Darkstar DD Build Thread

[MasonH]

Mason:

see me at CATO next week about your motor...I'm sure we can figure something out - I have one or two laying around Besides, you're gonna need some help to cert - where and when are you thinking? Going to Red Glare or METRA? I'll be at both, promise that one

Don't worry, I know your the one to talk to. I know we can work out something for motors, too. I will be looking for all of the advice (and parts) i can get from everyone. I do not know when and where I will cert though. It seems to me that the where depends on the when and vice versa. I might just do it all at LDRS if I am able

I also have a question. I have decided to work on the nose cone since I do not have the plastic rivets needed to start drilling the payload bay and coupler. I can get the bulkhead, coupler, and eye bolt assembly in no problem. I want to know what to do about the removable tip. Do I epoxy the tip on, or wait until after painting so I can still see the aluminum? I have scored the plate that the screw passes through, and I plan on using JB Weld to hold the nut in place. Is this the right approach? If so, where do I go from there?

[Fe Dude]

The tip anchors to a bold threaded through a small fiberglass disc at the front of the cone. The disc will pop out. For my vindicator I popped the whole bit out, measured the length of bolt thread ahead of the disc, then ran some nuts down a length of threaded rod, crammed the whole bit back up the nosecone, and made a stepped bulkhead (similar to the ones for the av bay) and ran the threaded rod through that.

The aluminum tip on the one end snugs up the small disc, and a nut on the back side of the stepped bulk plate keeps everything else snug.

This way, you do not seal off the nosecone, and everything is solid without being permanent.

SOOOO: in short, here's how it goes together:

tip, onto threaded rod -> nut-> disc->nut->nut-> long space of empty rod out the back of the NC -> stepped bulkplate-> washer-> lockwasher-> eye nut




the threads on the eye bold will be cut short so that everything fits nice and snug of course

Wildman has the rivets and shear pins you require, or you can get them from McmasterCarr

[MasonH]

That is a good idea! The problem for me is the weight. Even on a full I motor in SD mode, the thing only reaches 3000'. I am afraid that with all of the weight from the metal parts that this thing will not b safe to launch.

[cbrarick]

That is a good idea! The problem for me is the weight. Even on a full I motor in SD mode, the thing only reaches 3000'. I am afraid that with all of the weight from the metal parts that this thing will not b safe to launch.

Hey, my level one made it a whopping 1300 feet....so, it's more the power to weight rather then the total impulse, after all you want it to go straight up.

[Fe Dude]

All up with recovery gear and such my vindicator in SD mode (nose cone on top of the booster) weighed in at about 9.5 lb. it simmed out to about a thousand feet on a cti 4 grain ].

It would have gone up saturday if the winds had cooperated. I tend to go a little heavy on the glue, so 9.5 is probably on the heavy end of the spectrum. Yours will probably come out lighter. And hey, the at least the extea weight from the hardware is in the preferred location.


Sam

[MasonH]

Here are some more pictures of the nose cone assembly. I am following the build instructions from the Vindicator that I received. Enjoy!

[MasonH]

Ok, so I have an issue. I am ready to epoxy the bulkhead in place in the nose cone (the others are already sammiched together and ready for drilling for the av bay). I have the eye bolt with a nut and washer on each side of the bulkhead, and the back side is epoxied into place.

The problem is that the bulkhead is very loose inside the coupler. As you can see in the pics, there is a significant gap I would need to fill. The only solution I can find since the top is already glued into place is to epoxy the bulkhead far into the nose cone. It looks like it would have to be glued roughly 5" into the nose cone itself, plus the length of the shoulder. This is doable, as I have fairly small arms and hands. I would simply seal the already sanded shoulder with CA and epoxy the bulkhead in place with more sanding on the inside of the NC.

Is this something I will regret doing?

[crossfire]

Hello
What some guys have done is remove the nose cone metal tip stud and replace it with a threaded rod that runs full lenght of nose cone out the tip far enough to screw metal tip back on. Than you can use a nut on bulk plate end to help hold it in place. Tha bulk plate will not go anywhere. You could just seal the gap on the bulk plate. Or some guys will put bulk plate down in nose cone coupler for extra room.
Have fun it looks like your off to a great start.
Gary
TFRLLC

[MasonH]

Hello
What some guys have done is remove the nose cone metal tip stud and replace it with a threaded rod that runs full lenght of nose cone out the tip far enough to screw metal tip back on. Than you can use a nut on bulk plate end to help hold it in place. Tha bulk plate will not go anywhere. You could just seal the gap on the bulk plate. Or some guys will put bulk plate down in nose cone coupler for extra room.
Have fun it looks like your off to a great start.
Gary
TFRLLC

I am aware of this possibility, but was not anticipating a loose bulkhead. I already have the whole tip assembly epoxied in place, but the tip is still removable. This is why I cannot do the above suggestion.

[crossfire]

You could cut a new bulk plate out of plywood. I am useing a plywood plate on my Gizmo XL build in the nose cone.
GP

[MasonH]

You could cut a new bulk plate out of plywood. I am useing a plywood plate on my Gizmo XL build in the nose cone.
GP

I thought about that, and it can be done. I also thought that it would be easier, cheaper, and quicker to just mount the dang thing inside the NC.

[GRIFFIN]

I thought about that, and it can be done. I also thought that it would be easier, cheaper, and quicker to just mount the dang thing inside the NC.

you still can.....just slide it up into the cone until it gets tight. The higher up into the cone you put the plate, the more room you have for recovery gear, trackers and whatever else you want to put in there. I have one of my nosecone bulk plates half way up the nose for the same reason you have. Just my advice. No right answer here.

[gldknght]

That is a good idea! The problem for me is the weight. Even on a full I motor in SD mode, the thing only reaches 3000'. I am afraid that with all of the weight from the metal parts that this thing will not b safe to launch.

Only 3000'? in SD mode that's plenty. My DarkStar in DD weighed in at just a hair over 14lbs with motor, on my L2 cert in made to a whopping 1200'. I had to walk just about 300 yards to recover it. Flight was straight up.
Should I have used a bigger motor to get it higher? Why? it worked fine as it was. Just my penny's worth, fly what you want.

[MasonH]

Yes, only 3k on a FILL I motor. It goes about half of that on a small I motor, and about 600 feet on a mid-full H motor. The problem is that I am not willing to invest that much money into a full i motor. That limits me to about 2k feet. I am worried that if I put too much weight in the nose of the beast, then it will be too heavy and that I will end up breaking the bank. If I keep it light enough, I should still be able to get to a decent altitude on a smaller, less expensive motor. Basically, it is logistics at the moment since i don't have a real job yet, only a summer one.

That said, I have not made any more progress on the nose. I do however, have some free time today. I hope to get the all thread rods cut to length and the bulkheads drilled. This will complete the AV bay, minus the drilling for the rivets.

[eggplant]

Sorry if I misunderstood you, but there is no such thing as only 3000' in Connecticut. That is probably too high!

[MasonH]

Sorry if I misunderstood you, but there is no such thing as only 3000' in Connecticut. That is probably too high!

Connecticut?? Who Said anything about Connecticut?? LDRS is in New York this year my friend! And I plan to attend, and maybe even cert there!

[gldknght]

The problem is that I am not willing to invest that much money into a full i motor. That limits me to about 2k feet. I am worried that if I put too much weight in the nose of the beast, then it will be too heavy and that I will end up breaking the bank. If I keep it light enough, I should still be able to get to a decent altitude on a smaller, less expensive motor. Basically, it is logistics at the moment since i don't have a real job yet, only a summer one.

.

Oh, believe me, I understand about having a limited hobby budget. I wasn't meaning to insist you should use a bigger motor, quite the opposite. 1500' to 2000' on an apogee deployment is probably an ideal altitude in my opinion. 3k' could earn you a long walk.

[eggplant]

Oh, believe me, I understand about having a limited hobby budget. I wasn't meaning to insist you should use a bigger motor, quite the opposite. 1500' to 2000' on an apogee deployment is probably an ideal altitude in my opinion. 3k' could earn you a long walk.

Exactly my thoughts.

[JDcluster]

The Extreme version weighs a bit more than the DD version.
It has thicker fins; 1/8" vs 3/16" and a longer booster section; 48" vs 54".

If you only intend to go 1500' then: I sure hope you have a rather short recovery system. It may hit the ground before it fully deploys....

I haven't weighed mine properly but, I'm guessing it's 14lb+ without motor.
At the minimum on the Extreme I'd go for a mid sized J motor.

JD

[MasonH]

Ok, so yesterday I got some progress done. I cut the 24" section of 1/4" all thread I got from Lowes into two (2) 9" sections and a single 6" section. I also marked the positions for drilling on the bulkhead, and lined them up over the same eye bolt , as the instructions say. I hope to begin the drilling process tonight on the bulkhead. This will complete the AV bay, minus the fiberglass sled to hold the electronics. I will still need to drill the holes for the rivets and vent holes in the AV bay, but i can get the single vent hole in the payload bay.

Sorry, no pictures for now. I am at school writing this on my pal's laptop, and don't have them with me. I will post them tonight if/when i make more progress.

[Fe Dude]

Fast drill, light pressure. Tape and pressure to make sure nothing shifts around on you either. 8)

[gldknght]

The Extreme version weighs a bit more than the DD version.
It has thicker fins; 1/8" vs 3/16" and a longer booster section; 48" vs 54".

If you only intend to go 1500' then: I sure hope you have a rather short recovery system. It may hit the ground before it fully deploys....

I haven't weighed mine properly but, I'm guessing it's 14lb+ without motor.
At the minimum on the Extreme I'd go for a mid sized J motor.

JD

Unless I misunderstood, Mason is shooting for his L1, so kinda rules out a J motor.

[Stymye]

I did my L1 on a Loc ezi-65.. very simple cardboard plywood and wood glue construction.it was relatively low and slow and easily recovered intact
L1 done.

I did my L2 on the same rocket ... I added a bit of nose weight ..
it was a bit faster but still within sight range, and easily recovered intact.
L2 done

this thread is 8 days old .. anybody could have built ,took the test, launched, recovered , and received...an L2 cert in that time.
with a simple cardboard and wood glue rocket

just saying

fiberglass and dual deploy and days of analyzing is optional for L1 or L2

[gldknght]

fiberglass and dual deploy and days of analyzing is optional for L1 or L2

I'm chuckling about that. I must have flown my L2 rocket at least two dozen times on the computer before me actual cert flight. Necessary? Probably not, but me cert flight was almost anti-climatic. I knew exactly what it was going to do before the Lco pushed the button. The only what if was how far away and how tall that one tree downwind was. I cleared it by a good solid 25 feet.

[MasonH]

this thread is 8 days old .. anybody could have built ,took the test, launched, recovered , and received...an L2 cert in that time.
with a simple cardboard and wood glue rocket

I am aware of this. I also have high standards in school, scouting, and archery. These activities take up the week. I am also not allowed to build on weekdays. The weekend is usually devoted to spending time with my girlfriend, so there goes that. In all, I only get a few hours per week to build. I have a LOC Fantom that is almost done (just need some misc. parts 'cuz its not built stock) and THAT might be my level one. I am simply not sure, and I do not have all of the time I want.

[chadrog]

I am aware of this. I also have high standards in school, scouting, and archery. These activities take up the week. I am also not allowed to build on weekdays. The weekend is usually devoted to spending time with my girlfriend, so there goes that. In all, I only get a few hours per week to build. I have a LOC Fantom that is almost done (just need some misc. parts 'cuz its not built stock) and THAT might be my level one. I am simply not sure, and I do not have all of the time I want.

I think the Fantom would be a much better choice for a L1 flight. I flew my L1 on a LOC Lil' Diter, which is quite a bit smaller, with perfect results. Throw a baby H in there and you're ready to rock!

http://www.rocketreviews.com/locprec...kyle-yawn.html

Just my opinion, but I think you're really pushing it to fly the Darkstar on an I motor - I'm just getting started on a DS Extreme, which is not much different than yours, and kicking around the idea of using it for a shot at L3!

[gldknght]

I am aware of this. I also have high standards in school, scouting, and archery. These activities take up the week. I am also not allowed to build on weekdays. The weekend is usually devoted to spending time with my girlfriend, so there goes that. In all, I only get a few hours per week to build. I have a LOC Fantom that is almost done (just need some misc. parts 'cuz its not built stock) and THAT might be my level one. I am simply not sure, and I do not have all of the time I want.

Take your time and build as you want to. Contrary to what others may say, there's no rush or time frame for this to happen.

[MasonH]

THIS IS NOT OVER!!

I have been building slowly, as time permits. I have five rings on the motor mount, all epoxied in place. Four are up against the fin tabs, the other is to secure the shock cord. The nose cone is finished (no pics, sorry), the motor mount has been glued in, the fins roughed up and glued in, and I am about to put on the injected fillets sometime soon, I think.

I am also at my first point of trouble. I have never injected epoxy into fillets before, and want someone to walk me through it step by step, in addition to the instructions. I want to get this right the first time, since there might not be a second time.

The rocket, with the nose cone, comes in at right about 7 pounds. I hope to keep it light enough to fly on an I motor, and hopefully a relatively small-mid powered one at that. Income has been short lately...

[MasonH]

Sooooo.....I'm impatient. I decided to read the instructions CAREFULLY and tried the injection method of epoxy myself. I must say, I am proud of myself. I did as they said and did 5cc or epoxy per hole, and started with an aft fin, just to test it out. The epoxy formed a great fillet, and there is minimal running or any of it.

But that was with the small, aft fins. For the longer root edge of the front fins, will I need to use more than 5cc of epoxy per hole while injecting?

[blackjack2564]

NO.

The external fillets take the brunt of landing and flight punishment. Ya just add weight where you don't want it by adding more inside.