Servo arm fixed link to bellcrank arm length question Long or Short

[332_RC]

What is the three distances (center to center) of the holes on that servo horn?
Just curious I am.
View attachment 215205

The 1st hole center is 17mm from the arm horn center. 2nd is 20.5mm, 3rd is 24mm. 3.5mm apart each. This is a Hot Racing 25t arm. The link goes under the arm, it is a offset up arm. The link will go on top of the bellcrank arm. This will lay the connection link flat with the chassis.

 

[RustyUs]

The 1st hole center is 17mm from the arm horn center. 2nd is 20.5mm, 3rd is 24mm. 3.5mm apart each. This is a Hot Racing 25t arm. The link goes under the arm, it is a offset up arm. The link will go on top of the bellcrank arm. This will lay the connection link flat with the chassis.

I'm not gonna lie, I was hoping you were going to say you're using the middle one. I'm the type of guy who likes to get the most out of a servo's output (movement & torque) within reason of course. Those super long servo horns concern me with putting too much stress on things and, not to mention, make some RCs steering feel too fast. It burns me that manufactures don't go the extra step in supplying the distance specs of their holes.

Thanks for the measurements.

 

[WickedFog]

I'm not gonna lie, I was hoping you were going to say you're using the middle one. I'm the type of guy who likes to get the most out of a servo's output (movement & torque) within reason of course. Those super long servo horns concern me with putting too much stress on things and, not to mention, make some RCs steering feel too fast. It burns me that manufactures don't go the extra step in supplying the distance specs of their holes.

Thanks for the measurements.

Totally agree! It would be awesome to see a servo horn database. Getting the perfect servo horns are like one of the hardest things to source sometimes, because a lot of the horns you find don't have those numbers, and I don't buy them if they don't list that info, even if I think it's right.

 

[Littlemotor]

I'm not gonna lie, I was hoping you were going to say you're using the middle one. I'm the type of guy who likes to get the most out of a servo's output (movement & torque) within reason of course. Those super long servo horns concern me with putting too much stress on things and, not to mention, make some RCs steering feel too fast. It burns me that manufactures don't go the extra step in supplying the distance specs of their holes.

Thanks for the measurements.

All of my horns but one, have the measurements listed lol. I am pretty anal about my horns, and just went through this not three days ago on a manufacturer I’d never ran, but took a gamble on their stuff. I paid the price.. Also not the first time Nemo Racing got me. I’ll never buy from them again.

 

[332_RC]

I have a 25t 7075 Ruddog that has two holes 16mm & 20mm from the center for another build.

 

[Lumikko]

I literally said all of this to a tee sir…

Looks like you did, I missed it.

I was confused why you brought up the spline issue earlier since it doesn’t seem to affect the question at hand at all.

 

[Littlemotor]

Looks like you did, I missed it.

I was confused why you brought up the spline issue earlier since it doesn’t seem to affect the question at hand at all.

Clearly it does when the servo splines may not be clocked correctly to allow install of steering link without either adjusting the length, or rotating the splines-which is exactly what I said.

 

[Littlemotor]

Looks like you did, I missed it.

I was confused why you brought up the spline issue earlier since it doesn’t seem to affect the question at hand at all.

I had to go back and re-read what was typed. I can FULLY appreciate any confusion due to the fact that it said “spline COUNT”, rather than “spline TEETH”. I didn’t catch that autocorrected bullshiit.

 

[Lumikko]

Clearly it does when the servo splines may not be clocked correctly to allow install of steering link without either adjusting the length, or rotating the splines-which is exactly what I said.

I think I get what you’re saying and my intent is to not interpret it in the worst possible way to make your point look dumb. However, I disagree with the idea you present.

Clocking the servo splines only matters when it comes to centering the steering. If the servo link is fixed, clocking the horn into one position or the next also turns the bellcranks.

It does not affect the parallelism between the servo horn and servo arm on the bellcrank. You can only adjust the parallelism with the steering link length, or to a very slight degree by shifting the servo in its mounts, if there’s clearance.

A too long or short servo link cannot produce symmetric steering no matter how you put the horn on the servo.

 

[Littlemotor]

I think I get what you’re saying and my intent is to not interpret it in the worst possible way to make your point look dumb. However, I disagree with the idea you present.

Clocking the servo splines only matters when it comes to centering the steering. If the servo link is fixed, clocking the horn into one position or the next also turns the bellcranks.

It does not affect the parallelism between the servo horn and servo arm on the bellcrank. You can only adjust the parallelism with the steering link length, or to a very slight degree by shifting the servo in its mounts, if there’s clearance.

A too long or short servo link cannot produce symmetric steering no matter how you put the horn on the servo.

Ok pal. Not worth my time to argue with you. About all I’ve ever seen you do on this board is argue with everyone because you’re clearly far more experienced than anyone else, and know better than the rest of us for sure. You’re overthinking this BECAUSE you are trying to find fault where there is none. Funny how everyone understands exactly what I’m saying but Lummiko. I’m not even remotely surprised. You’re absolutely dead wrong, but do you, buddy.

 

[332_RC]

Chill. It's my thread. All I wanted to know, was is there a difference in an RC toy that has a longer or shorter link connector. That's all. Geometry. That's it. From what I gather, & already knew- no. It probably does not. Seems that it could. If done improperly- but that also is another discussion. I might mount the servo on its side. Like a Redcat. And do a double triangulated wishbone cantilever system with dual 100kg servos. In the back with links a mile long.

 

[WickedFog]

Ok pal. Not worth my time to argue with you. About all I’ve ever seen you do on this board is argue with everyone because you’re clearly far more experienced than anyone else, and know better than the rest of us for sure. You’re overthinking this BECAUSE you are trying to find fault where there is none. Funny how everyone understands exactly what I’m saying but Lummiko. I’m not even remotely surprised. You’re absolutely dead wrong, but do you, buddy.

That’s a spicy way of admitting you’re wrong. I hope it was worth your time.

Take it to PM's please. Not here.

 

[332_RC]

The two aluminum rod ends are M4 internal & 3mm hole. I made a center threaded rod using a long SHCS, grinding of the head, giving me a piece of all thread. I made 4 different delrin center tubes for the rod ends to tighten against. Had to get it right- for the eyes to align. So, I'll have adjustment there, the reg trim & sub trim. Should be no problem to align everything square, parallel or perpendicular, etc. I can always flip the servo & test this RC setup either way. I just can't stand those little plastic, short, fixed link connectors.

 

[HPIguy]

Guys, friendly discussion is fine, arguing is not, nor is cursing. This is all in the rules you agreed to when you joined the forum. I don't care who started it, or who added to it. Knock it off or vacations are incoming for all involved.

As @WickedFog said, if you guys want to discuss or argue about it, do it in PMs rather than cluttering up OP's thread please.

 

[Lumikko]

Had to get it right- for the eyes to align. So, I'll have adjustment there, the reg trim & sub trim. Should be no problem to align everything square, parallel or perpendicular, etc. I can always flip the servo & test this RC setup either way. I just can't stand those little plastic, short, fixed link connectors.

Sounds like a good solution if using a turnbuckle is not an option.

If you find the length adjustment of half-turns too coarse, adding or removing spacers under either ballstud to change the link angle will effectively shorten it. Transmitter settings won’t make the servo horn and servo arm on the bellcrank parallel.

 

[332_RC]

Sounds like a good solution if using a turnbuckle is not an option.

If you find the length adjustment of half-turns too coarse, adding or removing spacers under either ballstud to change the link angle will effectively shorten it. Transmitter settings won’t make the servo horn and servo arm on the bellcrank parallel.

Correct.

 

[sylentk]

This is an interesting convo for me as I just set up a new racer machine and broke the servo horn on the shake down run. Bah.

So, I do have an aluminum horn. ProTek package. That came with the BL170BSL. It is fast and strong.

And bought a server saver horn. From the LBS/Track. Which I had to modify to fit the AE RC10T.4.6. The shop guy did tell me I'd have to do it. No biggie.

Neither of them make anything parallel. But my QA check is to ensure the servo moves the turning to it's end points. Like it's locking out both L and R. Pretty basic.

I haven't really messed with ackerman, caster, steering, up/down etc. setup. And there are a lot of options on this kit.

My question is "am I missing anything here?" Comments? Suggestions? Currently running the "customized" servo saver.

 

[332_RC]

This is an interesting convo for me as I just set up a new racer machine and broke the servo horn on the shake down run. Bah.

So, I do have an aluminum horn. ProTek package. That came with the BL170BSL. It is fast and strong.

And bought a server saver horn. From the LBS/Track. Which I had to modify to fit the AE RC10T.4.6. The shop guy did tell me I'd have to do it. No biggie.

Neither of them make anything parallel. But my QA check is to ensure the servo moves the turning to it's end points. Like it's locking out both L and R. Pretty basic.

I haven't really messed with ackerman, caster, steering, up/down etc. setup. And there are a lot of options on this kit.

My question is "am I missing anything here?" Comments? Suggestions? Currently running the "customized" servo saver.

Add any pictures?

 

[sylentk]

I suppose I can space out the ball nut more forward to make it more parallel. There are plenty of threads on it for that.

Just really didn't think anything about it, since it seems to work?

 

[332_RC]

View attachment 216538

I suppose I can space out the ball nut more forward to make it more parallel. There are plenty of threads on it for that.

Just really didn't think anything about it, since it seems to work?

I think so too. Better if it were more parallel. I've only setup a few RCs that had a servo on the side but it wasn't that far away from the bellcrank. You could put spacers under the servo, moving it towards the front also, lessens the angle.