I wanna break records! BT60/38mm Size limits

Hello all,
After reading a post from Steve at Mach1, it gave me an idea.
Why don’t those of us who would like to try to become “record breakers” get together here, share really plausible ideas, and see what happens!
We can share data, Rocksim, OpenRocket etc, as well as hints.
I for one would be really appreciative for ideas.
I think we could keep the size limited to BT60/38mm only. FG, Carbon, Cardboard or phenolic would be acceptable, as would length, fin count, DD or SD.

Any one up for it?

What is your timeline? I build slowly.

may I present a payload rocket for you all to play with. designed to carry a 1 oz payload(minimum, unstable otherwise).
Rex

What record(s) do you want to break? That's a good starting place

of course after I built it the rules changed...payload weight dropped to 0.1 oz so it was overweight, still I can honestly say that nobody saw it go . you do need to spec your motor limits, a 38mm motor fits inside a bt60 . a big bertha on a G67 really gets up and goes.
Rex

I think all this may be hashed out here within. I don’t have a time limit, it’s not a competition, just a specific task of taking BT60/38mm rockets to their limits, and maybe even safely beyond what we think is their limit.
For example: Mach1 Omicron, 38mm min diameter- some have sights on highest attainable altitude. Others may go for incredible speed.
Here we would share ideas, show builds, discuss weight and how to trim it out without negative effect.
No competition, no start date, end date, no just a focus on performance.

If mach1 bt60 coupler ( like Estes bt60 coupler ) can allow 38mm casings... then it should be thoroughly doable to run either of the Loki 38/1200 K's.

There is a thread in here about the Omicron going 38mm min diameter, I’ve been watching that intently.
My Black Hole came with 29mm motor mount and rings, but I’m considering options
I think Steve at Mach1 sells parts. If I decided to go 38mm, it’s doable.
My big hurdle is to get Level one out of the way, and move up so more options are open.

Tomflysrc said:

There is a thread in here about the Omicron going 38mm min diameter, I’ve been watching that intently.
My Black Hole came with 29mm motor mount and rings, but I’m considering options
I think Steve at Mach1 sells parts. If I decided to go 38mm, it’s doable.
My big hurdle is to get Level one out of the way, and move up so more options are open.

Click to expand...

Just a suggestion, but when you do build a 38 ( and it doesn't have to be this one ), start it on a 38mm G or baby H. You're going to want to practice tracking when it's only barely out of sight.

Good advice! I have plans to put an Eggfinder Mini in the nose. Doing a few lower launches should be wise.

Steve also mentioned they now have sleeved LOC style (heavy) plastic nosecones that will now fit the BT60 tubes they run at Mach One rocketry, I have an alien interceptor and a heavy nosecone would be a nice addition to any of their BT60 stuff, for the more oompfy motors.

Well keep your eyes on SMT DESIGNS as that Steve is working on some awesome things for 38mm and BT60 tubes and nose cones.
I’m going to put his coupler bay and nose bay in my Black Hole build.

I'm keeping my Black Hole with the 29mm mount and may use a 24mm adapter for low flights. I have a Wildman mini with the heavier body tube and a Darkstar mini with lighter components as well. Since they are all similar sized rockets, I'm really curious how they will perform against each other.

I ordered the Starlight 38 kit with the 38mm stuffer tube and one of the SMT Designs retainers and AV bay kits. I may transfer electronics between these 3 rockers if I can. I'll have a better idea once I build everything over the Winter.

There’s a good idea! I could use my BH as is, 29mm. Then grab an Omicron or such from Mach1 for 38mm once I get bugs worked out, electronics sorted, etc.

If you are going for altitude and speed, pick one of the kits with the smaller/lower profile fins. Black Hole has some really large fins. Something like the Alien Interceptor with the small fletching-like fins will be your speed/altitude champ.

I'm here. Just ordered a Mach1 Black Hole BT60/38mm with the MD retainer. I have AT 38/600 case with the threaded forward closure. Looking for a 720 case for it. USPS say tomorrow???

David Schwantz said:

I'm here. Just ordered a Mach1 Black Hole BT60/38mm with the MD retainer. I have AT 38/600 case with the threaded forward closure. Looking for a 720 case for it. USPS say tomorrow???

Click to expand...

Tomflysrc said:

There is a thread in here about the Omicron going 38mm min diameter, I’ve been watching that intently.
My Black Hole came with 29mm motor mount and rings, but I’m considering options
I think Steve at Mach1 sells parts. If I decided to go 38mm, it’s doable.
My big hurdle is to get Level one out of the way, and move up so more options are open.

Click to expand...

He does, I just spoke to him on Monday, got the stuffer tube, MD retainer, light weight chute. Really looking forward to seeing his stuff.

I also ordered a 3" Black Hole, 54mm MD, and 2 Scats, one BT55 with 29mm MMT and the BT60. Going to try and put 38mm MMT in the BT60 Scat also.

Tomflysrc said:

Well keep your eyes on SMT DESIGNS as that Steve is working on some awesome things for 38mm and BT60 tubes and nose cones.
I’m going to put his coupler bay and nose bay in my Black Hole build.

Click to expand...

Thanks Tom! Of note, I will have a Loki 1/4-20 minimum diameter mount shipping late next week. It is on my site now, but I am waiting for a part for it. It is available for both 38mm and BT60.

David Schwantz said:

I'm here. Just ordered a Mach1 Black Hole BT60/38mm with the MD retainer. I have AT 38/600 case with the threaded forward closure. Looking for a 720 case for it. USPS say tomorrow???

Click to expand...

I placed 2 orders from his recent sale. My Exiter and Black Hole shipped immediately and arrived a day earlier than USPS said it would. My 2nd order with the 38mm Starlight hasn't shipped yet, I figure it's waiting on a part or two. Plenty of things to do in the mean time.

My order for Mach1 Omicron went in, has a three week delay (no big issue) I think this is my 38mm MD platform. My Black Hole is going to be my 29mm platform.
Between Mach1 and SMT, I think I’m covered.
Now to look for the right recovery harnesses at Onebadhawk, and chutes from TFR.
UNLESS... anyone have great suggestions?

I started to build my Black Hole 38 this afternoon. I have a 29P Aeropack retainer for my Darkstar Mini that's still in the bag, but it is a little looser than I would like on the thinner Mach 1 fiberglass. I'm going double check the tubing diameter with a caliper and order some retainers for some other kits too.

I wonder if I will be able to use the same coupler with the SMT e-bay installed on my Black Hole and Starlight?

I believe it will. They’re both the same BT.

I just measured my 29mm motor mount from Mach 1. The diameter is 1.2015 in, (I know, mixing systems here). Steve recommends the 29L2 or P retainers, but the 29L looks to be the closest fit at 1.215in. Is that too tight to allow for JB weld?

https://aeropack.net/retainerdimensions.asp

I’ve been considering this too, what’s the thoughts here on mounting shock cords so they are serviceable in the future?

SMT Designs has a 38mm Internal motor retainer kit that gives you a Kevlar loop to attach recovery harness.

Tomflysrc said:

SMT Designs has a 38mm Internal motor retainer kit that gives you a Kevlar loop to attach recovery harness.

Click to expand...

I bought this with my mach1 alien interceptor. I think maybe my rocket kit is missing its MMT - i emailed mach1

Either way I can't make heads or tails on how this retainer is supposed to work - it's like nothing I've ever seen. Any pointers?

I just got one from Steve also. The big, thicker, round part is glued, into the air frame at the distance that you will need it to fly the longest motor that you plan on. The smaller, thinner part is then screwed onto the part that was glued in place, but only after you tie the larger dia kevlar cord through the hole to form a loop to attach the longer shock cord to. You can also screw the thicker part into the tube if you want to be able to switch it between rockets. I think I will glue mine in place.

David Schwantz said:

I just got one from Steve also. The big, thicker, round part is glued, into the air frame at the distance that you will need it to fly the longest motor that you plan on. The smaller, thinner part is then screwed onto the part that was glued in place, but only after you tie the larger dia kevlar cord through the hole to form a loop to attach the longer shock cord to. You can also screw the thicker part into the tube if you want to be able to switch it between rockets. I think I will glue mine in place.

Click to expand...

Okay so if I'm understanding you..this only prevents the motor from thrusting through the rocket - it doesn't prevent the motor from being ejected. And it's not suitable for single deploy. Am I getting that right?

David Schwantz said:

I just got one from Steve also. The big, thicker, round part is glued, into the air frame at the distance that you will need it to fly the longest motor that you plan on. The smaller, thinner part is then screwed onto the part that was glued in place, but only after you tie the larger dia kevlar cord through the hole to form a loop to attach the longer shock cord to. You can also screw the thicker part into the tube if you want to be able to switch it between rockets. I think I will glue mine in place.

Click to expand...

Okay so if I'm understanding you..this only prevents the motor from thrusting through the rocket - it doesn't prevent the motor from being ejected. And it's not suitable for single deploy. Am I getting that right?