yes, Featherweight Is Still in Business

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jmmome

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Don't mean to be a jerk, but I asked a question online through Featherweight's website a couple of days ago, in advance of purchasing a Raven 4 which I also mentioned in the message, and got no response.

I need an altimeter with an accelerometer function, and heard great things about Raven. But if Featherweight is kaput, what other altimeter recommendation might you have? Thanks!
 

pondman

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I believe he is quite busy right now. Had a Raven repaired & returned to me. Took a few weeks, but what the heck. Great service!
 

pondman

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Don't mean to be a jerk, but I asked a question online through Featherweight's website a couple of days ago, in advance of purchasing a Raven 4 which I also mentioned in the message, and got no response.

I need an altimeter with an accelerometer function, and heard great things about Raven. But if Featherweight is kaput, what other altimeter recommendation might you have? Thanks!
 

Antares JS

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Thought it might be worth mentioning I had a Raven 3 survive a main deployment failure (my fault, not featherweight's) and go on to fly successfully in other rockets. Great altimeter.
 

jmmome

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Thanks for all the feedback, guys! I'll only need it for accelerometer apogee deployment of the main chutes, and for max. altitude reading, but I'm sure I'll find other ways to use it in some of my other multi-function rockets.

My six fee tall, four feet wide and 65 pound "Marvin Martian Jr", my homage to The Kaboom Krewe's gigantic "Space Oddity", needs the accelerometer deployment, just in case the funky body shape isn't kind to the Stratologger CF's baro-sensing functionality.
 

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jondub

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I had a problem setting up my Featherweight tracker recently and had excellent response from Adrian and Kevin Small...yes they seem to be very much in business.
 

JimJarvis50

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Thanks for all the feedback, guys! I'll only need it for accelerometer apogee deployment of the main chutes, and for max. altitude reading, but I'm sure I'll find other ways to use it in some of my other multi-function rockets.

My six fee tall, four feet wide and 65 pound "Marvin Martian Jr", my homage to The Kaboom Krewe's gigantic "Space Oddity", needs the accelerometer deployment, just in case the funky body shape isn't kind to the Stratologger CF's baro-sensing functionality.
Just curious, why does this rocket require accelerometer deployment?

Jim
 

HHaase

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Funky shapes can cause odd things to happen to barometric pressures at a static port. Anything on a tapered area of the airframe could very easily become affected by airspeed, either positive or negative pressure, depending on placement of the static port and airflow in the area. US Navy learned that the hard way with the Mk14 torpedo when they moved the pressure port used for depth setting.

-Hans
 

cwbullet

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Ordered and just shipped so yes, they are still in business.
 

watheyak

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Funky shapes can cause odd things to happen to barometric pressures at a static port. Anything on a tapered area of the airframe could very easily become affected by airspeed, either positive or negative pressure, depending on placement of the static port and airflow in the area. US Navy learned that the hard way with the Mk14 torpedo when they moved the pressure port used for depth setting.

-Hans
The Raven is one of the altimeters that's immune to this, however.
 

Buckeye

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I don't mean to be a jerk either, but maybe pause before posting an alarming-titled thread that can negatively impact the supplier. A couple days without an email doesn't mean the vendor is "kaput." If you saw the good comments about the Featherweight Raven, tracker, and other stuff, you should notice that they are recent, and Adrian is a good guy. A legit company like Featherweight is not going to just vanish in the night without a trace.

Your apogee and main deployments would probably be just fine with a baro altimeter. The data sampling before and after those events may be a little screwy due to the pressure gradients on the curved surfaces at speed. Apogee and main are at much lower speed however, and the baro will read that just fine. Personally, I think accel deployment is more problematic than baro for anything other than extreme flights. Raven can do both. Enjoy.
 

jmmome

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Noted for the future- upon reflection, you are so right. Still haven't heard back from him, though.....lol.

Based on your "problematic" comment about accel deployment, would you suggest using the baro altimeter as the primary, and the accel altimeter as the "apogee +1 second" backup, or visa versa? Another recommendation? I don't want a 65 pound "odd rocket" plummeting toward the ground. Thanks!
 

JimJarvis50

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I'm happy to share an opinion on your issue. I think most of the modern altimeters have some sort of filtering that will allow them to work on a vertical flight. My concern with your rocket is a non-vertical flight. I saw a rocket similar to yours that went sideways at AirFest last year. That's where I would focus.

The Raven has filtered barometric altitude. However, the default program for barometric deployment uses a "velocity less than" criteria as the mach lockout method, where the velocity is determined by accelerometer. If your flight is vertical, the use of a accelerometer-derived velocity will be fine. But if the flight is off angle, the accelerometer-derived velocity would still be high at actual apogee and barometric apogee deployment would be delayed - not good. I do not believe the Raven has any other logic associated with apogee deployment.

On the other hand, the Perfectflight CF has filtered altitude, but it also uses the altitude readings to determine a vertical velocity. The idea is not to allow apogee deployment if the calculated velocity is high. On an off-angle flight, that logic would, in theory, be more likely to result in deployment at actual apogee (because the logic would calculate a low vertical velocity and allow deployment).

I would use the CF with your rocket.

Jim
 

jmmome

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Thank you for your input!!! I have had extensive contact with a member of the Kaboom Krewe, who built the rocket you mentioned. I think that, by my location of the altimeters at the "fattest" point of the rocket body, as opposed to quite close to the bulbous nose as the Kaboom Krewe's design placed them, I avoided part of their premature deployment issue.

Plus, I moved my fin placement to emerge from the maximum diameter of my rocket's body as opposed to further aft, as the placement of their fins were for their design. My fin width to max. body diameter width ratio is greater than their design, so my hope is that my fins will catch more air, even if the "football" shape somehow creates dead air around some of the fin surface.

Lastly, my max. thrust to weight ratio is about 6.5 to 1. I'm not quite sure was theirs was, but I believe (trust?) that my L1520 Blue Thunder "sledgehammer" reload will keep in moving in the vertical direction during powered flight.

Based on what you and Buckeye stated, I may use two of my Perfectflite CF altimeters as opposed to buying a Raven. Don't want to take business away from him, but it sounds like I might inadvertently create the exact problem I was trying to avoid if my rocket also goes horizontal and I have an accel. altimeter.
 

kjs

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Noted for the future- upon reflection, you are so right. Still haven't heard back from him, though.....lol.
Mike - I sent Adrian an email to check in case you haven't heard back from him yet. You can email me at small@here-and-beyond.com . Don't be shy about re-sending an email if you don't hear back. I get a lot of emails each day (mostly garbage that I am working to cull down and unsubscribe from) but it means if I don't see something one day, it might be too far down for me to see it the next day.

We have flown the Raven4 in the nose cone on a Mach 2+ flight with the vent hole in side of the nose cone. We used baro (as I believe we thought we would max out the accelerometer range) and everything worked fine. "The other guy" (two of us were flying the same configuration) even had paint melt off his nose cone and bleed into the nose cone av bay and 'paint' his electronics... He might post a picture here (he is in this thread)....

I try to avoid horizontal flights so can't comment yet on the other suggestions.... Kinda makes me want to try one to test what happens..... :-D

Thanks!

/kjs
 

jmmome

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Knowing what happened when my rocket's big brother went horizontal, I decided to shy away from accel. deployment. I am trusting (praying) that my placement of the electronics bay at the fattest point on the rocket, and well away from the funky-shaped nosecone, will allow both the primary and backup baro altimeters to correctly sense and deploy the dual main 120" chutes at apogee- even if it might be a sideways apogee (please, no).
 

manixFan

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Ouch! That's some Mach rash! FWIW, I've been using DupliColor engine paint with ceramic for my Mach 2+ flights and have had pretty good luck with it, far less damage that what I was using before. I assume that was well past Mach 2 - for how long? Details now that you've shared the pic!


Tony

 

watheyak

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Ouch! That's some Mach rash! FWIW, I've been using DupliColor engine paint with ceramic for my Mach 2+ flights and have had pretty good luck with it, far less damage that what I was using before. I assume that was well past Mach 2 - for how long? Details now that you've shared the pic!


Tony

That was Mach 2.7 for maybe a couple seconds. I don't remember the exact time but now I'm curious.

The paint was acrylic color with Spraymax 2k urethane clear. I don't think the acrylic was up to the task. Kevin's nosecone fared much better.

Here's what it looked like before the flight. All the grandma flowers are gone. The yellow in the Mach rash picture was the bottom layer.

89885B51-B5BE-4E88-99D6-A17AF1A58559.jpeg


I think I might give the exhaust paint a try. Although my next project will be no paint, just high temp epoxy.
 

manixFan

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Wow! hard to believe that is the same nosecone. I've used just regular epoxy on the bodies of a couple of my Mach+ birds (based on Jim Jarvis's wipe on, wipe off method) and haven't had any issues. Even though the epoxy is very thin, it's still much thicker than paint.But I like to paint and polish the none cones and fins, and they get pretty 'rashy'. The ceramic engine paint seems to be a bit better than the exhaust and other engine paints I've tried before. There is a company that makes spray-on brake caliper paint that's supposedly good up to 900 degrees - VHT - I may have to try that as well.


Tony
 
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Adrian A

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Don't mean to be a jerk, but I asked a question online through Featherweight's website a couple of days ago, in advance of purchasing a Raven 4 which I also mentioned in the message, and got no response.

I need an altimeter with an accelerometer function, and heard great things about Raven. But if Featherweight is kaput, what other altimeter recommendation might you have? Thanks!
Yes, Featherweight Altimeters is very much alive. My day job (spacecraft avionics) has been busy, so sometimes it takes a few days before I can catch up on Featherweight emails, but my wife does the shipping and she almost always gets an order shipped out within 24 hours.

Thanks for all the kind words up-thread.

On high-temperature finishes, I did an experiment on a 38mm high-performance sustainer, and found that the silver high-temperature paint from Cotronics held up really well, as did a skim coat of Cotronics high-temperature epoxy.

and by the way, a PM here may go a long time without being answered, because sometimes I need to tune out from TRF for a months at a time, so if you need to contact me, please just email me via the website comment form which goes directly to featherweightaltimeters(at geemail, if you know what I mean, trying keep it challenging for spam robots)

-Adrian
 
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