nater Posted January 14, 2011 Posted January 14, 2011 I tried a new scoop made from a .40SW casing, it does make a good increment size for 1/2" motors, but now my motor is stuck on the spindle. I've tried twisting it out with pliers with no luck. I guess I should have coated the spindle with paraffin before ramming like I have with my other ones. What's worked for everyone else to pry them loose?
killforfood Posted January 14, 2011 Posted January 14, 2011 I’ve never made a rocket so I may be all wrong but this is what I would do. Drill and tap the end of the ram. Slip a bigger pipe over the casing that extends at least one inch above the ram end that you just tapped. Lay a fender washer on top of the pipe and insert a bolt through the washer into the end of the ram and tighten till the ram is free. If that doesn’t work, put a torch to it and aim it at the neighbor’s dog that keeps you up all night Oh and have 911 on speed dial. Obviously there are folks on here that have actual experience and may have better advice.
dagabu Posted January 14, 2011 Posted January 14, 2011 (edited) Sheesh! It took me how long to make the connection? Hey Nate, saw the post on Passfire too. Armstrong, that's what it takes in most cases. I ruined a rammer getting it unstuck last year when I didn't put enough clay in first. Killforfood, I think that is good advice, I just dont like your avatar, clowns really freak me out. That one downright makes me want to crap myself. Edited January 14, 2011 by dagabu
nater Posted January 14, 2011 Author Posted January 14, 2011 It's the motor that is stuck to the spindle, not the rammer. I've tried twisting it off with pliers and marred up the base of the tooling without getting it unstuck. After pulling a giant metal splinter out of myself, I'm tempted to sacrifice the motor. I might try using a couple sets of vice grips and hope it doesn't crack the motor grain before soaking the whole thing in a bucket of water.
killforfood Posted January 14, 2011 Posted January 14, 2011 I just dont like your avatar, clowns really freak me out. That one downright makes me want to crap myself.I had to find something with fire in it. The clown face is a left over avatar from when I was online gaming with my son. It was a lot of fun linking up a bunch of X-boxes in the basement for all night Halo battles
WSM Posted January 14, 2011 Posted January 14, 2011 It depends on the tools, the material they're made of and how they were stuck to each other in the first place! 1) If the spindle and rammer are untreated aluminum; write them off and order a new set. 2) If the spindle is nituff coated aluminum, there is hope but the rammer will never be the same again (try soaking the whole shebang in Liquid Wrench or Kroil and see if it'll come apart with force tomorrow). 3) If the spindle is stainless and the rammer is also stainless, see the first suggestion above. 4) If the spindle is stainless and the rammer is aluminum, see the second suggestion above. If none of these help, tell us more about the situation, and fill in some details listed in the opening line above. Thanks. Good luck! WSM Note: nothing galls together like aluminum to aluminum or stainless steel to stainless steel. I found this out the hard way (had to cut apart more than one tool set ).
nater Posted January 14, 2011 Author Posted January 14, 2011 WSM, it is aluminum tooling and aluminum rammer, but it was just the motor stuck to the spindle. I can't type too well right now, so I'll copy my response from passfire: Thanks for the tips. First I removed the bulkhead and tried supporting the tube with the rammer and coaxing it off. That still wasn't helping me much and I started marring up the base of my tooling even more. Then I thought I would cut the motor off, so I could at least inspect the grain and see how good of a job I did ramming. That was bad idea #2 for the night. The knife slipped, my thumb got in the way, and it is a good thing I'm not afraid of blood and know a thing or two about fixing lacerations. I did learn a few things tonight, so that is always good. It also good that my wife is very patient and just shakes her head when I hurt myself. Now my motor and spindle is sitting in a bowl of water, I'll finish dealing with it later.
WSM Posted January 14, 2011 Posted January 14, 2011 (edited) WSM, it is aluminum tooling and aluminum rammer, but it was just the motor stuck to the spindle. I can't type too well right now, so I'll copy my response from passfire: Thanks for the tips. First I removed the bulkhead and tried supporting the tube with the rammer and coaxing it off. That still wasn't helping me much and I started marring up the base of my tooling even more. Then I thought I would cut the motor off, so I could at least inspect the grain and see how good of a job I did ramming. That was bad idea #2 for the night. The knife slipped, my thumb got in the way, and it is a good thing I'm not afraid of blood and know a thing or two about fixing lacerations. I did learn a few things tonight, so that is always good. It also good that my wife is very patient and just shakes her head when I hurt myself. Now my motor and spindle is sitting in a bowl of water, I'll finish dealing with it later. I suggest polishing the spindle to a mirror finish with various grades of wet/dry sand paper and finish with Mother's polish. Waxing the spindle before making rockets may help, too. Even with a stainless spindle, I see rockets get stuck. I remove the spindle (with the stuck rocket on it) from the base and put it back on the base with a thick flat-washer between the motor and the base. When I tighten the cap socket screw, the motor starts to move, just a little. Then I give the finished motor a twist and it pops right off the spindle. Try this next time. Oh, and cut towards your buddy, not your body ! WSM Edited January 14, 2011 by WSM
killforfood Posted January 14, 2011 Posted January 14, 2011 The knife slipped, my thumb got in the way, and it is a good thing I'm not afraid of blood and know a thing or two about fixing lacerations.Sorry to hear about your cut thumb Nater, I hope you can save your spindle.I'm beginning to think I should make some junk tooling to learn on. It must be a real drag galling up an expensive set.
nater Posted January 14, 2011 Author Posted January 14, 2011 Sorry to hear about your cut thumb Nater, I hope you can save your spindle.I'm beginning to think I should make some junk tooling to learn on. It must be a real drag galling up an expensive set. The spindle looks fine, I didn't bend it. There are a few small scratches at the base of the spindle from the nozzles. I'll try making nozzles with just hawthorn clay instead of the mix with grog. I'm confident my tooling will polish up as good as new.
dagabu Posted January 14, 2011 Posted January 14, 2011 The spindle looks fine, I didn't bend it. There are a few small scratches at the base of the spindle from the nozzles. I'll try making nozzles with just hawthorn clay instead of the mix with grog. I'm confident my tooling will polish up as good as new. Nate, try the cheapest kitty litter you can find, it works well and spindles dont get stuck so bad. You need to use a sharpie and draw a NO-GO line on your rammer so you dont get that close again. WSM, the spindle is not removable, the trick wouldn't work on his set.
NightHawkInLight Posted January 14, 2011 Posted January 14, 2011 (edited) WSM, the spindle is not removable, the trick wouldn't work on his set.Could you not tap two or three threaded holes on either side of the spindle, find a big ol washer that fits right around the base of it, then use bolts in those threaded holes to push the washer, and thus the rocket right off? If you can't find a washer that big it would be simple enough to have a hole drilled in a small piece of plate steel. I'm sticking my nose where it doesn't belong with this rocketry stuff. Edited January 14, 2011 by NightHawkInLight
nater Posted January 14, 2011 Author Posted January 14, 2011 Could you not tap two or three threaded holes on either side of the spindle, find a big ol washer that fits right around the base of it, then use bolts in those threaded holes to push the washer, and thus the rocket right off? If you can't find a washer that big it would be simple enough to have a hole drilled in a small piece of plate steel. I'm sticking my nose where it doesn't belong with this rocketry stuff. I'm not sure that would be possible since the tooling is turned from a single bar of stock. If anything it would be more trouble than it is worth to me. For these small motors, I think my best bet is to polish my tooling up so it is nice and smooth again, use some sort of lube before I pound the motor, and use plain clay or kitty litter for the nozzles. I think if I do all that I will be less likely to get a stuck motor next time. When I'm ready to move up to bigger ones, I'll invest in tooling with a removable spindle so I can just unscrew the base, insert some type of shim, then the motor will pop right off when you screw the base back in. I want to get some rockets flying, then work on some headers before I move up to bigger ones. Good weather for club shoots will be here soon, so I'll be able to experiment more.
Guest no6 Posted January 14, 2011 Posted January 14, 2011 Try using a rubber glove. My 1 lb. rockets stick like a bugger. Grasp them above the nozzle and try to twist. Then challenge a friend's manhood. Give him the glove. And so on.
nater Posted January 14, 2011 Author Posted January 14, 2011 Now I'm picturing what Nighthawkinlight was talking about. It might be possible, but still sounds like more trouble than it is worth. All good ideas, keep them coming. I know I won't be the last person to get a motor stuck.
Guest no6 Posted January 14, 2011 Posted January 14, 2011 Wouldn't waxing the spindle cause a problem with ignition? Or does it work? I'm curious to know.
NightHawkInLight Posted January 14, 2011 Posted January 14, 2011 Wouldn't waxing the spindle cause a problem with ignition? Or does it work? I'm curious to know.I assume the amount of wax that would be ideal wouldn't be enough to coat the entire inside of the fuel core, but simply enough to fill the micro craters and scratches in the spindle. The amount left on the fuel grain if that were the case would only cover a minute percentage of the overall surface area. Not being a rocket guy I couldn't say that's the case as proven by my own experience, just an assumption. I am trying to learn, slowly.
WSM Posted January 14, 2011 Posted January 14, 2011 Some folks wipe a small amount of silicone oil on the spindle, and swear by the technique. I've seen nozzles with graphite added for compatibility issues with corrosive exhaust gases, and a side benefit is easier removal of the finished rocket motor. Just a couple thoughts... WSM
WSM Posted January 14, 2011 Posted January 14, 2011 Nate, try the cheapest kitty litter you can find, it works well and spindles dont get stuck so bad. You need to use a sharpie and draw a NO-GO line on your rammer so you dont get that close again. WSM, the spindle is not removable, the trick wouldn't work on his set. Ouch! Maybe the set can be polished mirror smooth and sent to Rich to be added to the next Nituff batch he does?! Rich is pretty cool about stuff like that, why not ask him how much that would cost? Hawthorne Bond is supposed to be very good stuff (for nozzles and not scratching the spindle) and is probably less prone to moisture problems than bentonite. I'd add either wax, mineral oil or boiled linseed oil to the clay mixture, anyway. Many have used toilet wax rings as the wax additive. The toilet wax can be synthesized by mixing canning wax with Vasoline (paraffin and petrolatum) to get that soft wax texture of the toilet seal. Sleeter has a method of incorporating wax into powdered clay that works well. Put the weighed amount of clay in a stainless steel bowl and heat it in an oven set to 300oF for half an hour. Next melt the weighed amount of paraffin wax in a small sauce pan. Now with gloved hands, pour the melted wax slowly over the heated clay while hand-mixing it till the clay/wax mixture is uniform. Do this last step outdoors over paper, of course, to minimize any mess. The heated clay helps evenly disperse the melted wax rather than cause it to rapidly harden on contact (with cold clay). The final product looks like regular fireclay, BUT it works so much better! Try it. WSM If you use boiled linseed oil, remember it needs to air polymerize for about a month before it reaches effectiveness. When it has polymerized, it goes plastic (flows) under pressure and bonds the clay grains to the tube fibers with amazing strength (which almost makes up for the weird, paint-like smell it has). The best method of incorporation involves thinning the oil with campstove fuel, 3:1, and mixing with the clay, then driving the stove fuel off (all outdoors and away from any source of ignition, of course). If a few drops of Japan Drier are added to the stove fuel, the linseed oil will polymerize much faster (a couple days). Enjoy!
dagabu Posted January 14, 2011 Posted January 14, 2011 Could you not tap two or three threaded holes on either side of the spindle, find a big ol washer that fits right around the base of it, then use bolts in those threaded holes to push the washer, and thus the rocket right off? If you can't find a washer that big it would be simple enough to have a hole drilled in a small piece of plate steel. I'm sticking my nose where it doesn't belong with this rocketry stuff. NHIL, that is EXACTLY the method we use to remove sheaves from the shaft on HVAC equipment driven by belts and a very good idea, thanks!
dagabu Posted January 14, 2011 Posted January 14, 2011 I have 100# of David Sleete's mix in my shop that I no longer use, it makes exceptional nozzles but it scratches my spindles due to the grog that Sleeter had posted in his mix. I like the rest of the mix but the grog just kills the metal. I use a spray silicone, Jig-A-Loo is the name, its available at Menards for $2.99 a can and it is on sale for $.99 a can with rebate. I press my rockets to 9000 PSI and I can twist them off the spindle by hand up to 3/4". Wax works fine to coat the spindle and if you rub a candle over the spindle, you will see how thin the film is and it causes no problems with ignition as far as I am concerned.
nater Posted January 14, 2011 Author Posted January 14, 2011 My nozzle mix is Ned's mix as posted on Skylighter, mixed up using Sleeter's technique. I have a few pounds mixed up, and enough Hawthorn Bond clay to last me a long time. I can pick up some Jig-A-Loo, someone else from my club suggested I try to find SailKote to lube the spindle. Now I have a lot of things to try, and I still need to pick up an arbor press and make a ptof gauge like I planned on this winter.
TYRONEEZEKIEL Posted January 14, 2011 Posted January 14, 2011 Oh definitely add graphite. I add a 2-3% graphite to all my rocket comps when ramming, not only do i find it makes a bit more spark, It really lubricates the tooling very well. I mean really well Oh definitely add graphite. I add a 2-3% graphite to all my rocket comps when ramming, not only do i find it makes a bit more spark, It really lubricates the tooling very well. I mean really well
dagabu Posted January 14, 2011 Posted January 14, 2011 Look, it lubes so well that it double posts!! I have not had favorable experiences with graphite but it makes a nice colored nozzle.
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