Raven Power Perch

patelldp said:

Adrian - Do you have a source for a female connector with leads to the li-po batteries you use so I could utilize the same batteries in other altimeters? Huge weight saver, and rechargeable to boot.

Click to expand...

https://www.all-battery.com/molexconnector80075.aspx

Interested in a pair.

I am eager to try on of these out. That his the biggest problems I have with the raven and several other altimeters is the lack of simplicity in the wiring. I have used them, but simpler connections.

I just talked with my assembler, and it sounds like the Power Perch might be done early, vs. the Jan 12th promise date. Fingers crossed.

Adrian A said:

I just talked with my assembler, and it sounds like the Power Perch might be done early, vs. the Jan 12th promise date. Fingers crossed.

Click to expand...

Yippee!

Yipee! Yipee!:clap::clap::clap::clap::grin::grin::grin::grin:

:impatient::impatient::impatient::santa-smile::santa-smile:

Nice work Adrian. Now I'm not going to do my av-bay layout on my current two-stage project until I get one of these "Raven Havens" things. Can't wait...

Adrian, I REALLY like these, they fit real well into to a modular plan I have for my fleet. But, how well would a pair of these work next to each other on a 7.5" inch sled? I've got some pretty knarly magnets handy but could I end up rapid cycling one or the other or both? (think twin Ravens for an L3 cert, this would cut exposed switches down to only two for ejection safeties)

-S

Scott Evil said:

Adrian, I REALLY like these, they fit real well into to a modular plan I have for my fleet. But, how well would a pair of these work next to each other on a 7.5" inch sled? I've got some pretty gnarly magnets handy but could I end up rapid cycling one or the other or both? (think twin Ravens for an L3 cert, this would cut exposed switches down to only two for ejection safeties)

-S

Click to expand...

Thanks, Scott.

If you put them on opposite sides of the sled it should work fine. The Raven works fine with either end up, so I would put the magnet-sensing edge of each of the Perches along the outer edge of the sled and just use a small magnet. The sensing range with the small magnets is between 1.5" and 2".

I'm sorry, Adrian! I just can't get past the mental image of a rocket powered flying fish...

WillMarchant said:

I'm sorry, Adrian! I just can't get past the mental image of a rocket powered flying fish...

Click to expand...

You can tell I'm not a fisherman, because the fish version of "perch" didn't even occur to me until I did a Google search .

I am playing with a 2 stage design that has a 4" airframe and a 54 mm MMT. I need something for the booster separation and parachute deployment.

Some of the spec's on the booster stage are
4" diameter x 20" long and it contains a 54 mm MMT that is 16" long
Thru The Wall Fins with a fin tab (per roc-sim) of .6875"

I would like to use a Raven to separate the stages and possibly lite the sustainer. My question is.........

If I mount the Raven in the booster or sustainer section between the fins will it be to close to the MMT that is can be damaged by the heat?

I think it's unlikely to be damaged. Most parts have max tempersture specs of 70 C, or 158F. The Raven records the temperature of the board, so you can at least see afterward how hot it got.

What's your plan for recovery for the booster?

Adrian A said:

I think it's unlikely to be damaged. Most parts have max tempersture specs of 70 C, or 158F. The Raven records the temperature of the board, so you can at least see afterward how hot it got.

What's your plan for recovery for the booster?

Click to expand...

That is good to know -

The booster will come down under chute - if all works right - from some where around 4500 - 5000'

troj said:

One question that comes to mind is how to retain the battery on the board, so that it does't pop loose?

The friction of the plug isn't enough for comfort, for me.

-Kevin

Click to expand...

troj said:

Or, use the L-shaped piece of wood, but then have a small strap mounted with a single screw to the side. Loosen a wingnut, pivot the strap out of the way and the battery comes free. Install battery, pivot strap into place, tighten wingnut, and done!

-Kevin

Click to expand...

Here's where I'm at so far. The rectangular part is 1/4" thick and goes behind the battery. Another piece on top pivots in and out of place for access to, or restraint of, the battery.

The piece going to the right would do the same for the back end of the Raven. That way, you would just need to mount the Power Perch and you can restain the Raven just by screwing down the terminals at one and and holding it down with the pivoting piece at the other end.

Questions for the group:

What kind of screws do you want for mounting the Power Perch? I'm thinking of providing 4-40 machine screws and no nuts. The can be threaded directly into a plywood sled drilled with a 3/32" drill bit. Or should I provide wood screws?

Adrian,

That is nice. Thanks for the hard work.

Adrian A said:

What kind of screws do you want for mounting the Power Perch? I'm thinking of providing 4-40 machine screws and no nuts. The can be threaded directly into a plywood sled drilled with a 3/32" drill bit. Or should I provide wood screws?

Click to expand...

I would almost always use 4-40 machine screws. Wood screws; not so much.

WOW! I need one.

For me, I'd use machine screws with nuts. Works well on plywood and G10 and less likely to work loose.

4-40 is a good size, as 2-56 is small and easy to drop and lose.

4-40 screws here, as well.

patelldp said:

4-40 screws here, as well.

Click to expand...

No metric love here??? I use M2/.4 everywhere.

darisd said:

No metric love here??? I use M2/.4 everywhere.

Click to expand...

M2 is close to #2, #4 is very close to M3.

darisd said:

No metric love here??? I use M2/.4 everywhere.

Click to expand...

M3, stainless steel, Torx. That's the common standard on my rockets as long as there is no good reason for an exception.

Below M3, availability becomes much worse. I don't want to see rust on my rockets and minimize magnetic interference. With Torx, I don't have to worry about slipping screw drivers and worn out screws.


Admittedly, this might not be the most pragmatic choice of screws, but thats my hobby. I don't have to be pragmatic here.

Reinhard

Looking good, Adrian.

Do you have the overall dimensions for the setup shown in post #46?

Need to hurry up with manufacturing. :impatient:

nh4clo4 said:

Looking good, Adrian.

Do you have the overall dimensions for the setup shown in post #46?

Need to hurry up with manufacturing. :impatient:

Click to expand...

1.44" x 2.54"

The good news is that I received 250 assembled Power Perches today.:w:
The bad news is that the polarized tantalum capacitor on all 250 was soldered on backwards. :sigh:

I'll see what my assembly company is going to do about it tomorrow. I need to wait for hardware and wood battery restraints anyway, so I'll try not to be too impatient. On the other hand, if I have an opportunity to get some fixed up tomorrow, are there people who would rather skip getting the screws and the little wood pieces in order to get one this week?

Is there any chance of you making a variant of these that uses a normal switch? I'm personally not a fan of the magnetic switches.

Adrian A said:

The bad news is that the polarized tantalum capacitor on all 250 was soldered on backwards. :sigh:

Click to expand...

Doh!



-Kevin

Adrian A said:

On the other hand, if I have an opportunity to get some fixed up tomorrow, are there people who would rather skip getting the screws and the little wood pieces in order to get one this week?

Click to expand...

Price for repaired first articles without hardware?

Rocketman248 said:

Is there any chance of you making a variant of these that uses a normal switch? I'm personally not a fan of the magnetic switches.

Click to expand...

+1 (9V compatible as well)