The Eggtimer - A full-function multiple-deployment flight computer for only $40

[thobin]

Was is still plugged in to the computer and in the update mode when you tried to test it? I have only tested continuity when in my test chamber disconnected from the PC and all four of mine have given a continuity beep.

That does sound weird, are both channels turned on I guess they would be if you got voltage. I do know that it only does a continuity check in the beginning of start up and if you disconnect it after start up it wont check again so its not a constant. Unless i'm mistaken I think that's how it works.


TA

 

[conman13]

Yes it was plugged in to the computer. I would test it but do not have a vacum chamber and don't plan on getting one anytime soon. I don't want to put it in a rocket and have it not work.

 

[Onebadhawk]

One more question going out to anybody. I got the board all soldered up and did a master reset. I was going to test the deployment channels and plugged in a lightbulb on both channels and pressed enter on my PC. However no continuity came up for either channel so I tested it and the bulb did not light. Both the channels are set to an igniter and have been saved. Us there something I'm doing wrong? I also checked the voltage in the deployment channel and it came up as 8v. There was also no voltage on the continuity bulbs. If no one has any ideas I may just get another and go from there. Thanks.

Your not doing anything wrong Conner,,,,
Just do a mayo jar flight,,,,,,
After the flight power down,,,,,,,,
Plug it back into your computer,,,
power back up again into monitor mode then test the deployment channels again..........

Teddy

 

[conman13]

Your not doing anything wrong Conner,,,, Just do a mayo jar flight,,,,,, After the flight power down,,,,,,,, Plug it back into your computer,,, power back up again into monitor mode then test the deployment channels again.......... Teddy

Can you say that again auto correct messed the second line up.

 

[Onebadhawk]

I've had to do a mayo jar flight before the deployment channels
would work in monitor mode............
Put it in a mayo jar,,,,,,,
do a flight,,,,,,,,,,
power down,,,,,,,,,,,,
reconnect to your computer,,,,,,,,
Then the deployment channels will work in monitor mode..............

Teddy

 

[Onebadhawk]

Auto correct keeps messing up what your saying. I didn't want to clog up the thread do you mind telling me one last time. It changes something to mayo jar! Sorry. Thanks so much.

That's too funny Conner,,,,,,,,,
I am typing mayo jar,,,,,,,,,,,,, or any jar that seals well,,,,,,,,,,,
Get a mayo jar,,,, or any jar that seals well,,,,,,,,,,, punch a hole in the lid,,,,,,,,, get a foot or 14"'s of fish tank air line or any plastic hose similar to it,,,,,,,,,,,,
Put the hose 1/2" through the hole in the lid and into the jar....... hot glue it in place,,, or epoxy,,, but hot glue is easier.........
You said you already did a master reset on your Eggtimer,,,,,,,,,,
You said you already set the flight parameters,,,,, Channel B is set to #1 for ignitor,,,,, channel A or main is set to #1 for ignitor.........
Power up with both batteries in place,,,, let it cycle like it's on the launch pad,,,,,,,,, put it in the mayo jar and put the lid on tight,,,,,,,,,
when it makes the warble sound,,, that means it has continuity on both channels and other things check out,,, your ready for flight,,,,,,,,,
put the fish tank tube in your mouth,,,,, suck on it,,, gently and steadily,,, never release the suction,,, slowly keep making more and more suction
but be certain not to release the suction....... Then hold the suction with the tip of your tongue,,,,, then move your tongue a bit just to allow a tiny bit of air back into the jar,,, this is apogee,,,,,,
very, very slowly keep letting tiny bits of air back into the jar,,, this is decent,,,,,,,, the rocket is falling,,,,,,,
you will see channel B Xmas bulb fire at apogee and you will see channel A or main Xmas tree bulb fire at your preset altitude.....
then you can take the Eggtimer out of the mayo jar,,, power down,,, hook it up to your computer,,, and you can see the test flight,,, and the deployment channels will work in monitor mode.........

Teddy

 

[thobin]

YA just made mine out of a jar as well not hard to do.


TA

 

[Onebadhawk]

I kinda think that Conner is thinking that making a vacuum chamber is difficult,,,,,,,,,,
It's not at all,,,,,,,,,
The only thing to watch is the seal,,,,,,,
If you don't have a good seal you will get both channels firing together............
With a good seal you can really simulate cool flights..........

Teddy

 

[conman13]

I kinda think that Conner is thinking that making a vacuum chamber is difficult,,,,,,,,,, It's not at all,,,,,,,,, The only thing to watch is the seal,,,,,,, If you don't have a good seal you will get both channels firing together............ With a good seal you can really simulate cool flights.......... Teddy

Yes I thought it was much more complicated from YouTube videos I have seen. This is a lot simpler and I will try it out and let you guys know how it goes.

- Connor

 

[Onebadhawk]

How are ya Thobin,,,,,,,,,,
It was such a pleasure having the traveling rocket with the Radical Rocketeers..........
So many flew it,,, so many thought it was so cool,,,,,,
You should tell Nasa about it,,,,
Maybe they'll send it up a bit higher then we can,,,lol,,,
Then put on display in Ft Lauderdale or somewhere........
That really was a fantastic idea..............


Conner,,,
If you don't understand everything I typed
your more then welcome to call me.....
I'm at my desk right now with an Eggtimer in front of me...........

Teddy

 

[thobin]

How are ya Thobin,,,,,,,,,,
It was such a pleasure having the traveling rocket with the Radical Rocketeers..........
So many flew it,,, so many thought it was so cool,,,,,,
You should tell Nasa about it,,,,
Maybe they'll send it up a bit higher then we can,,,lol,,,
Then put on display in Ft Lauderdale or somewhere........
That really was a fantastic idea..............

Teddy

Thanks, I just got it back today for some needed repairs. I'm going to clean it up a bit and give it a spray of lacquer to set all the signatures in, got to do a few test though to make sure up wont ruin any of the signatures, some used a sharpy and some sealers will make them run or dissolve them altogether. Hopefully I will get it back out in a few weeks.

It really wasn't my idea but I stepped up to get it going is all. I was thinking about submitting a article about it to Sport Rocketry IDK.


TA

 

[Onebadhawk]

Do
You have any ideas on what it could be?[/QUOTE]

First,,,
Inspect the entire build,, both sides,,, under a magnifying glass with a good light on it.....
Your looking for tiny pieces of metal,,, wire whiskers from cutting and stripping fine wire.....
They will short from one pad to another,,,,,,
Then look for poor solder joints,,,,,,
When you make a solder joint,, don't overheat it,,,,, that's probably how you had a problem with the battery pad...........

Teddy

 

[Onebadhawk]

Thanks, I just got it back today for some needed repairs. I'm going to clean it up a bit and give it a spray of lacquer to set all the signatures in, got to do a few test though to make sure up wont ruin any of the signatures, some used a sharpy and some sealers will make them run or dissolve them altogether. Hopefully I will get it back out in a few weeks.

It really wasn't my idea but I stepped up to get it going is all. I was thinking about submitting a article about it to Sport Rocketry IDK.

TA

Heck yea,,, that's a good idea,,,,,,,
And I'm not kidding about Nasa,,,,,,,,,,
If you catch the right person in the right frame of mind,,,,,,,
And he needs some positive public relations story..................

You never know,,,
and won't unless you ask.........
Can't hurt............

Teddy

 

[matthew]

One more question going out to anybody. I got the board all soldered up and did a master reset. I was going to test the deployment channels and plugged in a lightbulb on both channels and pressed enter on my PC. However no continuity came up for either channel so I tested it and the bulb did not light. Both the channels are set to an igniter and have been saved. Us there something I'm doing wrong? I also checked the voltage in the deployment channel and it came up as 8v. There was also no voltage on the continuity bulbs. If no one has any ideas I may just get another and go from there. Thanks.

When I first fired mine up, I wasn't getting continuity. Lots of checking and testing. I tracked it down to the Lipo battery I was using. Wired in a 9V and it all came up. It looks like the continuity test is powered by the deployment battery. I would check those connections. _{Ignore this. See below: You could also try a dead short across the channel to see if you get continuity in beeps or the interface, just DON'T test the charge if you do.}

 

[cerving]

Yes, you DO need to have a deployment battery connected in order to test deployment continuity. No battery, no circuit...

I would also caution against dead-shorting the igniter leads, use a miniature Christmas tree light instead (but not the LED type... ) 2S LiPos or 9V batteries work very well for deployment channel testing.

As far as the vacuum jar test goes, I would recommend testing one channel at a time, unless you have a vacuum pump or a vacuum cleaner and seal the jar really good and can get it to read at least 2000'. The reason is that the vacuum tends to subside very quickly once you turn off the pump, so if you have CHB set to fire at nose-over (apogee + 1 second) and CHA to fire at a reasonable altitude (600' or so), they may actually fire almost simultaneously because the pressure to get to 600' may be acheived within one second of your lowest pressure reading. When I was first testing the Eggtimer deployment channels with a vacuum box, I couldn't understand why both channels came on at the same time; once I started digging into the data dump, I figured it out. The vacuum test is good for making sure the circuitry is working, but it's definitely not a real-world simulation.

 

[Onebadhawk]

When I first fired mine up, I wasn't getting continuity. Lots of checking and testing. I tracked it down to the Lipo battery I was using. Wired in a 9V and it all came up. It looks like the continuity test is powered by the deployment battery. I would check those connections. You could also try a dead short across the channel to see if you get continuity in beeps or the interface, just DON'T test the charge if you do.

DO NOT DEAD SHORT THE PYRO OUTPUT CHANNELS.......
THIS WILL BLOW THE OUTPUT TRANSISTORS..............
There must be a "load" on them..............

Teddy

 

[Onebadhawk]

One more question going out to anybody. I got the board all soldered up and did a master reset. I was going to test the deployment channels and plugged in a lightbulb on both channels and pressed enter on my PC. However no continuity came up for either channel so I tested it and the bulb did not light. Both the channels are set to an igniter and have been saved. Us there something I'm doing wrong? I also checked the voltage in the deployment channel and it came up as 8v. There was also no voltage on the continuity bulbs. If no one has any ideas I may just get another and go from there. Thanks.

Connor,,,,,
When you get the Eggtimer in monitor mode and press b to test the B channel
you don't press enter on your computer keyboard,
you press the button on the Eggtimer............

Teddy

 

[conman13]

Connor,,,,, When you get the Eggtimer in monitor mode and press b to test the B channel you don't press enter on your computer keyboard, you press the button on the Eggtimer............ Teddy

No I know I was talking about when I first plugged it into the computer.

 

[matthew]

DO NOT DEAD SHORT THE PYRO OUTPUT CHANNELS.......
THIS WILL BLOW THE OUTPUT TRANSISTORS..............
There must be a "load" on them..............

Teddy

According to the assembly guide it will only blow the transistors if you try to fire the channel, and even then it depends on the battery used. You'll note I warned against attempting to then fire the channel if continuity was achieved. The guy needs to fault find his alt and maybe his test load is the issue. In any case, I sometimes forget that people of various skill levels build stuff like this and may not fully understand the issues. I have given advice that could lead to damage if the fault finding process isn't understood. Please, anyone reading this part of the discussion, use a resistive load and not a dead short. Teddy's advice is good.

Anyway, I can't wait to fly mine. It will be a couple of weeks before I can see a fellow who has previously invited me to launch at his farm, to then arrange that launch.

 

[Onebadhawk]

According to the assembly guide it will only blow the transistors if you try to fire the channel, and even then it depends on the battery used. You'll note I warned against attempting to then fire the channel if continuity was achieved. The guy needs to fault find his alt and maybe his test load is the issue. In any case, I sometimes forget that people of various skill levels build stuff like this and may not fully understand the issues. I have given advice that could lead to damage if the fault finding process isn't understood. Please, anyone reading this part of the discussion, use a resistive load and not a dead short. Teddy's advice is good.

Anyway, I can't wait to fly mine. It will be a couple of weeks before I can see a fellow who has previously invited me to launch at his farm, to then arrange that launch.

You are !00% right,,,,,,,,,,,
I should have made the distinction that you made...........
If the Eggtimer only looks for continuity,
it won't blow the output transistors...........

That what Cris must have meant when he said "use caution"
as opposed to "don't do it"

Very good point Matthew,,,,,,,,,,,,,,,

Teddy

 

[XJChris]

I flew my Eggtimer for the first time yesterday. It worked flawlessly on my first flight with electronics, my first dual deploy flight, and my level 1 cert flight! so far I'm very pleased with it and can't wait to fly it again!

 

[ksaves2]

I flew my Eggtimer for the first time yesterday. It worked flawlessly on my first flight with electronics, my first dual deploy flight, and my level 1 cert flight! so far I'm very pleased with it and can't wait to fly it again!

What a minute! Some smarty pants out there will say the ET is not the device for a "first time" flier due to the fact
it's a kit, the interface is crude and it's "baro only".:jaw:

Surely I speak in jest.:wink: I find the instructions are quite clear and as long as a person can read and is comfortable with using
a terminal as a control interface, it isn't that hard to understand the operating parameters or setup.

My only observation is if a person doesn't put a switch on the pyro battery and pre-preps the rocket in advance, there is a low level
current draw through the ematch circuit if the matches are connected to the terminals, Yes, yes, yes.:surprised: I know this is supposed to be poor form but in some parts of the country, the weather is so variable folks try to get as much prepping done before going to the
launchsite. Otherwise, one wastes more time prepping rockets than flying. Kurt

 

[SS/EA 6BBL 71 Cuda]

I flew my Eggtimer for the first time yesterday. It worked flawlessly on my first flight with electronics, my first dual deploy flight, and my level 1 cert flight! so far I'm very pleased with it and can't wait to fly it again!

YES! Congratulations Chris! :wave:
It's the start of something more fun'ur, expensive'ur, bigg'ur, evil'ur.....but, definitely more.....uhmmm...."ur"! Hey, we all have to start somewhere.

 

[Wayco]

I flew my Eggtimer for the first time yesterday. It worked flawlessly on my first flight with electronics, my first dual deploy flight, and my level 1 cert flight! so far I'm very pleased with it and can't wait to fly it again!

Congratulations! I bet the pucker factor was pretty high on that flight!
I should have posted up here last month when I flew my Eggtimer for the first time in a CF Li'l Rascal. Flew to 2400 ft. on a CTI I218 and had a perfect recovery.
I also got the first flight on my Eggfinder, and posted that up on the other thread.

 

[MCS]

A recommendation for Eggtimer.

The other day I tent-pegged a rocket from 10k ft into hard dirt. I am shocked the Eggtimer survived. The other electronics in the rocket were completely destroyed including mag switches and the batteries. I think the Eggtimer survived because the parts are mounted through-hole not surface mounted.

This is just one datapoint, but it is worth considering... esp when designing redundant systems.

(the Eggtimer was not responsible for the crash)

--MCS

.

 

[ksaves2]

A recommendation for Eggtimer.

The other day I tent-pegged a rocket from 10k ft into hard dirt. I am shocked the Eggtimer survived. The other electronics in the rocket were completely destroyed including mag switches and the batteries. I think the Eggtimer survived because the parts are mounted through-hole not surface mounted.

This is just one datapoint, but it is worth considering... esp when designing redundant systems.

(the Eggtimer was not responsible for the crash)

--MCS

.

View attachment 173749

Was it a battery contact problem? Also a strong eBay can have a big part in survival. Kurt

 

[cerving]

Wow. FYI, the next release of the firmware, which should be out shortly after ROCStock, will have a backup drogue function so you can delay the drogue by an extra second. Handy and necessary if you're going to use redundant deployment controllers.

A recommendation for Eggtimer.

The other day I tent-pegged a rocket from 10k ft into hard dirt. I am shocked the Eggtimer survived. The other electronics in the rocket were completely destroyed including mag switches and the batteries. I think the Eggtimer survived because the parts are mounted through-hole not surface mounted.

This is just one datapoint, but it is worth considering... esp when designing redundant systems.

(the Eggtimer was not responsible for the crash)

--MCS

.

View attachment 173749

 

[Wayco]

Wow. FYI, the next release of the firmware, which should be out shortly after ROCStock, will have a backup drogue function so you can delay the drogue by an extra second. Handy and necessary if you're going to use redundant deployment controllers.

I was considering using my second Eggtimer in my L-3 build of an Extreme Darkstar, this will make that decision easier.
Are you planning on attending ROCstock this month?

 

[cerving]

Yup, just don't know which day(s). I have something really neat to show off.. :wink:

 

[Wayco]

I think I have an idea what that might be....
If it's not too hot, I will be there also. Probably all weekend if I come all the way over there.