Workbench 2.0, Two-Stage 100K+ Build Thread and More

The test fin I made on Wednesday turned out not so great as expected. The Mylar didn't follow the airfoil angle at all, it just followed the outside of the fin.


So instead I did 3 layers of Cotronics by brushing on and removing excess with a foam roller. I moved the Cotronics back about 1/16" further back from the fin edge with each layer (started at 1/8"). I decided to just bite the bullet and do it all in one evening which wound up keeping me up till 5am - sanding, marking, masking, 1hr partial cure in the oven @ 150F .... Repeat. Topped off with a wipe of HTR 212.


Came out pretty nice. Tonight I am going to bake this stage for a while at 200F to post cure the Cotronics. This puts me on track to paint the stage this weekend.

I am going to leave the booster alone. It flew fine last year and I don't plan on ever pushing it faster.

Forgot to swap out my PVC stand for wood when going to higher temps. Whoops. Rocket handled it fine.

Kip_Daugirdas said:

So instead I did 3 layers of Cotronics by brushing on and removing excess with a foam roller.

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It looks like you done good.

One other problem with the built up leading edge is that every once and a while, you can get a perfectly aimed strike from, say, a heavy fiberglass bulkhead/coupler flying through the air

For that, another pint of glue ....

Jim

JimJarvis50 said:

It looks like you done good.

One other problem with the built up leading edge is that every once and a while, you can get a perfectly aimed strike from, say, a heavy fiberglass bulkhead/coupler flying through the air

For that, another pint of glue ....

Jim

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Ah that's gotta suck! I'm still surprised my sustainer didn't chip or lose a fin coming in at 50 fps with a loaded motor last year!

It didn't rain in Utah all summer then the world's most pathetic rain shower decided to show up right over my house between the 2nd and 3rd coat of Rustoleum high heat.



Caught it in time and threw it under the porch awning. All is good. On Monday I will do wet sand with 400 grit and add the final coat.

I didn't use any primer as the high heat primer requires a post cure. The high heat grill paint doesn't need one but there isn't a primer for it - weird. Oh well it turned out looking great and I'll treat these first few light coats as the "primer".


The tube is white again!

Alright, I am reprogramming the Easy Mega from last year. A recent change of plans is switching to an N2500 in the booster (no appreciable change in altitude) - it just has more kick off the pad than the Aerotech. If I get the opportunity to fly twice (doubtful), I'll use the N3300.

I've spent a lot of time messing with sims and decided to stage at 14 seconds allowing 2.5 seconds for the motor to come up to pressure. I will be around 15k, traveling at 730 ft/s.

Attached is a pic of what I have my Easy Mega set to. The redundant mega will be identically setup minus some timing delays so charges don't interfere with each other.

Let me know what you think!!!! (Seriously speak up!). Thanks!



- Main deploy at 2000m incase I'm over mtns

Pyro A, second stage ignition: above 3000m (10,000 ft), less than 20 deg from vertical and T+14

Pyro B, if the second stage doesn't light this is my backup apogee below 85k

Pyro C, Apogee given a good flight uses a timer at T+99 seconds

Kip_Daugirdas said:

View attachment 301880

- Main deploy at 2000m incase I'm over mtns

Pyro A, second stage ignition: above 3000m (10,000 ft), less than 20 deg from vertical and T+14

Pyro B, if the second stage doesn't light this is my backup apogee below 85k

Pyro C, Apogee given a good flight uses a timer at T+99 seconds

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I found an error!!!! Time for Pyro C should be greater than. I find it helpful to take screen shots of every setup then review them line by line. That goes along with taking pictures as you prep.

Kip_Daugirdas said:

Mark thanks for the data point this kind of stuff is very useful! What got abraded bad the paint or the Cotronics? What altitude did the rocket hit M 2.9? Fin thickness? I think this info will really help peeps designing. Thanks in advance!

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Question: Is the post curing for the Cotronics 4525? Says it will cure at room temperature. Is it to speed up the process or is an elevated temp cure procedure going to add some characteristic to the final product?

I've used it mainly in some builds where I was interested in the strength and durability of the 4525. Not bad fillet material but can't disturb it as it will get distorted during the cure process. I've use an out of production epoxy that I could pull the tape
and hit it with a heat gun to get it to reflow. Was nice to work with but was heavy and is out of production anyways. (PowerPoxy Weld)
With the 4525, I apply it quickly after mixing, smooth and pull the tape after 15 minutes. Longer wait if the shop is cold. Carefully hit the edges with a heat gun to see if I can get them to reflow a bit then done. CANNOT touch the fillet as it will get distorted and there is no going back until the cure is complete.

Proline 4500 is nice but doesn't have documented specifications like the Cotronics products so I wouldn't use it on something like you are trying to achieve. Kurt

ksaves2 said:

Question: Is the post curing for the Cotronics 4525? Says it will cure at room temperature.

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This was my first time using 4525. I'm just following Mr. Jarvis' lead. He said that it can be brittle if you just do a room temp cure. The sample fin I made I didn't post cure and sure enough it was brittle.

I post cured the Rustoleum grill paint too at 190F for 4 hours.

Kip_Daugirdas said:

This was my first time using 4525. I'm just following Mr. Jarvis' lead. He said that it can be brittle if you just do a room temp cure. The sample fin I made I didn't post cure and sure enough it was brittle.

I post cured the Rustoleum grill paint too at 190F for 4 hours.

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Here is the manual on their epoxies. Page 2 gives the specifics: https://www.cotronics.com/vo/cotr/pdf/Cotronics_InstructionalHandbook_Web.pdf Lists 16 hours for the 4525 or 5 minutes at 250F.
When one gets to the 600 to 700F products a 250F cure is mandatory for 4 to 6 hours.

I do believe there may be some liquefaction that may occur with the 4525 as long as the heat is applied early and not at 250F. That may allow for more soaking and penetration of the material for better adhesion.
Go 250F and they say it's fully cured in 5 minutes. I think the big thing is accurate measuring by weight and thorough mixing to avoid an inferior bond.

The old PowerPoxy Weld I tried some years ago did not have the temperature resistance but boy oh boy, one could reshape a fillet at least two or three times with application of a heat gun.
I did an autopsy of an unintended ballistic 4" ballistic rocket that was beyond salvage and the PowerPoxy fillet of course ripped off the cardboard fincan but I could not remove the epoxy fillet off
of the 1/4" plywood fin without using a chisel. I would have thought I could snap it off with my thumb but no way. The 40 grit gouging with sandpaper and heat reflowing of the epoxy
really allowed it to soak in and adhere tremendously well. Enough of my glue blubbering. Best of luck on your project. Kurt Savegnago

I heard this was hugely successful. N3301 booster with M685 sustainer at BALLS?

watermelonman said:

I heard this was hugely successful. N3301 booster with M685 sustainer at BALLS?

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Heard the same....with crazy altitude

It just kept going up...

Top Speed: 2183 mph (Mach 3.4) @ 39,000 ft
Tilt at staging was ~10 deg
Time to apogee was 105 seconds
Apogee per GPS: 145,253 ft

It wasn't a perfect flight and I was lucky to recover. More on that later but I'll give you a hint: Easy Mega issues - again. The motors were a CTI N2500 -> Aerotech M685.

Maybe not a perfect flight, but impressive nonetheless. 145000' with recovery is a win in my book. Congratulations.

Kip_Daugirdas said:

To about 145,000 ft or so...

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Congrats sir, well done!

markkoelsch said:

Maybe not a perfect flight, but impressive nonetheless. 145000' with recovery is a win in my book. Congratulations.

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Anytime you fly that high and get everything back with minimal damage it is a very impressive win! Congrats.

I remember BALLS 2005 and watching one go up to slightly 100,000 ft. It was a unique thing at the time because only 1 or maybe 2 flights had achieved that beforehand. Now, it seems like there's a few every year that are doing it will far less impulse and more sophisticated builds. I look forward to seeing your next project!

NateLowrie said:

Anytime you fly that high and get everything back with minimal damage it is a very impressive win! Congrats.

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Thank you! The sustainer got pretty banged up. I still have to tear it down and inventory what's reusable. I plan on just sticking with this design and perfecting it before moving any bigger.
I plan on rebuilding the sustainer airframe (and possibly making two copies while I'm at it). Having CADed everything up and made CNC code for all the parts will make rebuilding not too bad.

NateLowrie said:

Snipped
I remember BALLS 2005 and watching one go up to slightly 100,000 ft. It was a unique thing at the time because only 1 or maybe 2 flights had achieved that beforehand. Now, it seems like there's a few every year that are doing it will far less impulse and more sophisticated builds. I look forward to seeing your next project!

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"If I have seen further than others, it is by standing upon the shoulders of giants." - Isaac Newton .

Easy Mega issues - again.

Do tell. Problems with apogee deployment detection? I've heard that can be challenging for flights that go that high.
Only people who've seen those heights "live" are astronauts, some X-15 pilots and spaceship1 pilots.
Oh yeah there was some question of a super secret aerospaceplane project boosted up with an "XB-70 like"
mothership but that may have been disinformation. Anyways those fliers could be lumped in the astronaut
appellation. Kurt

MClark said:

"If I have seen further than others, it is by standing upon the shoulders of giants." - Isaac Newton .

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Hell ya Mark! I couldn't have done this without the help of those who have flown before me. Forum threads on this site like Jim Jarvis' and Aeropac's 100k write up have been really helpful. I hope what I post here will help and inspire others to fly even higher!

On another note my clutch died after getting to Fernley...

Kip_Daugirdas said:

Hell ya Mark! I couldn't have done this without the help of those who have flown before me. Forum threads on this site like Jim Jarvis' and Aeropac's 100k write up have been really helpful. I hope what I post here will help and inspire others to fly even higher!

On another note my clutch died after getting to Fernley...
View attachment 302340

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Ouch, sorry to hear that. In 2006, I blew 3 tires because I thought it would be a good idea to take the 80mi gravel road shortcut from the playa into lovelock. I'll never do that again. The Playa is hell enough on vehicles.

Hey Kip, fantastic results and I appreciate your openness and willingness to continuously improve the design and your build techniques. Does anyone have the project document for the Aeropac 100K project? I cannot find it on this forum or through Google, except behind a pay-wall at Scribd.

Cheers

Shannon

rugger09 said:

Hey Kip, fantastic results and I appreciate your openness and willingness to continuously improve the design and your build techniques. Does anyone have the project document for the Aeropac 100K project? I cannot find it on this forum or through Google, except behind a pay-wall at Scribd.

Cheers

Shannon

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Same here. I've had it previously, but I think something is wrong with where it was posted/maintained as I can't find it now.

Here's a link to the AeroPAC 100k documentation. https://www.dropbox.com/s/40l71mcpeg03cah/AeroPac 2012 100k' Program Report.compressed.pdf?dl=0
I'll alert them that their website no longer functions.

NateLowrie said:

Ouch, sorry to hear that. In 2006, I blew 3 tires because I thought it would be a good idea to take the 80mi gravel road shortcut from the playa into lovelock. I'll never do that again. The Playa is hell enough on vehicles.

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Jungo Road, a lot of tires have failed the test of driving it. A few years ago a day apart two cars were brought in totaled is single car wrecks on Jungo Road.
Playa damage can have a long reach. We drove off the playa Thursday in the rain, on the way home Sunday near Hawthorn a head size chunk fell off. The guy who had been tailgating me for 50 miles became sad.

M

Kip_Daugirdas said:

I downloaded everything from the sustainer tonight. Note that the apogee charge did not fire - I still have to delve into why. The main deployment, set for 10,000 ft, saved the rocket from becoming a permanent Nevada resident. Sustainer avionics are all okay but the airframe is trashed.

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That is awesome. What was your charge canister configuration for apogee? Did you test it in vacuum?

Also, how did the Av Bay configuration hold up?

NateLowrie said:

That is awesome. What was your charge canister configuration for apogee? Did you test it in vacuum?

Also, how did the Av Bay configuration hold up?

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All charges were extensively tested. Cannon charge 1.00g, T-charge backup 1.25g. Both had continuity throughout flight. The T charge is gone from the violent deployment but the cannon still has continuity.

I did have channels B and C spliced into the same ematch. I didn't want 4 sets of ematch wires running through my recovery bay. To test this, I fired several ematches with the Easy in this setup using the 'Fire Igniter' tab in the software - worked every time. Perhaps I needed a diode??

Also when I watch the on-board I can hear the Easy beep once at 99 seconds and the backup easy at 101. But obviously nothing happens. I'll be contacting Altus today.

The avionics bays suffered little damage and all of the electronics appear to be okay. One of the GoPros got its lens chipped.

The 75mm motor casing is dented along with the rear closure.

All in all not bad for such a late deployment and landing on rocks...

Hey Kip,

Just wanted to say "Great Job" buddy! That's an amazing accomplishment....I'm jealous! Nicely done and well executed...hope you get the apogee deployment down next time...in the meantime, dude, you just recovered from well over 100k'!

Cool.

-Eric-

Kip_Daugirdas said:

All charges were extensively tested. Cannon charge 1.00g, T-charge backup 1.25g. Both had continuity throughout flight. The T charge is gone from the violent deployment but the cannon still has continuity.

I did have channels B and C spliced into the same ematch. I didn't want 4 sets of ematch wires running through my recovery bay. To test this, I fired several ematches with the Easy in this setup using the 'Fire Igniter' tab in the software - worked every time. Perhaps I needed a diode??

Also when I watch the on-board I can hear the Easy beep once at 99 seconds and the backup easy at 101. But obviously nothing happens. I'll be contacting Altus today.

The avionics bays suffered little damage and all of the electronics appear to be okay. One of the GoPros got its lens chipped.

The 75mm motor casing is dented along with the rear closure.

All in all not bad for such a late deployment and landing on rocks...

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Wow, quite a ballistic curve you got there. The harness maker and the materials deserve kudos. So both the primary and backup apogee charges resulted in no event? Whoooo heeeee. Main chute didn't shred? Kudos to the chute maker too!

Will be interesting what Keith and B'dales input would be about the apogee situation. Might be a simple remedy for the next time.

Perhaps bench test the channels in question to see if they are still functional in a standard operation condition of one ematch (or LED) on each channel. If one or both don't work, it's obvious that setup should be avoided in the future.

I call this a breath taking achievement.:smile: Kurt Savegnago

Pretty serious altitude Kip , yes and to recovery , still quite an accomplishment! Hope you can figure out what happened.