ballmill Posted May 30, 2011 Posted May 30, 2011 I've been lately pressing 3 lb whistle rockets on my new grizzly press. After pressing in the first few increments my spindle is moving off center which is preventing me from using my second rammer. It rubs on the spindle when going in, and I understand this can be quite dangerous. I've been cutting my tubes square, and making sure my fuel is level in the tube before pressing. I've narrowed it down to my press being out of square.. I'll have to fix this soon. My question is, will it work to use the first rammer all the way to the top of the spindle? I guess it all depends on type of tooling. It's Wolter's 3 lb set which takes about 4 increments to fill the spindle. Pressing to 6500psi. I'm worried about CATO from possible poorly compacted fuel around the core from using a large opening rammer.
dagabu Posted May 30, 2011 Posted May 30, 2011 I've been lately pressing 3 lb whistle rockets on my new grizzly press. After pressing in the first few increments my spindle is moving off center which is preventing me from using my second rammer. It rubs on the spindle when going in, and I understand this can be quite dangerous. I've been cutting my tubes square, and making sure my fuel is level in the tube before pressing. I've narrowed it down to my press being out of square.. I'll have to fix this soon. My question is, will it work to use the first rammer all the way to the top of the spindle? I guess it all depends on type of tooling. It's Wolter's 3 lb set which takes about 4 increments to fill the spindle. Pressing to 6500psi. I'm worried about CATO from possible poorly compacted fuel around the core from using a large opening rammer. Don't bother, take the rocket off the spindle and start again. The rocket will CATO even if you finish the grain solidly. I have done this several times even with a square press. When you remove the spindle, the fuel grain will crack and it will CATO. You need to shim your press or have the plates surface ground or buy a thick aluminum plate. I would go for the third option myself. -dag
ballmill Posted May 30, 2011 Author Posted May 30, 2011 I'm already using multiple aluminum plates. It's the bed that's rocking on the titanium bars that are driven through the press frame. When I inspected the finished core with a flashlight I saw no indication of any cracking, and I also lube the spindle with WD-40 before pressing. The spindle wasn't too far off from center, just enough for the second rammer to rub on it. Will I get a CATO for sure or am I just taking chances?
ballmill Posted May 30, 2011 Author Posted May 30, 2011 I just checked my tubes for square and they were indeed off. My miter slide was out of square... however my press still needs work. I pressed another one after adjusting and it came out fine.
dagabu Posted May 30, 2011 Posted May 30, 2011 I'm already using multiple aluminum plates. It's the bed that's rocking on the titanium bars that are driven through the press frame. When I inspected the finished core with a flashlight I saw no indication of any cracking, and I also lube the spindle with WD-40 before pressing. The spindle wasn't too far off from center, just enough for the second rammer to rub on it. Will I get a CATO for sure or am I just taking chances? Shoot it since you took it off the spindle but I wouldn't waste a really good shell on it just in case. BTW- Jig-A-Loo is fine for spindles but WD-40 has Teflon and oil, it may not be the best choice in pyro. -dag
ballmill Posted May 30, 2011 Author Posted May 30, 2011 Thanks, ill take a video of a crooked spindle and post it in a few hours.. really this time
dagabu Posted May 31, 2011 Posted May 31, 2011 I may be able to fix the spindle for you, if not I sure can make a new one for you. Just send the base with it so I can align them. -dag
ballmill Posted May 31, 2011 Author Posted May 31, 2011 The spindle is fine, I meant the cored section of the rocket was a bit crooked when I pressed it. I fired this one and it didn't CATO, in fact it took off very very slow almost like girandola speed, extremely loud, then started cruising and flew very high. I suspect my fuel wasn't dry enough. I used 70/30 benzoate... but this is a different issue I need to work on.
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