Ar7100R Sensor, yea... They might need a recall

[JimLerch]

Well, if your flying 100% throttle curves in idle up, you better be on the ball! Here's why

This is after 6 flights on my YS-80-ST in the BBC Pantera. Yea, it got interesting for a moment. These connections are behind the black heat shrink tubing.

http://lerch.no-ip.com/Heli/Sensor1.jpg

http://lerch.no-ip.com/Heli/Sensor2.jpg

[JimLerch]

Oh, more fun, yup my antenna broke off like everyone else.

http://lerch.no-ip.com/Heli/Receiver-Ant.jpg

Spoke with Horizon regarding the problem, they don't have spare crank sensors yet, so my choices were


send in the defective via RMA tag, wait for spares to show up maybe end of August
Buy a new receiver from them, then send defective back in for return.

I choose option 2..

[warpspeed]

Jim, doncha think the new one might just be the same as the old?

I realize you're between a rock and a hard place.

But if Spektrum is going to continue to sell this crap they should offer insurance, or at the very least put a sticker on the box that says MAY FAIL AT ANY TIME!

[JimLerch]

I feel ya, but I aint ever getting my money back, that I'm certain. :roll:

So, I'll have to bite the bullet and solve their problem myself. Most have figured out the antenna issue, so that's easy enough.

The sensor, looks mostly like I just need to epoxy the thing into a solid with some wires poking out thru a good section of heat shrink for strain relief.

[warpspeed]

Which sounds like a perfectly good fix to me.....makes ya wonder why an ordinary guy (my apologies if you're extra-ordinary:)) recognized a fix for a potential problem area in what, a few minutes, and yet the manufacturer looks at a design and sees no issues at all. My guess is the Spektrum motto reads damn near exactly like PT Barnums.

Anyway I'm glad you got her down safely. You're certainly a lot calmer about it than I would be. I just lost one of my favorite planks to a faulty rx so I'm a little p.o.'d at the moment.

[Pinecone]

BTW Spektrum has a service bulletin out about the Rx antenna. And recommend the Goop fix.

http://www.helifreak.com/showthread.php?t=84763

[JimLerch]

Well, I got my replacement receiver in today, and shot these two little "rant" video's

My fix for the video below was to place slim folded over pieces of servo tape below the circuit board, and a larger piece on top of the board. In addition I added the prescribed 'goop' to the antenna, even though there was a tiny bit on it when I got it.

So, here is the video I shot on the receivers

http://www.vimeo.com/1449239 (caution, adult language)

Then I shot this video ranting about the crank sensor

http://www.vimeo.com/1449319

The sensor epoxy is almost cured, so I'll see if I can take some photo's once its done.

Let me know what you think...

[JimLerch]

Here are pictures of my modified sensor, in case anyone is interested. Clear epoxy covered in clear heat shrink. I'm thinking this one will last for a while.

http://lerch.no-ip.com/Heli/New_sensor1.jpg

http://lerch.no-ip.com/Heli/New_sensor2.jpg

http://lerch.no-ip.com/Heli/New_sensor3.jpg

[Finless]

:lolol:lolol:lolol:lolol:lolol

Nice whining vids Jim ;)

No seriously good work covering that stuff. Of note even if you stop the MAIN board RX from moving in the case check out the little middle board. It wiggles on it's own too! You need to stuff some foam in-between the boards to keep the middle board from moving around.

Finally my experience even after doing these mods is DO NOT hard mount the RX on a nitro! Just Velcro does not provide enough vibration dampening... Use foam between the RX and the heli....

Bob

[spike5150]

I bought this Rx for my first Nitro - a shiny Vibe 50 - and I am seriously considering returning it. I agree that the concept is TOP NOTCH, but now there are two HUGE problems.

I am ok with adding foam to the Rx - one question, though, is it going to cause the circuit boards to overheat now? How much do you need to put in there? I am planning on running 8V just for the simplicity at this point.

The sensor seems like it is harder to fix, but I guess I can try it... I have also read you can use the Align Gov sensor by reversing some wires - maybe that is more robust?

Jim - your rants are great and warranted (unlike your crashed helicopter). I think if Jack Black did a heli rant it would not be far off from yours. And thanks for the great advice and help to us freaks so we don't suffer the same fate.

Jeremy

P.S. - I must admit that I have a degree in Mechanical Engineering, but we all had to PASS a class on vibration theory...

[JimLerch]

Thanks for the compliments, and just an update. This receiver and sensor are installed on my Big Block converted YS-80 powered Pantera. Since I've done the repairs to the new sensor, I've had no problems!! One unscheduled landing and 4 or 5 gallons of fuel and no problems at all (100% throttle curves with an overpowered 50 class heli, if the rev limiter goes off line, I know about it instantly! :YeaBaby: )

Spike5150, the sensor is the easiest to fix. Slip the black heat shrink off, slobber epoxy on and between everything, put new heat shrink on, wait for it to cure..

Bob, I used that "Black Servo tape / foam stuff" with the blue release material. As I recall I rolled it up and stuffed four pieces in the receiver all stacked on top of each other to make a PCB / Foam "Big Mac" sandwich.

BTW, I really do like the receiver and the concept behind it. The only problem I have is the bird is so light from lack of electronics, it is a little tail heavy..