DecimusMaximus Posted January 15 Share Posted January 15 Hi All, Ive been building whistle strobe rockets the past couple of weeks and my last 3 test have gone CATO while my first one on my short spindle didn't lift enough but did not cato. Because of the lift issue on my short spindle (about an inch long), I made a longer spindle about 3-4 inches long. Pictures of both are attached. Ive uploaded a Youtube video of each of the demos and how the CATOs looked like with voice over commentary as well: Some info: I am pressing at 6500 PSI on the grain. I am using non-nept tubes. Just the convoluted tubes from pyrodirect or pyrocreations. Ive tried Sali and Benz mixes. Rammers and Spindles are home made by me on my metal lathe with aluminum. I wax with parrafin wax on the spindle and outside of the rammers before pressing. I am using Brass shim stock and 3d prints for tube supports. This actually works as I visibly do not see any bulges ( check my YouTube video to see the tube support) Problem: Whistle mix often gets stuck in the hole of the rammer and sometimes stop my pressing from reaching the 6500 psi and I need to remove and get it out and press it again. (ive never heard anyone complaining about this. Theoretically, everyone should be having the same problem as you press the mix gets into the rammer hole so I'm not sure why no one has mentioned it) I was pressing about 40% strobe and 60% sali whistle on the 3-4 inch tapered spindle. Because I had issues with the sali whistle on the long spindle, I decided to make potassium benzoate whistle as I kept reading in my research that it is more forgiving and can withstand any long spindle issues. Sadly, my first benz whistle CATO'd too I know that there are some recommendations to wax the tube but I have not tried that yet as the one time I tried, the rammer couldn't get in due to so much wax on the walls. Any ideas? Link to comment Share on other sites More sharing options...
DavidF Posted January 15 Share Posted January 15 That is great that you included so much info. It makes it way easier for folks to figure out what needs to be 'fixed'. In my opinion, that short stubby spindle is too thick with too much taper. The compaction of the whistle around the long spindle is no good. You need more rammers with increasingly smaller holes. Most tool sets have 3 or 4 rammers. Only the 'econo' tooling has a single rammer, but the spindle has a gentler taper. Short sali spindles might only come with 2 rammers. Try mixing the sali and potbenz whistle 50/50 on the long spindle. If you have problems with excess wax, it's due to not heating the wax hot enough. Alternatively, you can dissolve a bit of wax in a bit of warm naphtha (flammable!) and swab the inside of the tube to apply a much thinner layer of wax. Then let it dry. Some folks scoff at the idea of lubricating the tube. It wasn't my original idea, it was Takeo Shimizu's the brass shim stock I use is .005" thick. Yours seems like .0025"? You might also polish the spindles to a shine to disturb the grain less when removing them. Just a few thoughts from one rocket maker. I'm sure others will see stuff I might have missed. Link to comment Share on other sites More sharing options...
DecimusMaximus Posted January 15 Author Share Posted January 15 6 minutes ago, DavidF said: That is great that you included so much info. It makes it way easier for folks to figure out what needs to be 'fixed'. In my opinion, that short stubby spindle is too thick with too much taper. The compaction of the whistle around the long spindle is no good. You need more rammers with increasingly smaller holes. Most tool sets have 3 or 4 rammers. Only the 'econo' tooling has a single rammer, but the spindle has a gentler taper. Short sali spindles might only come with 2 rammers. Try mixing the sali and potbenz whistle 50/50 on the long spindle. If you have problems with excess wax, it's due to not heating the wax hot enough. Alternatively, you can dissolve a bit of wax in a bit of warm naphtha (flammable!) and swab the inside of the tube to apply a much thinner layer of wax. Then let it dry. Some folks scoff at the idea of lubricating the tube. It wasn't my original idea, it was Takeo Shimizu's the brass shim stock I use is .005" thick. Yours seems like .0025"? You might also polish the spindles to a shine to disturb the grain less when removing them. Just a few thoughts from one rocket maker. I'm sure others will see stuff I might have missed. Good eye!! Yes the brass is 0.002”. I polished the spindles more than these pics show after the pic was taken. These pics were fresh off the press haha. I didn't have much trouble getting them out of the tube after pressing 6500 psi. I’ll make another rammer than has a smaller hole so the comp can get packed better. That definitely could be the problem as the shorter spindle didnt cato because it was packed without that issue. But how do i know which optimal hole size i need to bore in the new rammer to efficiently press on the lowering taper size? Link to comment Share on other sites More sharing options...
cmjlab Posted January 15 Share Posted January 15 I don't make a ton of rockets like Dave, but I do go on whistle and strobe binges from time to time. Iin addition to multiple rammers, I clean my rammers out nearly everytime I remove it from the spindle (call me OCD). I clean them compulsively because I've thought of getting a rammer stuck on the spindle packed full of whistle (or worse strobe - though I don't have much issue with that one) and the friction of trying to break it free by spinning it! Id sure hate to see how fast that rammer could fly if the whistle did ignite! (Admittedly this has not happened to me, but I feel like it could be a plausible and possible hazard) Link to comment Share on other sites More sharing options...
DavidF Posted January 15 Share Posted January 15 I'm not a toolmaker, but I'd have the second rammer's hole sized to jam at a third of the way up the long spindle. Then the third rammer would jam at 2/3 of the way up. Then a solid rammer. And I would MARK JAM LINES ON THE RAMMERS using the tubes of the length you intend to use for these motors. You would also take into consideration that if your tube shortens due to compression, the jam lines would then be off- so you would not press all the way to the jam line, just in case. You don't want a rammer stuck on the spindle, especially with this kind of rocket. That CATO was quite beautiful. I've made a few like that To what cmjlab said: Some tool makers run the rammer holes all the way up to the puller holes. I got my custom tooling made that way. Also, I told Caleb the other day all spindle bases for long spindles should be able to be bolted to the tube supports he makes, or at least the option should be available. This would end spindle misalignment issues. He was not fond of that idea Link to comment Share on other sites More sharing options...
DecimusMaximus Posted January 15 Author Share Posted January 15 2 hours ago, DavidF said: I'm not a toolmaker, but I'd have the second rammer's hole sized to jam at a third of the way up the long spindle. Then the third rammer would jam at 2/3 of the way up. Then a solid rammer. And I would MARK JAM LINES ON THE RAMMERS using the tubes of the length you intend to use for these motors. You would also take into consideration that if your tube shortens due to compression, the jam lines would then be off- so you would not press all the way to the jam line, just in case. You don't want a rammer stuck on the spindle, especially with this kind of rocket. That CATO was quite beautiful. I've made a few like that To what cmjlab said: Some tool makers run the rammer holes all the way up to the puller holes. I got my custom tooling made that way. Also, I told Caleb the other day all spindle bases for long spindles should be able to be bolted to the tube supports he makes, or at least the option should be available. This would end spindle misalignment issues. He was not fond of that idea Good tip of the tube compression. Ive machined no pass lines on my tooling as well but didnt factor in the compression of the tube. Though, im thinking by the time compression of the tube is a factor, that rammer would be at least 1/4 higher up the spindle already but im not testing it haha. Looking back at the 3lb super bp Caleb tooling that i bought, i notice he has 3 rammers in decreasing hole diameters to compensate for the spindle taper. I didnt think this could have been that important but now talking with you guys, i think that could be my problem! I’ll keep you guys updated I agree these CATOs have been fun but what would be more fun is the feeling of the rocket going to the moon while strobing haha. If you slowed down the first cato, you can see 2 flashes. One is the fuel CATO then the salute header. It’s awesome that in normal speed, it all looks just like one explosion but its not! As far as supports, your brass shim method has worked amazing! With my 3d printed support design, i am able to hold everything, twist and maneuver much easier without having to worry about breaking the tube or something. I have a lot of leverage to hold it like for example when a rammer is stuck tight or the spindle needs to be pulled out. (I pull against my 3d printed supports and the base) That spindle base is actually Calebs. I made my spindles to fit his base by machining the slots and tapped screws to fit it. Link to comment Share on other sites More sharing options...
cmjlab Posted January 15 Share Posted January 15 The ability to machine what you'd like or need us a great skill to have! I put in another topic, that I also wish I was smarter on 3d printing. I seem to be one of the few that never capitalized on 3d printing technology, and never bothered with the know how to design 3d prints. I'm going to have to fix that soon. Link to comment Share on other sites More sharing options...
FrankRizzo Posted January 15 Share Posted January 15 16 hours ago, DavidF said: Also, I told Caleb the other day all spindle bases for long spindles should be able to be bolted to the tube supports he makes, or at least the option should be available. This would end spindle misalignment issues. He was not fond of that idea I guess it wouldn't be too difficult to do yourself if you have a drill press, but what was his issue with that idea? Link to comment Share on other sites More sharing options...
FrankRizzo Posted January 15 Share Posted January 15 (edited) 16 hours ago, cmjlab said: The ability to machine what you'd like or need us a great skill to have! I put in another topic, that I also wish I was smarter on 3d printing. I seem to be one of the few that never capitalized on 3d printing technology, and never bothered with the know how to design 3d prints. I'm going to have to fix that soon. They're really handy. If you want something fast and ready to use out of the the box, the Bambu printers are all the rage right now. If you want to save some cash and are OK with slower print times, the Creality Ender line is still quite good, IMO. If you have a Microcenter near you, they often have coupons for new customers that make the Enders a real steal. Check out this site regularly, if you're in the market: https://3dprintingdeals.com/ Edited January 16 by FrankRizzo 1 Link to comment Share on other sites More sharing options...
DavidF Posted January 16 Share Posted January 16 4 hours ago, FrankRizzo said: I guess it wouldn't be too difficult to do yourself if you have a drill press, but what was his issue with that idea? He said nobody else asked for that option and that he has replaced very few bent spindles, so just not worth the extra labor and expense of the items. Myself, I can't use the method because of the kind of tube support I use and because I use a little doodad to keep the spindle aligned anyway. Link to comment Share on other sites More sharing options...
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