LOC Minie-Magg for Level 1 cert.

[Reid]

Like the title says...
Sorry if TL/DR

Steps I have taken to date:

1. Bought LOC Goblin kit - done
2. Daughter wants to build it - so I gave the kit to her
3. Bought LOC Minie-magg - why have the same kit?
4. "Painted" fins with 50/50 Elmers wood filler & water
5. "Painted" body tube seams with 50/50 Elmers wood filler & water
6. CA glued the edges of the motor and body tubes
7. Sanded fins on all sides and edges with 220 grit
8. Sanded body tube with 400 grit
9. Wiped motor tube with damp paper towels to remove glassine
10. Didn't like it so I sanded motor tube lightly with 220 grit
11. Marked fin and centering ring locations on motor tube (1/8 Inch from the end of the motor tube fore and aft and let the fin shape dictate the middle ring's location)
12. Used a vice to set t nuts into the aft centering ring
13. Installed the nut, washers, and eye bolt in the forward centering ring
14. Used BSI 5 min epoxy to "lock" the metal hardware in place (used small pieces of painters tape to keep epoxy out of the threads on the t-nut)
15. Read the directions then decided to half follow them.... ooph 2/10 stars do not recommend
16. Put a masking tape blocker on the motor tube to hold the forward centering ring in place and used the aft ring to hold the motor tube in place.
17. Put 30 Min BSI epoxy just a bit lower than the final placement of the forward centering ring and pushed the centering ring up the body tube into place and used the aft centering ring to hold the motor tube "straight" so the forward ring would be in the correct position.
18. After the epoxy cured I pulled the motor tube and aft centering ring out
19. Added fillet to the bottom of the forward centering ring... so that sucker is in there
20. Used BSI 5 min epoxy to set the aft centering rings, middle centering rings, and fins in place on the motor tube
21. Used BSI 30 min epoxy to make fillets around the aft centering rings, middle centering rings, and fins (used 8 grams in each section) x3
22. Cut body tube to slide in the motor mount assembly (DO NOT cut on one side like I did, cut in the middle IMHO)
23. Struggled to get the body tube over the motor mount assembly
24. Read the instructions where it says you can't build the motor mount outside the rocket on this model .... cool cool
25. Cut the body tube between the fin slots and the rear so that you CAN slide the motor mount assembly into the body tube
26. Measured distance between fin slots on the body tube and used a piece of angle stock to make a vertical reference line for the rail buttons
27. Drilled a small hole 2.5 cm from the aft end of the body tube
28. CA glued the hole
29. Sanded the hole flush inside and out
30. Used BSI 5 min Epoxy to glue a 6-32 x 1/4" T nut (bought at Lowes) inside the body (this is between the the aft and middle centering ring)
31. Placed BSI 30 min Epoxy just forward and aft of the fin slits
32. Placed BSI 30 min epoxy on the forward tip of the Motor tube (to make fillet on backside of the Forward Centering ring which was already mounted in the rocket body
33. Inserted the motor mount assembly making sure the motor tube seated up in the forward centering ring
34. Used BSI 30 min Epoxy to make fillet on the bottom of the aft centering ring and stick the 3 pieces I had cut out back into the body behind the fins (worked OK)
35. Drilled a small hole a random height along the rail button reference line while making sure not to interfere with the shoulders of the nose cone
36. CA glued the hole
37. Sanded the hole flush inside and out
38. Used BSI 5 min Epoxy to glue the other 6-32 x 1/4" T nut (they come in packs of 2, NICE) inside the body
39. Put a 6-32 nut on a 6-32 x 1/2" machine head bolt (also bought at Lowes) and used a Dremel to cut the length so that when screwed into the t-nut the bolt will not protrude into the body tube and snag recovery gear.
40. Once the bolt was cut I backed the nut off the bolt to make sure the threads were not marred... it worked
41. Made a crude cradle out of a card board box to hold the body tube so that I could fillet the fins
42. Used painter's tape to mark fillet edges (note if you do this put the tape on your shirt a time or two to reduce the stickiness) I pulled some paper off the body tube getting the painter's tape off. Read about this technique AFTER putting the tape on.
43. Used BSI 30 min Epoxy to make fin fillets... Mixed for 1 minute by the clock, waited 3 minutes, applied once slightly thickened, and used a gloved finger and isopropyl alcohol to shape the fillets 8.8 grams per fin (although I put one fin down in the cradle and filleted the "up side of 2 fins" x 3)
44. Removed tape after 10 minutes (Not wild about how the fillets turned out but it's my first time 6.5/10)
45. Filled the damaged sections of the body tube with 50/50 Elmers wood filler and water
46. Sanded the body and epoxy fillets with 400 grit to prep for paint
47. Screwed in rail buttons
48. Used exacto knife to remove molding lines from nose cone and rail buttons

And that's where I'm at.... I do have some questions, but I'll put those in a separate post below. Thanks for reading this far...

 

[Reid]

I am using Open Rocket and the file that came from LOC. But there appears to be some differences between LOC's file and my model as built. (I know the model changed, but their file has not.)

I modified the file and attached it below

The questions I have so far:

1. Rail Button placement - I placed the forward rail button as far forward as possible without interfering with the nose cone. It's 11.5 cm aft of the top of the body tube. Since this model needs drag for stability I plan to use a motor that will generate good speed off the rail, but since I mounted this button so far forward that might lead to problems with the forward rail button clearing the rail before the drag stability takes over. Should I try to mount the forward button lower?
2. Rail Buttons don't spin... In reading it seems like it is beneficial to spin to reduce friction... Should I drill them out a little bit so the button will spin on the T- nut or should I Dremel off the T-nut or is it ok as is?
3. Parachute protection - I plan to use Cellulose insulation (dog barf?) and a heat shield for the parachute. I heard about people using ironing board covers or welding blankets. (I need 3 of them... not just for this rocket) Should I just buy 3 premade or is there a more cost efficient option?
4. Nose cone weight - I have read mixed reviews about the Minie-Magg stability. I attempted to add the drag cone hack to my rocket sim and it's still not at 1 caliber of stability. Combine an old / different (at least to my model) file from LOC and my lack of familiarity with Open rocket and HPR, I'm a bit on the fence. I'm sitting at 1530gms w/o paint or engine. LOC file shows 1753 (including 340gms of nose cone ballast) and I assume that extra weight is on the arse end of the rocket (extra centering ring and heavier fins)
5. Engine suggestions - I'm tempted to find a disposable engine for certification.. any suggestions? Or should I buy a motor case & a reload?

 

[Rocketjunkie]

I used the Mini-Magg to 'confirm' in 1989 on a H70. Confirmation was fly an H, then you could buy *any* motor. It was my first HPR rocket. There was no simulation software then. 1/2 caliber stability is fine for a rocket this short. Mine flew fine on any motor I put in it though marginal on a J350. It was built completely stock with 5 min epoxy.

 

[Handeman]

You really should wait until your rocket is finished, loaded with recovery gear, everything but the motor, and then determine the weight and CG. Use those to override what's in OR. You will get much more accurate stability calculations and simulations.
As for rail buttons, subtract the distance from your top button to the bottom of the rocket from the length of the rail you will be using. Use that number as the rail length in your OR simulations and you should get a pretty accurate idea of speed off the rail.

 

[thzero]

You really should wait until your rocket is finished, loaded with recovery gear, everything but the motor, and then determine the weight and CG. Use those to override what's in OR. You will get much more accurate stability calculations and simulations.

Certainly once the vehicle has been completed. But measuring, etc. and keep track while building can help inform of any issues and reduce surprises.

 

[Reid]

Certainly once the vehicle has been completed. But measuring, etc. and keep track while building can help inform of any issues and reduce surprises.

Yeah, agreed. I'm learning a lot as I go, and I'm trying to read a lot. It's just that I'm occasionally finding potentially import information after the fact.

 

[Reid]

You really should wait until your rocket is finished, loaded with recovery gear, everything but the motor, and then determine the weight and CG. Use those to override what's in OR. You will get much more accurate stability calculations and simulations.
As for rail buttons, subtract the distance from your top button to the bottom of the rocket from the length of the rail you will be using. Use that number as the rail length in your OR simulations and you should get a pretty accurate idea of speed off the rail.

Thanks thats a great idea. As for the Rail Button should I worry about having them rotate freely?

 

[Handeman]

Thanks thats a great idea. As for the Rail Button should I worry about having them rotate freely?

I wouldn't worry about that. If the mounting screw is really solid and tightly held, you can leave it slightly out so the button spins, but most of the time you need to tighten the screw and button down against the rocket to ensure a good solid mount.

If you get significant wear on the button, just loosen, turn 45° or 90° and retighten.

 

[Reid]

Just finished up painting (badly)... She comes in at 1710 grams without motor... so a bit on the heavy side.

still to do:

• Finish up parachute protector 10oz Orange Nomex from Amazon 24"x24"
• Sew up Shock cord protector
• Dig through garage for heavy duty barrel snap swivel (I have some, can I find it?)
• Figure out what motor/delay to use
• Figure out if I'll need nose cone ballast
• Nose cone is too loose, read about how to get the fit just right (I can't pick it up by the nose cone as is)

 

[jmasterj]

For nose cone fit, just use tape on the side of the shoulder.

 

[DAllen]

Thanks thats a great idea. As for the Rail Button should I worry about having them rotate freely?

nope

 

[86mustang408w]

Any more progress?!

 

[86mustang408w]

Just finished up painting (badly)... She comes in at 1710 grams without motor... so a bit on the heavy side.View attachment 571576

still to do:

• Finish up parachute protector 10oz Orange Nomex from Amazon 24"x24"
• Sew up Shock cord protector
• Dig through garage for heavy duty barrel snap swivel (I have some, can I find it?)
• Figure out what motor/delay to use
• Figure out if I'll need nose cone ballast
• Nose cone is too loose, read about how to get the fit just right (I can't pick it up by the nose cone as is)

Be careful what swivels you use, did you pick a motor yet? Most times nosecone won't need much weight thats easy to fix(And most times adding a bulkhead and eyelet is that weight), I use duct tape under making tape for the NC shoulder "tightness". You don't want a drag separation, holding the nosecone while the rockets off the ground will help you determine how much tape to use.

 

[Reid]

Any more progress?!

I think yes, but depends how you define progress.

I ordered some cheapo security alarms and attached one to the plastic nose cone loop to aid in recovery. I went to a local launch and got some opinions and advice from a some of the nice folks there. I purchased a motor H100-W and sim'd my planned flight with that motor on Open Rocket

Rocket with motor weighed 5lbs 6oz w/motor
1,133 Ft Altitude
6 Sec delay to deploy at apogee

I was worried about the stability since Open Rocket showed .25 Caliber.

I added 360grams to the nose cone (but just inside the base of the cone where I attached the shock cord) for a little insurance.

I felt pretty confident and went out to the next launch to give it a shot. Again the folks at the launch were really helpful and supportive and gave my rocket a going over. They helped me with suggestions about nose cone fit and let me feel the fit on their rockets. I borrowed a tool from the motor vendor and set the delay for the ejection charge. This is where I think I made my first (possibly second or third) mistake. I made sure to really press down and turn the tool to bore out some of the delay, but I don't have any experience doing this and all that came out of the motor was a tiny amount of the yellow plastic, I didn't see any other material come out, even when I taped it on the table top. I did this three times to be sure the tool seated all the way but it didn't seem to make any difference. Default delay for the motor was 14 Sec and I was trying to bore it out to 6. (I still don't know if I did it correctly or not)

There was about 12-15 mph wind out of the NW and I expected my rocket to weather cock but I did angle the rail slightly into the wind a little based on flights from other rockets in the earlier rounds. After all, If I can't find the rocket nothing else matters, and I was planning on deploying at apogee on a windy day.

At launch, the rocket left the rail and climbed to ~125' turned due West and flew roughly parallel to the ground. I was standing SE of the rail in anticipation of recovery so I got a good look at the flamey end of the rocket as it cleared a distant row of trees and slowly sank into the horizon. No parachute deployment.

I made note of where I last saw the rocket on the horizon so that I could begin looking for the remains.

The area has tall grass growing in deeper mud with a light sprinkling of gators, snakes, and mosquitos. Luckily there was a service road under some power lines that ran perpendicular to the rockets flight and my son and I were able to stroll pretty near the area I thought the rocket might be in. Let me tell you the bugs here sound more than a little like a distant Security Alarm. At this point, I was just enjoying a walk with my son when after about 15 mins he heard a faint sound of the Security Alarm. We walked back and forth on the road and zeroed in on the closest point to the rocket. I started wading into the waist deep grass and muck and was shocked when only 15' off the road I walked right to the arse end of the rocket. It was stuck in the mud at about a 15* angle. I slowly pulled on the fins and the body tube slid off the buried nose cone. The charge had gone off, but the body and cone were still together. I literally had to dig the nose cone out of the mud and muck.

Damage

• Fins and 85% of the body tube are pristine
• Top of the body tube has a slight wrinkle in it from impact (folks at the launch thought the damage was mostly cosmetic & OK to fly)
• Nose cone base was badly split and the weight completely detached and tore off the base of the nose cone
• Nose cone severely deformed and split on the seam in the front 1/4-1/3
• Security alarm comically sounded like slowly dying robot after it fell into the mud and muck when I pulled the BT off

Mistakes to address

• Forward rail button is too far forward on the BT - I'm going to move it back just forward of the CG to give the rocket more time on the rail
• Stability - I know short fat rocket/base drag etc... - I'm adding 6oz to the tip of the nose cone
• Choose a motor that generates more speed off the rail
• Make sure delay is properly set (I still don't know if the charge blew and the nose cone didn't separate or if the delay wasn't correct and it went off after impact but the charge didn't have the umph to blow the BT & fins off the back)
• Shoot the rocket straight up

So now I am in process of rebuilding the nose cone.

TL/DR Lawn Dart

 

[Art Upton]

I have seen many many Mini-Mags angle into the wind after about 100 feet or so. Keep the rail straight and do not fly in high wind.

 

[Rschub]

H100 sounds a little wimpy, I have used an H225 with good success.

 

[tim cubbedge]

I have seen many many Mini-Mags angle into the wind after about 100 feet or so. Keep the rail straight and do not fly in high wind.

I witnessed his flight. What was strange was it didn’t even turn into the wind. Everyone who witnessed it was pretty surprised as well by the direction it went.

 

[thzero]

Rocket with motor weighed 5lbs 6oz w/motor
1,133 Ft Altitude
6 Sec delay to deploy at apogee


Did you check the rail exit velocity before and after you added, unnecessary more than likely, weight to the nose cone? Unless you didn't build to manufacturers specs... If you didn't then there cg/cp ratio is a good guideline if adding weight.

Or use the cone method to help adjust.

How much does the security alarm weigh?

 

[Reid]

Rocket with motor weighed 5lbs 6oz w/motor
1,133 Ft Altitude
6 Sec delay to deploy at apogee


Did you check the rail exit velocity before and after you added, unnecessary more than likely, weight to the nose cone? Unless you didn't build to manufacturers specs... If you didn't then there cg/cp ratio is a good guideline if adding weight.

Or use the cone method to help adjust.

How much does the security alarm weigh?

I didn't build to manufacturer's specs, their weight was 3-4 lbs. I used epoxy and fileted the motor mount and fins because I wanted it to survive a hard landing. I did sim with the added nose cone weight and that improved the stability to .25 caliber and resulted in the flight profile above. I did check the rail exit velocity but don't have it saved... but to your point, I launched on a 6' rail and probably sim'd a 10' rail.

The amazon security alarm is ~30grams and was mounted to the nose cone, so I don't see how that would have made stability worse other than to reduce speed off the rail.

I will be going with a more punchy motor for the next launch. I'm in SE Florida and am unlikely to see launch winds less than 12mph.

 

[Buckeye]

H100 sounds a little wimpy, I have used an H225 with good success.

Rocket with motor weighed 5lbs 6oz w/motor
1,133 Ft Altitude
6 Sec delay to deploy at apogee


Did you check the rail exit velocity before and after you added, unnecessary more than likely, weight to the nose cone?

There was about 12-15 mph wind

At launch, the rocket left the rail and climbed to ~125' turned due West and flew roughly parallel to the ground.

H100 is a horrible choice for this rocket, especially into 12-15 mph wind. 39 fps from a 6 ft rail. Your sim doesn't seem correct, nor the advice you received.

 

[86mustang408w]

I think yes, but depends how you define progress.

I ordered some cheapo security alarms and attached one to the plastic nose cone loop to aid in recovery. I went to a local launch and got some opinions and advice from a some of the nice folks there. I purchased a motor H100-W and sim'd my planned flight with that motor on Open Rocket

Rocket with motor weighed 5lbs 6oz w/motor
1,133 Ft Altitude
6 Sec delay to deploy at apogee

I was worried about the stability since Open Rocket showed .25 Caliber.

I added 360grams to the nose cone (but just inside the base of the cone where I attached the shock cord) for a little insurance.

I felt pretty confident and went out to the next launch to give it a shot. Again the folks at the launch were really helpful and supportive and gave my rocket a going over. They helped me with suggestions about nose cone fit and let me feel the fit on their rockets. I borrowed a tool from the motor vendor and set the delay for the ejection charge. This is where I think I made my first (possibly second or third) mistake. I made sure to really press down and turn the tool to bore out some of the delay, but I don't have any experience doing this and all that came out of the motor was a tiny amount of the yellow plastic, I didn't see any other material come out, even when I taped it on the table top. I did this three times to be sure the tool seated all the way but it didn't seem to make any difference. Default delay for the motor was 14 Sec and I was trying to bore it out to 6. (I still don't know if I did it correctly or not)

There was about 12-15 mph wind out of the NW and I expected my rocket to weather cock but I did angle the rail slightly into the wind a little based on flights from other rockets in the earlier rounds. After all, If I can't find the rocket nothing else matters, and I was planning on deploying at apogee on a windy day.

At launch, the rocket left the rail and climbed to ~125' turned due West and flew roughly parallel to the ground. I was standing SE of the rail in anticipation of recovery so I got a good look at the flamey end of the rocket as it cleared a distant row of trees and slowly sank into the horizon. No parachute deployment.

I made note of where I last saw the rocket on the horizon so that I could begin looking for the remains.

The area has tall grass growing in deeper mud with a light sprinkling of gators, snakes, and mosquitos. Luckily there was a service road under some power lines that ran perpendicular to the rockets flight and my son and I were able to stroll pretty near the area I thought the rocket might be in. Let me tell you the bugs here sound more than a little like a distant Security Alarm. At this point, I was just enjoying a walk with my son when after about 15 mins he heard a faint sound of the Security Alarm. We walked back and forth on the road and zeroed in on the closest point to the rocket. I started wading into the waist deep grass and muck and was shocked when only 15' off the road I walked right to the arse end of the rocket. It was stuck in the mud at about a 15* angle. I slowly pulled on the fins and the body tube slid off the buried nose cone. The charge had gone off, but the body and cone were still together. I literally had to dig the nose cone out of the mud and muck.

Damage

• Fins and 85% of the body tube are pristine
• Top of the body tube has a slight wrinkle in it from impact (folks at the launch thought the damage was mostly cosmetic & OK to fly)
• Nose cone base was badly split and the weight completely detached and tore off the base of the nose cone
• Nose cone severely deformed and split on the seam in the front 1/4-1/3
• Security alarm comically sounded like slowly dying robot after it fell into the mud and muck when I pulled the BT off

Mistakes to address

• Forward rail button is too far forward on the BT - I'm going to move it back just forward of the CG to give the rocket more time on the rail
• Stability - I know short fat rocket/base drag etc... - I'm adding 6oz to the tip of the nose cone
• Choose a motor that generates more speed off the rail
• Make sure delay is properly set (I still don't know if the charge blew and the nose cone didn't separate or if the delay wasn't correct and it went off after impact but the charge didn't have the umph to blow the BT & fins off the back)
• Shoot the rocket straight up

So now I am in process of rebuilding the nose cone.

TL/DR Lawn Dart

Wow, that's a wild story!

I myself had an issue with the ejection charge, only thing about that is that it did go off. The only problem was it went off about 2 seconds after ignition and just right after the flame went out on a H135W-14A. I didn't exactly want the parachute to come out at 300 and some mph, that was interesting.

Now, I as well had to buy a ejection drilling tool. You say only some yellow plastic came out? Was the tool calibrated properly? There's also a washer you need to install too, and I've see some forget to add the ejection charge itself. It did me good to have a check list and take pictures/videos.

Myself have been paying attention to thrust to weight ratios especially now with high power rockets. A 5.6 pound rocket with an H100(its about 4:1) and the wind conditions you had was definitely one the line of iffy, unfortunately you found that out. I'm surprised the RSO said yes with the wind.

I would guess to say the delay wasn't drilled at all, and it just ejected way too late or not at all. Those charges are pretty wild they can be violent too, and with bigger body tubes you need to add more BP to the ejection charge or less if its a smaller diameter body tube from that vial they give you. Maybe your rocket didn't have enough black powder in th ejection charge to push the nosecone off ? They also have 2 different ejection tools too, one for RMS and one for DMS. Do you know which one you used? . Another thing I've noticed is some dont realize with composite motors that ejection delay starts burning at ignition. So if its 10, that 10 second delay is after ignition not when the motor loses thrust. I've seen some miscalculate that and have a failed flight. I'm racking my brain as well thinking of what could have happened.

But I agree as well, I launch straight up with a high power rocket as well, if the conditions don't allow for that, then Its a no-go. We all learn, I was curious to see how you made out. As bad as it looks you learned a lot, and you got it back. I'm happy you heard that beeping! That's another thing, I think im going with Featherweight GPS trackers. Keep up the good work, and sorry for Magg. She'll be ok, lol.

One thing I've also noticed, that the chute and shock cord should be as far down as possible. That may sound funny, but that amount of weight even moving or shifting downward just a little will drastically change the CG right after leaving the rod and before it stabilizes itself and also leads to "weathercocking". I've been using chute stops for high power, works well.


Here's a nice TWW calculator you can use in the field.

https://rocketrycalculator.com/rocketry-calculator/thrust-to-weight-ratio/

 

[86mustang408w]

H100 is a horrible choice for this rocket, especially into 12-15 mph wind. 39 fps from a 6 ft rail. Your sim doesn't seem correct, nor the advice you received.


View attachment 617431

Yeah I hate to say but think he may have been led in the wrong direction, and I agree the sims seems to be off a little. I missed if he said he was using OR or Rocksim.

 

[86mustang408w]

Another option would be to use 1515 rail buttons, that will give you a lot longer on the rail. Just a suggestion, I just like to see others succeed. Great work so far, and good luck in the future. All of my failures have just been steps on the way to success. Keep going you're doing great.

 

[Back_at_it]

Going to agree that it sounds like you got some really bad information. At 86oz, the H100 was no where near enough motor for that rocket. Even flying off a 10ft rail you wouldn't have had enough speed to keep that rocket stable.

I have a Minie Magg that I absolutely love to fly on H219's. Mine was built similar to yours with epoxy and weighs in at 78oz empty without motor. I normally cut the delay to 7 seconds.

For reference, my CG is right at the 20in mark and the stability shows .760. It has flown perfect every single flight.

The H219 jumps off the pad but only flies about 900ft. I've seen a few of them flown for Cert. flights a bunch of times. It's fun to hear the noise of an H motor but it doesn't go that high. It's like using an F44 is smaller rockets.

 

[86mustang408w]

Don't take any of my comments as trying to rub it even more. I really like to see others succeed, you did everything you were supposed to do. You really did do a good job. I was kind of kin a rush myself to get it back in May. I'm thinking I just got back into rocketry I'm 40 now, I've been doing this for 33 years I need something to show for it. I mean getting into the hobby for me wasn't about competition or climbing as high as I can go. It was just fun. And recently has been therapeutic to me thst anything ever has...

So don't give up or get frustrated or quit I know you haven't said but it may be in the back of your head "this isn't worth thr time or money anymore". If that's the case back down a little bit and just watch and ask at launch day about whatever your goals are. Most guys won't hesitate to share info it give you an earful of great advice. I was taking the wrong approach back in May, and took the advice of joining a club just going to fly low power or just go watch. That helped me tremendously to the point I was pretty confident in my L1 build that it would make it in a high power motor. It did. Keep up the good work, you ever have any questions shoot a message. Take care and have fun.

 

[2-0turbo]

I just completed my L1 (Thanks Sean @Theory ) with my "old-school" LOC MM with 1/8" fins and centering rings. My pad weight was 3lbs-3oz (~51 ozs) and I used a H135 motor. It was a good flight, but my breeze wasn't quite as stiff as yours. I added no nose weight and I think my stability was 0.3 calibers (perhaps even 0.25) as calculated by OR. Mine also did a bit of a wobble off the rail--I think marginally stable rockets that rely on base drag for stability need a good punchy motor to get moving. The H219 recommended above by @Back_at_it would be a great choice.

I agree with others that with the weight of your rocket, 100 N-s average wasn't quite enough. Also, if you look at the thrust curve for that motor, it comes up to full thrust a little slow--0.25 secs into the burn it's only at 25 lbs and doesn't reach peak thrust until almost 0.5 secs. With 100 N-s average thrust, this is just under 5:1 ratio (which is typically a minimum). Yes, I know you can look at peak thrust too, but just using average is a good rule of thumb.

I think next time I fly mine, I'll go with an H550.

 

[Reid]

Yeah I hate to say but think he may have been led in the wrong direction, and I agree the sims seems to be off a little. I missed if he said he was using OR or Rocksim.

I used Open Rocket.
For what it's worth, no one talked me into that motor, It was my decision. If there is one thing I am historically good at, it's making bad decisions! I appreciate all the feedback here. I'm not dissuaded.

 

[86mustang408w]

I used Open Rocket.
For what it's worth, no one talked me into that motor, It was my decision. If there is one thing I am historically good at, it's making bad decisions! I appreciate all the feedback here. I'm not dissuaded.

Awesome!! I look forward to future builds! That one has been on my wish list. I saw this thread on Google and thought I'd check it out orbI wouldn't have posted... Thanks for responding, I'm trying to gain knowledge myself. Thank you, and again have a good one. Michael B.

 

[Back_at_it]

I used Open Rocket.
For what it's worth, no one talked me into that motor, It was my decision. If there is one thing I am historically good at, it's making bad decisions! I appreciate all the feedback here. I'm not dissuaded.

Good deal. Looking forward to seeing this one rebuilt and flown for your level 1. If the fin section was intact then it’s an easy rebuild.

Since you need to buy a new nose cone, you might want to look at LOC’s options. There is a short and a long cone. The longer cone would lessen the amount of nose weight needed but of course it would change the look of the rocket

 

[Reid]

Good deal. Looking forward to seeing this one rebuilt and flown for your level 1. If the fin section was intact then it’s an easy rebuild.

Since you need to buy a new nose cone, you might want to look at LOC’s options. There is a short and a long cone. The longer cone would lessen the amount of nose weight needed but of course it would change the look of the rocket

Well,
One of the guys at launch told me that the nose cone might be salvageable. He recommended cutting off the bottom the cone and a hair dryer to make the material pliable. I had my doubts but I like tinkering and I LOVE the idea of patching up the old one and flying it all janky. (if it's safe)

I cleaned the mud off and out of it, cut the bottom off at the shoulder and popped out the side by the split seam and left it in the garage. The next time I picked it up to tinker with it, it was probably 85% better. I have a healing work bench! (or the material memory kicked in from a hot garage and sunlight from the window)

I took this pic after I started digging it out with my foot


After the healing bench, a little heat gun action, and re-gluing the split seam.


Still not perfect. But it has a lot more character!