SERVO Linkage alignment questions for new build.

[RCFinger]

Hi people!

*EDIT. Forgot to actually say i'm looking for a new servo...

I'm slowly getting getting all the parts i need before i begin building a (unbuilt kit) MT410 V1 while simultaneously converting it and upgrading it to a ET48.3 flying machine... Now i know i may have bitten off way more than i can chew but i am hungry...

Sooo, looking for servos and the specs, i have become overwhelmed with the numbers... I think
My understanding is that the linkage should be as horizontal as possible? Something i have noticed is (usually bashers) is that the linkage is really on the wonk and sloping down from the servo horn. Some people appear to shim either end of the linkage to get things level but i would really like to find a servo that has good alignment out the box. Shorter height from mounting tabs to horn mount?
Here is what i am hoping for (from another thread on here)

I have also attached an image (again from this forum) with a very exaggerated (all sorts of ill fitting) version of what i mean, but it does illustrate nicely what i'm trying to avoid.

Any help/advice,very much appreciated!

 

[Billl DeLong]

Thanks for posting one of my old videos above for reference!

Yes you definitely want the linkage to be as level as possible to ensure a linear steering rate, a steep angle may cause an unbalanced steering angle causing sharper steering one way and less aggressive steering the opposite.

In the photo you can see the aluminum mounting plate was not properly fastened to the plastic tray and the compounded the problem by not using a proper TEKNO servo arm, double-doh!

As far as servos go, I no longer recommend any of the AGF branded servos as that was referenced in the video you linked above for these reasons here:

• The Good, the Bad and the Ugly about AGFRC servos

Within the thread I just linked, I explained my experience shifting over to NitroPro servos which are upgraded AGF servos where NitroPro stands behind the products then sell with arguably the best warranty in the industry. AGF left me high and dry. There's a saying, "buy once, cry once", this would be my recommendation for you that will stand the test of time:

https://www.nitroproracing.com/product-page/ct2-jtp-rc-550


Now if the price scares you and you want to go cheap, then this is the best money can buy for the price, but understand that the gears will need to be replaced every 6 months to a year so be sure to get replacement gears as well:

https://www.amazon.com/PDI-HV7232MG-Coreless-Aluminium-Standard-Helicopter/dp/B08R9FL5DP

These gears are compatible here:
https://www.amainhobbies.com/ecopower-wp120t-metal-servo-gear-set-ecp-3099/p755536

More info here:

• Which servo is right for me?

 

[RustyUs]

Yeah, I don't know where you got the picture of that blue servo, or what context it's coming from. Somebody else was a similar steering linage issue...

Not all servos have the same dimensions/build I guess is the obvious thing. The servo horn shown above is what comes with the newer kits. The person used a DS Servo 30kg servo in their MT410 2.0 platform....

Sometimes you won't find all the measurements like the bottom of mounting ears to the tippy top of case (where output spline is) and, in the end, may have to deal with shimming/using proper servo horn to level things out at best as possible.

 

[RustyUs]

If I ran into a situation like above, I'd try to level the steering linkage, as much as possible, equally at both ends and go with it. Adding 1mm worth of washers on the bell crank side, and using the optional Tekno servo horn should lower the pivot ball on the servo side of things.

 

[RCFinger]

Thank you Bill for the very detailed response!
Boy, you really got deep into the weeds with servos! I had to read through the links in 2 sittings.. lol

You are into proper competitive racing (not something i will be doing), so i suppose the pursuit of perfection comes with the territory. I would expect this would expose weaknesses in design and/or manufacture sooner, as opposed to a basher hitting a tree at 50mph...

I probably worded my query poorly due to lack of knowledge. My main concern was the alignment of the linkage and that the mounting tab to horn height varied between manufactures. I'm in the UK so don't have quite the same luxury you have in the States. I was originally going to go with a Hitec D or HS series as they seem to exceed stated torque spec and are quiet, and also well represented here.
Maybe a better question is. What servos don't fit well...?

Thanks again!

 

[RCFinger]

Yeah, I don't know where you got the picture of that blue servo, or what context it's coming from. Somebody else was a similar steering linage issue...
View attachment 10464
Not all servos have the same dimensions/build I guess is the obvious thing. The servo horn shown above is what comes with the newer kits. The person used a DS Servo 30kg servo in their MT410 2.0 platform....
View attachment 10466
Sometimes you won't find all the measurements like the bottom of mounting ears to the tippy top of case (where output spline is) and, in the end, may have to deal with shimming/using proper servo horn to level things out at best as possible.

Aha yes! That is exactly what i'm trying to avoid. You are correct that the spec diagrams can measure from different points, making it difficult to decide.
The one you show above is at least 12.7mm from the underside of the mount tabs to the (difficult to see) top of the body. I think a ProModeler one i saw is at least 2mm lower, but not suggested for bashing.... Strange how so little could make all the difference. I appreciate shimming is an everyday thing, but would be nice to get as close as possible.

 

[Billl DeLong]

I would review setup sheets from TEKNO team drivers to see what servos they are using, this will give you a complete list of compatible servos to accompany the 2 brands of servos that I provided

If I was just bashing around then I would go with JX servo that I recommended, it will offer the best bang for the buck by a longshot. I found one here through eBay UK:
https://www.ebay.co.uk/itm/175613660586?itmmeta=01J3JJ1TB0WMCSTYFEDQWHBKE8

 

[RCFinger]

I would review setup sheets from TEKNO team drivers to see what servos they are using, this will give you a complete list of compatible servos to accompany the 2 brands of servos that I provided

If I was just bashing around then I would go with JX servo that I recommended, it will offer the best bang for the buck by a longshot. I found one here through eBay UK:
https://www.ebay.co.uk/itm/175613660586?itmmeta=01J3JJ1TB0WMCSTYFEDQWHBKE8

Thanks for that, i'll look into setups. I've seen JX mentioned a bit, but that link is for a U.S ebay shop and they want almost as much for postage as they for the servo itself, lol. I'll take a look around see if i can find one more local, thanks though!

I know (from another thread, @BashingBrian bought a KingMax servo from the UK Tekno distributo. Don't know how it worked out for him? The servo did look suspciously like the AGFRC that failed on you, and got rebranded 10th scale only, who knows...

 

[RustyUs]

That PDI-HV7232MG is almost what I paid for it's sister CLS5830HV servo. Billl DeLong right about the gearset needing replaced every so often. Those EcoPower WP120T gearsets are most likely rebranded JX Servo CLS5830HV gearset. I'm really surprised they lasted almost a year in my monster truggy.

I wouldn't recommend doing what I did. I just had to see how much punishment the lower budgeted servo could handle. Since then I repurposed my JX servo in a SCT, and put a ProModeler DS505BLHV in the monster truggy. Even though the description for the DS505 says it's not recommended for bashing and not recommended for BEC use... I just had to see for myself. For the price of a ProModeler, I probably should have went with something with a gear warranty, but I'm at a point in this hobby where I like trying different things.