Sudden Mach build thread

I finally have ordered the parts for the Sudden Mach. It's to be a 29mm minimum-diameter rocket, made from LOC tubing. Its primary purpose is to drag-race the Wildman Blackhawk 29. It's lighter than the Blackhawk - dry weight should be between 250g (8.8 oz) and 300g (10.5 oz) depending on configuration. As long as it's ready for NERRF (and I get to go...), I will drag race any Blackhawk on any 24mm or 29mm motor. :dark::y:

It's designed to satisfy a number of design goals:

• Using conventional materials whenever possible - the only exceptions are the two Blue Tube couplers. Unlike the Blackhawk, it needs no expensive carbon fiber, and I intend to do without even glassing it.
• Able to use LOC 29mm tubing and survive flight. This means, among other things, long couplers to ensure straight tube joints.
• Capable of dual-deploy, motor ejection, and combinations thereof, with interchangable electronics
• Easy-to-load payload bay capable of holding one aviatronic board plus a second small payload
• Capable of flying on smaller 29mm and 24mm motors on small fields
• Capable of high speeds (Mach 1+) and high altitudes (1 mile +)
• Cheap. I'm on a limited budget.

The simulated results look good. Capable of flying on every 24mm and 29mm motor, from C11-3s to baby Is - a range of 7 impulse classes, and altitudes from 130 feet to 6800 feet . The avbay is completely flexible; I can change the lengths of the central bay to whatever length allthread I have, and I can use modular sleds for the electronics. I can also remove all of it but one coupler, attach the two shock cords together, and fly it single-deploy.

The dual-deploy scheme will be somewhat unorthodox. Instead of an altimeter with two charges, I'll be using motor ejection near apogee for the drogue (8" to 12" nylon chute) and a Perfectflite staging timer, set to deploy at around 1000-1500 feet, for the main (12" - 18" nylon chute). That way, I only have to set up one charge (yes, I know I'll need an adult to set the charge) and I can use the small, cheap timer instead of a larger or more expensive altimeter.

I ordered from Apogee yesterday one 29mm nose cone, one 34" length of LOC tubing (I have one already), two 4" Blue Tube couplers, one Perfectflite MiniTimer 3, 30' of 300lb-test Kevlar, and a pair of rail buttons. Construction should start within a week.

The OpenRocket file is preliminary; it doesn't include some internal components, and only G-I flights will use DD. More pictures and a better explanation of the slightly unorthodox avbay design will come when I am significantly less sleepy.

View attachment Sudden Mach.ork

Yes! You have mentioned in in numorus threads, and it's finaly here! Good luck

Out of curiosity, what is you planned fin construction/attachment method? I've been tossing around the idea of a no-composites mach buster for a while, and had come up with some ideas, but I'd like to hear yours first.

This one got my attention and pulled me out from the shadows.

Terrific idea, not made from exotics, not overbuilt, done with a budget in mind.

2 q's so far:
-I also want to know about the fin attacment method.
- What nose cone?

Also nothing wrong with that DD metod. It will work.

My suggestion to anyone learning Dual Deploy:
Set up a low flying Test-bed rocket for your DD practice. Maybe an "F" impulse rocket that would go say.. 900 feet , keep a motor deploy (that way you have some sort of recovery no matter what) then
TIMER to deploy a secondary recovery event at 300ft.
It's good to practice. and that makes everything happen at Alts. where you can see and hear it.

Keep updating and include photos. Thank you for the "open" sim. I'm starting to really like Open rocket.

.

Fin attachment will be with plain old Elmer's Carpenter's Wood Glue. Given enough drying time, it is almost as strong as epoxy, and far stronger than the materials I'm making the rocket out of. Fins will be surface mounted, but the glassine will be peeled away first for a more solid mount. Fillets will be used, either one layer of epoxy clay or two of wood glue. I've flown a similar Machbuster to right around Mach with the same attachment method, no damage, and the fins were almost a centimeter larger in span.

Nose cone is a plain and cheap Apogee 29mm plastic cone. Nothing fancy, but the Sudden mach will only be in the transsonic regime for 2-3 seconds at most, so I expect it'll survive just fine.

I plan to fly the Sudden Mach on a D12 or E18 sometime in May or June before NERRF. That way I can get all the kinks worked out beforehand, and be ready to drag race on anything at NERRF.

For those of you who don't have Openrocket, here's a screenshot of the design and sims.

The EGE said:

For those of you who don't have Openrocket, here's a screenshot of the design and sims.

Click to expand...

There is really no excuse to not have openrocket, it is free afterall

And I also have a few questions, as i have never built something like this before.


A) would a Apogee (I know you are using a loc tube) 29mm tube survive stock?

B) would the fins survive if they were 1/8 Basswood?

Oh and all of this is asked ask if it was powered by an I200

1) No. Not a chance. I've used it as a motor mount with a G53, and that is as far as I will push the stuff. In the Machnum Force, I stiffened it with wood glue and it held together, but that would not take an I200. To answer the unspoken question - no, you can't stick an I200 in an Aspire, and it's a bad choice for L1 anyway.

2) Probably; If I can't get decent 1/8" ply then I'll use basswood and coat the fins with paper.

Here's a rough diagram of how the avbay goes together. The electronics sled will go inside the forward coupler.

schweet build.

Nice looking rocket. The Ebay is probably a good decision. Are you going drougeless, or drouge streamer? or are you going to put a tiny drouge chute on it? haha

No fiberglass or anything? and you plan an I200? You are a brave soul.

I am still haveing a little trouble understanding the Avi Bay layout.

UPscaler: Thanks

Drogue will depend on the flight, really. If I've got lots of recovery room I'll use an 8" chute so I can more precisely predict altitude for the main (descent under chute is easier to predict than freefall); if I don't I'll use a small streamer or go drogueless.

I'll prolly not use an I200, actually. Since I don't have much need for a 29mm I case, if I buy one special for a drag race, it'll be a CTI case. However, OR doesn't have Pro29 motors, so i just used the closest available substitute.

SD: There's two endcaps, both 2-layered. End caps fits onto the Blue Tube couplers. Couplers have 1/2" of 29mm tubing on their middles. Couplers into length of 29mm tubing. 9V battery goes into 29mm tubing. Two lengths of allthread run through the coupler and hold the whole thing together. It'll make more sense once i'm actually putting it together and have pictures.

I think I got it, it will be like the Ebay in the Areobee-Hi, internaly mounted.

it'll be a CTI case. However, OR doesn't have Pro29 motors,

Click to expand...

Try O.R version 1.0.0

Lots of CTI happyness. Your rocket seems exciting on the H410 Vmax:

apogee= 4144 ft
Mach= 1.15
Max accell = 1265 m/s2:y: o.k that is scarry.

Can't wait to see this one.

HotRod Rockets said:

Try O.R version 1.0.0

Lots of CTI happyness. Your rocket seems exciting on the H410 Vmax:

apogee= 4144 ft
Mach= 1.15
Max accell = 1265 m/s2:y: o.k that is scarry.

Can't wait to see this one.

Click to expand...

Wow! I will have to try the new version. 1265m/s/s.. that's 129 Gs :eyepop:


Package came from Apogee today... Less than 48 hours from order to arrival, with standard shipping.

I ordered two 4" Blue Tube couplers... they came as 7.4" lengths. I'm not sure what length I'll cut them too; longer couplers are heavier but better for a perfectly straight rocket.

The MiniTimer3 is TINY! It fits inside a 24mm tube even.

I'm not sure quite when I'll have time to start building. First will come a hardware store run for spray paint, 1/8" plywood, and allthread etc. After that, I'll start with the avbay.

Pictures are coming, I promise!

I'm seeing some problems with your design:
I not sure that Loc 29mm tubing will handle mach or beyond. Has anyone out there ever proven that it can?

If it does do 120+ G's that's: 120 x the mass of the rocket pressing down on it.....

You just might end up with confetti.


JD

The EGE said:

I finally have ordered the parts for the Sudden Mach. It's to be a 29mm minimum-diameter rocket, made from LOC tubing. Its primary purpose is to drag-race the Wildman Blackhawk 29. It's lighter than the Blackhawk - dry weight should be between 250g (8.8 oz) and 300g (10.5 oz) depending on configuration. As long as it's ready for NERRF (and I get to go...), I will drag race any Blackhawk on any 24mm or 29mm motor. :dark::y:

It's designed to satisfy a number of design goals:

• Using conventional materials whenever possible - the only exceptions are the two Blue Tube couplers. Unlike the Blackhawk, it needs no expensive carbon fiber, and I intend to do without even glassing it.
• Able to use LOC 29mm tubing and survive flight. This means, among other things, long couplers to ensure straight tube joints.
• Capable of dual-deploy, motor ejection, and combinations thereof, with interchangable electronics
• Easy-to-load payload bay capable of holding one aviatronic board plus a second small payload
• Capable of flying on smaller 29mm and 24mm motors on small fields
• Capable of high speeds (Mach 1+) and high altitudes (1 mile +)
• Cheap. I'm on a limited budget.

The simulated results look good. Capable of flying on every 24mm and 29mm motor, from C11-3s to baby Is - a range of 7 impulse classes, and altitudes from 130 feet to 6800 feet . The avbay is completely flexible; I can change the lengths of the central bay to whatever length allthread I have, and I can use modular sleds for the electronics. I can also remove all of it but one coupler, attach the two shock cords together, and fly it single-deploy.

The dual-deploy scheme will be somewhat unorthodox. Instead of an altimeter with two charges, I'll be using motor ejection near apogee for the drogue (8" to 12" nylon chute) and a Perfectflite staging timer, set to deploy at around 1000-1500 feet, for the main (12" - 18" nylon chute). That way, I only have to set up one charge (yes, I know I'll need an adult to set the charge) and I can use the small, cheap timer instead of a larger or more expensive altimeter.

I ordered from Apogee yesterday one 29mm nose cone, one 34" length of LOC tubing (I have one already), two 4" Blue Tube couplers, one Perfectflite MiniTimer 3, 30' of 300lb-test Kevlar, and a pair of rail buttons. Construction should start within a week.

The OpenRocket file is preliminary; it doesn't include some internal components, and only G-I flights will use DD. More pictures and a better explanation of the slightly unorthodox avbay design will come when I am significantly less sleepy.

Click to expand...

Actually, he would technicly win the drag race, the one who leaves the pad first, check, the one who goes the lowest check, and the one who torches down last, you better have a good eye to make sure all the pieces of the cofetti lands

KPM: It's a pretty standard avbay design, the only difference from normal is that the 9V battery has to be centrally located due to its size, so instead of one large sled I'll have a smaller sled (or two) off center. It'll make more sense when I actually build it, I hope...

JD: I'm pretty sure LOC tubing can handle Mach speeds. I've flown Apogee 29mm tubing to Mach on a G78, no damage, and that's half the thickness. It's also not as likely to buckle as unsupported tube; most of the lower section will contain a motor case when flown on Machbusting motors, the avbay is Blue Tube, and the upper section is only 12" long.

I also don't plan on using the H410; even the 200N - area motors don't give more than 40-45 Gs, which is much more survivable. Apogee tubing in the Machnum Force took 40 Gs, so LOC tubing should have no problem.

JDcluster said:

I'm seeing some problems with your design:
I not sure that Loc 29mm tubing will handle mach or beyond. Has anyone out there ever proven that it can?

If it does do 120+ G's that's: 120 x the mass of the rocket pressing down on it.....

You just might end up with confetti.


JD

Click to expand...

Honestly, I wouldn't be at all surprised if Loc tubing did fine at mach+ in those small diameters. As for the force on the tubing? It shouldn't be more than about 300N or so (the rest will be accelerating the motor itself). I'd bet that Loc tubing would be fine with 300N of force.

About the nosecone: The Apogee 29mm nose is made for their 29mm tubing, not the thicker LOC kind, so what do you plan to do about the resulting ridge?

Neutron95 said:

About the nosecone: The Apogee 29mm nose is made for their 29mm tubing, not the thicker LOC kind, so what do you plan to do about the resulting ridge?

Click to expand...

Sand it down a bit. It's a 1mm ridge, nothing to worry about.

Just for the record: The idea of the H410 was certainly a mental exercise.

I belive young Mr. "the egde" sort of understands my humor.
----------
He has also stated priviously in the thread that he intends to start with lower impulse motors and work his way up to Mach busting.

Maybe I'll build a version also and have a cheap Mach race?

'nother Question for the builder: I know you have adult help with these things, so.... does anyone have any radio retreival type systems you may incorporate into you design?
When you do attempt a Mach flight It could go far-afield even with Dual deploy.

?


.

I do not personally have a radio retreival system; however, I do plan to look into it. I'm just not sure how much on a transmitter one can fit into a 3.5" length or 25mm ID tubing. I do plan to use copious amounts of tracking powder.

I would love to get a Walston system.

However, the whole system is looking to be about $720

I believe out at black rock, they have receivers that you can use. You just have to have your own transmitter.


What do you use for tracking powder?

UPscaler said:

I would love to get a Walston system.

However, the whole system is looking to be about $720

I believe out at black rock, they have receivers that you can use. You just have to have your own transmitter.


What do you use for tracking powder?

Click to expand...

Flour. Cheap - a lifetime supply for 4 bucks - and very visible even high in the sky. I use chalk dust if I want color, but flour doesn't require breaking the chalk.

Finally made a run to the hardware store, and I now have almost all the parts together.

• 2x LOC Precision 29mm x 34" tubing
• 36" length of 3/32" allthread for the avbay
• 1/8" basswood for fins
• 2x 29mm x 7.4" Blue Tube coupler
• 12" x 1/8" styrene rod (for timer switch actuator)
• 30' of 1/10" Kevlar (300 lb test)
• baggie of nuts and washers for 3/32" allthread
• 3/16" plywood for bulkhead disks and sleds, and prototype disk
• 2x rail buttons
• 2x 1/8" quick-links
• Perfectflite Minitimer 3 and baggie of hardware
• Apogee 29mm nose cone

Not pictured:

• Screw eyes; I forgot to get them at the hardware store. They will be inserted into drilled holes in the bulkheads then epoxied into place.
• Streamer/parachute - will vary depending on flight profile and conditions
• Chute protector(s) - optional
• 9V battery for timer
• Primer and spray paint

1/8" quicklinks look monstrous in a rocket of this size. Would knots be more reasonable?

patelldp said:

1/8" quicklinks look monstrous in a rocket of this size. Would knots be more reasonable?

Click to expand...

Prolly, but for this I need the shock cords to be able to easily disconnect from the avbay, so knots just wouldn't work. I also love quicklinks for easily changing chutes and chute protectors.

These are also really tiny quick-links - 1/8" thick, 3/4" wide, and 1+3/8" long, roughly 5g apiece.

DId you say Basswood? I thought you were using Ply, or could you not find it?



Ya know, to think of it, i have a sheet of 1/8 in my WS...

The EGE said:

Prolly, but for this I need the shock cords to be able to easily disconnect from the avbay, so knots just wouldn't work. I also love quicklinks for easily changing chutes and chute protectors.

These are also really tiny quick-links - 1/8" thick, 3/4" wide, and 1+3/8" long, roughly 5g apiece.

Click to expand...

Just make sure you secure the closures on the quick links prior to flight!

Man, I would be so nervous about launching electronics in that thing. At 4000 feet I completely lost sight of my 29mm mach-thingy. I might have asked you this before, but do you have a game-plan for recovery?

~DTH