Darkstar DD Build Thread

[MasonH]

It has arrived!! Yesterday there was a very heavy box waiting for me when I got to my mothers work for the afternoon. It was the DS DD I have been waiting for!

I opened the box when I got home (yes, it was like Christmas again) to find LOTS of packing popcorn and the biggest, heaviest, most robust rocket parts I have ever seen.

This will be my first fiberglass rocket, so I will once again be looking to the masses for help. Assume I know nothing about how to build this, as I will need all of the help I can get.

Correct me if I am wrong, but I am aware that I will not be able to use the rocket in DD mode until I am certified level two and 18. I will still build the rocket DD, however.

So excited to start!!

 

[Pantherjon]

Correct me if I am wrong, but I am aware that I will not be able to use the rocket in DD mode until I am certified level two and 18. I will still build the rocket DD, however.

Dual deploy: Level 2 required? No..There is no certification requirement for flying dual deploy ..

Yes to being 18 to handle the black powder for the ejection charges and the motors for that matter..

 

[UPscaler]

As long as an adult sets up the BP charges and E-matches, there should be no problem with you flying it DD.

The very first thing you should do, put all the parts in the tub, this will get all the dust off the insides of the tubes, couplers etc. Then, sand everything that will be epoxied with heavy sandpaper (I typically use 60 grit). Use CA to tack the parts together, and epoxy for fillets. I highly recommend the injected fillet method, it's been done on our darkstars, so far the only one that hasn't flown is the ultimate, and they've been good! The fin can from my 2 inch DS fell from about 3000 feet and all it did was pop and external fillet.

Have fun!


Braden

 

[MasonH]

Just my luck. Pops has decided to start laying down new tile directly next to the tub, and nothing can get wet. This means that none of the FG dust will be going anywhere fast. I did, though, get some basic weight measurements. The rocket as a whole comes in at a whopping 149.6 ounces, or 9.18125 pounds. The kit in SD mode comes in at a mere 109.9 ounces, or 6.86875 pounds. If I am correct, this should be enough to get a level one certification with on an I motor. I have not gone into Rocksim yet to confirm this, but if it is true, I will need a much larger casing...so, who has a 54mm 1 grain laying around they want to let me borrow?

 

[eggplant]

Wildman had them for $40 at the sale if I remember correctly...

 

[MasonH]

Oh well. I am sure Al or Rick will let me borrow one of theirs for the certification if I need to borrow one.

 

[eggplant]

Are you ready to spend $50 on the cert flight? That is ironic that the rocket cost as much as two flights.

 

[MasonH]

Are you ready to spend $50 on the cert flight? That is ironic that the rocket cost as much as two flights.

I will be come spring! And the rocket costing as much as two flights only means hat I'll get my money's worth!

 

[KevinDunn]

Don't forget that CTI runs a cert special. For L1 you buy your cert reload and get the matching case free. For 54mm you need a closure (not included).

 

[Disaster_Guy]

Don't forget that CTI runs a cert special. For L1 you buy your cert reload and get the matching case free. For 54mm you need a closure (not included).

Interesting that you bring this up as I have been eyeing Wildman's website for his CTI Cert special. I am going to need a 54mm case for my L2 cert. Is this something that isn't specific to Wildman? (even though Tim will be the one I buy my stuff from if he is at Red Glare in April).

 

[MasonH]

Ok, so using the file i got from here I ran some sims on the SD version of the rocket. I simply deleted the part files for the payload bay, switch band, and coupler. This left the nose cone, BT, MMT, fins, and NC bulkhead. It sims out to around 1300' on a 29mm CTI I motor (can't remember which one) and a little over 2700' on an I540. This gives me plenty of room to play with, and it also means that weight is not as big of an issue as I thought.

I already have a 29mm CTI casing, so I am not sure whether I will simply get a longer casing of the same diameter, or go to CTI or Wildman for a cert. special. This is my only rocket with a 54mm motor mount, so a 38mm motor would allow me to use the casing in more rockets. The 29mm motor can fit in more rockets still.

So the question is: do I get a cert special on a 29, 38, or 54mm casing? Simply get a longer 29mm casing, or start out with a larger diameter? My wallet is not very deep at the moment, so logistics is a big issue right now. It might not be by spring, but I am not certain.

 

[Aksrockets]

The cert special requires you to purchace a motor beforehand. This means you have to be 18+ (unless you have an already certified adult). The best plan is to buy a motor at the launch site. I would go with a 38mm casing set. I wouldn't invent in 54s untill AFTER you are comfotable with L1 motors. A cti starter set is well worth the investment.

Also............................ I wants pichers!!!

Good luck,
Alex

 

[Fe Dude]

I can add in my suggestion for a 38mm starter set. I got one along with my L1 load, it ended up being more economical to do it that way, than to use the "cert special" and buy the other cases and spacers separately.

You could easily use a 54-38mm adapter and cram a hard hitting 38mm load in the pipe for your cert. I'll be doing something similar with my Vindicator DD here shortly (I'm planning on the 54mm starter set, they are just too good of a deal)

 

[MasonH]

Ok, so what I am getting from this is that the cert. special is out of the option. I also understand that the Pro38 is a good option, but I am still weary about that. I am not sure how much money I will have to spend on motors and casings after I get all of the hardware and recovery components I will need to complete the project.

I also ran some more simulations on the computer, and found that a small I motor gets this thing to about 1300'. And by small I motor, I mean a motor with about 400 ns, such as a Pro 29 6XL I motor. I have my mind on the I243 White. This motor is cheap enough, and all I need is the longer casing. I already have the DAT tool and 29mm adapter, spacers, and closure. I think that this will likely be what I go with, but I will have to build the rocket and THEN run more simulations with the rocket at the correct weight.

As for pictures, I have notorious problems posting pics to the forum. I will continue to try, but I make no promises.

 

[MasonH]

Ok, I am almost allowed to build. I havent actually BUILT anything yet because I am busy with my Eagle Scout project and the bathroom is being redone. However both are almost complete, so building should begin soon. I have a few questions though...

I noticed that the Rocksim file for the rocket had a switch band on it. However the kit did not come with one and it is not one of the parts listed on Wildman's website. Am I missing one? If not, should I cut a section of the payload (22" instead of the listed 20")?

I will probably start with the payload bay and avionics bay instead of the sustainer. I am assuming that since there is no switch band, that the AV bay is just held in place with rivets. I can't imagine gluing in the AV bay. If this is correct, how many rivets will I need? Three? Four?

Also, the kit only came with three rings for the motor tube...shouldn't there be four??

This is my first DD rocket, so please have patience with me.

Also, my high school has a 3D printer in the engineering room. Instead of getting metal tubing to hold the sled to the rails, I am planning to make a separate pair of sled guide that slides freely on the rails, yet holds the sled securely in place, both centered in the bay and screwed down to the guides. They will weigh less and will be positionable so as not to interfere with the wires and electronics. Drawings to come soon I hope...

 

[jsargevt]

I am pretty sure that the $99 DS 4's DO NOT come with a switch band - you can just do a half hole like what CJ outlines in his 4" Vindicator build thread.


I am sure that you CAN cut your own switch band too if that is how you roll.

Additionally, the $99 kits only come with 3 centering rings...you can make a tape dam for the 4th...as outlined in CJ's 4" Vindicator build thread.

I think that you only need 3 rivet holes...just use the fincan to mark the positions for them on the AV Bay. Again...check CJ's 4" Vindicator thread.

The Vindicator is basically the Dark Star with a different fin shape so that build guide ought to be extremely helpful.

The $99 kits are amazing deals but they are really bare bones - nothing wrong with that of course - but it helps to know about that when planning the build!

JS

 

[bill2654]

You need to cut your switch band off your longest BT.

 

[Aksrockets]

Feel free to email me pictures and I'll post 'em!

Alex

Aksrockets(at)Gmail.com

 

[Fe Dude]

No, the larger kit does not come with a switch band. You are supposed to use the half hole method like here

It goes together quite smoothly. Just take your time and make sure you hold the two sections of airframe together tightly when you drill the center hole. I wedged mine up against the wall and had tape over the seam with rivets in the rivet holes to keep everything steady.

Sam

 

[blackjack2564]

I noticed that the Rocksim file for the rocket had a switch band on it. However the kit did not come with one and it is not one of the parts listed on Wildman's website. Am I missing one? If not, should I cut a section of the payload (22" instead of the listed 20")?

I will probably start with the payload bay and avionics bay instead of the sustainer. I am assuming that since there is no switch band, that the AV bay is just held in place with rivets. I can't imagine gluing in the AV bay. If this is correct, how many rivets will I need? Three? Four?

Also, the kit only came with three rings for the motor tube...shouldn't there be four??

.

https://www.rocketryforum.com/showthread.php?t=29533

Much simpler to just use the 1/2 hole method here post# 58 than trying to cut a straight square 1in. section off a tube.


Your DS and the Vindicator are virtually identical other than fin shape. If you use these instructions all your questions are addressed & ya can't go wrong.

Mark your coupler and NC BEFORE doing anything else using slots in fincan for guide.

If you PM me your E-mail I can send you the actual Vindicator manual so you don't have to sift through all the noise in the build thread.


CJ

 

[MasonH]

Ok so lets bring this thing back to life, shall we?

I haven't had much time but there was a party at my house last night that I was not even invited to. I took the time to give the rocket a nice wipe down with wet rags. I wet, cleaned, and dried each piece twice.

After reading through the build manual for the Vindicator, I decided to start work on the Payload/Av bay portion. I have so far marked the coupler and then the payload bay for rivet positions. I hope that tonight I will find some time to drill the holes before archery practice.

Basically only a wipe down and making of the markings on the payload bay and coupler have been done. Nothing much has happened, but it is progress...

 

[Disaster_Guy]

 

[MasonH]

thank you for your :2:
Thank you, and I am aware of this. I have a chronic issue with posting pictures to the forum, so if anyone will care to host the pictures and post them for me, that would be much appreciated. Any takers?

 

[eggplant]

1. I will!
2. I will also try to help you get them up on your own. PM me!

 

[KenRico]

I am pretty sure that the $99 DS 4's DO NOT come with a switch band - you can just do a half hole like what CJ outlines in his 4" Vindicator build thread.


I am sure that you CAN cut your own switch band too if that is how you roll.

Additionally, the $99 kits only come with 3 centering rings...you can make a tape dam for the 4th...as outlined in CJ's 4" Vindicator build thread.

I think that you only need 3 rivet holes...just use the fincan to mark the positions for them on the AV Bay. Again...check CJ's 4" Vindicator thread.

The Vindicator is basically the Dark Star with a different fin shape so that build guide ought to be extremely helpful.

The $99 kits are amazing deals but they are really bare bones - nothing wrong with that of course - but it helps to know about that when planning the build!

JS

Smoking untouchable deal, and complete rocket. Had another order in play from the Wildman and grabbed a fourth centering ring for cheap - Thanks Tim. !

Kenny

 

[Aksrockets]

thank you for your :2:
Thank you, and I am aware of this. I have a chronic issue with posting pictures to the forum, so if anyone will care to host the pictures and post them for me, that would be much appreciated. Any takers?

Feel free to email me pictures and I'll post 'em!

Alex

Aksrockets(at)Gmail.com

...

 

[MasonH]

I did it! Not sure what I did or how I did it but I did it!!

 

[Disaster_Guy]

Excellent, glad it is working now. I really look forward to this build and will be doing one myself soon.

BTW, I do hope you know that I was just bustin your chops over the pics because this should be a great build to follow. :headbang:

 

[MasonH]

Excellent, glad it is working now. I really look forward to this build and will be doing one myself soon.

BTW, I do hope you know that I was just bustin your chops over the pics because this should be a great build to follow. :headbang:

Haha no problem, I would have done that too. Good luck on your build! I hope mine can provide a little help if you need it!

 

[cbrarick]

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 :y: 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