RC Conversion of Estes Skydart II

Yeah, that's more like it!

Plugged in my micro receiver......and got the cutest little "POP!" and puff of smoke. :kill:

So, we are on hold here for a while.

UGH! Let the magic smoke out.

Hmm, is is possible that the battery polarity was reversed?

Did you have to customize any connector wiring such as battery to Rx or Servo to RX?

Sometimes the pinout sequence for one brand of receiver, and a different brand of servo, are different. Not sure that the wrong wiring to a servo plug could cause the Receiver to smoke, but perhaps (more likely to damage the servo).

BTW - don't ever use a 4.8 to 5V servo with a receiver powered directly 7.8V battery. The servo may not smoke, but the feedback pot will burn out in a few seconds and then the servo stops working. learned that the hard way once, and then stupidly did not pay attention and did it again. I use Dymond D-48 servos with a lot of R/C RBG's and those are rated for 8 volts, and for those I usually use 2 cell 7.4V packs except for really small stuff. So, I get used to it. So when I do need to use a servo not rated for 7.4V, when using 7.4V or above, I need to have a 5V voltage regulator. In electric planes that is not a problem as the ESC's to control the throttle for electric motors also provide 5.0V for the R/C gear. Again I get used to that, too. Indeed the other day I plugged a servo in while using a 7.4V pack to power the receiver..... and only realized later that servo was NOT known to be rated for 7.4V. Fortunately it did not burn out the servo pot but I unplugged that servo as soon as I realized it.

I'm sure the above paragraph does not apply in this case (since 3.7V was used) just a general warning for other R/C gear when using over 5 volts (some servos are rated up to 6V).

georgegassaway said:

UGH! Let the magic smoke out.

Hmm, is is possible that the battery polarity was reversed?

Did you have to customize any connector wiring such as battery to Rx or Servo to RX?

Sometimes the pinout sequence for one brand of receiver, and a different brand of servo, are different. Not sure that the wrong wiring to a servo plug could cause the Receiver to smoke, but perhaps (more likely to damage the servo).

Click to expand...

It appears that I reversed the polarity. Apparently "black" is positive on some lipo batteries.

Soooo.......I decided to reverse the polarity (after comparing to other lipo setups) and plugged things in......



Linked right up to my transmitter [Tactic transmitter & receiver & servo], and appears to be functioning well.

My brain is now fried.

Moving right along....

The aileron servo installed.

General arrangement of components:

Looking underneath:



The servo is held w/ hot glue, and the receiver is velcro. Debating putting Blenderm tape over receiver.

Looking at the top, the battery is forward for balance.



Also increased the length of the rudder, and did a better job of installing it.

GLIDE TESTS

Sorry, no pics or video of the glide tests. Just chunked it forward in the back yard.

The Skydart seemed to glide well, and in the short glide distance I was able to get it to react to the rudder.

Just as in George's descriptions, the model seemed to bank well to rudder input (which surprised me).

Crawf56 said:

It appears that I reversed the polarity. Apparently "black" is positive on some lipo batteries.

Soooo.......I decided to reverse the polarity (after comparing to other lipo setups) and plugged things in......

View attachment 314529

Linked right up to my transmitter [Tactic transmitter & receiver & servo], and appears to be functioning well.

My brain is now fried.

Click to expand...

Wow, that's incredible that after a "pop" and smoke, the Rx is still working!

Actually, on those small Lipos with that kind of connector, you now have it connectoed correctly. The photo with them plugged in, I can see you have the small opening on the side of the wiring connector alingne with the small tab on the side of the battery's end connector.

I have made that mistake a few times early on myself. But either I didn't force it enogh for te connectors to mechanically touch, or if it did make contact the reversed voltage didn't hurt anything.

That red dot.... I didn't think of that as a "+" voltage sign, since it s at 90 degrees to the two connectors. There are some female connectors for that type of battery design, with an very long offset tab that covers over that red dot, while the same tab is blocked by the two upright little posts (molded black plastic) on the opposite side of the battery if reversed. That's how I learned about it, the female connectors without that offset tab are definitely a lot easier to get wrong

Photo below shows the different sides of the battery. I didn't have a female connector on-hand to include. The longest battery at right has a foil label on it that does not show up well, but that is the Face-Up label side of that battery, as is the one in the middle. Contrast the battery connector's rectangular bumps of those two, with the battery at left showing the other side (red dot, no label), which is smooth.

So the wiring connector's rectangular opening fits the label side, not the red dot side.

What might help you would be to use a red magic marker, on the female connector, to color the side of the connector that matches the "red dot", as red itself. Even though it would be a "face this with red dot" mechanical indicator, not a true electrical polarity indicator (since it's at 90 degrees to the two electrical connectors).



BTW - An example of a female connector with tab, on a brick receiver. I first used these kinds of batteries with a Parkzone "Ember" using what many referred to as a "brick" receiver (Because it had servos and receiver all in one, as a very few R/C systems have had before then). If a battery was plugged into this as shown, the battery would be label side up, red dot down.

Thanks for your comments, George. I am still amazed that the Tactic micro receiver works; and I can't find a black spot or melted wire/board/plastic. Maybe I had too much LDS in the 1970's.....:wink:

To begin, here is the 1s 70 mAh lipo battery. I am pointing to what I thought was a "black wire":

The most difficult part of this little project was sorting out the @#$%^& connectors.

By looking at the connectors for my servo (and from my RC aircraft experience), I could figure out where the positive [red] & negative [black] connections went on my micro receiver:



I ordered a micro servo lead to adapt my battery to the receiver:

https://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXGVD6&P=7

And here is everything laid out:



Note that I am holding the tip of a small pair of scissors against the negative lead (top center of pic).

The connector for the lipo battery did NOT designate black/red wires; both wires were red. I cut the wires, and soldered what I thought was positive and negative. I was wrong the first time...

Here is the connector I got:

https://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXFCVE&P=ML

I still have not found an "off the shelf", pre-made adapter to connect the 1s lipo to the micro receiver.

Those batteries are made to plug into small copters and unfortunately for some nebulous reason some companies wired theirs backward to convention. The only way to be sure of which is - or + is to measure with a VOM and then mark the connector with a marker pen. You can occasionally see warnings to that effect on some websites.


Richard

Crawf56 said:

The connector for the lipo battery did NOT designate black/red wires; both wires were red. I cut the wires, and soldered what I thought was positive and negative. I was wrong the first time....

Click to expand...

Man, that is dumb that the wires would be the same color.

When I'm in doubt as to polarity, I use a Volt Ohm Meter (VOM) to check.

If you do not have that, you could use a piezo beeper, if you have one and know its polarity. Or an LED if you know its polarity (at 3.7V, an LED is probably OK without a dropping resistor). Beeper or LED will only work if the polarity is right, if reversed there is no damage to them.

Flight, and SUCCESS!.

I did one launch today with a B6-2 motor.

However, I think I need to give more thought to my launch characteristics. I was worried about the 'drift' of the pod, so I angled the boost glider into the wind.

The Good News: The pod parachuted down relatively close to me (30 yards away).

The Bad News: This meant that, when the glider was at apogee, it was too far upwind from me to continue flying into the wind. So, I had to turn the glider toward me, which gave it a tailwind. This tailwind took away some of my lift, on a glider with no elevator control.

However, the glider responded well to the Rudder-only control. I had a 10 mph tailwind, and still had a "not-so-terrible" glide path.

All this brings me to the conclusion that I needed to launch downwind, so that I could turn INTO the wind for a better glide path back to me. And I need to have a second set of eyes to track the pod as it parachutes down.

Hopefully in the next month I can get some flight pics.

Also had another Lipo Learning Experience....:eyeroll:

I am using velcro to hold my 1s 70 mAh lipo battery in place. To do this, I put 'fuzzy' velcro on the lipo battery.

The E-flite USB lipo charger that I am using has a red LED light to show that it is charging. When the light goes off, the charge is complete.

The Problem was that the velcro I attached to the lipo battery interfered with the connection to the charger. When I plugged in the battery, the charger would light up for a second or two, then the charging light would go out. I thought, "hey, it's charged."

Wrong! Fortunately, I did "one more" pre-flight check (wiggled the rudder using the transmitter), and got......... nothing.

Got everything sorted out, got the lipo charged. Saved by a pre-flight check.

I've found prefer to launch upwind, and then just do S turns and let the headwind blow me back without having to do a full downwind turn, just do lateral turns left and right always turning back into the wind....

Frank

Here are my thoughts on this "RC Estes Skydart" project.

MADE IT WORK - Thanks for the advice, folks. I was surprised how well the rudder-only control worked.

BUT........ not sure this is a viable idea. I think this is a great model by Estes for a rocket boost glider. But it is just too small for radio control.

PROBLEMS:

Pop-pod: I have lost two of them. For my situation and flight area, it is very difficult to keep track of where the engine pod lands.

RC gear: The Tactic micro gear has performed well, but piecing the connectors together was a big headache. So much easier (and cheaper) to go with larger RC gear.

I have been flying RC models for 35 years. I hate to say this to the Rocketry Folks, but you have to learn RC before you go RC rocket glider.

Really cool project. Have you given any thought to conversion of this one: (probably needs some re-scaling of wing to make it glide, not a glider in the first place)
https://www.estesrockets.com/rockets/kits/skill-1/003230-estes-jetlinertm

Reflective streamers are really easy to spot across a field in the sunlight, that might help find a pop-pod. Also known as bird-deterrent tape at hardware stores.

GlenP said:

Really cool project. Have you given any thought to conversion of this one: (probably needs some re-scaling of wing to make it glide, not a glider in the first place)
https://www.estesrockets.com/rockets/kits/skill-1/003230-estes-jetlinertm

Reflective streamers are really easy to spot across a field in the sunlight, that might help find a pop-pod. Also known as bird-deterrent tape at hardware stores.

Click to expand...

ESTES JETLINER - Good looking model rocket, but small, and therefore sensitive to weight.

Also, one problem with the smaller models is dealing with the ejection charge (or ignition charge from a boost motor).

REFLECTIVE STREAMERS - That is a good idea. I used a parachute on the Skydart pop-pod, because I feared it was too heavy for a streamer (the pod has 3 or 4 washers on the nose). I used a "hot pink" streamer on my ARCIE II boost glider pod.

My "pod problems" have more to do with where I fly. I launch rocket gliders in two places:

1) Kennett, MO, RC Club - A 100 yard long RC airplane airfield (20 yards wide). Open on the north, east, and south..............with a line of trees to the west. Fantastic for RC airplanes, but not great for rockets.

2) Walcott, AR, "Old Airstrip" - An abandoned WW2 training runway; looks like a wide dirt/asphalt road. Located in middle of nowhere, surrounded by farmland. Great place to launch after harvest. Other times, depends on the crop; lost one pop-pod to a wheat field.

Future Projects: I am currently "heavily engaged" with a 1/3 scale Nieuport 28 WW1 RC model airplane. Trying to get it done for several 1918/2018 events, commemorating the end of WW1.

Once the 10 ft. wingspan N28 is finished,I will work on:

Dynasoar Rocketry - Klingon Battlecruiser

J&H Aerospace - Switchblade XL

Convert an old delta wing rc model to rocket boost.

R&R Rocketry - Delta Star II

Fun, fun, fun!