Der Big Red Max Build.

[Scott_650]

Yeah, kind of a gap. It's surprising that with the parts they do have that some aren't kitted up. They clearly have a lot of those PSII parts. Motor tubes, retainers, shock cords, chutes, body tubes and nosecones. Fins are the piece preventing profits?

Lack of in-house production motors is why we don’t see a return of the PSII builder kits - even the lightest version probably wouldn’t meet Estes’ stability standards on a BP 29mm motor. During the time the Leviathan, MDRM, etc were in the catalog Estes sold relabeled Aerotech motors to fly them, since motor sales are the primary profit generator for Estes it’s not likely we’re going to see any of those kits return.

 

[user 35280]

I’m kicking around building a 3 inch goblin. Maybe I should skip the 3 inch and build a 4 inch instead.

Might as well build a 5.5” and 7.5” diameter Goblin too.
https://locprecision.com/collections/loc-precision-rocket-kits/products/lc-goblin55
https://locprecision.com/collections/rockets-7-675-diameter/products/goblin75

 

[user 35280]

Estes sells a 4” NC???

https://estesrockets.com/product/072415-pro-series-ii-4-plastic-nose-cone/

 

[user 35280]

Este has the 3" and 4" DRM nose cones. Easiest way to find them on the site now seems to be typing 3" or 4" into the search...

-Bob

https://estesrockets.com/product/072415-pro-series-ii-4-plastic-nose-cone/
https://estesrockets.com/product/072304-pro-series-ii-3-plastic-nose-cone/

 

[Back_at_it]

Time to wrap this one up. We got one warm day last week so I took advantage of it an got the paint sprayed on. I tried something different with this one. I picked up a can of Ace brand Safety Red. I read good reviews and thought the color would work nicely.

Sprayed on three coats about 15 mins apart. The Nose Cone was painted with Krylon Gloss Black. I let everything sit for a few days. The Ace Brand paint took a full day before it stopped being tacky. After day two it's hard as a rock. I'm actually liking the finish more than the Krylon brand.



Next it was time for the vinyl.





Once the rocket was completely assembled, Vinyl installed, full recovery gear etc. I inserted the largest motor I plan to run in this rocket which is a G74-9 and added nose weight until I got the stability where I wanted it. I cut the bottom off the nose cone and added 2oz of BB's using 30min epoxy. Once that was cured I added a plywood bulkhead and screw eye.



With the nose weight the CG is sitting right at 19.75" from the tip of the nose cone and stability is 1.18.

Finally I decided to weigh the finished rocket. This with the Shock Cord and Parachute installed but no motor. Finished weight of 20.3oz.

 

[DigBaddy]

Really, really nice!!!

Got an Ace a mile away, so point noted on the paint.

Just hosed primer on my MDRM. You're definitely faster

 

[Scott_650]

Really, really nice!!!

Got an Ace a mile away, so point noted on the paint.

Just hosed primer on my MDRM. You're definitely faster

Ace Premium is pretty good stuff - they don’t have the range of colors that Rusto or Krylon comes in but that’s really kind of ok since everything I build seems to end up one combination or another of red, white, blue, black, green or orange with the occasional yellow

 

[Back_at_it]

Ace Premium is pretty good stuff - they don’t have the range of colors that Rusto or Krylon comes in but that’s really kind of ok since everything I build seems to end up one combination or another of red, white, blue, black, green or orange with the occasional yellow

I'm pretty happy with it so far. Granted this was only a single color so I don't know how it reacts to multiple colors, clears or cure times. But for simple one color rockets, I like it.

 

[dpower]

That turned out great, nice work! At 20.3 oz, what do you plan to fly it on? My stock-built weighs 12 oz w/o motor, and I'm not fully comfortable on an E16 or F15, will probably use at least an F20.

 

[Back_at_it]

first flight will be the E30 but I also have F43’s and F67’s.

At 12oz I would be completely comfortable flying the on the E16. I’ve flown a number of rockets in the 13oz range on them Just point it straight up and fly off a 6ft rod.

 

[drlsly]

I may be daft for asking, but how did you get the fin/motor can into the tube assembled? Slit the body tube?

 

[Back_at_it]

I may be daft for asking, but how did you get the fin/motor can into the tube assembled? Slit the body tube?

Yes. If you look back at page1, post #22 you can see the slits in the bottom of the body tube.

Basically make a slit from the bottom of the fin slot to the end of the body tube. Once the fin can is complete you can slide the tube over the fins and tuck the tube in under the bottom of the fins.

With the heavier tube construction, I didn’t need to do anything special to get to tube to fit. Just tucked it under the bottom of the fins and let it dry

 

[maxim]

Hello experts, could anyone please suggest a baffle. I'm building der red with plywood upgrades. Where can I buy a good baffle ? would one from apogee would work or maybe something else ? Thanks guys

https://www.apogeerockets.com/Build...74mm_Ejection_Baffle_Fits_3in_thin-wall_tubes

 

[Ronz Rocketz]

I think it's too short for a baffle. Should be about 4" from the end of the MM plus the length of the baffle plus the length of the NC shoulder, doesn't give much space for the laundry. Dogbarf and a few sheets of wadding does the trick or nomex blanket to wrap the chute.

 

[maxim]

I think it's too short for a baffle. Should be about 4" from the end of the MM plus the length of the baffle plus the length of the NC shoulder, doesn't give much space for the laundry. Dogbarf and a few sheets of wadding does the trick or nomex blanket to wrap the chute.

Thanks for explaining, will do that. If I get nomex blanket I won't need the dogbarf or wadding at all ?

 

[Ronz Rocketz]

Thanks for explaining, will do that. If I get nomex blanket I won't need the dogbarf or wadding at all ?

True. For my flights, I think I did use dogbarf and wadding. For my 3" Citation Patriot and Leviathan, I used the Nomex blankets. I bought a 12" square and cut it into fourths.

 

[Back_at_it]

Hello experts, could anyone please suggest a baffle. I'm building der red with plywood upgrades. Where can I buy a good baffle ? would one from apogee would work or maybe something else ? Thanks guys

https://www.apogeerockets.com/Build...74mm_Ejection_Baffle_Fits_3in_thin-wall_tubes

There aren't any over the counter baffles that would work that I am aware of. Because of the length of the body tube, the baffle needs to be relatively short. Something in the 2.5 to 3.0 inch range if you still want to have ample room for the recovery gear. The baffle I made for this rocket was 2.5 inches in total length.

There are also differing opinions with the distance the baffle needs to sit from the top of the motor. I've heard everything from 3 inches to more than a foot is required. In practice, I have built multiple rockets with the baffles as close as 1 inch from the top of the motor tube and flown them successfully without deployment failure or any type of negative effects on the baffle itself. This Big Red Maxx has 4 flights since being built and all were successful with good strong ejections.

As for the room required. The pic below shows the position of the internal components. If you keep the Baffle compact there is more than enough room easily get the recovery in there without forcing anything. I've even flown with an altimeter on board.



The baffle for this rocket was made using a 2.5 inch long piece of coupler. I then cut two pieces of 29MM motor tubing for the internal tubes. Each internal tube is 1.5 inches long. I don't have pics of the inside of this baffle but I do have pics of the exact same baffle built for another rocket. The only difference is the other baffle is 4 inches long. Otherwise the materials and build process is the same.



The internal tubes were glued in place on the inside walls of the coupler. The end of the tubes overlap approx. 1/4 inch so that none of the ejection could jump from one to the next.

The baffle was capped top and bottom with lite ply caps.




Since I added additional weight to the rear of the rocket using plywood fins, rings and a baffle, I needed to add additional nose weight. TO make this easier I cut the bottom of the cone off and replaced it with a bulkhead. Note that I also recessed the bulkhead giving me additional space inside the tube. This isn't mandatory but it is another way to gain more room if you need it.

 

[maxim]

There aren't any over the counter baffles that would work that I am aware of. Because of the length of the body tube, the baffle needs to be relatively short. Something in the 2.5 to 3.0 inch range if you still want to have ample room for the recovery gear. The baffle I made for this rocket was 2.5 inches in total length.

There are also differing opinions with the distance the baffle needs to sit from the top of the motor. I've heard everything from 3 inches to more than a foot is required. In practice, I have built multiple rockets with the baffles as close as 1 inch from the top of the motor tube and flown them successfully without deployment failure or any type of negative effects on the baffle itself. This Big Red Maxx has 4 flights since being built and all were successful with good strong ejections.

As for the room required. The pic below shows the position of the internal components. If you keep the Baffle compact there is more than enough room easily get the recovery in there without forcing anything. I've even flown with an altimeter on board.

View attachment 533672

The baffle for this rocket was made using a 2.5 inch long piece of coupler. I then cut two pieces of 29MM motor tubing for the internal tubes. Each internal tube is 1.5 inches long. I don't have pics of the inside of this baffle but I do have pics of the exact same baffle built for another rocket. The only difference is the other baffle is 4 inches long. Otherwise the materials and build process is the same.

View attachment 533673

The internal tubes were glued in place on the inside walls of the coupler. The end of the tubes overlap approx. 1/4 inch so that none of the ejection could jump from one to the next.

The baffle was capped top and bottom with lite ply caps.


View attachment 533675View attachment 533677View attachment 533678

Since I added additional weight to the rear of the rocket using plywood fins, rings and a baffle, I needed to add additional nose weight. TO make this easier I cut the bottom of the cone off and replaced it with a bulkhead. Note that I also recessed the bulkhead giving me additional space inside the tube. This isn't mandatory but it is another way to gain more room if you need it.

View attachment 533674

Yes thank you very much, I did look at your baffle and the whole build. You did inspire me awesome work!

 

[gldknght]

Time to wrap this one up. We got one warm day last week so I took advantage of it an got the paint sprayed on. I tried something different with this one. I picked up a can of Ace brand Safety Red. I read good reviews and thought the color would work nicely.





With the nose weight the CG is sitting right at 19.75" from the tip of the nose cone and stability is 1.18.

Finally I decided to weigh the finished rocket. This with the Shock Cord and Parachute installed but no motor. Finished weight of 20.3oz.

What did you use for a parachute in this? (Forgive my sarcasm here, I was really disappointed with Estes on this kit, but your build looks amazing) That piece of heavy garbage bag plastic included in the kit, or did you put in an actual parachute?

 

[Ronz Rocketz]

There aren't any over the counter baffles that would work that I am aware of. Because of the length of the body tube, the baffle needs to be relatively short. Something in the 2.5 to 3.0 inch range if you still want to have ample room for the recovery gear. The baffle I made for this rocket was 2.5 inches in total length.

There are also differing opinions with the distance the baffle needs to sit from the top of the motor. I've heard everything from 3 inches to more than a foot is required. In practice, I have built multiple rockets with the baffles as close as 1 inch from the top of the motor tube and flown them successfully without deployment failure or any type of negative effects on the baffle itself. This Big Red Maxx has 4 flights since being built and all were successful with good strong ejections.

As for the room required. The pic below shows the position of the internal components. If you keep the Baffle compact there is more than enough room easily get the recovery in there without forcing anything. I've even flown with an altimeter on board.

View attachment 533672

The baffle for this rocket was made using a 2.5 inch long piece of coupler. I then cut two pieces of 29MM motor tubing for the internal tubes. Each internal tube is 1.5 inches long. I don't have pics of the inside of this baffle but I do have pics of the exact same baffle built for another rocket. The only difference is the other baffle is 4 inches long. Otherwise the materials and build process is the same.

View attachment 533673

The internal tubes were glued in place on the inside walls of the coupler. The end of the tubes overlap approx. 1/4 inch so that none of the ejection could jump from one to the next.

The baffle was capped top and bottom with lite ply caps.


View attachment 533675View attachment 533677View attachment 533678

Since I added additional weight to the rear of the rocket using plywood fins, rings and a baffle, I needed to add additional nose weight. TO make this easier I cut the bottom of the cone off and replaced it with a bulkhead. Note that I also recessed the bulkhead giving me additional space inside the tube. This isn't mandatory but it is another way to gain more room if you need it.

View attachment 533674

The risk of inserting the baffle too close to the MM is that it might create excessive back pressure and push out the motor rather than eject the laundry. Just be sure the motor is well secured from popping out.

That said and with the 3" tube, I rely on the asbestos blanket... I mean the chute protector. There's plenty of room for a 12" sheet to wrap around the bottom of the chute.

 

[Back_at_it]

What did you use for a parachute in this? (Forgive my sarcasm here, I was really disappointed with Estes on this kit, but your build looks amazing) That piece of heavy garbage bag plastic included in the kit, or did you put in an actual parachute?

No worries. I was really disappointed with Estes on this kit as well. As you can see from the build, The only parts I used from the kit were the tubes and the nose cone. Could have saved myself a lot of money buy just buying the nosecone as I already had a ton of 3" tubing laying around. Live and learn.

The first flight was on an E30 with a 24in nylon chute from LOC and I felt that it came down a little too quickly from that altitude. With an altitude of only around 500ft it really didn't have a ton of room to open and slow the decent. Thankfully it landed in tall grass so no harm done. The next flight I used a 30in chute from Apogee and that really slowed the decent down to what I felt was more acceptable for low altitude flights.

The last and most recent flight was on a F67 and with a recorded altitude of 1006ft. That flight had the 24" chute on board as the grass was tall and I knew it had tons of time to slow down. I certainly wouldn't go any smaller than a 24". Depending on what surface you are landing on, I'd say anything between 30 and 36 inch if you build like mine and yours weights 20+ oz.

 

[Back_at_it]

The risk of inserting the baffle too close to the MM is that it might create excessive back pressure and push out the motor rather than eject the laundry. Just be sure the motor is well secured from popping out.

That said and with the 3" tube, I rely on the asbestos blanket... I mean the chute protector. There's plenty of room for a 12" sheet to wrap around the bottom of the chute.

Agreed. If you are going to use baffles you need to ensure that they have sufficient flow so that pressure doesn't get excessive below the baffle. As Ron mentioned, you are risking blowing the motor out the rear so some type of positive retention is required. Often times, friction fitting isn't enough. You also run the risk of over pressurizing the body tube below the baffle and blowing the tube apart.

When using tube baffles like I have on this build, I like to use the largest tubes that will fit inside the coupler. For me the tubes need to be AT LEAST the same diameter as the motor tube. If larger would have fit I would have used larger. In this case the motor mount is 29mm so the tubes inside the baffle need to be at least 29mm. If I cannot fit at least the motor tube size I'll go with a plate style baffle which is less restrictive by design or simply stick with wadding or a blanket.

Typically 3in. is right where I start using fire blankets but I wanted something more permanent on this build.