Mad Rocketeer
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OK, I messed up (mildly, I guess, but frustratingly) on my new LOC Graduator. I'm using J.B. Weld on the places where anything attaches to the MMT and Bob Smith 30-minute epoxy everywhere else. I added milled glass fiber to the 30-minute epoxy at the front of the front centering ring (applied to the body tube before sliding the MMT in). I've left the rear centering ring unglued until I get the internal fillets done.
Well, like a dummy, I read the epoxy instructions (30 minutes to set up, 2 hours before handling) and timed my fin attachments for the first two fins at 2 hour intervals. This morning when I went to attach the third fin, I saw that the first wasn't straight any more. I'd gone to great lengths to get it perfect too, and when I went to do the second fin last night, the first was arrow straight and felt firm. Upon looking at it this morning, I could see that the first fin had drooped while the second was drying in a vertical position overnight. I went back and read the J.B. Weld again, and it said 4 to 6 hours to handle. Rats! I'd have gladly let the first fin harden overnight before doing the next one, had I noticed in time.
Lesson: Wait the full time before going on to the next fin when using J.B. Weld. Even if it feels firm, it can slip if left at an angle long enough.
Now, what? Just eyeballing it, I'd guess that the fin is off by just under 10 degrees. The place where it meets the MMT has probably slid at least the width of the fin (1/8 inch) to the side. Once the third fin has had its full 6 hours of curing time (especially since the garage is cool today), I'll try to get a better estimate of the extent to which the angle of the fin is off. I could figure it with a little math too, I guess, but I'm feeling lazy today.
So, my questions:
1.) Can this be fixed? I hate to leave it like this, but the fin is attached to the MMT (unfilleted as yet) with J.B. Weld, and to the body tube (above and below the tab only, no fillets) with 30-minute epoxy. J.B. Weld has been used (so they say) to repair tractor engines. Any chance I can get this to turn loose or dig through it without risking or destroying the fin and/or MMT? [I'm doubting it.]
2.) How bad is a tilt of this magnitude? Would it:
a.) Interfere with safety, from an RSO's perspective, for a mid-to-low-L1 bird?
b.) Disqualify this rocket for an L1 attempt?
c.) Interfere with the durability / survivability of the rocket?
d.) Interfere significantly with the performance? [I don't intend using this as a competition rocket.]
3.) Will this significantly affect the appearance of the rocket? [Seems like it would be most noticable right now, while the rear centering ring is still uninstalled.]
4.) Now what? Just finish it and ignore the tilt, taking it as a lesson learned?
Thanks in advance for the good advice. I know there will be people here with the experience to answer my questions and guide my next move.
Well, like a dummy, I read the epoxy instructions (30 minutes to set up, 2 hours before handling) and timed my fin attachments for the first two fins at 2 hour intervals. This morning when I went to attach the third fin, I saw that the first wasn't straight any more. I'd gone to great lengths to get it perfect too, and when I went to do the second fin last night, the first was arrow straight and felt firm. Upon looking at it this morning, I could see that the first fin had drooped while the second was drying in a vertical position overnight. I went back and read the J.B. Weld again, and it said 4 to 6 hours to handle. Rats! I'd have gladly let the first fin harden overnight before doing the next one, had I noticed in time.
Lesson: Wait the full time before going on to the next fin when using J.B. Weld. Even if it feels firm, it can slip if left at an angle long enough.
Now, what? Just eyeballing it, I'd guess that the fin is off by just under 10 degrees. The place where it meets the MMT has probably slid at least the width of the fin (1/8 inch) to the side. Once the third fin has had its full 6 hours of curing time (especially since the garage is cool today), I'll try to get a better estimate of the extent to which the angle of the fin is off. I could figure it with a little math too, I guess, but I'm feeling lazy today.
So, my questions:
1.) Can this be fixed? I hate to leave it like this, but the fin is attached to the MMT (unfilleted as yet) with J.B. Weld, and to the body tube (above and below the tab only, no fillets) with 30-minute epoxy. J.B. Weld has been used (so they say) to repair tractor engines. Any chance I can get this to turn loose or dig through it without risking or destroying the fin and/or MMT? [I'm doubting it.]
2.) How bad is a tilt of this magnitude? Would it:
a.) Interfere with safety, from an RSO's perspective, for a mid-to-low-L1 bird?
b.) Disqualify this rocket for an L1 attempt?
c.) Interfere with the durability / survivability of the rocket?
d.) Interfere significantly with the performance? [I don't intend using this as a competition rocket.]
3.) Will this significantly affect the appearance of the rocket? [Seems like it would be most noticable right now, while the rear centering ring is still uninstalled.]
4.) Now what? Just finish it and ignore the tilt, taking it as a lesson learned?
Thanks in advance for the good advice. I know there will be people here with the experience to answer my questions and guide my next move.