Blue Raven in 29mm bulkhead form factor

[Neutronium95]

My unit arrived today. I broke out laughing like a madman from seeing how small it is. I'm looking forward to some truly ridiculous builds with it in the near future.

 

[manixFan]

I got mine as well. Not sure I’ll get my build done by Balls, but I may at least have it go as a ride along in another rocket. It does open a lot of doors to small rockets.

Thanks Adrain for your continued innovation.


Tony

 

[bad_idea]

@Adrian A , I don't think it was discussed specifically (if it was, I apologize for missing it), but is it safe to assume that the 29mm pancake Blue Raven is orientation agnostic at launch like the regular Blue Raven? I'm wondering if this could be familiarity-tested on its side on a conventional sled.

 

[Adrian A]

@Adrian A , I don't think it was discussed specifically (if it was, I apologize for missing it), but is it safe to assume that the 29mm pancake Blue Raven is orientation agnostic at launch like the regular Blue Raven? I'm wondering if this could be familiarity-tested on its side on a conventional sled.

Yes, any orientation is fine.

 

[bad_idea]

Yes, any orientation is fine.

Excellent. Thank you. This will help me with several things as I test out electronics for a future two-stage. (Ordered earlier today, BTW; order didn't depend on the answer but is good news for me.)

 

[kjhambrick]

Yes, any orientation is fine.

@Adrian A --

Is there a new accelerometer calibration procedure for the 29mm Blue Raven ?

Thanks.

-- kjh

 

[Neutronium95]

Is there a drawing showing the locations of the holes for the threaded rods? Would make designing my avbay a lot easier.

 

[Adrian A]

@Adrian A --

Is there a new accelerometer calibration procedure for the 29mm Blue Raven ?

Thanks.

-- kjh

@Adrian A --

Is there a new accelerometer calibration procedure for the 29mm Blue Raven ?

Thanks.

-- kjh

@Adrian A --

Is there a new accelerometer calibration procedure for the 29mm Blue Raven ?

Thanks.

-- kjh

No, though the accelerometer orientations do require me to do an extra command when I do the initial programming during production. The Blue Raven remembers after that so subsequent calibrations should be fine.

 

[Adrian A]

Is there a drawing showing the locations of the holes for the threaded rods? Would make designing my avbay a lot easier.

Not yet. And I’m currently in a tent at 11,900 feet waiting for the rain to stop, so it will be a couple of days before o can provide that.

 

[Neutronium95]

Not yet. And I’m currently in a tent at 11,900 feet waiting for the rain to stop, so it will be a couple of days before o can provide that.

I'm not in a rush, hope you have an enjoyable trip.

 

[kjhambrick]

@Adrian A --

This can absolutely wait until you return but I meant to follow up back on Aug 5 ...

I asked just about the same question as @bad_idea about laying the 29mm Blue Raven flat on a sled and proper alignment back in post #54

You replied in post #56 that I should identify the accelerometer chips and try for 45 degree alignment on the sled so that the 32G accelerometer range could be extended to 45G ( where 32G / sin( 45 degrees ) = 45.25G ).

Will the accelerometer chips be identified in the hole alignment guide that @Neutronium95 asked about ?

That would also be helpful I think ...

Thanks and have fun up there at 11,900 feet -- stay warm and dry !

-- kjh( now I need to order one to play with too )

 

[bad_idea]

I asked just about the same question as @bad_idea about laying the 29mm Blue Raven flat on a sled and proper alignment back in post #54

Aha, it was discussed, and I did miss it.

 

[Neutronium95]

Not yet. And I’m currently in a tent at 11,900 feet waiting for the rain to stop, so it will be a couple of days before o can provide that.

Would it be possible to get the hole layout in the next day or two? I've taken some preliminary measurements, but that's just been enough to notice that they don't form a perfect equilateral triangle.

Also, can you indicate the polarity for the battery? I have some tiny batteries with the same connector, but I really don't want to accidentally fry it by hooking up a battery backwards. I'm a bit extra paranoid after seeing a group fry their Featherweight GPS with reverse polarity.

Finally, what is the angle of the battery with respect to the line connecting the nearest two holes? I can tell it's not inline, but I'm not sure how to measure it better. I'm designing and printing some parts to support the battery and hold my tracker.

Thanks for making this amazing altimeter, I'm planning on smashing the H record with it if everything goes to plan.

 

[rharshberger]

This device looks like a fantastic reason to bring Vanishing Act out of the scrap pile.....and with a Featherweight tracker all in the same bay, it would be even easier to find the little monster after those 29mm MD flights.

 

[kjhambrick]

This device looks like a fantastic reason to bring Vanishing Act out of the scrap pile.....and with a Featherweight tracker all in the same bay, it would be even easier to find the little monster after those 29mm MD flights.

Still trying to wrap my head around the concept that the physical orientation of the accelerometers and gyros does not matter for this little beauty ...

But being a blatant borrower of great ideas, I'll be following all Featherweight AV-Bay Threads with my most shameless plagerist hat on

-- kjh

 

[Adrian A]

Would it be possible to get the hole layout in the next day or two? I've taken some preliminary measurements, but that's just been enough to notice that they don't form a perfect equilateral triangle.

Also, can you indicate the polarity for the battery? I have some tiny batteries with the same connector, but I really don't want to accidentally fry it by hooking up a battery backwards. I'm a bit extra paranoid after seeing a group fry their Featherweight GPS with reverse polarity.

Finally, what is the angle of the battery with respect to the line connecting the nearest two holes? I can tell it's not inline, but I'm not sure how to measure it better. I'm designing and printing some parts to support the battery and hold my tracker.

Thanks for making this amazing altimeter, I'm planning on smashing the H record with it if everything goes to plan.

The JST1.25 battery connector, unlike the JST 2 mm, has a consistent standard for polarity. The batteries that plug into it are all the same, and the connectors you can get for it have the correct red/black convention.

Here is a .dxf, zipped so that TRF will accept it.

And a photo of the battery polarity

 

[Neutronium95]

The JST1.25 battery connector, unlike the JST 2 mm, has a consistent standard for polarity. The batteries that plug into it are all the same, and the connectors you can get for it have the correct red/black convention.

Well that's a relief. I decided to stick with the battery you use for the avbays, since my tracker ended up takint up almost as much length as the battery, so there isn't any benefit for a smaller battery.

And thanks for the drawing. I hope my CAD skills are up to snuff.

 

[Neutronium95]

My dad turned the DXF into something more human readable. I'm not certain that the battery location is perfect, but I'll know once my parts are done printing.



@Adrian A I'm going to be getting the threaded rods for my avbay tomorrow. Can I get away with just steel from the hardware store, or do I need to get something more conductive like Aluminum or Brass? It's not a big deal, since I need to place a McMaster order anyways for some smaller nuts due to my silly avbay design.

 

[kjhambrick]

Thanks $1M @Neutronium95 !

I downloaded and installed FreeCAD on my Linux Box and while it can alegedly import .dxf files the procedures elluded me ...

I ended up with a screen full of disjointed 'sticks'

-- kjh( I imagine I better learn how to read AutoDesk files if I ever want to get into 3D printing )

 

[OverTheTop]

You can use Solid Edge, a 2D CAD program by Siemens, for free. Full-featured at a price you can't beat .

 

[Adrian A]

My dad turned the DXF into something more human readable. I'm not certain that the battery location is perfect, but I'll know once my parts are done printing.

View attachment 604254

@Adrian A I'm going to be getting the threaded rods for my avbay tomorrow. Can I get away with just steel from the hardware store, or do I need to get something more conductive like Aluminum or Brass? It's not a big deal, since I need to place a McMaster order anyways for some smaller nuts due to my silly avbay design.

Thanks for that drawing!

I did a test a couple of weeks ago measuring the resistance of stainless steel 4-40 threaded rods of 3” length, running an Amp of current and measuring the voltage drop. They add about 15 mOhm which is pretty negligible.

If your local hardware store carries 4-40 threaded rod it’s better than mine. I normally order it from McMaster Carr.

With my 38mm av-bays that have 4 threaded rods, I stick with aluminum for the weight savings. But with just the 3 rods that are closer to the centerline I found that I needed steel to have enough strength to bolt my chute cannon onto the end of my av-bay.

 

[Adrian A]

After a failed prototype production run late last year and then a successful one, I ordered a full production run in December and it should arrive to me next week. I still need to update my production test fixture so I won't promise when they will be available, but it's getting close, just in time for build season!

 

[kjhambrick]

@Adrian A --

Now that I have come up with Av-Bays built around the Power Perch, and the 38mm, 29mm and 24mm Featherweight Av-Bay packages, I am almost afraid to ask, but here goes nuttin:

Will the 'classic' Blue Raven continue to be available after the 29mm Bulkhead Form Factor Blue Raven goes into full production ?

And I am a little embarrased to ask ... I am a little leery about moving a single Blue Raven among my four Blue Raven Av-Bay configurations.

It takes 15 minutes to to remove the nuts and move the Blue Raven to a different Av-Bay and I imagine I'll eventually break something.

So I really need a total of four Blue Ravens so I can leave them installed on the Power Perch or in the 24mm, 29mm, 38mm FW Av-Bay ...

Is there a volume discount if I buy two or three Blue Ravens on one order ?

Sorry, but I had to ask

Thanks !

-- kjh

 

[Adrian A]

@Adrian A --

Now that I have come up with Av-Bays built around the Power Perch, and the 38mm, 29mm and 24mm Featherweight Av-Bay packages, I am almost afraid to ask, but here goes nuttin:

Will the 'classic' Blue Raven continue to be available after the 29mm Bulkhead Form Factor Blue Raven goes into full production ?

And I am a little embarrased to ask ... I am a little leery about moving a single Blue Raven among my four Blue Raven Av-Bay configurations.

It takes 15 minutes to to remove the nuts and move the Blue Raven to a different Av-Bay and I imagine I'll eventually break something.

So I really need a total of four Blue Ravens so I can leave them installed on the Power Perch or in the 24mm, 29mm, 38mm FW Av-Bay ...

Is there a volume discount if I buy two or three Blue Ravens on one order ?

Sorry, but I had to ask

Thanks !

-- kjh

Yes, I'll continue to produce the regular Blue Raven and the 29mm Blue Raven indefinitely.

A quantity discount is a good idea. I updated the Blue Raven pricing so that if you get 2, you'll get $20 off of the second one. If you buy three, you get $20 off of the 2nd one and $30 off of the third one, for $50 of savings.

 

[SolarYellow]

Would be awesome if that somehow worked across the 24mm and 29mm av-bay units. So 1 and 2 or 2 and 1, still get the discount for 3.

 

[Adrian A]

The first production run of 29mm Blue Ravens has arrived. I'll be working on my fixture for programming and testing them today.

 

[Adrian A]

I finally completed my production test fixture, and the first production units are ready to ship.

I'm working on information about this product for the website.

One way to install this altimeter is just flat on a sled like a regular altimeter, but taking up less space. As an example, here is an av-bay sled that fits into a 29mm coupler. The only wiring needed was to connect the battery via an extension cord, because the magnetically-activated power switch is built into the altimeter. This makes it even easier to install than the original Blue Raven.



The charges are connected to the mounting screws on the underside of the board, like so:



This example is for an av-bay sled that fits into a 29mm coupler. In a more typical av-bay you could do it the same way, but with more breathing room.

I'll include the hardware needed for this type of installation in the standard product. I will also have mounting kits available for an installation where the 29mm Blue Raven is mounted across the diameter, and the threaded rods for the av-bay are the terminals. More on this in another post.
These new altimeters will be ready to order from the website today or tomorrow.

I should have the website updated for ordering today or tomorrow.

 

[Adrian A]

Here's how the battery extension cable in the photo above was made:

 

[SolarYellow]

I am definitely in for one or more of these eventually.

Just to confirm, it fits in the coupler with a 0.977 ID that is a centering ring between 29 MMT and BT-50?

 

[Adrian A]

I am definitely in for one or more of these eventually.

Just to confirm, it fits in the coupler with a 0.977 ID that is a centering ring between 29 MMT and BT-50?

It’s 1.000 inches in diameter, so no go for 0.977” ID. But it does fit into thick couplers for 29mm airframes.