MAC Hyper 54 L2 cert build

[Andrew_ASC]

Continuing on from these threads for advice. This is my yearly 2019 goal/rocketry project. Due to an ongoing job search for mechanical engineering jobs/interviews this won’t be finished quickly until finances improve. I’ll go ahead and start the thread to give others an insight into these awesome kits. This is my first kit from MAC and impressed at part fitment is an understatement.

https://www.rocketryforum.com/threads/minimum-diameter-for-l2-cert.150047/

The build plan,
Motors:
Aerotech J-250W DMS
Tracking:
TeleGPS (primary)
Telemini V3 (secondary RDF)
Altimeters:
Telemini V3 (primary dual deploy altimeter)
Perfectflite StratologgerCF (back up dual deploy altimeter.)
Recovery:
Two OneBadhawk 3/16” Kevlar harnesses x 20-25ft and two to three loop.
Two quick links.
IRIS fruity chute 24” drogue as main. (High drag coefficient)
Top flight recovery 9” thin mill nylon chute as drogue.
Nomex.
MJG firewires and deployment ejection charges.
Launch accessories:
Additive aerospace 54mm FARG

 

[Andrew_ASC]

MaxQ Fincan installation. Dry fit the fastback 54 motor retainer to the airframe. Slide the fincan plate to the retainer. Insert fins and tighten the trailing and leading edge screws. Alignment is critical to not cross thread parts. Once these are in your on easy street. There may be slight profanity involved at first. There are 21 set screws. Alternate screw positions.

The coolest thing is no one will say your fillets suck on a Hyper 54 because it has none. Fins are beveled. The fincan is removable. Do not paint under the fin can as alignment is critical and the fincan fits extremely snug when all set screws are torqued with included Allen key.

 

[Andrew_ASC]

Sand where the fastback 54 motor retainer fits on. I used 60 grit and 150 grits. The instructions specify JB weld at 80 grit.

 

[Andrew_ASC]

Then I had this thought Oh Sh*t I so don’t want to permantly JB weld a fincan designed to be removable into the retainer with excess epoxy drippings.

So I loosened all 21 set screws and cleaned up the mess with alcohol and paper towels then slid the fin can up.

 

[Andrew_ASC]

While waiting for the JB Weld to cure I peeled the protective tape off.

 

[roytyson]

View attachment 373356 Continuing on from these threads for advice. This is my yearly 2019 goal/rocketry project. Due to an ongoing job search for mechanical engineering jobs/interviews this won’t be finished quickly until finances improve. I’ll go ahead and start the thread to give others an insight into these awesome kits. This is my first kit from MAC and impressed at part fitment is an understatement.

https://www.rocketryforum.com/threads/minimum-diameter-for-l2-cert.150047/

The build plan,
Motors:
Aerotech J-250W DMS
Tracking:
TeleGPS (primary)
Telemini V3 (secondary RDF)
Altimeters:
Telemini V3 (primary dual deploy altimeter)
Perfectflite StratologgerCF (back up dual deploy altimeter.)
Recovery:
Two OneBadhawk 3/16” Kevlar harnesses x 20-25ft and two to three loop.
Two quick links.
IRIS fruity chute 24” drogue as main. (High drag coefficient)
Top flight recovery 9” thin mill nylon chute as drogue.
Nomex.
MJG firewires and deployment ejection charges.
Launch accessories:
Additive aerospace 54mm FARG

Hey Andrew, good luck on the build. Another point of view (mainly mine), you have options to save quite a bit of money.
DMS- Good call
Your altimeters, you have a lot of options. You can go Eggtimer (even if you pay someone to assemble them) and strattologger as we have discussed. Way cheaper.
You can get an all in GPS from Eggtimer for less than $200. I have been running them and never had issues in any of my stuff. My max alt is 11000, and have found rockets over 1.5 miles away.
Fruity Chute? Only if I win the lottery and need to burn money. Im sure they are nice, I just can't see it. Get a nice Rocketman or Thinmill Topflight.
MJG, get you some wildman ignitors. Never had an issue with them.

i am not one to tell anyone how to build or spend their money. Its yours and there are a hundred people that can poke holes in all my builds. Just some thoughts I had when you mentioned finances.

Good luck!

 

[mpitfield]

Hey Andrew, welcome to the MAC clan. Mike's kits are addictive. I like your choices so far, not the least expensive way to do it but they are all solid choices. I think you made a good call on not permanently adhering the fincan to the airframe. This will make things easier in the event you need or decide to do maintenance or modify something down the road. What decent rate are you targeting with that 24" Iris? I wasn't aware that Gene was producing a 24" Iris, I thought 30" was the smallest.

 

[Andrew_ASC]

The TeleGPS and Telemini V3 I already own. I already have a fruity chute on a quick link on my L1. I’ve been using their ultra compact drogue that you can get from Apogee. They directly sale via fruity a 12” but not from many vendors (SEDS trick). I’m targeting a 25-32 FPS descent rate J-L. I already own a 9” TFR chute. The higher descent rate will be for a Loki L1040 or equivalent L motor eventually. Instead of stressing about money I will take my time with this project. Mainly I need shock cords, a stratologger, motor, and switches to complete this project.

Pending an entry level position or even a internship I could have the funds to finish it in a week.

 

[Andrew_ASC]

This is the .ORK I'm working with currently. I've made some changes to the one MAC published for the kit. One of the coupler lengths was dead wrong, the av bay band was outright missing, and the retainer wasn't modeled. The fincan mass was so wrong, the fins were CF and wrong thickness, and the chute mass was so far off.
Oh and the nosecone was Ogive while the actual is a Von Karman. So a bunch of technical details out of the way here's the corrected file, lol. I'm proud it closely matches mach numbers people are reporting from flights up to L motors. Altitudes match up to K motors, the L's are getting wonky (overpredict L1040).

 

[mpitfield]

the L's are getting wonky (overpredict L1040).

Having simed the L1040 in both OR and RS for a 54 mm MD CF rocket I had similar "wonky" sims. RS said 19k and OR said 24k.

Ultimately the rocket hit 23k and that was with a good 5° launch angle and into a medium wind. Adjusting for the wind and launch angle I estimated that OR was not as wonky with the L1040 afterall.

Out of all the Loki 54 mm loads, and I have launched them all several times except the 2050, the 1040 was the one sim that I had the least amount of confidence in.

So your sim may be off, but if it ended up being close it wouldn't surprise me either.

 

[gtg738w]

That’s a great looking kit, congrats! Good luck with it-

 

[Andrew_ASC]

Here is the snap ring and spacer for AT/CTI cases on the Fastback54 retainer.

 

[Andrew_ASC]

Tossing some compressible gas dynamics knowledge at the Hyper 54 for epoxy selection. Prediction is 572.63 degrees Fahrenheit with a Loki L1040 shoved up the tailpipe. Guess I’ll want to order some Cotronics 4525 IP. That aluminum nosecone tip should soak some heat up. Might Rocketpoxy the Av bay band. I’ll sleep on it. Concerned of thermal loadings on nosecone coupler although the thermal loadings are brief.

 

[GalantVR41062]

I have a 2.2" MC Tomach MD project. I simulated a Loki L1040 (6.5lb motor) in the 3.5lb rocket and did have an issue with the decent weight, and space for the main. I like to have 15'/s or less for certification flights.

I was looking at the 48" Iris ultra light from fruity, but settled on a 58" thin TFR chute for the main, and I have a TFR 18" ultra xtype for a drouge.

I was hoping decent rates on the Loki L1040 would be 16-18'/s under main. But the thin fiberglass fins may not hold up to such abuse. I might pick up some thicker WM BH fins, or these MaxQ fin cans look sweet.

Any idea what the final build weight will be? How do the sims look for the DMS cert attempt? Any plans to fly it on some L1 38mm motors first to get the bugs worked out? Study for the test, ground test, and good luck with the cert flight.

~John

 

[Andrew_ASC]

Any idea what the final build weight will be? How do the sims look for the DMS cert attempt? Any plans to fly it on some L1 38mm motors first to get the bugs worked out? Study for the test and good luck with the cert flight.

1. Final estimate build weight no motor is 1594 grams or 3.5 pounds. My L-1 was 2.76 pounds empty on same chute and lands at 23 FPS and It was fiberglass.

2. Sims for J-250W DMS motor 26.6 FPS descent rate, 6850 ft Apogee, 53 FPS off of launch rail. 2302 grams loaded. Stability 2.6 cal.

3. Thought about a L1 54mm I229T, but undecided atm. Rail exit velocity over min. Stability fine.

As far as descent rates 25-32 FPS I don’t think I’ll hurt the tube or the fincan to be honest. It’ll minimize drift. Open to tweaking things as I see fit. I know an IRIS 24” drogue fits in a 54mm airframe from experience.

 

[Nytrunner]

Pending an entry level position or even a internship I could have the funds to finish it in a week.

Don't blow it all on the rockets though. A few years ago I was in a similar position as you, and got some very good advice from my hiring manager: "Pay your future self first"

As paychecks come in, start to automatically sock part of them away into an investment or retirement account. The rockets will be there, and future/older you will be really appreciative of present you looking out for him. The rockets will be there

Have fun!

 

[Andrew_ASC]

****... it’s about OpenRocket...

Mac asked me to use my OR file I told him yes... Now I recheck everything. That tubing coupler should be 55 grams not 227 grams as it was in his file. Arghhhhhh. Gotta pm and fix mistake.

 

[Andrew_ASC]

Slight oversight issue on my part. This is the corrected tubing coupler mass. When I put the rocket on the scale it was heavier in the sim than actual! Then I saw the tube coupler overrode was way off too.

 

[Andrew_ASC]

Any idea what the final build weight will be? How do the sims look for the DMS cert attempt? Any plans to fly it on some L1 38mm motors first to get the bugs worked out? Study for the test and good luck with the cert flight.

~John

Ignore previous data. Sim error corrected.

1. Final weight estimate 1422 grams no motor or 3.13 pounds.
2. J-250 DMS, Apogee 7096 ft, ground hit velocity 25.39 FPS, stability 1.92
3. Same as previous answer.

 

[mpitfield]

I have a 2.2" MC Tomach MD project. I simulated a Loki L1040 (6.5lb motor) in the 3.5lb rocket and did have an issue with the decent weight, and space for the main. I like to have 15'/s or less for certification flights.

I was looking at the 48" Iris ultra light from fruity, but settled on a 58" thin TFR chute for the main, and I have a TFR 18" ultra xtype for a drouge.

I was hoping decent rates on the Loki L1040 would be 16-18'/s under main. But the thin fiberglass fins may not hold up to such abuse. I might pick up some thicker WM BH fins, or these MaxQ fin cans look sweet.

Any idea what the final build weight will be? How do the sims look for the DMS cert attempt? Any plans to fly it on some L1 38mm motors first to get the bugs worked out? Study for the test, ground test, and good luck with the cert flight.

~John

In my L-1040 sim vs actual results example to Andrew, that was a MC 54mm MD Tomach, but the CF version. It is 5151g on the pad so 11.35lbs with the L1040. I use a 36" Fruity Chutes Iris Ultra Compact with a 12" Fruity Chutes Classic Elliptical as the drogue and I have 13 or 14 flights on her. With that config it does come in hotter than some like (25f/s), but that is my preference. If you wanted to bring her down a bit softer you might consider the 42" Iris Ultra Compact.

 

[Andrew_ASC]

Dry fit again. It’ll stay like this until budget increases.

To be continued...

 

[Andrew_ASC]

Sanded with 150 grit 6 cm below the BT line. Used masking tape to protect the part where the av bay connects.

 

[Andrew_ASC]

Just an update about the Job searching... VW declined on internship. EPB fiber optics offers an interview next Monday for an Autocad drafter position worth $43.2k/yr. And Johnson Controls has a mech engineer position $55k/yr which I need to interview for. I’ll be excited to finish this build eventually.

 

[blackjack2564]

Good luck Andrew!

 

[Andrew_ASC]

Ditching the epoxying shock cord to BT idea. It seems I can put a epoxied Aluminum cross pin through drilled holes in BT and attach Kevlar there or go with tapping the powder charge area of the motor like how CJ and Tfish show in other threads.

I just don’t want the shock cord separating from the body tube. Personally I like the cross pin idea because every time I get a new motor I don’t have to mess with it.

 

[Nytrunner]

I forget who, but someone was thinking of installing a pin (stainless I think) in a thick coupler, shaping the ends to match OD, and then installing that in the airframe. That gives no outer airframe damage, thicker coupler walls to hold the pin, and a large cylindrical bonding surface to hold it in there.

 

[GalantVR41062]

https://aeropack.net/min_dia_retainers.asp

They have them with or without holes, if you wanted to fly with motor eject or rely on your electronics.

I am using these on my WM BH 38 and MC 2.2" Tomach.

~John

 

[rfjustin]

Just an update about the Job searching... VW declined on internship. EPB fiber optics offers an interview next Monday for an Autocad drafter position worth $43.2k/yr. And Johnson Controls has a mech engineer position $55k/yr which I need to interview for. I’ll be excited to finish this build eventually.

You refer to the job's "worth" as it relates to compensation exclusively, it does not. Pay attention to what the total compensation package is and what type of upward mobility you might have opportunity to explore in future. Discussing one's compensation is really frowned upon in the workplace, and I don't think discussing in in public is in your best interest either.

My .02 for the day...

 

[OverTheTop]

Rocket is looking good Andrew. Nice work on the fin fillets .

See if Agilent Technologies has any positions for you. Really good remuneration packages and good to work for.

 

[mike2wander]

Ditching the epoxying shock cord to BT idea. It seems I can put a epoxied Aluminum cross pin through drilled holes in BT and attach Kevlar there or go with tapping the powder charge area of the motor like how CJ and Tfish show in other threads.

I just don’t want the shock cord separating from the body tube. Personally I like the cross pin idea because every time I get a new motor I don’t have to mess with it.

How about a stepped bulkplate added to a piece of coupler. Install an eye nut to the center of the plate and install it in the frame with the plate on the aft side of the coupler? If you plan to use motor eject you can drill holes in the plate before you install it to make it a blast baffle and anchor point.