Servo throw or travel

[Itali83]

I have a brand new HH HV 500 servo. When building my custom leafed ascender, I was manually moving the servo by hand from lock to lock which is about 180degrees. I don't need 180 degrees from full left to full right. But, when I finally powered the rig, I've only got about 90 degrees of throw at the servo from full left to full right. I've got a spektrum dx4c radio, and even with the steering travel maxed out at 150% both left and right, that's all I've got for servo travel. What's up with that? I set the suspension and steering up based on what the servo can physically turn by hand and was expecting that. My front axle is custom and can get well over 45 degrees of tire turn but now I'm lucky to get old school scx10 steering. WTF!!?? Any help would be great.
Thanks.
Ben

[mikemcE]

Upside down ? Flip the arm over does it have more ?


Hang up and Drive

[Jeepy84]

I was going to ask if the servo without horn is as limited but I think Mike is thinking the same thing I am

Sent from my XT1585 using Tapatalk

[CODYBOY]

Originally Posted by Itali83

I have a brand new HH HV 500 servo. When building my custom leafed ascender, I was manually moving the servo by hand from lock to lock which is about 180degrees. I don't need 180 degrees from full left to full right. But, when I finally powered the rig, I've only got about 90 degrees of throw at the servo from full left to full right. I've got a spektrum dx4c radio, and even with the steering travel maxed out at 150% both left and right, that's all I've got for servo travel. What's up with that? I set the suspension and steering up based on what the servo can physically turn by hand and was expecting that. My front axle is custom and can get well over 45 degrees of tire turn but now I'm lucky to get old school scx10 steering. WTF!!?? Any help would be great.
Thanks.
Ben

Hey Ben, this may be a dumb suggestion but have you tried to set your EPA lower and reprogram your radio to the speed control. I have done this before with some success with my gtc3.
Ernie

[Itali83]

Like re-bind it to the receiver Ernie? I haven't done anything except almost smash the whole truck and walk away. I'm so bummed it isn't even funny.

There is no binding of any type. Even with no horn, the servo only has about 90degrees total throw. Haven't tried another servo yet. I guess I'm asking if any of you can get the same throw out of servos when powered up as when you turn them by hand unpowered if that makes any sense. You know how there is a pin on the output gear of the servos to keep them from going round and round? Should be able to damn near hit that pin with endooints adjusted to max I'd think.
Ben

[CODYBOY]

Originally Posted by Itali83

Like re-bind it to the receiver Ernie? I haven't done anything except almost smash the whole truck and walk away. I'm so bummed it isn't even funny.

There is no binding of any type. Even with no horn, the servo only has about 90degrees total throw. Haven't tried another servo yet. I guess I'm asking if any of you can get the same throw out of servos when powered up as when you turn them by hand unpowered if that makes any sense. You know how there is a pin on the output gear of the servos to keep them from going round and round? Should be able to damn near hit that pin with endooints adjusted to max I'd think.
Ben

Yes, that was the word I was looking for. Or maybe it was "calibrate", I think it has to do with your radio/ speed control. Just try running your end points back 25 on both left and right and recalibrate your radio to your esc, just to see if it gives you more throw on the servo.
Just set everything on your work bench, tell it good night and walk away for the night.
I think you should be able to go at least 150 with it turned on. Good luck my friend, bring us up to date tomorrow!
Ernie

[svt923]

I see you checked the endpoints on the radio but also check to make sure the dual rate on the steering hasn't been turned down by accident.

[Itali83]

Originally Posted by svt923

I see you checked the endpoints on the radio but also check to make sure the dual rate on the steering hasn't been turned down by accident.

At risk of looking like an idiot, what's the dual rate? How to adjust it and what does it do? Thanks

Ben

[svt923]

Originally Posted by Itali83

At risk of looking like an idiot, what's the dual rate? How to adjust it and what does it do? Thanks

Ben

Dual rate basically reduces both endpoints by a percentage simultaneously, it is assigned to the D lever on the DX4C by default. Make sure it is turned up to 100% for full throw.

[Itali83]

Originally Posted by svt923

Dual rate basically reduces both endpoints by a percentage simultaneously, it is assigned to the D lever on the DX4C by default. Make sure it is turned up to 100% for full throw.

Thanks I'll check that!!

Ben

[hotwheels000]

I am not sure if the HH servos can be programed, I know most Hitecs can be. If you know anybody with a servo programmer see if you can open up the range of travel with it. A lot of servos are capable of 180* of travel but are programmed at the factory for far less.

If all else fails you can put a longer arm on the servo or a shorter arm on the knuckle(or drill a hole closer to the knuckle). This will make your steering throw greater but you will loose a bit of torque.

[mikemcE]

Have you called or emailed Holmes?


Hang up and Drive

[Itali83]

If nothing helps that you guys have mentioned, I will call Holmes to see what can be done. Just wanted to see if I wasn't missing something simple. Thanks again guys!

Ben

[84yoda]

This isn't the first time I've heard this happening with a holmes servo. Try longer steering arms or longer drag link first. If those don't help, longer servo horn but that's the last resort.

[Itali83]

So, after rebinding, checking the steering rate on switch D, swapping out servos with another good used one, bypassing BEC, I still have only about 90 degrees of servo travel full left to full right. I've never tested or had an issue on another truck so I don't know if throw is the norm but my mind is blown. Why have a servo that is mechanically able to rotate 180 degrees yet only do half that on its own. Damn.

Ben

[Motorider]

Originally Posted by Itali83

So, after rebinding, checking the steering rate on switch D, swapping out servos with another good used one, bypassing BEC, I still have only about 90 degrees of servo travel full left to full right. I've never tested or had an issue on another truck so I don't know if throw is the norm but my mind is blown. Why have a servo that is mechanically able to rotate 180 degrees yet only do half that on its own. Damn.

Ben

I have the same servo and same problem. Mine only turns 90 degrees with EPA set to 150 and dual rate set to 100. Just figured it was the servo. I never thought it was a problem since I have no other rc with these steering ranges. Please give feedback here if you find a resolution.

Sent from my SM-N920V using Tapatalk

[Orange peel]

Sounds like the steering throw is limited in the servos programming. I bought a brand new Hitec that was limited down to about 60 degrees of throw last year out of the box. I hooked it up to my hfp-30 and restored full throw.

[hotwheels000]

Originally Posted by 84yoda

This isn't the first time I've heard this happening with a holmes servo. Try longer steering arms or longer drag link first. If those don't help, longer servo horn but that's the last resort.

SHORTER Steering arms require less throw from the servo. The longer the steering arm the more it has to move to acheive full lock to lock.

[Itali83]

Well, no dice with all of the tips. I sent an email in to Holmes Hobbies to see what they say. I'll let you all know how it goes.

Ben

[Itali83]

SO heard back from Holmes Hobbies and they said that it's standard for servo's to only turn 90 degrees under their own power. HH servo's can't be programmed to turn more than what they do. So that sucks in my book anyway. I know I'm new and have to learn things the hard way but for anyone out there who's building a custom rig, you'd better set up the steering last, because you need the servo to be powered to see how much throw it actually has under it's own power, not what it can physically move by hand.