Push button stooge

Bob:

Here is what I ordered. There are many similar devices. I picked these by just guessing. Luckily, it worked.

https://www.amazon.com/gp/product/B0105UOV1I/ref=ppx_yo_dt_b_asin_title_o00__o00_s01?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B07H4VK882/ref=ppx_yo_dt_b_asin_title_o00__o00_s00?ie=UTF8&psc=1

Rusty:

Looks to be about a 3-4 second impulse. Roger on the spring. I was going to incorporate that but didn't have one light enough. Will have to wait 'til I get to the hardware store.

Now that is a great idea! Good job.

Ingenious

That is Cool , Nothing like having that string wrapped around your feet getting tighter as you turn I got a stooge for holding the tail section STAB that i haven't tried yet ,, Next time out this spring !!

Watch out!! The FAA might call your c/l model an unlicensed UAS.

RknRusty wrote:
You may want a light spring to help hold it closed so it doesn't vibrate open. I wouldn't trust just the tension of the plane pulling on the pin to secure it from possibly moving from engine vibration.
Rusty

There are similar solenoids available with a return spring built in. The one being used looks like it has a small ring or clip on the plunger. He may be able to install a light return spring under there.

Oldenginerod wrote:

RknRusty wrote:
You may want a light spring to help hold it closed so it doesn't vibrate open. I wouldn't trust just the tension of the plane pulling on the pin to secure it from possibly moving from engine vibration.
Rusty

There are similar solenoids available with a return spring built in.  The one being used looks like it has a small ring or clip on the plunger.  He may be able to install a light return spring under there.

As I was going on the cheap with this project, I passed on the spring loaded options. Not that they're that much more expensive but I was in a "low as you can go" mode. As the plunger is not captive, I opted for the bellcrank to contain it and will rig a spring in some fashion when I find one. I'd opt for a "pre-sprung" if I had it to do over. My main engineering concern was compatible electronics and 9V battery functionality. I lucked out in that regard and was giddy with the results. All that said, I look forward to other's improvement of the mechanics. This was a shot in the dark design in as simple a format as I could imagine. Rigged as it is, I think it'll work after some tweeking.

rsv1cox wrote:

Slick049 wrote:Bob:

I miss R/S, I used to prowl that store while my wife shopped clothes.....

I remember having a “battery a Month” card. Used to replenish my D Size starter batteries. Yup, definitely miss browsing that store!

"UAS" = Unmanned Aircraft SYSTEMS All it would take to get the fed SWAT team out would be just one creative and abusive bureaucrat to call the whole thing a "System".

So, I went this morning and picked up a couple of "return" springs. The lightest they had. Got home and tested them and they proved too strong. Replaced the battery with a new one and got a little more pull out of the solenoid, but not enough. So I got to figuring that an increase in voltage would produce a stronger pull and considered doubling up the 9Vs. Got to reading up on the remote controller and it allows up to 36V, so would be safe there. Don't want to burn up the electronics if I can help it. Anyway, went on Amazon looking for a couple of 9V battery holders and low and behold, ran across some 12V (A23). Look to be a little fatter and maybe a little shorter than AAs. Admittedly, I had no clue they even made them. Come to find out they are very common for doorbells, garage door openers and such. Who knew?
So, the plan is, once delivered, is to gang up a couple of A23s for 24V and see what happens to the strength of pull of the solenoid. And then go to three if necessary. I'm trying to keep the stooge as compact as possible. Don't want to be lugging around a cinder block if I can help it.
And yea, Radio Shack. Ditto on what everybody else said.

I'll try flipping the bellcrank. Have it half way disassembled as it is. Moving stuff around won't be an issue. Goal is to keep it small. Will see what the A23s will do and upgrade to a bigger battery if necessary. Initial plan is to mount it to a piece of Masonite or peg board, say 2' X 3'. Do the landing gear side chock thing. Will peg it to the ground or set a block on it if needed. Will be flying 1/2A stuff w/.049s so I'm not too worried about it being overpowered and end up being drug around. Although, that would be a sight.

Keep 9 Vdc... make lever fulcrum very close to 3 or 4 to 1 mechanical advantage... Narrow the guide to accommodate 2 times string width... max throw under 1/8th inch....no spring needed

my adjustments for a very cool design

fredvon4 wrote:Keep 9 Vdc... make lever fulcrum very close to 3 or 4 to 1 mechanical advantage... Narrow the guide to accommodate 2 times string width... max throw under 1/8th inch....no spring needed

my adjustments for a very cool design

I think the 3-4 to one advantage is an excellent idea. The narrower guide makes sense. 1/2" is a bit much/unnecessary.

ON TO PLAN uh L? Guess I should have kept track of the changes.

I like your idea for the remote. I'm going to try a different design using the solenoid to trip a sear allowing a spring loaded pin to retract, releasing the plane. Amazon here I come!

coxaddict wrote:I like your idea for the remote. I'm going to try a different design using the solenoid to trip a sear allowing a spring loaded pin to retract, releasing the plane.  Amazon here I come!

I think you're on to something!

Here are some details of my design.  Made use, mostly, of what I had laying around.  Here is the pivot for the bellcrank.  A short piece of K&S tubing with a washer on either end with a bolt to hold it all.



If I retain the bellcrank option (see "sear" system in previous comment), I will get a longer piece and glue it in the board as this one has gotten wallered(sp?) out, what with all the testing.

The wire guide is a long shank rivet head, glued into the angle piece, with a lock nut glued on for the overkill that's in it.



As all this is being concocted, I have just finished this Brodak trainer (Baby steps.  It was long ago since I last flew.) (Or built anything to fly)


And have just started the P-51.


A Lil Satan is third on the build list.

Just waiting for a warm, calm day.

Those A23 cells are pretty weak. They only have a 55mAh capacity down to 6V. I doubt it will pull in the solenoid.

The 9V battrry is about 600mAh and can supply a max of 500mA before the voltage sags. You may get a few actuations out of it before it gets too weak.

It’s all about ESR or equivalent series resistance. How much current can the battery supply and for how long (mAh).

A 3S1P 1000mAh lipo battery pack would be far superior to the above two batteries. It requires a special charger and voltage monitoring that most modelers have.

The other option is to use a boost regulator with 4 D batteries. It will take 2-24V and convert up to 28V DC at 2A of current. It has a potentiometer to adjust the output voltage. This way with the 2A of regulated current a solenoid with a return spring can be used.

Can find the boost converters on Amazon or eBay. Most ship from China and take a few weeks to get.

So.  Took Jason_WI's comments to heart.  The little A23s are not capable.  Went looking for the smallest(size) 12V I could find.  Ran across this:


Specs say battery puts out 3A.  The remote circuit can take up to 5A, which was my main worry.  The solenoid isn't bothered by much of anything, within reason.  Early testing proves it to be more than adequate.  Snatches the plunger out of my fingers.  Makes a very audible click.  More than enough pull.

Serendipitously, the battery fits perfectly in my field box.



And about that going cheap part on the front end?  Well, game over.  Besides the battery being free(which would cost $20-$30), I ordered one of those Hobbico power panels.  Basically doubled the initial investment.  Kissin' $70 total right now.  Oh well.  I've wasted more money on a lot less.  Upside is I'll break even on the weight thing as I'll rid myself of the glow plug battery array/box.

Now back to re-engineering the setup.  Looks like I'll go with a spring loaded plunger and go straight in without the need for the bellcrank.  Simpler is gooder.