This blog covers the day to day progress of water rocket development by the Air Command Water Rockets team. It is also a facility for people to provide feedback and ask questions.

Wednesday, May 14, 2008

Repairs and New Development

This past week we have been making repairs to the Polaron V rocket as well as doing some new development for Acceleron.

All the plastic retaining tubes have been removed from the Polaron V main stage. On inspection one other tube was cracked (other than those that were shredded) . Because of the forces involved we didn't want to take any more chances with plastic, so we replaced them with thin walled brass tubes. Although adding a little more weight, they should be up to the job. We will need to do some tests first though before giving them the all clear. We are giving the PL a week to fully cure. Other than the tube replacement the rest of the rocket and boosters are ready to go. The plan is to launch the rocket at the next NSWRA launch event in a couple of weeks time.

Acceleron has been mostly repaired with the exception of the staging mechanism. Over the last month or so we have been working on yet another staging mechanism, and with the repairs needing to be done for Acceleron's staging mechanism we decided to complete it and put on Acceleron IV. We still have a long way to go with it, and need to do more testing, but so far the development has been going well. I will post full details once it has flown. It is a lot more compact and lighter than what was used on Acceleron previously.

Since we are rebuilding the staging mechanism it was a good opportunity to upgrade the Tachyon sustainer. We are building a completely new sustainer that has ~30% more capacity, more streamlined shape and new parachute deployment based on V1.5 of the flight computer. The fin section now integrates a ring fin with 4 smaller conventional fins. The ring fin struts are made from 6mm carbon fiber tubing and act as supports for the sustainer during the boost phase. The sustainer also carries both the altimeter and camera. As of last night the pressure chamber (3.35L capacity) is now complete, as are the 4 fins.

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3 comments:

Da-water said...

hi, my name is da-water, i'm from Italy, you might know me.. we both attend the wra2 forum..

i've been building water rockets for about one year.. now i'm going to build a parachute deployment system...

i have some questions to ask you..

what's the difference between the PIC16F628A and the PIC16F628??

can i program both with the same programmer??
what's your programmer's name?

thank you...

p.s.: on youtube i'm apitei :D

George Katz said...

Hi Da-water,

Actually I am not on the WRA2 forum, (I'm on the Yahoo Water rocket forum). I have seen your videos on YouTube though - very cool! I'm glad to hear you are working on the deployment system for your water rockets. There are a few differences in the PICs (16F628 and 16F628A) For a discussion see here:

http://www.edaboard.com/ftopic91688.html

Generally the letter after the number is a newer revision of the chip, and typically backwards compatible.

You should be able to program both with the same programmer. The programmer we use is K150 (V21)

http://www.oceancontrols.com.au/microprogrammers/pic_programmers.htm

Although there are lots of others that will work as well.

Good luck!

Da-water said...

thanks, i hope i will finish the system before the 1st jule..

i'll show you my system as soon as possible..