XR10 Blown Tekin FX-R Pro Wiring Issue

[dcharman]

Hey Guys,

I purchased my Axial XR10 MOA kit about 2 months ago and piece by piece I've been putting it together. Finally last week all my electronics arrived in the mail and me and my mate (who is experienced with kits) helped me solder it all together.

First my rig consists of 2x Integy 45T motors, 1x HiTec 24kg Servo, 1x Spektrum AR61000e receiver (because I use the Spektrum DX6i remote with my other cars), 2x Tekin FX-R Pro ESC's, 1x 1500mAh LiPo.

The problem occured after we wired the car up. Everything appeared to be working fine. After about 3 minutes of driving out the front on my mates rock garden, smoke started billowing out from under the body (black and red smoke - red because of the body paint). We quickly disconnected the battery to try and save what we could.

I ended up losing one ESC (melted completely with one of the soldering posts falling out completely) and we arent sure about the condition of the second ESC. All the other components seem ok at this stage and I have ordered 2x new ESC's.

Getting to my point, I have put together a rough wiring diagram of how we wired the car and I was hoping some more experienced members could take a look and let me know where Im going wrong, or if we did it right and perhaps it was a faulty component.

Also another point is we did not wire a BEC into the car, simply because the Tekin FX-R says it has a built in BEC. Should the builtin BEC be enough or should I invest in an external BEC?

Anyways, hopefully someone can help me out. Many thanks in advance.

[SMR 510RR]

1. You dont need the FXR Pro's, the regular ones are fine to use.
2. That looks like a faulty ESC, send it in to Tekin (or possibly the distubutor in your part of the world) and they should replace it.
3. Yes, you need a BEC. The internal units are not designed to feed crawler servos and will eventually cause you problems. We all recommend the Castle Creations 10a BEC.

[Charlie-III]

Originally Posted by SMR 510RR

1. You dont need the FXR Pro's, the regular ones are fine to use.
2. That looks like a faulty ESC, send it in to Tekin (or possibly the distubutor in your part of the world) and they should replace it.
3. Yes, you need a BEC. The internal units are not designed to feed crawler servos and will eventually cause you problems. We all recommend the Castle Creations 10a BEC.

+1.

I have dual FX-R's (not the Pro) in my 2.2 Bully with 35T motors & 3S. No issues.

Your diagram looks fine.

When you get to ~200inoz, you will need an external BEC since most ESC internal BEC's can't handle the load. The one exception is the Holmes Hobbies BR-XL which has a decent internal BEC.

I usually run the external BEC direct to the servo.

[The Violator]

On issue I have with the FXR is the solder posts are very close together, and leave themselves open to shorting out. Special care needs to be taken to make sure there is no solder between the posts, or even extra glob that tightens up an already small gap. Looks like ( and it is hard to actually tell from your pic ) that something could have gotten across the 2 center posts. A loose screw bouncing around could really reek havoc. Otherwise I would write it off to a bad esc. A while back, Tekin had a rash of so many fxr's burn up, you were more likely to get a bad one than a good one. I would send them both back to tekin and I am sure they will take of care them as long as they are in Tekin's horribly short warranty. Just remember Castle has 12 months to Tekins 4. Mamba Micro are about the same size, work just as well, cost less, and come with 3x the warranty, just an FYI.

[Colgout]

Saw your post at CANZ as well.

Your diagram should work provide the polarity of the power cap was fitted correctly. But since it worked for 3 minutes, that should be fine. Maybe it is a bad Tekin. There are another thread here regarding some new tekin blown recently, you should definitely try to contact Tekin. Probably return both to them to check it out. On the photo, there is some connector (look like from a receiver), what is that? Is that your melted Rx?

For MOA rig you only need FXR. FXR Pro seems overkill. FXR will drive a 35T using 3s, and people here even uses 4s (with upgraded cap) and lower turn motor. I personally have FXR and 35t HH Pro using 3s with standard cap.

Any crawler should use external BEC to get the most out of the steering servo.

Good luck.

[dcharman]

Yes, you need a BEC.

I have now ordered a CC BEC as you recommended - hopefully this will prevent any additional issues.

On issue I have with the FXR is the solder posts are very close together

This was one of the issues we were very cautious about, because your right - they are really close. after we soldered, we made sure no solder was connecting and used some special paste/glue to cover the wires and posts to prevent any connectivity. you should be able to see some black goop on the ESC in my photo.

Your diagram should work provide the polarity of the power cap was fitted correctly

I believe it was, but we thought it may have potentially come lose after driving around for 3 minutes. in the booklet that comes with the ESC, it does say you can bugger up the ESC if its not fitted at all or correctly. but like i said it all seemed to be working fine - maybe it somehow (unlikely) got loose?

For MOA rig you only need FXR. FXR Pro seems overkill.

If I knew this initially I probably would have saved myself a few bucks, but at the time (being a newb) i thought I cant go wrong if I went for the next product up.

[SMR 510RR]

I would not cover the posts, they are the heatsink for the ESC so letting them breath is best. As long as you take note that anything metal that touches both posts at the same time will fry something you will be fine. I actually like soldering to those posts but maybe that is just because I have done it so many times.

To solder to them this is what I do:

1. Tin the post
2. Tin the wire and pinch it with pliers right after to get it the right thickness to fit in the slot in the post
3. lay the wire in the post (I work from the middle out so I dont have to reach over another wire/post...Just have a plan)
4. Hit it with the iron, everything should melt and flow out
5. Pull the iron off
6. Pat yourself on the back!

[dcharman]

That is a nice process, I will definately keep that in mind when I have to redo everything soon.