Duty cycle on servos??

[W900snowman]

I was wondering if there is a duty cycle rating or concern for servos, particularly ones that are hacked for full rotation?

[fhhhstix]

There is no real rating for a duty cycle. It really depends on the servo and what you are planing to do with it. If you buy a $10 standard servo and use it for a winch it probably wont last long. Tell us what you are wanting to do with the servo and maybe we can make a recommendation I know small haul has a lot of experience with the continuous run servos.

Travis

[SmallHaul]

I have a lot of time on servos that were converted to continuous rotation and they are still going strong. I believe the gears actually last longer because the final output gear use all of its teeth the more often/evenly than if it were to just swing back and forth like a stick servo (the last gear in the chain receives the most stress). Also because of the slow final output speed the bearings last for a very long time.

[SmallHaul]

Originally Posted by fhhhstix

There is no real rating for a duty cycle. It really depends on the servo and what you are planing to do with it. If you buy a $10 standard servo and use it for a winch it probably wont last long. Tell us what you are wanting to do with the servo and maybe we can make a recommendation I know small haul has a lot of experience with the continuous run servos.

Travis

That is funny, I wrote up my post and then hit "submit reply" and then see this

[W900snowman]

Thanks guys, I bought another Manitowoc 4100 1:50 crane this week and got me thinking about still wanting to build a 1/16 scale eventually. I haven't done much research yet but was kind of thinking I could use servos for all of the functions if I convert them. I think that it would be much easier than trying to find gearmotors/ gearboxes for some functions. Hopefully after I finish my apprenticeship I'll be able to get started.

[fhhhstix]

I have done the same thing Scott.

Travis

[SmallHaul]

Originally Posted by fhhhstix

I have done the same thing Scott.

Travis

like minds..

Originally Posted by W900snowman

Thanks guys, I bought another Manitowoc 4100 1:50 crane this week and got me thinking about still wanting to build a 1/16 scale eventually. I haven't done much research yet but was kind of thinking I could use servos for all of the functions if I convert them. I think that it would be much easier than trying to find gearmotors/ gearboxes for some functions. Hopefully after I finish my apprenticeship I'll be able to get started.

I'll warn you though, micro & sub micro servos have open frame style potentiometers and it isn't easy to lock them without damaging them and the output gear rides on the pot shaft to boot so, it is easy to damage one trying to convert them. But, they are cheap so, just buy an extra one and take your time.

[fhhhstix]

Some servos do not have 360 deg final gears as well. A HiTEC HS-85MG only has half of a gear for the out put I found that out after I cut the mounting tabs off to fit it in my Service Truck Boom and when I opened it and seen half of a gear I was upset with myself for not checking that first but that is a mistake I won't make again.

Travis

[W900snowman]

Thanks Smallhaul I'm not sure what size I'll be using yet but I will have to keep that in mind about the micros. I never gave any thought to the gear train life I was mostly concerened with the motor's life but I'm getting the impression that they will last a long time.

Thanks Fhhhstix, I didn't realize that they could have only a partial gear, I will definetly have to check on that before I get any.

[Espeefan]

Servocity has a nice chart that lists which servos are easier to convert then others. They also offer the continous rotation modifications for servos too, if you don't feel like doing it yourself. The standard sized servos are actually quite easy to convert.

http://www.servocity.com/html/contin...nformatio.html

[SmallHaul]

Originally Posted by Espeefan

Servocity has a nice chart that lists which servos are easier to convert then others. They also offer the continous rotation modifications for servos too, if you don't feel like doing it yourself. The standard sized servos are actually quite easy to convert.

http://www.servocity.com/html/contin...nformatio.html

I checked with them in the past and they only convert the easy to do standard sized ones. The wouldn't convert any of the micro or sub micro servos.

[Espeefan]

Good to know Scott. I was actually looking to buy a continous rotation micro HiTec servo from them. Under the buy it options, you could select the continuous rotation mod, and that is probably the best way to judge if they would offer it or not. If the option is listed, they will do it. If not, then no.

For example, the HS-85MG. http://www.servocity.com/html/hs-85m...hty_micro.html

The beauty of the HS-85MG is that it is a micro servo, but accepts the standard sized servo horns because the output shaft and splines are identical. Basically that means the sprockets Serov City designed for the standard sized HiTec servos would fit this micro, and that would be perfect for a project I have in mind.

[fhhhstix]

Nathan the Hs-85 is the one I converted to run the telescope screw drive on my service truck s boom and I just want to say it has a good amount of power but it sacrifices speed to get it it is very slow but if you need slow it will work well.

Travis

[Espeefan]

Thanks Travis. Sounds good to me, as I prefer it to be slow, for what I need.

[SmallHaul]

You are right Nathan, here is there list of servos that can be modded and they do list some small ones:

http://www.servocity.com/html/rotati..._difficul.html

$50 total for a modified continuous rotation sub micro servo really isn't that bad of a price.