Dynacom 4.1" Scorpion Build Thread (bonus Python data too!)

Dan,

I was hoping to check the Scorpion out this weekend at the field. I always enjoy watching your builds. You managed to take a kit that was top shelf back when it was made and bring it to a level that rivals some of the kits being produced today.

Mike Crupe
MAC Performance Rocketry
FLY CANVAS!

As far as fit and quality I think Dynacom still is king over kits produced today. Eric would not let a kit out the door unless all parts fit perfect.

First set of fin fillets have been applied. RocketPoxy is the adhesive of choice, no pigment added as it thins the epoxy a touch and causes it to run. Fillets were pulled using a piece of 7/8" diameter Delrin using the tape method that has been in use since the time of Dynacom, inventors unknown and numerous.



I used some leftover RocketPoxy to fillet the nosecone bulkhead that is epoxied in. This is a tough one to do neatly, so I sloshed it in there and used a craft stick to filletize it. Not pretty, but I plan to go back and clean it up after the epoxy sets up a tad.

Looking fantastic, Dan! As it gets closer to completion, I grow more jealous. Really nice looking Scorpion!

-Eric-

ECayemberg said:

Looking fantastic, Dan! As it gets closer to completion, I grow more jealous. Really nice looking Scorpion!

-Eric-

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Thanks Eric. It has been a very enjoyable build. It has gone exactly as I expected without any surprises. Just a really nice design with great workmanship and completeness.

I have one more set of fillets to complete before Saturday. That will mean the rocket is 100% complete structurally and only requires finishing work. Electronics are a different story, I have plenty to do there!

Enjoying the build Dan, please keep the updates and pics coming.

rfjustin said:

Enjoying the build Dan, please keep the updates and pics coming.

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Thanks Justin. The internet will never be void of Dynacom information again! I plan to start another thread focusing on the rebuild of my Python as well.

Laid the last set of fin fillets today. Here's a picture with my grandfather's level showing that the fillets should be nice and symmetrical! Rumor has it he used this level while building his first home back in the 50's. My son will get it some day!



Here's a look up the tail pipe to show all of the work done. Here you can see the body tube, canvas sleeves, motor retainer, AeroPack adapter, plus the FWFG spacer and spiral retaining ring. Because I can't use the AeroPack aft retainer plate, I had to tape the motor case just in front of the adapter thrust ring to keep it from sliding out. The motor is actually loaded with four Plain Jane propellant grains and the motor will be a K650. Should be a nice first flight.

DanP said:

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Beauty!

dhbarr said:

Beauty!

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Thank you! Lots of concentricity in that picture.

It appears that the launch this weekend will be canceled. It looks like there's no rush to finish this rocket after all. That said, here's some full-up pictures.

Outside in the driveway (need to bury/hide that ethernet cable one of these days...)



On my dirty-ass basement floor:



I wish I lived near train tracks so I could take elegant pictures like Eric C.!

Electronics bay is done and wired! There's a lot going on here and I don't really feel like explaining it all, so here's the basic run down:

• All wires are stranded and tinned
• The two switches are from www.missileworks.com
• 2S 1000mAh battery for the Aim XTRA (currently discontinued, but here's the same battery with a new connector: https://www.sparkfun.com/products/11855)
• 1S 400 mAh battery for the Perfectflite (https://www.sparkfun.com/products/10718)
• The batteries are at the bottom, with the Perfectflite battery held in high-density foam

It all fits! Time to program everything as previously described, wire up some e-matches and make sure all of the circuits are correct.





After the first flight I will be installing some of APE RC's screw switch locators.

DanP said:

Electronics bay is done and wired! There's a lot going on here and I don't really feel like explaining it all, so here's the basic run down:

• All wires are stranded and tinned
• The two switches are from www.missileworks.com
• 2S 1000mAh battery for the Aim XTRA (currently discontinued, but here's the same battery with a new connector: https://www.sparkfun.com/products/11855)
• 1S 400 mAh battery for the Perfectflite (https://www.sparkfun.com/products/10718)
• The batteries are at the bottom, with the Perfectflite battery held in high-density foam

It all fits! Time to program everything as previously described, wire up some e-matches and make sure all of the circuits are correct.

After the first flight I will be installing some of APE RC's screw switch locators.

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Maybe you will have enough time for that yellow and black paint job. I will be doing a yellow/black paint job using the Dupli-color pant shop system in the next few weeks, but with the matte finish. Looking forward to seeing your first launch report and hopefully some video. Will you have any on-board video?

mpitfield said:

Maybe you will have enough time for that yellow and black paint job. I will be doing a yellow/black paint job using the Dupli-color pant shop system in the next few weeks, but with the matte finish. Looking forward to seeing your first launch report and hopefully some video. Will you have any on-board video?

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Sounds like you'll be doing it correctly. I'll just be spraying a bunch of Rustoleum Primer, wet sand it, then spray on a bunch of Rustoleum Safety Yellow. Follow that up with some Nu Finish and I'll call it a paint job.

Launch was rescheduled to this coming weekend and I was actually able to get someone to watch our son. Assuming the weather is fine, the Scorpion will go up on the K650 Plain Jane.

wow , great jop man u are pro

The launch that was canceled last weekend was moved to this coming Saturday and I was able to get my mother-in-law to watch our son so I can get a day out at the field! The Scorpion is back on the clock with only prepping to go.

Here is a picture of the aft (apogee) bulkhead of the altimeter bay with e-matches installed. This shows how I do this and it's as simple as applying small piece of masking tape to the OD of the canister to make sure that the match head stays securely in the bottom of the cavity. The wires are clipped, stripped, folded, then clamped in the terminal blocks. The "A" designates the Perfectflite Stratologger CF, while the "B" designates the AIM Xtra 2.0.



Here's the fore (main) bulkhead. This shows my method to protect the rubber duck antenna that protrudes out of the bay. The sleeve is just the pant leg cuff from a pair of Nomex pants that firemen wear. I cut the cuff off just above the hem and it leaves a nice sleeve that slips over the antenna and is taped at the end to seal it off. Huge thanks to Tony A. for providing me with a lifetime supply of these cuffs!



The next picture shows how well this method works. This is the sleeve and antenna from my Old School Cool rocket, a 54mm FWFG sport flier as mentioned before. The antenna sticks into the bay in the same manner as this rocket and is in close quarters to the main deployment charge. The sleeve and antenna shown have endured 6 flights and the antenna shows little to no sign of damage (the brass fitting has lost its sheen, but the plastic antenna is fine).



Last but not least, here's the fully prepped aft bulkhead. I weighed out the BP for this rocket. For the apogee deployment I am using a 2.0g primary charge and a 2.6g backup charge. For the main deployment I am using a 1.7g primary charge and a 2.8g backup charge. I want to make sure that main gets out of there...



Next up is the launch! No need for recovery prep pictures, there's plenty of those out there.

That is one fine looking avionics set up. Good luck on the flight Dan.

Dan isnt around here anymore, so there arent going to be anymore posts in this thread.

SinfulDarkLord said:

Dan isnt around here anymore, so there arent going to be anymore posts in this thread.

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Strange, he posted to the forums yesterday???

Ban, tragedy, or just "Over it"?

Ban


Again

Really? WTH?

I must not be reading the "fun" posts lately, because there are at least 3 members I like and respect that are currently banned.

GRIFFIN said:

Ban


Again

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If it has anything to do with his question about the Dynacom.inc removal , I will be very disappointed . I think , no , I strong believe the mods need to speak up . I see the use of trolling all to often . I was banned for the same reason last time I asked a legitament question .

3stoogesrocketry said:

If it has anything to do with his question about the Dynacom.inc removal , I will be very disappointed . I think , no , I strong believe the mods need to speak up . I see the use of trolling all to often . I was banned for the same reason last time I asked a legitament question .

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It's a sad state, when real forum contributors are banned...

It honestly makes me feel like I shouldn't even do a build thread on my Mach 2 capable Mac performance 3 fins and a nose cone rocket. I am not trying to troll , I am not trying to start a war , I'm not trying to do anything negative , or give bad influences towards the fourm. I just strongly believe some of the moderators sometime overtake and overstepped their boundaries. If there was a separate reason that Dan was banned ,and I'm going to talk to him tomorrow when I see him and find out his side of the story , please inform the general public so we " adjust " ourselves to follow the rules better . If the sole reason for his ban was trolling because he asked a legitimate question , wouldn't anybody who mentions a dealer in any one of their posts be elgible for a ban? It's been a good 20 year ride in HPR for me . Darrell was the man and forms like his sank the hook hard in me . Stuff like this severs the line . I am not making any personal remarks , all of the mods work hard , no ill felling towards anybody .

Eric
TRA 9638
LVL 3

WHATT!!!???

Speak up moderators. Please explain what looks like a heavy handed application of the rules by someone who isn't an actual rocket guy.

It is not fun being a moderator sometimes- it really is not. That said, I have really have not seen anything here lately that I thought would merit banning anybody. Now, I could have missed it, and I totally admit that.

This is another example of why I am glad I said no when Troj asked me to be a Mod.

Keep moderating folks for little reason and folks will be driven away. I know- I speak from experience.

Seems to me lately that the rules are really being broken and made up as we go along.

Moderation is fine, as long as it's done based on the rules and not from someone's biased opinion.

Someone had a post pulled today and a warning given for something that wasn't breaking ANY rules. This entire Forum has gone in a bad direction lately and I wish there was a way to get the traffic to see that and make a shift in another direction.

GRIFFIN said:

Seems to me lately that the rules are really being broken and made up as we go along.

Moderation is fine, as long as it's done based on the rules and not from someone's biased opinion..

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This... Some months ago, a moderator expressed his opinion on a subject and in the same post closed the thread... It appeared to me that in his opinion, "his contribution to the content was all that mattered and no response to his post would be appropriate or allowed"... IMO, if a moderator believes a post has run it's course or posting content is not appropriate and, "locking down the thread is the fix", then the proper moderator comments should be limited to those comments that indicate the reason for shutdown, with out adding subject content...

That being said, moderators are necessity for any well run forum but, as Griffin indicated, should be done within the context of a specified set of rules... Not doing such is nothing more than arbitrary and capricious moderation and IMO will drive folks away...

Interesting now "DanP" isn't even showing up in the members list. I've been banned before, but I was still on the members list.

dixontj93060 said:

Interesting now "DanP" isn't even showing up in the members list. I've been banned before, but I was still on the members list.

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Pm me if anybody would like to discuss this . Doing so publicly will put my future here in limbo .

3stoogesrocketry said:

Pm me if anybody would like to discuss this . Doing so publicly will put my future here in limbo .

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I think it's been made clear anyone who deviates from the marching orders around here has their future in limbo. " Family Forum, All friendly, no debates, and support the chosen vendors" Step away from any of that...and you'll run into trouble.