Thingiverse, in all its lameness, has somehow broken the link to this design. However, I've also posted the files for 3D printing here: www.prusaprinters.org/prints/131862-desktop-whomp-rocket (Joel, maybe you could update the link in the video description. Thanks.)
Just wanted to drop a quick thank you for sharing your struggle with scaling up the design. I only printed at 2X, but I also found that I had poor performance. Because of your video, I increased the scale of the piston by 0.3 mm. It is amazing how truly significant such a small change made.
@@3DPrintingNerd Maybe you should try to change the dimensions. Use a big plunger with a small diameter but longer rocket and a launcher tube that is in proportion to the rocket. That way you'll have more propulsion and time to get a higher speed with a lower amount of mass to launch. I would like to see if that works better but don't have a 3D printer to test it on my own. I like your content keep it coming.
Looking at the launch footage of the purple rocket, it seems that the rocket hit you before going past, causing it to not fly directly upwards and tumbling in the air. I like this idea overall. Neat print.
Adding some tape to the pipe for the rocket might help as well. Also, since you are printing the rocket in flexible filament, you could reduce the wall thickness to reduce the weight of the rocket. Remember every gramm you save increases your delta v.
I learned the lesson of tolerances and scaleing when I upsized a lego figure. It's an issue everyone comes across and is a great learning/teaching moment
Perhaps you could also try adding some blue tape at the bottom of the launching tube, to create some resistance and create some additional pressure inside. Once the pressure is enough, the rocket would go past the blue tape and work as before (but with the increased pressure hopefully).
Very entertaining! On your 400% Big Boy, try adding some blue tape to the top of the launch tube as well, as you've also increased the rocket-to-launch tube clearance with your scaling. You'll have to do a neater job, though, because you really don't want to add any friction between rocket and tube. (Jeff Kerr aka Lobocnc)
I'm surprised that someone with years of blue tape application experience didn't do a neater job! LOL I guess planar tape laying skills don't transfer to curvilinear surfaces.
Looks like a very fun print and LOTS of room for experimentation and learning! I think the square-cube law is biting you in the butt on the bigger prints as well as the leaky piston you fixed with tape. General other suggestions to improve performance: Lower the weight of the bigger prints (less walls, infill, etc) Use straight fins rather than spiraled. Longer drive piston. Tape to seal the bottom of rocket to the launch tube to build up a little pressure before release. And as Scott Manley always says: "Fly safe!"
That was fun! I love when you make stuff that does things. I was thinking you could thicken up the model in the needed parts before 3D printing, rather than using tape. Also maybe a few made the whole mechanism taller to have more air push the rocket, but leave the rock at the same size? By the way there's a RU-vidr that just hit 100,000 followers who uses the name puppet nerd. I thought you might want to do a collaboration with them at some point. They're very accomplished puppet builder and puppeteer and have worked on tons of TV shows and movies. They also have a very positive upbeat channel like you do. If you need ideas I've got lots of ideas for 3D printing puppet related stuff I could make some models for you if you like. High-5!
Do you think if all the parts it were printed sideways (so the layers were in the direction of the flight path) it would help cut down on friction, and go even higher? Maybe adding oil to prevent loss of air around the gaps between parts would help too?
I know a lot about physics and rocket science and I saw this coming is because something bigger doesn't mean better and if you make a rocket too big it won't go as high but if you make a rocket compact as you can it can go pretty high
The reason the rocket is traveling shorter distances the bigger the print gets is because It takes a lot more force to move progressively larger volumes of air through the space to propel the rocket. If you want the big one to go up super high again, you'll need to modify the print to make it safe to stomp on
And yes, I see that I was correct, lol. Another addition you might want to make is filling the interior of the plunger with silicone, but only on the bottom of the interior so that at the end of the stomp it's not plastic on plastic.
An o-ring of TPU with a notch to fit over the top rim of the button post would make for a good air seal. Can use petroleum grease to lube it up. I was surprised at how water tight TPU is even before calibrating print settings for a given spool. My first test cube with no top holds water.
Joel, as an Astrophysicist.... It's called a STOMP rocket.... You are correct about the air coming out between the parts, but the same thing happens on the smaller scale as well. Bigger object = bigger force required to launch. More air also = more pressure required.
Fun print. My space-obsessed four year old would love this. As others have mentioned, all the air gaps (plunger and launch tube) both need to be reduced in the scaled up versions. It would be possible to do this by importing the STLs and trying to align new cylinders in CAD, but to avoid doing that, I've commented on the Thingiverse page asking LoboCNC if he would create scaled versions.
@@3DPrintingNerd sounds like he's game from his quick response on Thingiverse. He said he'll post a scaling formula which allows the rocket and plunger to be under-scaled slightly to maintain a 0.5mm clearance. Look what you've started, you maniac! LOL
I printed this a while ago but only after um errrr changing the look of the 'rocket'. Works great though and no real need to rescale from the original. I think lovehoney have started selling the original version. Can't think why!!! 😆
Its apparent he didnt read the description of the print on thingiverse (unless it was recently changed) as it provides the proper scaling formula to keep the tolerances the same.
its basic physics, you cant apply the same amount of force (the ammount of strength your hand has going down) And expect something far heavier and with more surface area against wind to go further
