Mile High build thread

Looks excellent, captain! I'll be following this closely. I'm going to be attempting my first DD flight in the next few months as well.

Alex

I think my first DD flight will be in either my NPM or in the Squat I plan to get tomorrow...

Where is your switch?

qquake2k said:

You know, it looks like the coupler in the Striker kit is pretty short. You might need to get a longer one for the av-bay. The Blue Tube coupler I got from ARR is 8" long, which I thought would be excessive. But as it turns out, I'll end up needing the length. There's not much room inside a 2.6" coupler.

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I was looking at the ones that Barry at LOC has,he sells the kit but told me that I could make one up with out much trouble.We have a few guys in the club that only fly duel deploy and they said the same about extra length.But I need to finish my current build.I was looking at altimeters, sure is a wide range in cost.I do like your choice.

Looking great as always!!

Really like how you did the AV bay!!!

bill2654 said:

Where is your switch?

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I haven't gotten around to the switch yet. I prefer the pull pin style switch, so I can use a Remove Before Flight flag. I bought a switch a while back for the Hyperloc, and JB Welded a piece of tubing to it, but now I can't find it. I'll have to get another one from Radio Shack.

qquake2k said:

10-4, Rampart. Yes, the battery holder is off the sled enough to put a zip tie under it. I learned that trick from the forum. Roger wilco.

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Excellent idea, especially since that small plastic tab on the back end of the battery holder would be the only thing keeping the battery from shifting backwards during acceleration. I got one of the holders for my first DD build, and decided it was worthless, just adding weight and bulk to a tight (2.1") bay. I ended up strapping the battery directly to the sled with zip-ties, and because the sled runs the full length of the AV bay I positioned the battery so that it would butt up against the aft bulkhead for good measure.

qquake2k said:

I haven't gotten around to the switch yet. I prefer the pull pin style switch, so I can use a Remove Before Flight flag. I bought a switch a while back for the Hyperloc, and JB Welded a piece of tubing to it, but now I can't find it. I'll have to get another one from Radio Shack.

Click to expand...

What type of Radio Shack switch is that, and what mods did you have to make to it? And how are you planning on connecting to the switch? I can't find terminal spades that small and when I've soldered directly to the switches in the past I'm right on the edge of melting something inside the switch when the solder melts. (This experience was from a few kids' science projects as well as the rocketry...I seem to go through two switches to get one good one, on average.)

qquake2k said:

Got the fins cut out. I hope they didn't ruin my bandsaw blade. That fiberglass is pretty tough stuff. Even got sparks a few times.

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Can you let us know how that worked out for you (re: the bandsaw blade)? I will have to borrow a friend's bandsaw to cut some fins, and it would be good to know if he will still be my friend afterward.

Aksrockets said:

Looks excellent, captain! I'll be following this closely. I'm going to be attempting my first DD flight in the next few months as well.

Alex

Click to expand...

I've had a dual deploy capable rocket, the Hyperloc 835, for a couple of years now. For some reason, I just couldn't get interested in dual deploy until now.

MasonH said:

I think my first DD flight will be in either my NPM or in the Squat I plan to get tomorrow...

Click to expand...

What is an NPM?

I use 1/4" phono jacks as switches (1/8" in smaller applications). A switching phono jack disconnects the built-in speaker when you plug in an external one. I connect the circuit I want to interrupt where the built-in speaker would go, and use an empty plug as the switch. Insert the plug to break circuit, remove it to arm.

In this case, I use a rechargeable battery (this is for Vulcan), and my wiring does even more: I have an empty plug that only disconnects the battery (bottom), and I have another one that plugs into a charger and allows me to charge the battery without removing it from the rocket (top). In the latter case, the phono jack effectively switches the battery between its load and a charger.

An additional, side benefit is that the jack acts as a static port for your altimeter.

Ari.

cjp said:

I was looking at the ones that Barry at LOC has,he sells the kit but told me that I could make one up with out much trouble.We have a few guys in the club that only fly duel deploy and they said the same about extra length.But I need to finish my current build.I was looking at altimeters, sure is a wide range in cost.I do like your choice.

Click to expand...

A kit might be easier, since it includes everything, including the sled. The av-bay that my Hyperloc came with was nice.

https://www.rocketryforum.com/showthread.php?13227-Hyperloc-835-Build&p=115073#post115073

https://www.rocketryforum.com/showthread.php?13227-Hyperloc-835-Build&p=115138#post115138

iter said:

I use 1/4" phono jacks as switches (1/8" in smaller applications). A switching phono jack disconnects the built-in speaker when you plug in an external one. I connect the circuit I want to interrupt where the built-in speaker would go, and use an empty plug as the switch. Insert the plug to break circuit, remove it to arm.

In this case, I use a rechargeable battery (this is for Vulcan), and my wiring does even more: I have an empty plug that only disconnects the battery (bottom), and I have another one that plugs into a charger and allows me to charge the battery without removing it from the rocket (top). In the latter case, the phono jack effectively switches the battery between its load and a charger.

An additional, side benefit is that the jack acts as a static port for your altimeter.

Ari.

Click to expand...

I'm familiar with the disconnect function in phono jacks, and don't know that I would trust it for an altimeter. All it would take is a split second of disconnect to ruin your day.

Spooks said:

Looking great as always!!

Really like how you did the AV bay!!!

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Thank you! I'm pretty happy with how it's turning out.

qquake2k said:

I'm familiar with the disconnect function in phono jacks, and don't know that I would trust it for an altimeter. All it would take is a split second of disconnect to ruin your day.

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Ah, but someone mentioned that the rrc3 would have bounce detection, making it immune to that sort of thing.

CarVac said:

Ah, but someone mentioned that the rrc3 would have bounce detection, making it immune to that sort of thing.

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But I'm using an Adept 22 which doesn't have that function.

Dad Man Walking said:

Excellent idea, especially since that small plastic tab on the back end of the battery holder would be the only thing keeping the battery from shifting backwards during acceleration. I got one of the holders for my first DD build, and decided it was worthless, just adding weight and bulk to a tight (2.1") bay. I ended up strapping the battery directly to the sled with zip-ties, and because the sled runs the full length of the AV bay I positioned the battery so that it would butt up against the aft bulkhead for good measure.

Click to expand...

I thought about using this type of 9v battery connector, but I wanted an actual holder.

Dad Man Walking said:

What type of Radio Shack switch is that, and what mods did you have to make to it? And how are you planning on connecting to the switch? I can't find terminal spades that small and when I've soldered directly to the switches in the past I'm right on the edge of melting something inside the switch when the solder melts. (This experience was from a few kids' science projects as well as the rocketry...I seem to go through two switches to get one good one, on average.)

Click to expand...

It's Radio Shack #275-0017. I just bought another one. I pulled the arm off the first one I had, and epoxied a tube to it. But I think I'm going to leave the arm on this one, and attach the tube to the sled. Sounds like you're getting the terminals too hot. What wattage is your soldering iron? I wouldn't use over 40 watts for something like that. And I use soldering flux, which helps a lot.

Dad Man Walking said:

Can you let us know how that worked out for you (re: the bandsaw blade)? I will have to borrow a friend's bandsaw to cut some fins, and it would be good to know if he will still be my friend afterward.

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As far as I can tell, it didn't hurt the blade. I cut four fins out at once without a problem. But If your friend's bandsaw is a smaller one, you might need to cut them out one at a time.

The best way to cut G10 is a polycrystalline diamond blade. It grinds away instead of slicing chips off, and you can cut through tons of material really fast.

In short, your friend might still be your friend afterwards, but perhaps not your wallet:

https://www.mcmaster.com/#band-saw-blades/=kallvz

Interestingly, the PCD blade we have at our school is not a continuous edge, like that one, but distinct lands with notches between them. Hmm.

EDIT:

It's actually called 'gullet' style, and I guess it's just carbide grit. https://www.mcmaster.com/#band-saw-blades/=kaln5a

So your wallet might be less hurt by it.

qquake2k said:

A kit might be easier, since it includes everything, including the sled. The av-bay that my Hyperloc came with was nice.

https://www.rocketryforum.com/showthread.php?13227-Hyperloc-835-Build&p=115073#post115073

https://www.rocketryforum.com/showthread.php?13227-Hyperloc-835-Build&p=115138#post115138

Click to expand...

I agree with getting the kit.When I'm ready for that build,I might just do that.Then after build one for a future rocket.

A switch is the last thing I need for my DD, just haven't figured out what I want to go with, was looking at the magnetic ones...

CarVac said:

The best way to cut G10 is a polycrystalline diamond blade. It grinds away instead of slicing chips off, and you can cut through tons of material really fast.

In short, your friend might still be your friend afterwards, but perhaps not your wallet:

https://www.mcmaster.com/#band-saw-blades/=kallvz

Interestingly, the PCD blade we have at our school is not a continuous edge, like that one, but distinct lands with notches between them. Hmm.

EDIT: It's actually called 'gullet' style, and I guess it's just carbide grit. https://www.mcmaster.com/#band-saw-blades/=kaln5a

So your wallet might be less hurt by it.

Click to expand...

I didn't have a diamond blade, just a Timberwolf. However, I have noticed that it is noticeably duller than it was before cutting the fiberglass. But I can't see paying over $100 for a diamond blade, since I this is the first time I've ever had to cut G10. If I start using more of it, I'll have to find a cheaper solution than diamond.

cjp said:

I agree with getting the kit.When I'm ready for that build,I might just do that.Then after build one for a future rocket.

Click to expand...

I like that their kits come with a Stiffy tube coupler that goes inside the payload section. That way you only need one bulkhead for each end.

I started on the altimeter wiring, and mounting the switch.

This is my first dual deploy setup, but the wiring was pretty straight forward. I printed out the wiring diagram, and double checked myself as I went.

More photos of the wiring process.

I used a piece of brass tube for the switch's pin guide. I roughed it up with 80 grit sandpaper, and attached it to the sled with JB Weld.

The switch pin will be a length of 3/16" brass rod, tapered on one end. When inserted through the brass tube, it will push up on the switch lever. This particular switch can be wired either normally open (N.O.) or normally closed (N.C.). In this case, it needs to be normally closed, so that it will provide power to the altimeter when the lever is released.

Which way is up on the board? That switch orientation is susceptible to acceleration (in one direction or the other). Probably shock cord yanking is gonna be harder than the motor acceleration, though.

CarVac said:

Which way is up on the board? That switch orientation is susceptible to acceleration (in one direction or the other). Probably shock cord yanking is gonna be harder than the motor acceleration, though.

Click to expand...

The battery holder is down.

Strong negative g's WILL activate the switch. If you can measure the force required to depress the lever vs the weight of the roller, you can calculate the amount. I would be surprised if 10 g's didn't activate the switch. Removing the lever makes the switch harder to activate, but far less sensitive, would probably require over 100 g's to activate.

Rocketjunkie said:

Strong negative g's WILL activate the switch. If you can measure the force required to depress the lever vs the weight of the roller, you can calculate the amount. I would be surprised if 10 g's didn't activate the switch. Removing the lever makes the switch harder to activate, but far less sensitive, would probably require over 100 g's to activate.

Click to expand...

CarVac said:

Which way is up on the board? That switch orientation is susceptible to acceleration (in one direction or the other). Probably shock cord yanking is gonna be harder than the motor acceleration, though.

Click to expand...

Well, I though I had it all thought through. I can totally see the switch activating from G forces, because I left the lever and roller on it. The lever is long enough, and the roller is right at the end of it, adding weight to it. I'll have to redo it, or use a different type of switch. Plus, I didn't get the tube lined up with the vent band. Failure.