R/C Tech Forums - Digital Servos from China

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Quote:

Originally Posted by billdelong (Post 15746935)

So I had 2 more failures with the A80 servos at the track yesterday.

The one that has been in my SCT410.3 for nearly a year, 45 race days per my race log is having an electrical failure where the servo still operates, but it no longer returns to center, when you turn left it stays left at full lock... when you turn right it stays right at full lock... sometimes it will sort of return to center, but pathetically slow to the point where the servo is absolutely useless.

While I was averaging 10 race days before total electrical failure with the A80 in my EB48 2.0, the 3rd A80 servo in this buggy had snapped a pin in the gear box after only 5 race days. I plan to pull the pin out of the other bad servo and will keep this one as my last spare AGF servo for the SCT. Some might argue that 1 year of use is reasonable, perhaps for $45 which I paid, but these are selling for $80 now and at that price I feel the servo should last around 2-3 years even though AGF has downgraded the spec on this servo from 1/8 to 1/10.

Fortunately Jared Tebo had traveled to race at our track this weekend for Thornhill's 1st Series race of the season and I bought one of Tebo's CT1 servos to start testing in my EB48 2.0:
https://www.shopjtp.com/product/ct1

https://live.staticflickr.com/65535/...021a2938_b.jpg

What I learned is that while this servo is a rebrand from AGF, it's not the same inside. The quality of the internal components have been improved to handle the rigors of 1/8 racing. The case is identical to the A80, but is far better than any AGF branded servo you can get.

While I am not a fan of AGF and will never buy an AGF branded servo again, I decided to support Jared Tebo and give this highly upgraded version one last shot and will update my final findings over time. It's not very often where you get the chance to buy a custom branded servo directly from the worlds #1 ranked driver in person!
https://www.top25rc.com/nitro-buggy

https://cimg3.ibsrv.net/gimg/www.rct...e4471d9279.jpg

Sure enough Tebo would take the win in Nitro Buggy yesterday:
https://trc.liverc.com/results/?p=view_event&id=343259

https://cimg2.ibsrv.net/gimg/www.rct...c8f1415cce.jpg

Some have given me some grief that my driving skill is the cause for premature wear on these servos, and I finally have some results for a decent size turnout and lots of pro level drivers where almost the entire A Main was filled with factory drivers, I was able to qualify for the B Main in the #11 spot on the grid and finished 9th where we had an E-Main of Expert Level drivers in this class:
https://trc.liverc.com/results/?p=vi...ult&id=2811629

55 entries in Expert Electric Buggy
50 entries in Sportsman Electric Buggy
https://trc.liverc.com/results/?p=vi...list&id=343259

Normally the club just puts all the electric buggies together for regular club races, which would've put me 19th overall in a field of 105 electric buggies, which is what I would consider above average skill, though certainly not pro level, ha!

I would love to see a comparison of the internals. It's one thing to claim they've been improved, it's another to actually do so. I've yet to see a rebrand that gives proof of its improvements other than "trust us."

Quote:

Originally Posted by frewster (Post 15747239)

I can guarantee that I will be providing my honest feedback... 10 race days (or less) seems to be breaking point for AGF servos in my buggy so look for an update in about 6 weeks or so to see how the CT1 holds up!

Quote:

Originally Posted by billdelong (Post 15747259)

Thank you Bill. I have yet to have trouble with any of my A80 servos. I haven't been keeping a tally but I would think I have at least 10 races on them. Of course I'll let everyone know if I do run into problems.

well...not off to a good start with the MKS servo. i can't get the screw into the center of the spline to hold the horn on. it just won't start to thread on. like the top isn't machined out or something. i can see there are threads inside, i just can't get the screw started. tried several M3 screws. sigh....

Quote:

Originally Posted by RC*PHREAK (Post 15747759)

do you have a M3 tap?

I sure don’t. I’ll just hit up amain and swap it out...

funny thing was when I plugged the servo in to center it prior to putting the horn on. There was no movement with the servo. Nothing. Fortunately I remembered that the AGF servo was ran in SSR mode. So I re-bound the receiver in SHR mode and it was fine.

I would consider investing in a set of taps, although I haven't had this happen to my EB48 2.0 yet, I've had to re-tap and extend the threads in the motor mounts on previous versions of TEKNO where the thread lock tends to gum up on the bottom of the threads and I find it necessary to drill all the way through so the thread lock can escape over time, took about a year for this motor mount to fill up on my SCT410.3:

https://www.teknoforums.com/threads/...389/post-16802

https://cimg1.ibsrv.net/gimg/www.rct...70635c1a74.jpg

Another benefit to this is if you ever strip the threads out then you can use longer screws... I've also used this trick on the A-D blocks as well on some cars ;)

Quote:

Originally Posted by RC*PHREAK (Post 15747759)

That's because it's not an M3. I have an MKS servo and just tried to put an M3 into it, no go. The supplied phillips head screw threads in just fine. It's visibly smaller than an M3, but I have no idea the thread on it since I can't seem to find my thread checker.

edit: https://www.rctech.net/forum/radio-e...-thread-4.html
Post #45 says M2.5

Yeah, I'd be replacing that M2.5 phillips with a socket cap ASAP!

I've never heard of a 1/8 servo that uses M2.5 for the spline before, that's just stoopid

Quote:

Originally Posted by WhiteLX (Post 15748192)

WOW. sure enough. two M2.5 screws came with the servo and it threads right in (it is not a phillips head. they are button head hex screws). i also have the 550lx (shorty servo) in my B6.2 carpet car and it uses an M3 screw. anyone care to opine as to why the 1/10 servo uses an M3 and the 1/8 uses an M2.5? not feeling super good about the purchase at this point....

i mean, i get it. the logical side of me says, "not a lot of force pushing or pulling the horn off the servo". most of the force (bad force) is centrifugal which would perhaps strip the horn, spline, or the gears inside. but the emotional side of me says, "c'mon. who does M2.5 in a 1/8 servo? especially when your 1/10 servo uses M3."

Although I have M2.5 screws in my pit box for some odd ball ESC fan and steering assembly needs, industry standard is M3 screws for virtually all brands of 1/8 servo splines, at least it's not SAE hardware, ha!

ive been spun hunting for the lowest cost AGF rebrand, drawn in only because the programmer enables ssr mode for my mt4s, whats the difference between the reefs, powerhobby, and now the tebo ct1? all three brands seem to have a 7.4v .10 at 500in rated servo but at varying price points, power hobby 729mbl being the lowest at about 120 with the programmer off ebay... theres two faster but lower torque rated models ive been going back and forth on, one at .08 at 400oz (which all rebrands seem to be based on the A80 Bill had disappointments with) and one at .06 at 265oz (which is similar specs as the BK 7002hv id be replacing)

the only compare review i could find was of the Reefs 444 vs the 729 in separate tests and the reef sounded way different than the powerhobby, also Send It servos seem to be agf but no programmer option, the options vs pricing are driving me insane... going into a tekno ebuggy, help!

I was assured that the CT1 has upgraded internals, and while it shares the same case as the A80 series, it is properly rated to handle the rigors of 1/8 racing so I decided to give it a try, honestly I only made an exception to buy the servo because I bought it directly from the man himself, ha!

https://www.facebook.com/groups/Tekn...1008834813995/

Supposedly NitroPro has sold over 1K units and not a single unit has had any type of electronic failure like I've experienced with the AGF branded servos.

I can guarantee you that I will be posting a follow-up once my CT1 has hit the 10 race day mark which is about the average point when my AGF servos were failing... as of right now I just finished my 5th race day on the CT1 plus 2 additional days of practice.

Quote:

Originally Posted by billdelong (Post 15753074)

thanks for the quick reply Bill, hoping for your teardown and compare soon, the nitropro servo seems to be the agf a80bhmw spec sheet wise, i was thinking of going with the reefs 444 winch servo, as its just rebranded magnetic encoder deal, the 444 standard version is a coreless motor, unsure if i can use ssr mode with it, regardless its such a nightmare having too many choices.. all within 20 dollars of each other.. the powerhobby 729 is only 89 without the programmer but i think its an agf a80bhm which is 79 direct from agf, bummed i missed out when they were 50$ poor mans tekin digital goodness!

I'm not interested in taking the CT1 apart, though if it ever snaps a pin on one of the gears then I will certainly compare pin thickness to see if they upgraded to thicker pins or not, as far as getting into the circuit board, I tried that already with a burned up servo and couldn't figure out how to get any farther than replacing the gears.

When I installed the CT1, I didn't have to change a single setting on my trim, car tracked perfectly straight and EPA was spot on with the A80, the feel of the CT1 was identical as the A80 on the track as well. I was always VERY happy withe A80 performance... while it was working, ha!

They're going to do a new layout for the Lonestar Challenge in a few weeks, and Joey The Dirt is known for making extremely challenging layouts so that will put the CT1 to the test for sure!