I am currently working on modifications during initial build of a Estes Prowler (# 2156). I have the bottom section ready to go (instead of 18mm M/M, I have substituted a 24mm 18" long motor mount/stuffer tube which has been capped with a Semroc BT-60 Baffle; I substituted basswood for the balsa fins and appropriately CA/paper treated). Basically what I have left to build is the top (1 of 3) main BTs and the nose cone.

I would like to stick a altimeter into this vehicle. But all the research has pointed to altimeters mainly being installed on BT-80 and bigger sections. This will be my first dealing with any type of avionics since becoming a BAR. Since my vehicle is only a BT-60 diameter, can I stuff 2 altimeters into the top section??? One being MAD type and the other one being atmospheric pressure type. ** Trying to get all the basics down as far as familiarity and functionality before moving into high power **

With this particular vehicle, I am not interested in the altimeter controlling recovery/ejection charge. But I do want to use an altimeter that is the same type as the one that does control ejection charges/dual deployment (get me use to setting it up, reading, etc).

Here is my specific questions:
- Is there a online source that could tell me how to mount the altimeters in the rocket?? And build the electronics bay??? If so, where??

- I know that the normal source of power is a 9 Vdc battery. Are there alternate sources of power that can be mounted in??? Electrolytic Cap and resistor network??

More questions to follow. I have found that answers to previous questions usually spawn more questions. Sort of like your kids asking you "Why xxxxx?".

vr/
Anthony Jackman
US Navy Senior Chief Petty Officer (ret - CTO2/ATCS)

There are several altimeters on the market now that are postage stamp sized. I know of one in particular that you can use any number of battery sources, including watch batteries.



This is the Pico P1, listed at $40. It will fit in a 10mm tube and needs around 4.5v-5.5v so three watch batteries will work.

Pico Altimeters


Here's their dual deployment version, which should easily fit in a BT-60.

Thanks tbzep. I was looking at that PICO altimeter late last night while santa was placing presents. Looked good for a first altimeter.

- are there sources for how to build a electronics bay???

- also, if I build a eBay (no pun intended), will the weight of the althread be too much?? are there sources for nylon/plastic version of althread???

Tony

There's really no need for a special built bay, especially for something this small. The guys at PicoAlt even mention loosely wrapping the little units in tissue paper and sticking them into payload sections of smaller rockets. Just don't forget to put your vent hole in the payload section.

They do make nylon allthread, but I think most of those altimeter bays you see are overkill. When I flew with much larger Adept altimeters, I just used the smallest dia. tube that the altimeter would fit in, glued into the payload section. I installed the altimeter via the bulkhead and had a sealed cap that protected it from ejection. The altimeter fit solidly, so it needed no padding.

Al (GreenDragon) knows my buddy Jim, who for single event ejections, often just stuck his altimeter in the payload section protected only by a soft foam beer can huggie and some paper towels. The ejection charge leads came out through the drain hole in the bottom and the altimeter was positively held in the huggie with some good masking tape. It never failed, and he built some awesome sledgehammer powerhouse motors!

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