.
TH-cam was almost 30 minutes in late sending me the notification for this video. Smh
Love your videos. I never made a rocket before. My buddy Alex did though when we were kids. His dad made little ceramic washers for his nozzles out of tiles from the hardware store. They got pressed down into the rocket over the clay plug in the bottom. It might be worth a try.?.🤔
That's a very cool idea!
@@ElementalMaker I just spoke with Alex. He said they used two washers. One before the clay plug and one after. The inner washer having a smaller hole in the center than the outer.to make the shape of the forcing cone, like a bell rocket engine.
Good Lord I can't stand when my nozzle erodes. Piss everywhere. Oh, oh, motor nozzles... Nevermind...
You need the clay they put in a kiln that stuff will work perfectly for that type of heat or you could have a threaded end with an aluminum nozzle that screws on
"They are turning fricking motors gay!"
Some great tests BTW. thanks for the uplaod
Watch every video, no matter the topic , real talk and hilarious while teaching. You need to make the holes do kegels .
Do you think a sodium silicate binder would improve the original bentonite formula?
Legit the best channel
Let's not get too carried away here. It's alright. 😁
can the spikes be a result resonance? If the nozzle slowly deteriorates due to a high temperature it might get the geometrical shape that has the acoustic properties to make the outgoing material resonate at its resonant frequency, hitting the nozzle even harder until its shape is such that it eventually drops in efficiency? And I was wondering why cement is mainly used in this area of rocket design, why not some light weight metal? I was also wondering what the mass will be of the rocket as a whole. This video was amazing, thank you very much!
Instead of using bentonite clay and WAX, use glue or epoxy. That would be MUCH more heat-resistant and erosion resistant. Another thing you could try is restrict the opening with a washer. Tamp in the propellant, apply the washer and hold it in place with the clay/epoxy
I wonder if you could substitute smashed-up carbon electrode for the grog, as it was too hard for gunpowder, and carbon can handle mega-heat, while it also doesn't conduct heat very well. If you can keep the heat from propagating through your wax as long as possible, that will likely increase the lifespan from 'momentary' to 'brief'. Also, there are many paraffin wax formulations, so you can select one with a higher melting point, but I think Bee's wax was demonstrated to have a significantly higher heat capacity to change phases (melt) than synthetic waxes (per Cody's Lab). I've also heard that it's more sticky than paraffin, so it's got that going for it.
What about taking the paraffin out of the mix? I wonder if as it heats up it contributes to the nozzle breakdown.
While you have the printer fired up, why not make a protective enclosure for the arduino and relays?
Ever hear of Satanite? It's an insulating coating for forges and such. If you keep having problems with nozzle erosion, you might try adding that to your mix instead of fire clay
Can you do a video on modern smokless propellant? I know it can be dangerous at the same time, so i completely understand if can't.
Just use anchoring cement ( comes in powder just get it wet and put a metal washer ,you will not have problems
Jeez your desk is messier than mine lol
Make a video of the motor failures.
I wonder if hydraulic cement would work as a nozzle material. It can be made into a thick putty-like material. The dry time is quite short too. It's hard as a rock.
Add 1% powered Aluminum or Rust to your mixture.