looking for timers

I am planning on taking the plunge into hybrids and will need a timer. I want to do some tinkering so I want to get the cheapest timer out there. I have been toying with the idea of building my own and was wondering what the available options are

Reply to
Tater Schuld
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Perfect Flight -

Phil Stein

Reply to
Phil Stein

Why not try a magnetic apogee detector (MAD)?

Have a look at:

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I have MAD kits available for $30.

- Robert Galejs

Tater Schuld wrote:

Reply to
Robert Galejs

as Phil suggested, the Perfectflite is a great value!

here's a timer lineup to compare. Notice distinctions in the number of events (channels), current capacity for ignitor load, and the means of timer triggering

PerfectFlite ($25 - $43) at

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Xavien ($33 - $47) at
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Adept Rocketry ($64 - $81) at
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MissileWorks PET2 ($75) at
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Blacksky ($50 - $80) single channel at
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channel at
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PML AcuFire ($85) at
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and a number of Transolve timers described at
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from Red Arrow Hobbies at
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the Olsen timers appear to be out of production

there's a avionics comparision table at

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it is missing a few timers shown above

- iz

Phil Ste> Perfect Flight -

at

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Reply to
Ismaeel Abdur-Rasheed

These will certainly take the guess work out of drogue deployment with a timer. I recently got one and can't wait to try it.

Phil Stein

Phil Stein

Reply to
Phil Stein

Tater, I would recommend the Perfect flite altimeter rather then a timer for ejection.

Timers can't predect well. They are used for air starts and staging mostly.

I do have both timers and altimeters at:

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Reply to
ArtU

I did a review on the Xavien timers. I liked them.

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another option.

-- Drake "Doc" Damerau

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NEPRA President NAR Section 614 NAR 79986 L3
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Remove "My Shorts" to reply

Reply to
Doc

My personal favorite -

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!!!

Reply to
Mike G

Xavien timers have done the job very well for us too.

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Kevin Patterson
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Reply to
TOOLS R US

hey, how did I miss that one!? ;)

- iz

Mike G wrote:

Reply to
Ismaeel Abdur-Rasheed

One of the things I forgot to mention is that I want it to be able to fire off Estes igniters....

Reply to
Tater Schuld

Hi Tater,

can you give me an idea of the project ?

I might be able to help out, no matter whose product you end up using.

Is it for ejection or something else, you got me real curious.

Art Upton

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Reply to
ArtU

just for ejection. I wanted something that would fire an estes ignitor that would burn some triple seven or equivalent. these materials are easily accessible to us and would save a lot of fidlin' around

Reply to
tater schuld

Quickburst igniters are still available without a permit.

"The new ATFE regulations coming into effect May 24th this year will not affect your QuickBurst purchases. In short you will not need to hold any type of Federal Permit to buy any of the items listed on this site."

see their robust product offering at

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(left frame) -> igniters

Pyrodex also requires neither permit nor storage, and has been used successfilly for ejection charges.

from "Use Pyrodex "P" Instead Of 4F Blackpowder" at

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-- The topic has come up from time to time about using Pyrodex instead of

4f black powder for ejection charges. We have found the secret to using Pyrodex as a direct substitute for 4f black powder after conducing a series of ground tests and successfully flying 11 rockets with various sized ejection charges all of them using 100% Pyrodex instead of black powder.

The Pyrodex to use is Hodgdon "P" or FFFG Equivalent for ejection charges in PVC pipes sealed on one end or phenolic tubes sealed on one end. The sealed end is usually a PVC fitting with a hole in the middle for the electrical wires to the e-match or flashbulb. If you use a flashbulb, make sure the tip of the flashbulb is in the Pyrodex powder. Flashbulbs do work with the Pyrodex as we had 100% success in ground tests and two flight tests.

We used an equivalent volume of the Pyrodex "P" as a substitute for the

4F black powder. After putting the powder in the open end of the tube, we would put a wadding material in the tube. We filled the rest of the open tube with wadding so that the powder stays at the base of the tube.

On the open end of the ejection charge tube, we would normally use masking tape to seal the tube when using black powder. For the Pyrodex, we used electrical tape to seal the tube. We put one piece across the open end of the tube with the ends of the tape going down the side of the tube. Then, we put another piece of electrical tape across the open end of the tube 90 degrees to the first piece with the ends going down the side of the tube. Looking at the end of the tube, it makes a cross pattern. Finally, we put a piece of electrical tape circumferentially around the tube at the end where we had put the electrical tape. This piece of tape goes over the ends of the first two pieces of tape. That's it.

We are flying just with Pyrodex now as it does not leave the residue or stink you get with black powder. Also, it is generally easier to obtain than blackpowder.

Reply to
Ismaeel Abdur-Rasheed

I would recommend strongly to use only a MAD or an Altimiter for ejection. Timers are not safe really for ejection.

If you are going to get into hybrids, get a dual deploy altimiter, perfect flight or ge-wiz as a starter unit.

Also, In my opnion, recovery is a safety issue, and I always recommend Orxl or davy-fire low current matches for ejection. Hi current ignitors can be asking for trouble, as they can fail, and you don't want recovery to fail. A Orxl will always fire.

Also, if using pyrodex (I don't recommend it), you need to contain it to build up pressure in a special ejection container. more that can go wrong. BP in a cardboard tube from a pants hanger will just fire contained by dog barf on one end and hot glue on the other and blow your nose every time !

I would get some go-ex black powder from a real gun store. Much more reliable. I'd hate to see a rocket destroyed due to a bad containment and the Pyrodex just fisseld. And those hy-brid tubes can get heavy so it's going to be shovel recovery time.

Is you local gun store (not wal-mart) saying they can't get you BP ?

Did you call about to others nearby ?

Just ask for FFFF, heck even FFF will work if they got that much better then Pyrodex.

Just trying to help, I went though all this early this year and gave up the Pyrodex thoughts and stuck to BP.

BTW, I sent a few emails to you at two different addresses, I gues your using a spam proof fake email like I am on rmr ?

Art

Reply to
ArtU

If you overlook the electronics-related risk (same as for any other electronic device), a timer is no less safe than motor ejection.

Reply to
RayDunakin

Reply to
tater schuld

While I'd agree with your suggested preference, isn't "timer" based ejection effectively what all of our motors use? Are you implying that motor ejection is unsafe?

:-)

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Reply to
Bob Kaplow

WARNING! The MAD makes extensive use of surface mount parts. I can build Heathkit level stuff no problem (like the AYUCR for my Pencam), but the MAD was beyond my expertice. Fortunately another NIRA member built mine for me. If you're experienced with SM or have a friend to help out, go for it.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Reply to
Bob Kaplow

Really, in the PRK maybe ?

Reply to
ArtU

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