LOC Viper IV (build, brainstorming, and various other ramblings...)

[MikeyDSlagle]

Edit- Why didn't someone tell me the title was LOV Viper?! LOL

Got me a LOC Viper IV during LAST years Black sales from Mr Bob at Countyline Hobbies. Well I am wanting to try something new so I figure clusters and air starts is a good place. I have had the MMTs glued together for a few weeks but have only recently moved forward with the build.

Lets pretend for a moment I do not have a JLCR. I don't want to put it in and risk losing it or incinerating it. It survived one lawn dart already and I don't want to push my luck. That would sure enough simplify things, but I am not going for simplicity. I will decide later if I want to put my Eggfinder in it as well. Will get a final weight and altitude first.

I intend to light 2 motors on the pad then light the other 2 right after burnout. Probably be E30 to E20, or E20 to Estes D12. Will see how I feel when I get closer to launch. The first sims to around 2500 feet, almost too high for me to see. The second one will be a more comfortable 1700. But after weight is added, I can probably shave 300 or so feet. That is the norm for my sims.

I intend to go full dual deploy, if I can keep the weight down, and have everything controlled from a mid mounted E-bay via an Eggtimer RevD. I have a 3d printed side access bay inbound as I type this to go directly in front of the MMTs. I intend to use it for a terminal block to hook up motors (unless I decide to put the whole electronics package in there). I will wire the terminal block to the Eggtimer through a piece of conduit through the booster tube and connect to the Eggtimer via a DC plug that will pull free when the apogee charge fires. In theory.

Secondary option will be to mount the Eggtimer right above the MMTs and try to do some sort of hybrid dual deploy set up. Would utilize some sort of chute canon and would only have one break in the airframe.

Two other options would be to use a Quark mid mounted to control deployment with the RevD in the lower bay or toss in the JLCR. If I must, I must.

Concept picture:

The skinny grey tube is the conduit mentioned. It will be glued to the inside of the booster tube and to the upper bulkhead of the lower bay. The bay, as of now, consists of two parts. The blue frame and the white panel. There will be a sled inside to hold the terminal block. The frame will be attached to the inside of a coupler via six 4-40 screws, the coupler will also be glued in place. The panel attaches to the door via 4-40 screws.

The voids around the MMTs will be filled with foam. This kit didn't have any rings and I am just now thinking I could have had some printed. So foam it is.
The MMTs will be sealed and possibly vented unless I get some D12-P motors, not sure they exist.
If I fly on D12s, I will have to vent the ejection charges. Could use some ideas here. One option is a bulkplate in front of the MMTs, leaving about 1/4" to 1/2" space. And use the voids around the MMTs to vent the ejection gases out of the aft end of the body tube. Of course, I will put small tubes in to make it look stylish.

Comments welcome. I would love to hear from folks experienced with air-starts, clusters, and what not.

Mikey D

 

[MikeyDSlagle]

Reserved for:
Fins, MMTs, motor retention

So the MMT cluster assembly is pretty straight forward. Glue four tubes together and done. I used Titebond II to glue the tubes together and put fillets on each pair. That leaves two joints with no internal fillets but the outside fillets will hold just fine. Also put a slight bevel on the fins.

I beveled the root edge so the fins would fit down snugly between the MMTs. Titebond II to hold the fins on. Before I put all four fins, I light bulb came on for motor retention.



Motor retention. I have seen ideas tossed around on the 29SS about using a hollow lamp rod between the MMTs to act as cable access and motor retention all in one. The only ones I could find wouldn't fit the smaller bird. I could have used a coupler, I think 1/4" was the one I test fit and it fit perfect. But that left no room for to run the cable. I had some 1 1/2" #8 aluminum standoffs that I had ordered extra for another project. I cut one in half, roughed them up real good, notched the root edge of the two remaining fins and epoxied the standoff pieces in the fin notches. There are two, on opposite sides. One screw holds two motors. This frees up the void inside the tube cluster for running my airstart wires, and my break wire wire/switch whatever I used.



With fillets and the retainer standoffs embedded. Fillets are US Composites with their faring compound. Standoffs embedded with JB Weld. I had to clean off some excess to get my screws back in, but all is well now.



Still undecided on how I am going to utilize my couplers. The kit came with a 2" piece that holds the cluster, that in turn glues into the aft end of the body tube. I also have a full AV bay kit courtesy of Chris Short and I had Mr Bob throw in a payload section from LOC which includes a coupler, piece of body tube and a bulkplate. When my printed pieces get here, I'll know more about what I need to do.

I did know one thing. The cluster assembly had lots of slop inside the coupler. To remedy that I cut some Estes 24mm body tube into chunks, sanded the glassine off and glued them to the cluster tubes.
Like so: It looks pretty rough but it will be glued into the coupler and never seen again...hopefully.

 

[MikeyDSlagle]

Reserved for:
Electronics, payload, recovery

I'll add that this build is sponsored in part by Rocket Junkies. Thanks to Dave for his support and advice on getting the prints done and for tossing in the sweet charge wells.

Had a little time to get some things done today. From here on out it will likely slow down as I design my A/V bay and nose cone bay.

So here are my prints:
Two sets. The larger frame with the hole in it goes inside the coupler, secured with screws. The other part is the access panel. The orange one was the first print. Dave made a few recommendations for me to implement and then he did up the white set. Perfect fit.



Then to hack the holes in the airframe and coupler. It wasn't exactly easy transferring the patterns to the outside. Managed to do it with a small drill bit and my Exacto. Just went slowly with an Exacto knife and got them pretty darn close. Too close in fact. The panel is supposed to sit recessed to where it will be flush with the body tube. So I had to get out the Dremel and the end result wasn't near as pretty, but I'll get it cleaned up. If there is a next time I'll use a different design and get a template printed as well. I glued the frame in the coupler using US Composites Fastek glue, we'll see how that holds. It will have six screws holding it anyway. No pictures of that yet. By the time I had the excess glue cleaned up it was dinner, then Daddy duties so rocket time was done for the day.

Safety tip. When applying pressure to a small drill bit with your fingers, put electrical tape or something on your fingertips. Let's just say it only took me a minute to figure out what the red smears were on my coupler. Don't know if the shank went in or the cutting edge cut me (I think both), but it got two fingers and a thumb.



And the charge wells. Very nice indeed.



Should be able to get some done tomorrow.

 

[LithosphereRocketry]

Got me a Viper IV during LAST years Black sales from Mr Bob at Countyline Hobbies. Well I am wanting to try something new so I figure clusters and air starts is a good place. I have had the MMTs glued together for a few weeks but have only recently moved forward with the build.

Lets pretend for a moment I do not have a JLCR. I don't want to put it in and risk losing it or incinerating it. It survived one lawn dart already and I don't want to push my luck. That would sure enough simplify things, but I am not going for simplicity. I will decide later if I want to put my Eggfinder in it as well. Will get a final weight and altitude first.

I intend to light 2 motors on the pad then light the other 2 right after burnout. Probably be E30 to E20, or E20 to Estes D12. Will see how I feel when I get closer to launch. The first sims to around 2500 feet, almost too high for me to see. The second one will be a more comfortable 1700. But after weight is added, I can probably shave 300 or so feet. That is the norm for my sims.

I intend to go full dual deploy, if I can keep the weight down, and have everything controlled from a mid mounted E-bay via an Eggtimer RevD. I have a 3d printed side access bay inbound as I type this to go directly in front of the MMTs. I intend to use it for a terminal block to hook up motors (unless I decide to put the whole electronics package in there). I will wire the terminal block to the Eggtimer through a piece of conduit through the booster tube and connect to the Eggtimer via a DC plug that will pull free when the apogee charge fires. In theory.

Secondary option will be to mount the Eggtimer right above the MMTs and try to do some sort of hybrid dual deploy set up. Would utilize some sort of chute canon and would only have one break in the airframe.

Two other options would be to use a Quark mid mounted to control deployment with the RevD in the lower bay or toss in the JLCR. If I must, I must.

Concept picture:
View attachment 333095
The skinny grey tube is the conduit mentioned. It will be glued to the inside of the booster tube and to the upper bulkhead of the lower bay. The bay, as of now, consists of two parts. The blue frame and the white panel. There will be a sled inside to hold the terminal block. The frame will be attached to the inside of a coupler via six 4-40 screws, the coupler will also be glued in place. The panel attaches to the door via 4-40 screws.

The voids around the MMTs will be filled with foam. This kit didn't have any rings and I am just now thinking I could have had some printed. So foam it is.
The MMTs will be sealed and possibly vented unless I get some D12-P motors, not sure they exist.
If I fly on D12s, I will have to vent the ejection charges. Could use some ideas here. One option is a bulkplate in front of the MMTs, leaving about 1/4" to 1/2" space. And use the voids around the MMTs to vent the ejection gases out of the aft end of the body tube. Of course, I will put small tubes in to make it look stylish.

Comments welcome. I would love to hear from folks experienced with air-starts, clusters, and what not.

Mikey D

There is no D12P but there is a very similar D11P IIRC. It's commonly used in big BP clusters like Boris Katan's various rockets.

Sent from my LGL44VL using Rocketry Forum mobile app

 

[MikeyDSlagle]

 

[jd2cylman]

There is no D12P but there is a very similar D11P IIRC. It's commonly used in big BP clusters like Boris Katan's various rockets.

Sent from my LGL44VL using Rocketry Forum mobile app

Or you could use D12-0's with dog barf and tape covering the front end.

 

[MikeyDSlagle]

Or you could use D12-0's with dog barf and tape covering the front end.

After doing research this seems the best solution. No venting required. I can probably glue a dowel in the end or use some putty of some sort. Or just settle with dog barf and tape. I was thinking the Estes -0 motors had ejection charges just no delay. Seems I was wrong. No experience with using these motors so don't hate on me. I may have to get me another 24/40.

And if I go with the BP motors, I will have to add something to keep it from boosting up through the MMT. Already working on that idea too. Either rings on the nozzle end or screws/pins through the MMT, that are easily removed.

Post 2 updated.

 

[jd2cylman]

And if I go with the BP motors, I will have to add something to keep it from boosting up through the MMT. Already working on that idea too. Either rings on the nozzle end or screws/pins through the MMT, that are easily removed.

Post 2 updated.

Just 1/4" wide masking tape. Several wraps (OK, lots of several) to make a thrust ring...

 

[MikeyDSlagle]

Just 1/4" wide masking tape. Several wraps (OK, lots of several) to make a thrust ring...

Yeah, I've done it once before. Got frustrated and went a different route if I remember right.

 

[Nytrunner]

I've been having good luck with a single 1/4" wrap at the back, followed by a Thin 1/2" wrap over it. Makes a nice slope ridge and doesn't take forever to wrap.

 

[dhbarr]

I roll out about four circumferences of tape, then cut it at a long shallow angle. I put the fat end on first, factory edge down toward the nozzle.

Wrap as usual, then jam it in. The top skinny tail layer or two will wrinkle up, the bottom will jam into the motor tube.

 

[MikeyDSlagle]

I did the whole tape wrapping thing on something before. I had the wrinkles and it was wedged in pretty good. I think I scrubbed the flight because of the adapter I was using. Was trying a homemade 29-24 adapter and didn't like the looks. But tape oughtta work fine for this. Got my prints today so I can move forward a bit, except I start shift work tomorrow and expecting a bunch of TBD on my schedule. I hate those.

 

[MikeyDSlagle]

Post #3 updated.

 

[Mendal]

I like the progress and I'm glad I could help out with the printing and the charge wells!

Does the bay door look like it is going to match up well with the diameter of the tube?

As for the motors, I would look into some of the single use composite motors. When I flew my last cluster, I took the end caps out and dumped the black powder out. Put the cap back in and not you have a motor with a smoke grain and no ejection charge.

I'll be watching this build.

 

[Nytrunner]

As for the motors, I would look into some of the single use composite motors.

Just be dang sure those motors will light!
My first turn behind the RSO table, I had a guy come up with a 4xE composite. It was his first time doing a comp-cluster, so I gave him the spiel about checking them for continuity, properly seating the igniters at the top, and carefully hooking up the launch leads.

He did everything right, yet still only 3/4 lit immediately. It had a bit of a left turn, then the 4th motor came to pressure about 5 seconds into the flight. Looked like a beautiful airstart lol.

Bystander: "Wow! Is that what it was supposed to do?"
Flyer: "Ummmm no......not really....."

An hour later he was back doing it again and everything worked great!

 

[LithosphereRocketry]

I haven't personally flown a composite cluster but everyone recommends CTI, and having seen them fly, I can see why. They have a little Pyrodex pellet or something in the top grain, so they light really easily. However CTI motors in that size are kinda expensive.

Simple solution- build a 1.5x upscale to justify Pro38 motors in the outboards...:wink:

Another technique I used once on an old G80 with no thrust ring that might work on D12s is friction fit. Yes, friction fit. I put a diagonal wrap of tape around the motor and then sat on it. The trick is getting the end of the tape to go inside the MMT rather than scrunching up. The rocket worked perfectly but slid about 1/8 inch up the MMT during the burn. It took quite a bit of work with pliers to get it out...

 

[MikeyDSlagle]

I like the progress and I'm glad I could help out with the printing and the charge wells!

Does the bay door look like it is going to match up well with the diameter of the tube?

As for the motors, I would look into some of the single use composite motors. When I flew my last cluster, I took the end caps out and dumped the black powder out. Put the cap back in and not you have a motor with a smoke grain and no ejection charge.

I'll be watching this build.

Yep. Everything fit great. The diameters are pretty much spot on, close enough to make it look like these were designed by someone who knew what he was doing.

As for the motors. We think a lot a like. I am mostly looking at SU composites. And dumping out the BP.

But for the first flight I want to try to keep it low(ish). E20W to D12 is simming to 1716 ft. But the final build will weight a bit more so 1200 to 1400 feet is probably closer. Composite to composite takes it up around 2000. A white rocket in a blue sky at 2000 feet...I can't see it. Motor selection will be based on final weight of course.

In my experience, the E20Ws take a bit to come up to pressure. Probably about half a second. If they both pressurized at the same time it would be great. The Blue Thunders and Fast Jacks light the fastest. Since there are no single use Fast Jack E motors in 24mm, I may have to try the Blues, which I really don't like. Thinking air-starting the D12s because they light pretty easily. I will use something else other than Estes igniters.

Too bad there are no greens..we all know how easy they are to light.:wink:

Just be dang sure those motors will light!
My first turn behind the RSO table, I had a guy come up with a 4xE composite. It was his first time doing a comp-cluster, so I gave him the spiel about checking them for continuity, properly seating the igniters at the top, and carefully hooking up the launch leads.

He did everything right, yet still only 3/4 lit immediately. It had a bit of a left turn, then the 4th motor came to pressure about 5 seconds into the flight. Looked like a beautiful airstart lol.

Bystander: "Wow! Is that what it was supposed to do?"
Flyer: "Ummmm no......not really....."

An hour later he was back doing it again and everything worked great!

Were they Whites? All of the AT Whites I fly usually pop, fizz...then roar.

I haven't personally flown a composite cluster but everyone recommends CTI, and having seen them fly, I can see why. They have a little Pyrodex pellet or something in the top grain, so they light really easily. However CTI motors in that size are kinda expensive.

Simple solution- build a 1.5x upscale to justify Pro38 motors in the outboards...:wink:

Another technique I used once on an old G80 with no thrust ring that might work on D12s is friction fit. Yes, friction fit. I put a diagonal wrap of tape around the motor and then sat on it. The trick is getting the end of the tape to go inside the MMT rather than scrunching up. The rocket worked perfectly but slid about 1/8 inch up the MMT during the burn. It took quite a bit of work with pliers to get it out...

Pro38 isn't in my foreseeable future. I am fairly heavily (to me anyway) invested in Aerotech and to a lesser extent Loki 38mm. But you make good points on the ease of starting using the pellet, it is probably BP but I don't know. Casting a BP pellet may not be too difficult, but making it fit inside a 24mm..eh, unlikely.

An upscale Viper IV would be pretty awesome. Two Loki H144s to two AT H73Js could be knocking on a mile. Lots of smoke and roar. That would be cool. Thanks for putting that idea into me head.

Larger clusters are likely in my future. I like the idea of clustering, airstarts, detaching boosters and all the engineering and designing that go along with them. This Viper IV is just the first step.

 

[Mendal]

Simple solution- build a 1.5x upscale to justify Pro38 motors in the outboards...:wink:

Now we are talking!

I'm actually working on a Nike-Hercules with a 4 38 cluster for the booster. I'm thinking I will light the cluster as 2 motors diagonal wired in parallel and the 2 sets in series. Worse case 2 of the 4 will light. The fail safe is that 2 motors have enough thrust to safely lift the rocket. In the sims the booster alone is going to 3000 feet. The sustainer is siming out to over 10,000.

 

[Mendal]

Yep. Everything fit great. The diameters are pretty much spot on, close enough to make it look like these were designed by someone who knew what he was doing.

As for the motors. We think a lot a like. I am mostly looking at SU composites. And dumping out the BP.

But for the first flight I want to try to keep it low(ish). E20W to D12 is simming to 1716 ft. But the final build will weight a bit more so 1200 to 1400 feet is probably closer. Composite to composite takes it up around 2000. A white rocket in a blue sky at 2000 feet...I can't see it. Motor selection will be based on final weight of course.

In my experience, the E20Ws take a bit to come up to pressure. Probably about half a second. If they both pressurized at the same time it would be great. The Blue Thunders and Fast Jacks light the fastest. Since there are no single use Fast Jack E motors in 24mm, I may have to try the Blues, which I really don't like. Thinking air-starting the D12s because they light pretty easily. I will use something else other than Estes igniters.

Too bad there are no greens..we all know how easy they are to light.:wink:



Were they Whites? All of the AT Whites I fly usually pop, fizz...then roar.



Pro38 isn't in my foreseeable future. I am fairly heavily (to me anyway) invested in Aerotech and to a lesser extent Loki 38mm. But you make good points on the ease of starting using the pellet, it is probably BP but I don't know. Casting a BP pellet may not be too difficult, but making it fit inside a 24mm..eh, unlikely.

An upscale Viper IV would be pretty awesome. Two Loki H144s to two AT H73Js could be knocking on a mile. Lots of smoke and roar. That would be cool. Thanks for putting that idea into me head.

Larger clusters are likely in my future. I like the idea of clustering, airstarts, detaching boosters and all the engineering and designing that go along with them. This Viper IV is just the first step.

From conversations I've had the Blues might be the way to go, from what I have been told they are by far the easiest to light.

 

[MikeyDSlagle]

The near-wife had to go shopping with her grandma so I was with the two kids today. But I did manage to get a little bit done before lunch and park time.

The all the glue was cured so I was able to do some more fitting. Had to cut some off the coupler around the access hole but not much. It is going to be hidden anyway so looks wasn't a big concern. Luckily the vaseline on the screws worked as intended and kept the screws from getting glued in place. A little sanding and what not and got a good fit.

There is a small gap between the frame and the body tube. That's because there is a coupler between the two and it was cut farther back. I may fill the gap with epoxy but I don't think it will be necessary.



Like I say, a bit rough around the edges but the panel fits flush with the body tube. The far end doesn't look like it but that is just the rolled up edge. I need to put a small hole or something in the panel to be able to lift it easier, but that will be easy enough.



I went to soak some CA into the edges only to find my CA bottle was empty. Got the near-wife to bring me a bottle from Hobby Lobby and got the edges soaked real good, and the screw holes. Soaked every tube end I had, some were already getting damaged from being moved and banged around. Hopefully a light sanding will smooth the edges down quite nice.

I started with the main avionics bay, but just got the tubes cut. Didn't want to get elbow deep in epoxy and wood glue and have the baby suddenly realize she wasn't in my lap helping. LOL.

Will have to drag out the shop tools tomorrow and set up to cut some stuff.
I need two rings, two bulkplates, and two sleds. Will be a productive day if I can get those cut. I have a 1 1/2 inch hole saw but it is OD, so close. Looks like I will have to use my (dull) butterfly cutter / knuckle remover - gets me every time.

Dave, if you have no objections, I think I will try to get this printed and/or cut and put in on the side of the bird somewhere, probably on the access bay panel.

 

[MaxQ]

Now we are talking!

I'm actually working on a Nike-Hercules with a 4 38 cluster for the booster. I'm thinking I will light the cluster as 2 motors diagonal wired in parallel and the 2 sets in series. Worse case 2 of the 4 will light. The fail safe is that 2 motors have enough thrust to safely lift the rocket. In the sims the booster alone is going to 3000 feet. The sustainer is siming out to over 10,000.

Love to see a build thread.
I bought a 4" Nike Hercules sustainer with a 38mm MMT installed from a former member here that abandoned the project.....lots of things to consider.

A clustered booster with four 38's staged to a 38 MM sustainer calls for a dual deploy recovery...I set it aside since the available space between the balsa tail cone and nose one (both nicely turned components from Sandman) is only 8inches..not much room to deal with to get a droque and forward located main on opposite ends of a central av bay, not to mention where the break in those long extended sustainer fins will be.

Now that we have single point dual deployment available with a Jolly Logic chute release it may be more feasible.

 

[Mendal]

Love to see a build thread.
I bought a 4" Nike Hercules sustainer with a 38mm MMT installed from a former member here that abandoned the project.....lots of things to consider.

A clustered booster with four 38's staged to a 38 MM sustainer calls for a dual deploy recovery...I set it aside since the available space between the balsa tail cone and nose one (both nicely turned components from Sandman) is only 8inches..not much room to deal with to get a droque and forward located main on opposite ends of a central av bay, not to mention where the break in those long extended sustainer fins will be.

Now that we have single point dual deployment available with a Jolly Logic chute release it may be more feasible.

In your case I would go with the JLCR. My sustainer will fly on a single 54. I believe I’m going with a more traditional dual deploy or head end deployment. The biggest issue I have right now is that it is looking like I might require quite a bit of nose weight. Those big sustainer fins move the CP pretty far forward. One has to remember the original middle probably carried a couple hundred pounds worth of nuclear warhead.

 

[Mendal]

The near-wife had to go shopping with her grandma so I was with the two kids today. But I did manage to get a little bit done before lunch and park time.

The all the glue was cured so I was able to do some more fitting. Had to cut some off the coupler around the access hole but not much. It is going to be hidden anyway so looks wasn't a big concern. Luckily the vaseline on the screws worked as intended and kept the screws from getting glued in place. A little sanding and what not and got a good fit.

There is a small gap between the frame and the body tube. That's because there is a coupler between the two and it was cut farther back. I may fill the gap with epoxy but I don't think it will be necessary.

View attachment 333391

Like I say, a bit rough around the edges but the panel fits flush with the body tube. The far end doesn't look like it but that is just the rolled up edge. I need to put a small hole or something in the panel to be able to lift it easier, but that will be easy enough.

View attachment 333390

I went to soak some CA into the edges only to find my CA bottle was empty. Got the near-wife to bring me a bottle from Hobby Lobby and got the edges soaked real good, and the screw holes. Soaked every tube end I had, some were already getting damaged from being moved and banged around. Hopefully a light sanding will smooth the edges down quite nice.

I started with the main avionics bay, but just got the tubes cut. Didn't want to get elbow deep in epoxy and wood glue and the baby suddenly realized she wasn't in my lap helping. LOL.

Will have to drag out the shop tools tomorrow and set up to cut some stuff.
I need two rings, two bulkplates, and two sleds. Will be a productive day if I can get those cut. I have a 1 1/2 inch hole saw but it is OD, so close. Looks like I will have to use my (dull) butterfly cutter / knuckle remover - gets me every time.

Dave, if you have no objections, I think I will try to get this printed and/or cut and put in on the side of the bird somewhere, probably on the access bay panel.

View attachment 333392

I would be honored if you flew our brand on your bird. I should talk to mark at sticker shock about making some stickers.

Next time we make something like this we should add a little finger catch on the aft end of the door.

 

[MaxQ]

In your case I would go with the JLCR. My sustainer will fly on a single 54. I believe I’m going with a more traditional dual deploy or head end deployment. The biggest issue I have right now is that it is looking like I might require quite a bit of nose weight. Those big sustainer fins move the CP pretty far forward. One has to remember the original middle probably carried a couple hundred pounds worth of nuclear warhead.

it did indeed...had active guidance as well.
What is your sustainer diameter?

This one was 5.75 inches with a J275, with four I211s in the booster.

View attachment 333433

Guess we should not hijack....and start a new thread.

 

[MikeyDSlagle]

I would be honored if you flew our brand on your bird. I should talk to mark at sticker shock about making some stickers.

Next time we make something like this we should add a little finger catch on the aft end of the door.

I have some printable vinyl I've never used and CriCut I am going to try to print and cut some. Won't be StickerShock quality, but I'll see how it works.

Yeah some sort of finger hold would be handle. A good tap will probably get it out though.

Today I got everything sanded down and did more fit testing. Was able to get all my rings and plates cut as well as the small sled that will go into the terminal bay. Pretty much just did everything that required my shop tools. No pics because its nothing more that parts and pieces at the moment.

I set down and did a rough wiring diagram for the Eggtimer. Now I am having second thoughts about using it. And so many battery connections! Will be quite a few jumpers or splices. The transistors set up high and will just fit inside the a/v bay if mounted between the rod guides. The AUX board will not fit between the rod guides. I may have to redesign my sled. I can go with the RRC3 but I built the Eggtimer for this rocket. I'll see what develops. May need something printed.

 

[Mendal]

I set down and did a rough wiring diagram for the Eggtimer. Now I am having second thoughts about using it. And so many battery connections! Will be quite a few jumpers or splices. The transistors set up high and will just fit inside the a/v bay if mounted between the rod guides. The AUX board will not fit between the rod guides. I may have to redesign my sled. I can go with the RRC3 but I built the Eggtimer for this rocket. I'll see what develops. May need something printed.

I might know someone that can help with that.

I should post some photos of the sleds I designed. I built a set for a friend that packs an AIM Xtra, AIM USB, 2 WiFi switches, 2 batteries in holders, and 4 terminal connectors into a 3” AV bay. I also started to design a set that is modular so you can put 2 sleds with electronics packages back to back. So you can have multiple sled with different setups (one might be a eggtimer quantum with battery, another might be an rrc3 with battery), you can choose two packages and they mate together and slide onto one pair of all threads.

 

[Mendal]

it did indeed...had active guidance as well.
What is your sustainer diameter?

This one was 5.75 inches with a J275, with four I211s in the booster.

View attachment 333433

Guess we should not hijack....and start a new thread.

I will probably start a thread soon. The sustainer is 4-4.25 inches and has been the must challenging part to design. I’m going to pm you about your sustainer. And the one you posted a photo of... active guidance?!

 

[MaxQ]

I will probably start a thread soon. The sustainer is 4-4.25 inches and has been the must challenging part to design. I’m going to pm you about your sustainer. And the one you posted a photo of... active guidance?!

"Active guidance" was on the real thing.
Although Andy Shecter's Nike Hercules in the picture did have had RC control for staging and recovery...apparently didn't work on flight #2 - pranged under power after one of four booster motors failed to light.
Sent a PM.

 

[MikeyDSlagle]

Edit: Fixed the pictures.. I hope

So now I am having problems loading pictures. Crashed Firefox a few times but now it seems I can do one at a time.

The assembled bay. Looks like a miniature smoker or a walkie talkie. The tube/conduit coming out the top is where the wire will run through and plug into the aft bulkplate on the A/V bay. It uses a DC jack and is meant to come unplugged when the apogee charge fires. The conduit will help shield the wires from ejection charge and tangling with the harness. I will use some sort of grommet or O-ring to help seal against gases as well. Intended to have the plug end of the cable fit into the conduit but that idea got lost somewhere along the way.

There is a small plate with two holes in it in the first two pictures. In the board there are two weld nuts. Together they will form a clamp to hold the wire secure so the stress will not be on the terminal. I went with the larger terminal because it is easier to fiddle with the larger one and I will be putting two wires in each terminal. Just easier with the larger terminal down in the hole.

The idea is the wires will run into the bay via the conduit, under the clamp and into the terminal. I have some stress relief clamps somewhere but am only just now remembering them. Once plugged into the A/V bay, the slack will be pulled through the clamp and secured. Wires from the air start motors and possibly the breakwire will run from the aft end up through the hole in the bottom of the bay. Slack and excess wire will be brought into the bay.



I used the US Composites Fastek to glue the bay. The stuff is sticky but slick. Didn't have to worry about it grabbing too soon. Had plenty of time for adjustments. The excess pushed out by the forward bulkhead will form a fillet, albeit not a great one, but I will tend to that later. I did a jam up job countersinking some screws to attach the frame. I may eventually pull these and fill the holes. Don't know how necessary they really are. If the glue doesn't have them that is.



The booster section. Still rough around the edges. But that will all come out in the wash...maybe. I went with 1/4" Kevlar because of the tight space and I just had a piece 10' long. Trying the Double Davy knot, we'll see how that holds. Did a fancy shmancy anti-zipper/anti-rub-through get up on the harness but didn't get pictures of it.

I aligned it between the fins so I could prop it up to get in there instead of fighting with it sitting on one fin.

 

[MikeyDSlagle]

Playing around with my electronics bay a little bit. Looks like the Eggtimer is (likely) out unless I come up with a new sled, either built at home or printed. The transistors sit up too high to fit into this bay. Had I left out the stiffy coupler, it may had fit. I can put it on the back side, between the rod guides, but will also need the AUX board in there as well - running out of room lengthwise. So..

The RRC3 will fit with room to spare. Will have to acquire an auxiliary harness and I'm not seeing it on the website. Looks like I need to send Mr Missileworks an Email. *Paging Jim Amos...Jim Amos*

Before everyone rushes to Eggtimer's defense, let me say I am not bad-mouthing Eggtimer. I have several ET products in my rockets, and two kits here on my desk to be built. Always had good experiences with them. Toasted my first Quark, but that was my fault. Just the transistors are too tall. Like I mentioned elsewhere, I built it just for this rocket so I am a bit bummed it won't fit. Didn't intend to purchase an extra harness for the RRC3, I had to go back and purchase an AUX board for the Eggtimer after all.

So anyway...fixed the pictures in the previous post I think. Will commence working on the A/V bay and nose cone bay once I sort out the details there.