BT-50 - BT-70 Altimeter

I'm currently designing a BT-60 a/v bay. It's for a Mean Machine this time, but I have other uses planned as well. What's the smallest DD altimeter I can get commercially? Logging would be nice but is not required. I'd at least like to get altitude reading from it. Other than that, I just want it to do drogue and main.

I have a BT 60 AV bay and use an Eggtimer and 2 1S LiPo for power. The Eggtimer does everything.

I am currently finishing up a BT55 and BT60 AV bay that will use an Eggtimer Quark (really small deployment only).

You can see photos of the Quark and BT55 AV bay here: https://www.rocketryforum.com/showt...ic-ports-are-very-small&p=1486580#post1486580

An RRC3 fits in a BT-50 and does just about everything.

I've heard of the Eggtimer. I thought it was a staging timer originally. I've never seen one in use that I know of. The only altimeter I'm familiar with is the Stratologger series. Who makes the Eggtimer? And who makes the RRC3?

Kruegon said:

I've heard of the Eggtimer. I thought it was a staging timer originally. I've never seen one in use that I know of. The only altimeter I'm familiar with is the Stratologger series. Who makes the Eggtimer? And who makes the RRC3?

Click to expand...

Yes and nope. It is an economical flight computer with a no frills approach to programming. It can do DD "and" staging but an additional, affordable outboard add-on board is necessary.
Yes it can do DD alone and yes it can stage but it doesn't have some of the safety check options that the pricier devices offer.
If one does their simulation homework, I believe it's a workable device for staging smaller and medium projects. You will have to read the instructions though.

It and the Quark one has to build. I think a Quark would be good if you want the smaller size for the Mean Machine and you can do without recording. If you can stand the space requirement, the EggTimer will work. You have to build it so if that's an obstacle, get something else or have someone build it for you. If you want to go "whole hog", the Raven 3 at $155.00 will get you baro/accel data and then some.

https://www.eggtimerrocketry.com/page19.php Kurt

Kruegon said:

I've heard of the Eggtimer. I thought it was a staging timer originally. I've never seen one in use that I know of. The only altimeter I'm familiar with is the Stratologger series. Who makes the Eggtimer? And who makes the RRC3?

Click to expand...

Eggtimer Rocketry makes the Eggtimer, Eggfinder, Eggtimer TRS, and the Quark. Missleworks makes the RRC3 (which is what I use) and MW is soon to add expansion boards for GPS and realtime telemetry.

Is there a timeframe on the MW GPS?

I'm surprised the Stratologger or Stratologger CF from PerfectFlite haven't come up in this discussion yet.....either will fit in BT-50.

My Strato is indide a rocket for tomorrow's launch. I have an idea on a bay sled setup for the BT-60 but it'll require refinement.

nmartin said:

Is there a timeframe on the MW GPS?

Click to expand...

Hopefully the next couple of months.

I'd like to help, but I have no idea what "BT-50" means. Millimeters, please. Time for Estes to move beyond their 1960's naming convention and align with rest of the industry. I'd even settle for inches, hands, or fathoms!

Buckeye said:

I'd like to help, but I have no idea what "BT-50" means. Millimeters, please. Time for Estes to move beyond their 1960's naming convention and align with rest of the industry. I'd even settle for inches, hands, or fathoms!

Click to expand...

BT-50 is a 24mm ID thin walled tube. As for Estes aligning with the rest of the industry, they started the industry. Generation after generation have built and flown their rockets. Every old school BAR and most children starting out known these tubes by their current designation. It's easier to learn this than to try and have everyone else change just for you.

Kruegon said:

BT-50 is a 24mm ID thin walled tube. As for Estes aligning with the rest of the industry, they started the industry. Generation after generation have built and flown their rockets. Every old school BAR and most children starting out known these tubes by their current designation. It's easier to learn this than to try and have everyone else change just for you.

Click to expand...

As a BAR, the Estes BT sizing is the preferred method for me to. I know that some day I will have to step out of my comfort zone, but just not ready yet.

Kruegon said:

BT-50 is a 24mm ID thin walled tube. As for Estes aligning with the rest of the industry, they started the industry. Generation after generation have built and flown their rockets. Every old school BAR and most children starting out known these tubes by their current designation. It's easier to learn this than to try and have everyone else change just for you.

Click to expand...

I am happy to learn that some of the new altimeters will fit in this tube. 38mm (err, BT-58.65?) with the ol' Perfectflite MAWD is the smallest I have done.

I am an old fart BAR as well, and I never bothered to learn the "BT-something" convention now nor then. Seemed silly when a ruler is a much more useful tool. Anyway, I moved quickly to HPR, where millimeters rule the day.