Tommy R's TTC Build - "Big Oly"

[Tommy R]

nice! if ya need some hardcore testing before nats, we'll hit up the rock the lake location, its amazing right now twice the rock exposed.

Oh, I wish! Unfortunately, I'll only have time for some testing on my backyard course. The good news is that the only changes are 4s power (vs. 3s) and rear steer. The rear steer, however, will definitely take some getting used to! :shock: But it'll be fun! :mrgreen:

 

[hotwheels000]

Tommy, if it hasnt been suggested already. A nylon/stocking works well to keep the crud out.It also allows the motor to breath still,those little pullers(compared to a T-8 ) can get warm in a hurry in a heavy rig,especially on 4s.

Looking forward ot seeing OLY in person"thumbsup"

 

[Tommy R]

Tommy, if it hasnt been suggested already. A nylon/stocking works well to keep the crud out.It also allows the motor to breath still,those little pullers(compared to a T-8 ) can get warm in a hurry in a heavy rig,especially on 4s.

Looking forward ot seeing OLY in person"thumbsup"

That's kinda what I was initially thinking. Back in the day we'd tape coffee filters to the motors to keep dirt and dust out. I was going to do that 'til John recommended the tape idea. I figured he should know, right?

I suspect in time a T-8 may make it into Oly....along with one of them there fancy schmancy t-cases you Nor'westerners are running these days. :mrgreen:

 

[ecoli]

The events are short though, and you're in water for 1/2 the time, so I wouldn't worry too much about heat. Definitely cover it up though, I didn't last year, and had all sorts of motor issues during the TTC eventually smoking the motor I had in there.

More importantly, is Oly back together again ?

 

[Tommy R]

The events are short though, and you're in water for 1/2 the time, so I wouldn't worry too much about heat. Definitely cover it up though, I didn't last year, and had all sorts of motor issues during the TTC eventually smoking the motor I had in there.

More importantly, is Oly back together again ?

Well, hopefully the tape is enough. We'll find out, I suppose! :mrgreen:

Oly is probably an hour or two from being D-O-N-E. The re-assembly is taking longer because I'm Loctiting everything and trying to do a clean job of wiring, etc. I'm wanting to leave nothing to chance in Montana! "thumbsup"

 

[justinart24]

Thanks, Erik! Regarding the motor, I mentioned it to John Holmes and what he recommended was to tape over the slots in the motor to keep the larger crud from entering the motor so that's what I've done. Hopefully it'll hold up!

Hmm...this is why I am running a Traxxas "Waterproof" velineon brushless system, no drag brake but water proof.:mrgreen:

So, you painting a new lexan body too? Also, how do you like the rear steer, get a lot of practice?

 

[Tommy R]

Hmm...this is why I am running a Traxxas "Waterproof" velineon brushless system, no drag brake but water proof.:mrgreen:

So, you painting a new lexan body too? Also, how do you like the rear steer, get a lot of practice?

No practice yet. Was hoping for some tonight, but I'm having a problem. I've got a BEC powering my Hitec 7950 with 7.4V. But there's no steering at all. I disconnected it from the BEC and plugged the servo directly into the receiver and when it's powered on the servo oscillates violently! Going through the BEC it does nothing. I tried different channels and it's not the radio.

Anyone know what may be going on? This servo has worked great with the BEC before now. And I can't imagine what's causing it to freak out like it is! Help?

 

[team3six]

No practice yet. Was hoping for some tonight, but I'm having a problem. I've got a BEC powering my Hitec 7950 with 7.4V. But there's no steering at all. I disconnected it from the BEC and plugged the servo directly into the receiver and when it's powered on the servo oscillates violently! Going through the BEC it does nothing. I tried different channels and it's not the radio.

Anyone know what may be going on? This servo has worked great with the BEC before now. And I can't imagine what's causing it to freak out like it is! Help?

Could be several things.
Ok first try switching the servo to the throttle plug and see if its fine.
if it is still twitching, then you know its low battery, or he servo, or worse the esc.
if its fine, then its something with your programing, the bec or the reciever.

The only other thing I can think of is the servo needs so much power to opperate, you might be starving it. Try switching to another bec before you do anything.

 

[Tommy R]

Well, I tried different channels of the rx with the same twitching. I also tried swapping the front/rear steering servos and the problem remained with the 7950 servo. I also verified the BEC is putting out 7.4v. Lastly, I tried two full charged batteries (2s in series for 4s) and no improvement. I also tried a different servo to replace the 7950 and it worked fine.

Basically, everything is pointing toward the servo. But why would it act dead when running through the BEC, but twitch like mad getting power through the receiver?

I'm totally lost on this one. And it's happening at a really, really bad time. :evil:

 

[team3six]

Well, I tried different channels of the rx with the same twitching. I also tried swapping the front/rear steering servos and the problem remained with the 7950 servo. I also verified the BEC is putting out 7.4v. Lastly, I tried two full charged batteries (2s in series for 4s) and no improvement. I also tried a different servo to replace the 7950 and it worked fine.

Basically, everything is pointing toward the servo. But why would it act dead when running through the BEC, but twitch like mad getting power through the receiver?

I'm totally lost on this one. And it's happening at a really, really bad time. :evil:

So my guess is the servo. If you switch the rear servo into the other port is it fine?
would it help if I call you

 

[Tommy R]

So my guess is the servo. If you switch the rear servo into the other port is it fine?
would it help if I call you

Yeah, if I plug the rear steer servo into Channel 1 it functions fine. Likewise, if I plug the front steer servo (the 7950) into Channel 3, it still twitches.

Yes, Norm, if you've got some insight to share, please feel free to call. I'll PM you my number.

Meanwhile, if anyone else has any ideas, please don't hold back!

 

[eric113]

Yeah, if I plug the rear steer servo into Channel 1 it functions fine. Likewise, if I plug the front steer servo (the 7950) into Channel 3, it still twitches.

Yes, Norm, if you've got some insight to share, please feel free to call. I'll PM you my number.

Meanwhile, if anyone else has any ideas, please don't hold back!

You may have to set the deadband on the servo thur hitech servo programmer since you are using hitech servo with futaba rx/tx.

I know Greg said he had to do that with all his hitech servo to run with his 4pk.

 

[Tommy R]

But it worked fine with this rx/tx before. This problem just started happening tonight. I spoke with Norm on the phone (thanks again for the help, Norm!) and we came to the conclusion that the ESC is likely kaput. The sad part is I've got ONE RUN on this servo and it's crapped out on me. I'll send this one back to Hitec under warranty, but will get a new servo in the meantime 'cause I can't take the time to ship this one off and get it back and installed before MSD.

I may run to Hobbytown tomorrow to see what they have in stock...

 

[hotwheels000]

Does the radio have a setting to choose digital or analog settings for the servo ? Worth a shot.

 

[Tommy R]

Does the radio have a setting to choose digital or analog settings for the servo ? Worth a shot.

I don't think so (Futaba 4PL). I just spoke with Hitec and they feel it's a problem with the servo. The good news is that it's under warranty and will be repaired. The bad news is they have a 7 day turnaround time right now. So I'm going to buy a replacement servo for use through Montana. I'm now trying to find a reasonably priced 7950th in stock somewhere. Servocity.com is out.

I may pick up a 7980th (611 oz @ 7.4v!!), but it's physically larger and I'm not quite sure if it will require any work to fit it or if it'll fit standard servo mounting dimensions. Anyone know? I'm going to see if Hitec's site lists the dimensions I need.

 

[willipmartinni]

the 7980's are 10% larger, all I know

 

[Tommy R]

Wow, I'm no longer getting e-mail notifications to replies to this thread. Strange.

the 7980's are 10% larger, all I know

Yeah, that's all I've found, too. Looking at them side by side on servocity's site, I don't think it'll work for me. So I ponied up for next day shipping of a 7950TH from Tower (had them in stock). Fortunately, I had a coupon that helped ease the pain a bit. :mrgreen:

If all goes well, both my Montana rigs will be completely finished tomorrow night. Fingers = crossed!

 

[Difuser]

Tommy also watch the mode that the 4PL is in. When they switched to the 3pk alot of people had issues and Futaba warned that the HRS high response mode would burn up regular servos due to the digital fast rate pulse. I think the 7950 is digital so you should have no worries on that side but for shi-grins you should try changing the mode in programming I don't have my radio but it is labelled ___1 or ___2.

 

[hotwheels000]

7980 will not line up with the same mounting points as a standard servo.It is longer and wider so to speak in the ears/tabs area.

 

[Tommy R]

7980 will not line up with the same mounting points as a standard servo.It is longer and wider so to speak in the ears/tabs area.

Thanks, Devlin. That's what I feared so I'm glad I went with the 7950.


And a big THANK YOU to everyone who voted for me and Big Oly for the MSD TTC Competition! We made it in thanks to you all! I'll definitely give 'er hell!! :mrgreen: