I’ve purchased the Der Big Red Max and planned to buy the upgrade for it.
I noticed the Vander-Burn kit doesn’t come with a bigger motor mount like other upgrade kits do. That’s no big deal to me. But I do see that it says you can fly bigger motors with this kit.
Are their bigger motors to buy that aren’t past Level 1 cert?
When you say "bigger motor mount" do you mean "longer", or "larger diameter"? In the former case, a longer motor can fit into a shorter motor tube with no problem, so long as there is no motor block in the way. The DBRM does not come with a motor block, so there is nothing preventing the adventurous flyer from stuffing an I200 into it.
(Well, maybe the body itself is too short. I fly mine on I200s, but only after I stretched it following a crash that accordioned part of the original tube.)
In the latter case, as
@tsmith1315 mentioned, there aren't many 38mm G motors. If you don't intend to fly the rocket on high-power motors, there's not a lot of reason to go larger than 29mm. On the other hand, a 3" tube with only a 29mm seems like wasted space in a way, and there's no reason a DBRM with upgraded fins can't be flown on mild high power motors. If I build another one (or - more likely - the similar Great Goblin), it will probably have swapable motor mounts to fly clusters and larger diameter motors.
FYI; making it a 38mm Motor mount will also likely need to make the motor tube longer as well, which limits your available space to pack a parachute.
For a given impulse, a 38mm is shorter, ceteris paribus. For instance, Aerotech's 38/120 case, with four G reloads available (one of them high-power) is shorter than either the 29/100 case (two G loads, one of them high power) or the 120 case (three G reloads, all low power).
Which isn't necessarily true, because you can build DBRM to be fairly stout with the components that come with the kit (check out other build threads here).
<snip>
The plywood is great for the fins as it's much stronger than the Balsa, but I don't think the rings do anything other than add weight. Either way, it will take a punchier motor if you build it nice and strong.
Agreed, the stock rings are fine. Through the wall fins epoxied to the motor tube and the body can take up any load the stock rings give up.
My inclination these days though is to eschew the plywood kits and just fiberglass the stock balsa fins. We'll see if that bites me eventually. My I-flying stretched DBRM has the fins significantly cut down; perhaps they wouldn't hold up to landings as well if they had remained full size.
FYI however; the G-80 has a lot of initial thrust but I believe a G-40 is longer burning, so for a rocket like the DBRM, you'll likely get more altitude from a G-40...
Pretty sure that on such a heavy, draggy rocket you'll find that the punchier motor will get you more altitude. Certainly that's the case when I sim my DBRM in its original, mostly stock configuration.
Sure there are... Here's a list of 29mm motors up to a G80, which anything bigger is considered HP.
Go to Apogee Components website and search for
29mm motors.
Beware that anything that's over 80N average thrust or is a sparky is a high power motor. That's the majority of CTI G motors, at least six of Aerotech's 28 G motors, and 2 of the 5 Loki G motors.