Advisory on the Eggtimer Apogee

[cerving]

It has come to our attention that when using a very skinny screwdriver such as a #0 Phillips to activate the Eggtimer Apogee's integral screw switch it is possible to miss the center of the switch and possibly short the screw against other components on the board. The #4 screws are designed for a #2 Phillips screwdriver, so we recommend that you use ONLY a #2 Phillips screwdriver for the Apogee's screw switch, particularly if you have it mounted in an Easy Mount or other installations where there may be significant distance between the screw and the outside of your rocket.

Cris Erving, Eggtimer Rocketry

 

[cerving]

Bumping this so that anyone that didn't see it before can see it now. We also recommend that you put epoxy around the exposed pads of the transistor, on the screw head side of the PC board to prevent any shorts.

 

[FlyBy01]

Any way you can help me troubleshoot my tracker?

 

[cerving]

LOL, that's what we do... send an email with your issues to [email protected]

 

[tOD]

Hey Cris!
Is it absolutely necessary to hook up the Apogee to a PC to do the power-up serial diagnostics? I downloaded puTTy and the Prolific driver but I can't get it to work. This sort of thing is a steep learning curve for me.
It passed the continuity test and the vacuum cleaner test. Should I have confidence that it'll work or should I keep trying to figure out the serial output test? I've got time to figure it out since the rocket I plan to install it in isn't even built yet.
Thanks

 

[cerving]

No, you can do a vacuum test with a Christmas tree light bulb. If it "fires" after you remove the vacuum, it should be fine. There ARE startup diagnostics, if it can't "see" the baro sensor it's going to give you an annoying continuous beep-beep that lets you know it's not happy.

 

[DaHabes]

It has come to our attention that when using a very skinny screwdriver such as a #0 Phillips to activate the Eggtimer Apogee's integral screw switch it is possible to miss the center of the switch and possibly short the screw against other components on the board. The #4 screws are designed for a #2 Phillips screwdriver, so we recommend that you use ONLY a #2 Phillips screwdriver for the Apogee's screw switch, particularly if you have it mounted in an Easy Mount or other installations where there may be significant distance between the screw and the outside of your rocket.

Cris Erving, Eggtimer Rocketry

The instructions for the Apogee say to use a hole punch to make the hole in the tube that covers the altimeter in the Easy Mount, but a #2 Philips is wider than the hole punch and does not fit. The instructions also said to not use a #0 Philips and to use a #1 Philips which fits into the hole and which I did not have, so I bought one.

I suggest, in terms of the Easy Mount, to make the opening narrower to precisely allow a #1 screwdriver to fit the opening to the screw. That should eliminate the ability to miss the screw head. In the absence of updated assembly instructions with pictures, I would not be comfortable epoxying components and a device that has already been built and tested to work properly.

Re: "We also recommend that you put epoxy around the exposed pads of the transistor, on the screw head side of the PC board to prevent any shorts.", the only way a short would occur would be when turning the altimeter off, since the screwdriver head will be extracted from the screw head when arming the altimeter and shouldn't product a short unless said user does a krazy klutz move. In the absence of the epoxy, as long as the charge went off at apogee, extract the altimeter from the Easy Mount to turn it off as a short term work-around to avoid a possible short on disarming the unit when mounted in the rocket.

 

[cerving]

The latest version of the Easy Mount has a smaller opening for the screwdriver bit. If you're using one of those screwdrivers with interchangable bits, it will NOT fit, with either version of the Easy Mount. You need to use a "real" screwdriver with a shank that goes all the way to the handle. A #2 screwdriver with a round shank will definitely fit... that's what I used for testing.

The shorting issue came up when I mounted it in an Estes Leviathan, I mounted the Easy Mount about 1" from the edge of the tube. I was using a #0 screwdriver because that's what I had in my range box. There's lots of fumbling around required to find the screw because it's not "right there"... with the newer Easy Mount, not so much. It IS possible to short the screw head to the transistor with the power "turned off", which is why we recommend covering up the pads on the transistor with epoxy.

We have made changes to both the Apogee and the Easy Mount to prevent this from happening.

 

[tOD]

No, you can do a vacuum test with a Christmas tree light bulb. If it "fires" after you remove the vacuum, it should be fine. There ARE startup diagnostics, if it can't "see" the baro sensor it's going to give you an annoying continuous beep-beep that lets you know it's not happy.

Tested it with the e matches I always use. Worked fine.

 

[cerving]

Tested it with the e matches I always use. Worked fine.

OK, then you're all set!

 

[tOD]

While we're on the subject...
Does the Apogee need any other "sampling ports" in addition to the access hole for the screw switch?

 

[cerving]

The hole that you use to access the screw switch is just fine... you don't need any more holes.