Rouse Tech CD3 anyone??

[ColumbiaNX01]

Can anyone tell me info about this product, Rouse Tech CD3? I see that Apogee makes these now. I called them and spoke to the lady there. I dont think the receptionist knows anything. What I wanted to know is there a redundant set up with this product when using 2 altimeters or do you have to have 2 separate CD3 systems like having 2 separate BP charges?

Is there a certain way these are mounted? Can high thrust G forces cause premature ejection?

 

[dhbarr]

The plastic e-match holder does have room for two separate ematches, but you'd be counting on that single co2 bottle.

2x 12g should fit side by side if bridle mounted per instructions.

Either end can go up, but in one orientation the G's look like they could be tugging on the unsupported piercer. All of the directions show a particular orientation, so probably should stick w/ that.

https://www.rouse-tech.com/pdfs/CD3 MANUAL DIST.pdf

HTH!
-dh.

 

[rharshberger]

The plastic e-match holder does have room for two separate ematches, but you'd be counting on that single co2 bottle.

2x 12g should fit side by side if bridle mounted per instructions.

Either end can go up, but in one orientation the G's look like they could be tugging on the unsupported piercer. All of the directions show a particular orientation, so probably should stick w/ that.

https://www.rouse-tech.com/pdfs/CD3 MANUAL DIST.pdf

HTH!
-dh.

Or Tinder Rocketry has a dual Peregrine 12g system.

 

[dhbarr]

Or Tinder Rocketry has a dual Peregrine 12g system.

And, regardless of which system one chooses, free nose ballast! Worth noting that the cd3 system takes a more expensive co2 cartridge having different threads than the peregrine.

I'd be interested to find out if the cd3 system can be downscaled to dual 8g', and/or whether anyone knows of a smaller co2 system.

 

[ColumbiaNX01]

Or Tinder Rocketry has a dual Peregrine 12g system.

The Rouse Tech is cheaper. It seems the CD3 is more reliable. But IDK.

 

[jderimig]

It seems the CD3 is more reliable. But IDK.

Why?

 

[JohnCoker]

I have used the Rouse-Tech CD3 a lot over the years and am glad it is continuing to be supported.

Each CD3 unit accepts two electric matches, so you can use redundant electronics. It was designed for the DaveyFire matches, but the J-Teks work fine with a bit of trimming of the plastic sleeve.

They can be mounted any which way (orientation doesn't matter for function). I have generally used bulkhead mounting, but people have also just used plastic ties to attach them to the bridle.

The plunger has a significant mass, but the force required to puncture the end of the CO2 cartridge and the O-rings around the plunger prevent it from moving freely. So I would say no chance of triggering during thrust.

During the period it appeared that it would be discontinued, I planned to use a Peregrine system and this comparison image of the two may be interesting:
https://jcrocket.com/solar-sailer.shtml#recovery

 

[JimJarvis50]

The plastic e-match holder does have room for two separate ematches, but you'd be counting on that single co2 bottle.

2x 12g should fit side by side if bridle mounted per instructions.

Either end can go up, but in one orientation the G's look like they could be tugging on the unsupported piercer. All of the directions show a particular orientation, so probably should stick w/ that.

https://www.rouse-tech.com/pdfs/CD3 MANUAL DIST.pdf

HTH!
-dh.

Plastic ematch holder? The CD3's I have used in the past were metal, and would hold 2 matches. I used to use the lithium grease that came with the unit. With that, the plunger would not move due to G forces.

Jim

 

[dhbarr]

Plastic ematch holder? The CD3's I have used in the past were metal, and would hold 2 matches. I used to use the lithium grease that came with the unit. With that, the plunger would not move due to G forces.

Jim

Yes, it appears they've switched to what looks like delrin acetal or similar for the ematch holder. Still 2 matches, and the piercer still looks stainless.

 

[ColumbiaNX01]

Plastic ematch holder? The CD3's I have used in the past were metal, and would hold 2 matches. I used to use the lithium grease that came with the unit. With that, the plunger would not move due to G forces.

Jim

Jim, with your high altitude ejection set ups do you use the CD3 or did you make up your own? I like the CD3

 

[ColumbiaNX01]

I have used the Rouse-Tech CD3 a lot over the years and am glad it is continuing to be supported.

Each CD3 unit accepts two electric matches, so you can use redundant electronics. It was designed for the DaveyFire matches, but the J-Teks work fine with a bit of trimming of the plastic sleeve.

They can be mounted any which way (orientation doesn't matter for function). I have generally used bulkhead mounting, but people have also just used plastic ties to attach them to the bridle.

The plunger has a significant mass, but the force required to puncture the end of the CO2 cartridge and the O-rings around the plunger prevent it from moving freely. So I would say no chance of triggering during thrust.

During the period it appeared that it would be discontinued, I planned to use a Peregrine system and this comparison image of the two may be interesting:
https://jcrocket.com/solar-sailer.shtml#recovery

2 ematches with one CD3? Yes you are using 2 separate altimeters with 2 separate ematches, so that is redundant, but you are still relying on one co2 canister? Could the single c02 canister fail?

 

[JimJarvis50]

Jim, with your high altitude ejection set ups do you use the CD3 or did you make up your own? I like the CD3

I used to use the CD3. As far as I know, it worked, although I always flew a BP backup charge, so it isn't possible to know for sure. I taped it to a harness, but I kept losing it on those rare occasions where I shredded a rocket. Now, I just use BP no matter how high I'm planning to go. It's the most reliable approach.

Jim

 

[ColumbiaNX01]

I used to use the CD3. As far as I know, it worked, although I always flew a BP backup charge, so it isn't possible to know for sure. I taped it to a harness, but I kept losing it on those rare occasions where I shredded a rocket. Now, I just use BP no matter how high I'm planning to go. It's the most reliable approach.

Jim

Ok thanks. Then how much do you know to use when you go 30,000 +. I flew a few yrs back to 28,000 feet. I used surgical tubing in a 5 inch rocket but when I do I used more than I needed after ground testing.

 

[JimJarvis50]

Ok thanks. Then how much do you know to use when you go 30,000 +. I flew a few yrs back to 28,000 feet. I used surgical tubing in a 5 inch rocket but when I do I used more than I needed after ground testing.

The surgical tubing method provides no advantage at altitude at all. None. So, at 30K feet, it will "work" if you use more BP, and it will work at higher altitudes as long as the chute containment area is confined. I might use an extra 50% at 30K with a surgical tubing charge, which I've done before. However, the BP method I use now is discussed in the attachment. With that method, 100% of the BP burns regardless of altitude. So, what you get on the ground is what you get at any altitude - no guesswork. I've posted this BP method many times. For those of you that have seen it before, there's nothing new.

Tony (Tfish) is working on a modified method using containment in a more rigid plastic tubing rather than a metal tube. I think that is very promising.

Jim

View attachment Article on high altitude deployment charges_May 2013.pdf

 

[ColumbiaNX01]

The surgical tubing method provides no advantage at altitude at all. None. So, at 30K feet, it will "work" if you use more BP, and it will work at higher altitudes as long as the chute containment area is confined. I might use an extra 50% at 30K with a surgical tubing charge, which I've done before. However, the BP method I use now is discussed in the attachment. With that method, 100% of the BP burns regardless of altitude. So, what you get on the ground is what you get at any altitude - no guesswork. I've posted this BP method many times. For those of you that have seen it before, there's nothing new.

Tony (Tfish) is working on a modified method using containment in a more rigid plastic tubing rather than a metal tube. I think that is very promising.

Jim

Thanks Jim. How do you build the tube that mounts on the bulkhead. I really did not understand how it works.

 

[JimJarvis50]

Thanks Jim. How do you build the tube that mounts on the bulkhead. I really did not understand how it works.

It is just a metal tube that is submerged a little into the bulkhead. The ematch is at the bottom of the tube. I route the wire through a small hole through the bulkhead and seal it with a little epoxy. Then, the BP is put into the tube, covered with a little wadding, and then I put a very thin seal of epoxy on the top of the tube so that air is retained in the tube. This helps the ematch burn at high altitude; however, none of my tests ever showed that such a seal was actually necessary. If this isn't clear, let me know and I can do a simple sketch.

On a 4" rocket, I only use about 1.25 grams of BP. Deployment is very energetic and must be ground tested.

Jim

 

[ColumbiaNX01]

It is just a metal tube that is submerged a little into the bulkhead. The ematch is at the bottom of the tube. I route the wire through a small hole through the bulkhead and seal it with a little epoxy. Then, the BP is put into the tube, covered with a little wadding, and then I put a very thin seal of epoxy on the top of the tube so that air is retained in the tube. This helps the ematch burn at high altitude; however, none of my tests ever showed that such a seal was actually necessary. If this isn't clear, let me know and I can do a simple sketch.

On a 4" rocket, I only use about 1.25 grams of BP. Deployment is very energetic and must be ground tested.

Jim

Yea that would be great. What is the material of the tube? How is it mounted on the bulkhead?

andrew

 

[JimJarvis50]

Yea that would be great. What is the material of the tube? How is it mounted on the bulkhead?

andrew

OK, sketch attached.

There is the blue bulkhead, the yellow ematch wires, the red ematch head, the orange tube, the brown BP, the gray hatch Estes wadding and the blue epoxy cap.

The tube is just a brass tube from Lowes. Just scuff it up and mount it in a hole in the bulkhead. The size of it can be varied depending on the amount of powder to be used. I seal the ematch wire at the bottom of the tube with epoxy. When the charge is used, I just drill out the match/epoxy/wires and reload.

As stated in the article, this is very energetic - deployment by shotgun. You must ground test your setup.

Jim

 

[ColumbiaNX01]

OK, sketch attached.

There is the blue bulkhead, the yellow ematch wires, the red ematch head, the orange tube, the brown BP, the gray hatch Estes wadding and the blue epoxy cap.

The tube is just a brass tube from Lowes. Just scuff it up and mount it in a hole in the bulkhead. The size of it can be varied depending on the amount of powder to be used. I seal the ematch wire at the bottom of the tube with epoxy. When the charge is used, I just drill out the match/epoxy/wires and reload.

As stated in the article, this is very energetic - deployment by shotgun. You must ground test your setup.

Jim

That helps alot thanks. Do you insert the ematch from the outside to inside? The tube is just epoxied onto the bulkhead? Is epoxy applied on surface of the inside of bulkhead plate?

 

[tfish]

I hope people notice that Jim has stated...this is very energetic!...in his last 2 post. Heed his warning. I made up some of his devices, and after a couple of ground tests (not in a rocket) I decided my rockets were not built well enough to handle them! Shotgun is a very good term.

Tony

 

[JimJarvis50]

That helps alot thanks. Do you insert the ematch from the outside to inside? The tube is just epoxied onto the bulkhead? Is epoxy applied on surface of the inside of bulkhead plate?

Yes, outside to inside. The hole through the bulkhead is for the wire, not the head. Just epoxied in. Sometime, these fittings have a threaded end, and if so, they might be threaded into the hole just to help secure them. Sometimes I put a little epoxy on the other side of the bulkhead just to ensure a gas seal.

Jim

 

[ColumbiaNX01]

Yes, outside to inside. The hole through the bulkhead is for the wire, not the head. Just epoxied in. Sometime, these fittings have a threaded end, and if so, they might be threaded into the hole just to help secure them. Sometimes I put a little epoxy on the other side of the bulkhead just to ensure a gas seal.

Jim

Whats the diameter of the tube? For a 3 inch rocket with this design how much BF do you use Jim for a starting point for me?

 

[JimJarvis50]

Whats the diameter of the tube? For a 3 inch rocket with this design how much BF do you use Jim for a starting point for me?

Looks like the tubes I have now are 0.34" ID and a little over a half inch OD. These would work with 1.0 to 1.5 grams of powder. I used 1.2 grams on a 3" flown to 130K. The amount of power doesn't change that much. It's just that it all burns "quickly" so the kick is greater.

Jim

 

[ksaves2]

I hope people notice that Jim has stated...this is very energetic!...in his last 2 post. Heed his warning. I made up some of his devices, and after a couple of ground tests (not in a rocket) I decided my rockets were not built well enough to handle them! Shotgun is a very good term.

Tony

Yeah, I did an open air test with a 7.5 gram canister with a screw on lid. Drilled like a 1/4 inch restrictor hole in the lid. I didn't want it to be sealed "all the way" because
I wanted to see if I could avoid fragmentation. I had it out in the open and remotely set it off. Oh, boy was it an energetic bang. The canister didn't fragment but the lid blew off.

Didn't want that to happen in a cardboard rocket so gave up on it. I can appreciate the work that others have done. Sounds like a way to conserve BP. Kurt

 

[JimJarvis50]

Sounds like a way to conserve BP. Kurt

I don't think this is the correct interpretation. BP only produces a certain amount of gas. If it's contained, though, it burns faster and with a louder bang than if it is loose, even if all of the powder burns in each case. The high altitude use of BP requires more containment, and for the way I do it, the consequence is that the charge container needs good support to avoid inadvertent damage to the rocket. The point is to make all of the BP burn, not to use less of it.

Jim