What the newest cheap servo hotness?

[happymachinist]

Originally Posted by svt923

Stumbled upon this while searching on Banggood:



https://www.banggood.com/JX-BLS-12V7...r_warehouse=CN



After experiencing the Holmes SHV500, I am a big fan of servos that run directly off 3s voltage. This is the first cheap 12+V servo I have seen.



650 oz of torque on 14V is pretty serious for a $60 servo.



Also available with a standard cordless motor for a few dollars less.



https://www.banggood.com/JX-CLS-12V7...r_warehouse=CN

So I pulled the trigger on 2 of the 46kg 7.4 volt models for a plow build for my Summit. In the description they claim the servos are programmable.

Any idea how one would program one of these? I’ve only ever programmed my Hitec servos, I’m honestly just wanting to slow them down so they don’t slam the blade up and down/left and right


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[durok]

I saw that claim, too - I personally don't see how they can be programmable. I think it may be a typo or a translation issue, or someone just got a little "happy" on the claimed features list.

Didn't bother me enough to prevent me from ordering one...

I'll certainly check mine out and report my findings here when it arrives.

Not sure on shipping time!

(Ordered 2 days ago)

[happymachinist]

Originally Posted by durok

I saw that claim, too - I personally don't see how they can be programmable. I think it may be a typo or a translation issue, or someone just got a little "happy" on the claimed features list.

Didn't bother me enough to prevent me from ordering one...

I'll certainly check mine out and report my findings here when it arrives.

Not sure on shipping time!

(Ordered 2 days ago)

I’m also thinking they may have went a little overboard with the servo buzz words...as a Tool Maker I and a couple coworkers always laugh when we see “CNC machined from aircraft grade billet aluminum” the more buzz the better I guess.

I’m also thinking they might be a little ambitious with their 46kg rating, seeings how I couldn’t find any servos manufactured by the name brands with that much torque in a standard size. My tests went well with a Hitec 7954 on 6.5 volts so as long as it has 3-350oz I should be good


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[svt923]

Originally Posted by happymachinist

I’m also thinking they might be a little ambitious with their 46kg rating, seeings how I couldn’t find any servos manufactured by the name brands with that much torque in a standard size.

The Savox 2290 and Protek 170TBL are both rated for more torque.

Not saying the JX rating is accurate but there are standard servos out there that have torque ratings in excess of 650+ oz.

[happymachinist]

Originally Posted by svt923

The Savox 2290 and Protek 170TBL are both rated for more torque.



Not saying the JX rating is accurate but there are standard servos out there that have torque ratings in excess of 650+ oz.

Yes they do!!! They slipped under my radar...that’s encouraging honesty. I’d be happy if the JXs were 500 oz in or above for $53. I don’t need that much to lift the plow but something tells me the servo that pivots the plow left and right could take a beating

I was very close to pulling the trigger on a couple of Hitec D845WPs but they are huge! And heavy! I didn’t want to add a pound of weight to an already chunky truck...and finding a place to shoe horn them in was proving troublesome


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[Hydrocarbon92]

I've been lazy but I do want to make a testing jig for servos. I've got a KG scale that's more than accurate with a full metal connection between both sides of the strain gauge. The few tests I've seen put the 20KG servos in the 11-12KG range, but they also don't test against any "known" servo like HiTec or Savox. I have a avg Savox and Tactic servo I'll be comparing them all to.

I know the 32kg servo is far stronger than their 20KG from 1st had experience, and I can't imagine 12v thru the same motor wouldn't give it at least 33kg or 450oz. Considering there's a brushless version, it's most likely an even stronger motor than what's in the coreless 32kg.


Also I just remembered on page 15 Teng posted a bad experience with what looks like the same 46kg-14v servo. I guess you guys who got the brushless version will see if it was a fluke or not. His pic does show the gears, which look pretty beefy and definitely not some cheap brass/alum gears.

[dweano]

It'll be interesting to see those big 46kg servos! Did you get the brushless or coreless ones there happy machinist?

They can run on 3s eh? I could just convert my whole rig to 3s and eliminate BEC's and not have to worry about amp draw and whatnot

[durok]

I just got notified that my Brushless JX BLS-12V7146 46kg will be here in a couple of days. It's rated at 14.1v, going to use this part to make the wiring super easy:

Gear Head RC JST In-Line Power Adapter - XT60

[Hydrocarbon92]

Just be aware JST connectors are barely enough for 5 amps. I'm using Deans-style micro plugs which are enough for 10 amps.

[TheLetterJ]

I recently bought a $33 Turnigy/Towerpro mg959v2 and have 2 runs on it. Besides that it sounds like a parakeet chirping when it cycles, it seems to work well and has a fancy cnc milled housing. It's rated at 30kg @ 6v (or 32kg @ 6v depending which site you get your info from) which is adequate for my application, but I can't help but wonder... has anyone run one on 7.4v? If it works, what would the calculated torque be? I didn't want to be the guinea pig this time since I'm out of spare servos and this one took a month to arrive.

[durok]

Originally Posted by durok

I saw that claim, too - I personally don't see how they can be programmable. I think it may be a typo or a translation issue, or someone just got a little "happy" on the claimed features list.

Didn't bother me enough to prevent me from ordering one...

I'll certainly check mine out and report my findings here when it arrives.

Not sure on shipping time!

(Ordered 2 days ago)

LOLz - looking back on this post makes me chuckle a bit - I was just emailed a shipping notification that states it has actually finally left the warehouse - only 10 to 25 more days!

My earlier post was a screw-up, it was something else I ordered from overseas.

It's OK, cuz (of course) the rig ain't built yet.

[TheLetterJ]

I came across this in another thread, but it's good, relevant info for this thread: https://youtu.be/7zylqOIHdKA you can just jump to the 6min mark for some very surprising results!

[thewildblue77]

Has anyone run 8v through a JX6221 ? Ive got the 5932 as a steering servo and the 6221 as a shifter. My mamba X can deliver up to 8v....will the JX cope...its been on 7.4 for a while now...

[intheworks]

Originally Posted by thewildblue77

Has anyone run 8v through a JX6221 ? Ive got the 5932 as a steering servo and the 6221 as a shifter. My mamba X can deliver up to 8v....will the JX cope...its been on 7.4 for a while now...

I was told no. it wont like 8v

[thewildblue77]

Ok I will turn it back to 7.4...thanks

[dweano]

I wanna see the review of the 46kg 12v servos! Every time this thread is bumped I hope it is the happymachinist haha

[gonper]

This is what happens when going dirty cheap:

https://www.aliexpress.com/item/5pcs...311.0.0.k0Q1Fk

I ordered this servos offer, 5 x DS3120, but I received 5 x DS3218
I ordered the 180º version but it is not true they are normal travel, and for what I read the 270º turns 180º https://youtu.be/AVd_-v9HCBY


Anyway I think I can use them...
DS3120 and DS3218 are almost identical if not the same.
About the turning angle (I need around 140º) lets see if with endpoints programmatic at the TX I can solve the issue.

They seem to work quite well but they are a bit slow at 6V than what I will like, anyway I am going to use them at 7.4V so that will fix the a little the speed issue.

[high plains drifter]

My 2075X finally bit the dust. Just installed the DS3218 so will be interesting to see how it does tomorrow. Using a Samix TRX4-6022F 25t horn with it. Gonna try to run for at least a couple hours continuously.

I had hooked up a super-cheap Tower Pro MG995 but without even having to shake it down I knew it wouldn't work. Thing was glitchy as all hell and fairly noisy. Turning the wheels on my TRX4 seemed to be the LAST thing in the world that this servo wanted to do.

[Hydrocarbon92]

Originally Posted by TheLetterJ

I came across this in another thread, but it's good, relevant info for this thread: https://youtu.be/7zylqOIHdKA you can just jump to the 6min mark for some very surprising results!

Thanks a ton for that, that's roughly the test rig I want to make. I hope this surprises some people - the name-brand servo only hitting 3/4 of it's rating and the cheap-o going far beyond it's rating.

Also nearly all of them stalling at 5+ amps, I think that is the most important part. A BEC's "peak" is usually limited to a fraction of a second while continuous is what you're seeing in that test (stalled). If it doesn't burn out your BEC, an underpowered UBEC will turn your 400oz+ servo into mush when you actually need 400+.

Originally Posted by thewildblue77

Has anyone run 8v through a JX6221 ? Ive got the 5932 as a steering servo and the 6221 as a shifter. My mamba X can deliver up to 8v....will the JX cope...its been on 7.4 for a while now...

The 6221 will run at 8v, but not very long under load. Mine was okay on a BEC for mild testing then burned out after a minute straight off a 2S battery. Just keep it at 7.4v and you'll be fine.

Originally Posted by gonper

for what I read the 270º turns 180º https://youtu.be/AVd_-v9HCBY

It's not a servo issue, they WILL go 180* or 270* as rated if your radio allows. Most radios will not, as they only increase travel by 20%, not 100-200%. For instance my GT3C will turn a 6221 only 110* when set to 120%, but I can get it to 180* if I send a 2.5ms or 0.5ms pulse from my arduino.

[gonper]

Quote:
Originally Posted by gonper View Post
for what I read the 270º turns 180º https://youtu.be/AVd_-v9HCBY

It's not a servo issue, they WILL go 180* or 270* as rated if your radio allows. Most radios will not, as they only increase travel by 20%, not 100-200%. For instance my GT3C will turn a 6221 only 110* when set to 120%, but I can get it to 180* if I send a 2.5ms or 0.5ms pulse from my arduino.

Thank you for your input. With and arduino you can do what ever you want but this is not the case.
And yes, it is a servo issue; a standard servo usually rotates 90º, a 180º servo rotates around 180º, and a 270º servo rotates 270º, with standard TX travel set at 100%, actually they usually turn a little bit more than those angles.
The +- 20% of the servo travel TX adjustment should be used for minor adjustments, not in order to major increase the stock servo travel.
In other words they sent me the wrong servos or the information on their product is incorrect.