# Eggtimer Rocketry Holiday Sale 2016

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#### cerving

##### Owner, Eggtimer Rocketry
TRF Supporter
[Last Day to get these savings...]

It's that time again...

For us, the official start of the Holiday Season is ROCStock, which starts on Saturday Nov. 12th. We're actually starting the sale on Friday the 11th since that's when the vendors show up. It will run through Monday, Nov. 28th. (Cyber Monday). So without further ado, here it is:

o Eggtimer Classic Altimeter, $28 (normally$35)
o Eggtimer Quantum WiFi-Enabled Altimeter, $32 (normally$40)
o Eggtimer Quark Altimeter, $16 (normally$20)
o Eggtimer WiFi Switch, $16 (normally$20)

o Eggfinder TX GPS Transmitter, $50 (normally$70)
o Eggfinder LCD Starter Set (TX transmitter + LCD handheld receiver), $100 (normally$120)
o Eggtimer TRS GPS/Altimeter, $70 (normally$90)
o Eggtimer TRS Starter Set (TRS + LCD handheld receiver), $120 (normally$140)

We have a decent amount of stock on just about everything, if we run out we'll make some more of them, that should add a week or two depending on whether or not we have to order any parts. Let us know right away if it's time-sensitive.

Cris Erving
Eggtimer Rocketry

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#### fyrwrxz

##### latest photo
(Best James Cagney voice "Why you sneaky rat, I was savin' dem dollars for da wife and kids. Christmas is comin'-ya knows. Ain't you got no heart?"
One way or another, I 'll see you there prolly Saturday. Thanks for the sale!

#### KenRico

##### 'Just the Tip'
Wow !

I just destroyed my radio tracker ... may have to jump in for non-RF replacement.

No ugly sweater required !

Kenny

#### jrkennedy2

##### Well-Known Member
Just killed my GPS tx by goofing and replacing my power cord to the grnd and 3.3+ ports instead of the batt + and - The older battery cable was breaking the connection when I wiggled it so a new one was in order. Regardless, the RF unit got REAL hot when I plugged in the 2s lipo. My stupidity fried it.

Order placed...

#### Ccolvin968

##### Well-Known Member
Anybody know how difficult the Eggfinder GPS and the LCD Handheld receiver are to build?
I just built an Eggtimer Classic with no issues except for a little troubleshooting required.
I'm looking for a basic GPS with no frills just to give me the lat long of where I landed.

#### cerving

##### Owner, Eggtimer Rocketry
TRF Supporter
The LCD receiver shouldn't be a problem, but the TX is more challenging. If you haven't done any SMT soldering, a Quark is a good place to start... if you can build that, you can probably build a TX.

#### KenRico

##### 'Just the Tip'
Anybody know how difficult the Eggfinder GPS and the LCD Handheld receiver are to build?
I just built an Eggtimer Classic with no issues except for a little troubleshooting required.
I'm looking for a basic GPS with no frills just to give me the lat long of where I landed.
I did a Quark , WiFi switch, then a Quantum - but sent the TRS out to Connor for assembly ..very happy here !

Most of the time I fly the TRS with the deployment channels turned off , like a TX - but it is worth it to me to have the additional LCD programming features and live, real time status available .

Fyrwrxz Dave should be posting soon as I saw him buy a Quark yesterday , taking advantage of the Sale !

Kenny

#### cerving

##### Owner, Eggtimer Rocketry
TRF Supporter
I did a Quark , WiFi switch, then a Quantum - but sent the TRS out to Connor for assembly ..very happy here !

Kenny
That's probably a good strategy... do the ones you're likely to succeed with yourself (LCD, Quantum, maybe Quark) and ship out the more intricate builds (TX, TRS). Given the discounts that you can get on them right now, you'll still come out ahead even paying for the builds.

#### NorthwoodsRockets

##### Well-Known Member
That's probably a good strategy... do the ones you're likely to succeed with yourself (LCD, Quantum, maybe Quark) and ship out the more intricate builds (TX, TRS). Given the discounts that you can get on them right now, you'll still come out ahead even paying for the builds.
So that's an approximate ranking of assembly difficulty (LCD, Quantum, Quark, TX, TRS)? Where does the WiFi Switch fit in? I assume the Eggtimer is the easiest?
Thanks,
Matt

#### rharshberger

##### Well-Known Member
So that's an approximate ranking of assembly difficulty (LCD, Quantum, Quark, TX, TRS)? Where does the WiFi Switch fit in? I assume the Eggtimer is the easiest?
Thanks,
Matt
I would think the original Eggtimer is easiest followed by the Quark, IMO.

#### KenRico

##### 'Just the Tip'
Quark and wifi switch , quantum - seems to me was alot less to solder overall .

Kenny

#### OverTheTop

##### Well-Known Member
TRF Supporter
I am getting a Quantum, WiFi Switch, and a TRS starter set. I'll let you know how they go :wink:

I'd rather build somebody else's electronics for rocketry, as I do this stuff for my day job.

#### NorthwoodsRockets

##### Well-Known Member
Am I correct in thinking that the Original Eggtimer, Quantum, and TRS are appropriate for staging? The Quantum is not.

#### cerving

##### Owner, Eggtimer Rocketry
TRF Supporter
The Eggtimer has staging features, including breakwire and velocity-at-time checks. The Quantum will be getting them in a future software build. The TRS will not... there's no room in the firmware storage for it.

As far as ease of assembly, the WiFi Switch and Quantum are virtually identical, I personally think they're a little easier than a Quark because the passive parts are larger, but that's my opinion. A lot of people have told me that they thought the Quark was easier.

#### dshmel

##### Well-Known Member
The Quantum will be getting them in a future software build. The TRS will not... there's no room in the firmware storage for it.
I am getting ready to pull the trigger on a couple of Quantums, Q - How will the software be updated? Will I be able to update in the future myself?

#### cerving

##### Owner, Eggtimer Rocketry
TRF Supporter
You update it with the data cable using Windows and a .bat file with a binary image, it's very easy. It's a lot less finicky than the Atmel-based devices (Eggtimer, LCD, TRS). If you don't have an Eggtimer data cable, you need one... it's used by almost everything we sell.

#### dshmel

##### Well-Known Member
You update it with the data cable using Windows and a .bat file with a binary image, it's very easy. It's a lot less finicky than the Atmel-based devices (Eggtimer, LCD, TRS). If you don't have an Eggtimer data cable, you need one... it's used by almost everything we sell.
Excellent. Yes, I have the data cable. I already have 2 Quarks, 2 Wi-Fi switches, 3 TRS controllers and the LCD receiver in a 3D printed case. I haven't used the TRS system yet. I like the idea of WiFi for powering up the system (versus separate switches) - and like the idea of a single board Wi-Fi solution for smaller rockets. I have tested (but not flown) the separate Wi-Fi switches and they are nice. I like the idea of eliminating the wiring between the boards and like the idea of the failsafe main deployment feature. I am surprised that this failsafe feature is not offered (maybe it is?) on more flight controllers. It would have come in handy this past weekend when I lawn darted my Demon 98 from 5900'. The main did not deploy (at all) - I was using a Quark. Turns out that I had a bad apogee e-match (despite a continuity and Ohm check with a MM). After digging it out of the ground, I tested the main deployment e-match and it lit with a single AAA battery, while the apogee match was intert even after connecting it to a 2S LiPo. Although the battery was disconnected by the impact, the Quark beeped out the altitude when I connected power to it later. Pretty good considering the deceleration. I will have to vacuum chamber test it before sending it up again.

#### cerving

##### Owner, Eggtimer Rocketry
TRF Supporter
What kind of ematches were those? Just curious... I know that some of the early FireWire ematches were bad (although the current ones are fine, that's what I've been using) and the newer formulation Q2G2's take more current and light slower than they used to.

#### dshmel

##### Well-Known Member
What kind of ematches were those? Just curious... I know that some of the early FireWire ematches were bad (although the current ones are fine, that's what I've been using) and the newer formulation Q2G2's take more current and light slower than they used to.
Purchase them from "Crazy Jim" a couple of years ago. They are the 0.3 meter long, orange wire with nichrome wire chip head, coated in red pyrogen variety. I also have some 0.5 meter e-matches from China (via e-Bay). Same orange wire with red pyrogen coated chip head. I test each one before use. This is the first time I have had a bad one.

Specs for the Chinese e-matches are:

21C (70F) resistance: 1.30 &#937; &#8212; 1.70 &#937;
Fire current: 0.40A /0.37A
Safe current: 0.25A 5S/0.18A 5S
Test current: 0.5MA

Question - will your products fire two e-matches in parellel assuming I am using a "robust" 2S or 3S LiPo?

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#### BDB

##### Absent Minded Professor
Question - will your products fire two e-matches in parellel assuming I am using a "robust" 2S or 3S LiPo?
My TRS won't fire two matches in parallel using a fresh 9V battery. I use the Chinese e-matches too. I set mine up with two e-matches in series for each charge. Mike from Binder Design suggested this to me several months ago to prevent failed ignition from a bad e-match.

#### cerving

##### Owner, Eggtimer Rocketry
TRF Supporter
Have you tried using a 2S LiPo?

#### ksaves2

Excellent. Yes, I have the data cable. I already have 2 Quarks, 2 Wi-Fi switches, 3 TRS controllers and the LCD receiver in a 3D printed case. I haven't used the TRS system yet. I like the idea of WiFi for powering up the system (versus separate switches) - and like the idea of a single board Wi-Fi solution for smaller rockets. I have tested (but not flown) the separate Wi-Fi switches and they are nice. I like the idea of eliminating the wiring between the boards and like the idea of the failsafe main deployment feature. I am surprised that this failsafe feature is not offered (maybe it is?) on more flight controllers. It would have come in handy this past weekend when I lawn darted my Demon 98 from 5900'. The main did not deploy (at all) - I was using a Quark. Turns out that I had a bad apogee e-match (despite a continuity and Ohm check with a MM). After digging it out of the ground, I tested the main deployment e-match and it lit with a single AAA battery, while the apogee match was intert even after connecting it to a 2S LiPo. Although the battery was disconnected by the impact, the Quark beeped out the altitude when I connected power to it later. Pretty good considering the deceleration. I will have to vacuum chamber test it before sending it up again.
When you test on power up, put a little torsion/twisting force on the board with your hands and see if it goes intermittent on you or recycles. I had a snap clamp slip when I was epoxying the large capacitor on a Raven III altimeter and it slapped the board. I tested it and with the slightest torsional force on the board, it stopped beeping and recycled/reset. Couldn't see any damage but it was a $155.00 loss I had to swallow as the device is unsafe to fly. I didn't test beforehand but doubt it was a defective device to start with. Kurt #### dshmel ##### Well-Known Member When you test on power up, put a little torsion/twisting force on the board with your hands and see if it goes intermittent on you or recycles. I had a snap clamp slip when I was epoxying the large capacitor on a Raven III altimeter and it slapped the board. I tested it and with the slightest torsional force on the board, it stopped beeping and recycled/reset. Couldn't see any damage but it was a$155.00 loss I had to swallow as the device is unsafe to fly. I didn't test beforehand but doubt it was
Thanks for the tip. I will most likely just "retire" the altimeter so as to not risk another rocket. Not to mention the safety issue.

#### cerving

##### Owner, Eggtimer Rocketry
TRF Supporter
Purchase them from "Crazy Jim" a couple of years ago. They are the 0.3 meter long, orange wire with nichrome wire chip head, coated in red pyrogen variety. I also have some 0.5 meter e-matches from China (via e-Bay). Same orange wire with red pyrogen coated chip head. I test each one before use. This is the first time I have had a bad one.

View attachment 305564

Specs for the Chinese e-matches are:

21C (70F) resistance: 1.30 &#937; &#8212; 1.70 &#937;
Fire current: 0.40A /0.37A
Safe current: 0.25A 5S/0.18A 5S
Test current: 0.5MA

Question - will your products fire two e-matches in parellel assuming I am using a "robust" 2S or 3S LiPo?
1A shouldn't be a problem with a 2S LiPo, especially if it's dedicated to the deployment side. Those are a little lower than J-Teks (1.5 ohms), but it should be OK. Ground test first, though...

#### OverTheTop

##### Well-Known Member
TRF Supporter
My TRS won't fire two matches in parallel using a fresh 9V battery.
The internal impedance (imagine an imaginary resistor in series with the battery, inside it) of the standard 9V batteries is quite high. Voltage can drop significantly when large loads are applied.

As per other suggestions go for some 2S LiPos. I use the 120mAh or 180mAh from Hobby King which I think are rated to 25C. So that means the 120mAh can deliver a rated 3A (without significant sag). I would think it could deliver over 10A with a bit of a voltage drop (not tested this though).

I would suggest not going higher than 2S for the LiPos as the current through the eMatch with the higher voltages can destroy the transistors on the avionics if you get too enthusiastic. Check ratings to be sure.

I must check my logging to see what the voltage gets down to on firing!

#### cerving

##### Owner, Eggtimer Rocketry
TRF Supporter
These are BJT's not FET's, the inherent current limiting on the transistors will generally prevent them from destruction (unlike a FET, which will happily overcurrent until the MOS junction fries).

#### OverTheTop

##### Well-Known Member
TRF Supporter
Good to hear Cris. BJTs are not immune to overcurrent, but their inherent higher junction resistance help in that regard.

My "check the ratings" comment was a general one and always worthy of considering!

#### cerving

##### Owner, Eggtimer Rocketry
TRF Supporter
We still have a lot of stock on everything except Quantums and antennas, and those should be available for shipment by Monday or Tuesday. If you haven't placed an order yet, don't hesitate to do so... it will be filled as soon as we can kit them. You gotta put something in the AV bays of all those kits you got from Madcow and Wildman...