Brief:
Here is a couple o' new timers from Xavien, at www.xavien.com . Avast! T' XSSRT-1, 'Xavien Single Stage Rocket Timer'. Well, blow me down! This is a 1 second t' 63 seconds single event timer. Aye aye! Begad! I tested this one for future use in air starting. Ya scallywag! I also have the XDSRT-1, 'Xavien Duel Stage Rocket Timer'. Well, blow me down! This one is a 1 second t' 63 seconds dual event timer. Avast, me proud beauty! I used this timer wired in as back-up for altimeter ejection. They both come with an easy t' read 7 page manual and a 1 year warranty. Begad! Their website at www.xavien.com has t' manuals for these in pdf files. Well, blow me down! Bonus!

Specifications:

XSSRT-1 Single Timer

• Power Requirements 8-15 VDC
• PEAK Firin' Current 2A @ 10sec.
• Dimensions 0.95" W x 2.5" L
• Nominal Battery Load 15mA
• Delay Settings 1 second t' 63 seconds (in 1 sec. Well, arrr, blow me down! Blimey! Blimey! Blimey! increments)
• Weight 14.2 grams

XDSRT-1 Duel Timer Specs

• Power Requirements 8-15 VDC
• PEAK Firin' Current 2A @ 10sec.
• Dimensions 1.225" W x 3.8" L
• Nominal Battery Load 15mA
• Delay Settings 1 second t' 63 seconds (in 1 sec. Avast, ya bilge rat, me proud beauty! Blimey! increments)
• Weight 21.4 grams

Settin' t' timer:

There are six DIP switches t' set t' delay timing. Ahoy! T' dual event has two separate banks o' switches. Well, me hearties, blow me down! Here is a breakdown o' t' switch positions and their correspondin' delay.

Switch # Adds:

1. 1 second
2. 2 seconds
3. 4 seconds
4. 8 seconds
5. 16 seconds
6. 32 seconds

Each DIP switch adds seconds t' t' total. Begad! For example: if you have switches 1, me hearties, 2 and 3 on, me hearties, you'll get a 7 second delay. Ya scallywag! It's actually very simple and easy t' do. Avast, me proud beauty! Just flip a switch t' add time.

In Use:

I put them in me Prometheus; a 12 foot tall, 7.5" scratch built rocket with a central 54mm and four 38mm motor mounts. For this first flight, I used a K1050 in t' center and air-started four Pro 38 J330's. Avast, me proud beauty! Blimey! I used t' duel event timer as a backup for deployment. Aye aye! Well, blow me down! T' rocket went somewhat horizontal just before t' four motors lit. Avast! This threw off t' calculations on when t' deploy the chutes. When usin' a timer, ya bilge rat, shiver me timbers, you have t' calculate t' flight based on motor burn time and assumin' a straight boost. Avast! Well, arrr, blow me down! If t' rocket doesn't go straight, matey, the events happen sooner than you calculate. Thus, t' altimeter deployed the drogue and t' main but t' duel timer did light its ejection charges.

I used t' single event timer t' test its ability t' light 4 Davyfire igniters. Begad! As I put t' rocket together at t' field, arrr, I decided nay t' use the timer t' air-start t' motors because t' air-start system that was built into the rocket was mounted and wired much better. Well, blow me down! Arrr! I also didn't want t' put two igniters in each motor in fear o' cloggin' t' nozzles. Avast, shiver me timbers, me proud beauty! I wired four igniters outside t' rocket and tested its ability t' light four o' them. Arrr! Although I didn't have them in t' motors, arrr, it did light all four igniters.

Summary:

Limitations:

• There is no internal trigger t' start t' timers, me hearties, like a G-switch. The timer is started by a physical break in an electrical contact. T' example given is usin' a piece o' solder that melts in t' heat o' t' exhaust t' start the timer. Arrr! Aye aye! Because I have so much power in t' Prometheus, I went with a wire tied t' t' pad bein' pulled apart at a point where I twisted them together. This worked well.
  
• Timers are just that: a timer. Begad! Avast, me proud beauty! Blimey! If t' rocket doesn't fly as expected, shiver me timbers, me bucko, the timin' can be thrown off. Avast, me proud beauty! Blimey! This is no fault o' this timer though; it is true with all timers.
  

Advantages:

• These things are pretty tough. They both survived an extremely violent flight, ya bilge rat, a 3 foot zipper and shredded drogue, when t' drogue came out at high speed. Well, arrr, blow me down! Blimey! They were also an 'afterthought', ya bilge rat, so t' mountin' be nay planned during the build. Ya scallywag! Blimey! Because o' this, they were mounted and wired less than perfect and yet still performed perfectly.
  
• Settin' t' delay is easy. Ahoy! Unlike some other timers, me hearties, t' timin' is digital, nay set with a potentiometer. Well, blow me down! Thus, ya bilge rat, timin' is exact.
  
• T' single event timer lit four igniters, impressive.
  
• They both have a super-bright power indicatin' LED that was real easy to see in t' full sun. Begad! Ya scallywag! A real nice added feature.
  
• Even t' battery connecter is better quality that other ones. Well, blow me down! It's nay the cheap flimsy type; it's a hard plastic heavy duty connector.

Overall Rating: 5 out o' 5