Cliff Secord

My mom got me some hs 81's for Christmas(because that's what I asked for) she then went online to make sure she was getting the right thing & got scared when she found posts online saying the hs 81 was garbage & would cause a crash. fact or fiction? if they are, what is a good option instead?

TFF

It depends on the usage. They may have a bunch of torque, but they are still small servos. I think they are great servos if used the right way.

Cliff Secord

Thanks, I thought they were ok, just got scared when she said her online research said they weren't. they will be used for a hyperion super chipmonk 10e so should sufficient. Thanks for the quick response

JohnBuckner

My Feedback: (1)

I have a ton of them and use them primarily on larger glow aircraft for throtle but also use them elsewhere on small 10 sized glow planes. They are fine.

Bottom line with forums no matter what you are researching you will find people badmouthing every product and the key is to figureout if those who are doing the badmouthing are using the product appropriately.

John

Jetdesign

My Feedback: (8)

Anyone have thoughts on the single screw (per side) mounting? I would like to use a pair of HS81 or HS82 for split, stab mounted elevator servos on a .40 size plane. The torque is enough, and the metal gears would certainly be enough, just not sure of the mounting strength.

It was not hard to strip an HS81 with a mis-adjusted throttle linkage; system bound up once and destroyed the gears. Of course that's user error, but I was surprised at how easy it happened.

airbusdrvr

I've used them over he years with good results.

speedy72vega

I have had the worst luck with HS81's. Just to clarify, I'm not a HiTec basher, as almost EVERYTHING I fly has HiTec servos. Ordinarily, HiTec seems to me to be the best bargain for the buck for servo's, but not the HS81 IMO.
Here's my experience:

I have a Great Planes 39 1/2" P47. I absolutely love the plane, and it flies great, but it was a handful for me to learn how to land at first, as it comes in kinda hot.
I used HS81's for all control surfaces, separate Aileron servo's, so that's 4 total.
On the second or third landing, the plane bounced a bit on a landing, but didn't crash, just bounced a bit- left Aileron servo gears stripped. The Ailerons aren't very big on this plane, less than 1" wide, about 6" long, so there isn't exactly a huge amount of mass there.
I replaced the gears and continued to fly.
A few weeks later, same thing, but the right Aileron this time. Replaced the gears again, but servo would no longer center properly. If I just barely gave Aileron input right or left, the servo would center with the Aileron either above, or below the wing T/E, depending on which way I moved the stick, but wouldn't center.
I replaced that servo after that.
I had since learned to land the plane like butter, so no more bouncy landings, however I still lost the plane to a faulty HS81. About a month or so ago, I took the P47 up for a flight, and it was very twitchy, almost uncontrollable. I decided to land so I could check the plane over, so I came around for a low pass to see how the plane would react for landing. It flew right over the runway nice and smooth, so I decided to come around again and land. On my final downwind leg, coming around for the final, the plane suddenly rolled hard to one side, and I was never able to recover. The plane went in hard, nose first.
After I recovered the wreckage, I looked the plane over, and to no surprise, another stripped HS81 on the left Aileron.

I have since rebuilt the plane, and have switched to the metal gear version of the HS81, and so far no problems.

This post is for info only, you decide for yourself if you want to run the HS81's.

jooNorway

I have used a lot of HS-81. Especially in my sailplanes. Never had much problems, except from some I bought 5-6 years ago. They did buzz sometimes, but I cleaned the potmeterts and they have worked since then. Propably a not so good batch, because all was bought at the same time.
And I never use them for throttle. Both me and some of my friends have had failures when doing that...

Gray Beard

My Feedback: (-1)

Joe, I use then on small 40 size race planes quite often and the single mounting screw has never been a problem. I use them on ailerons most the time and usually something bigger on elevator and rudder though. The 81s have a very small motor and gears and the elevator and rudder are producing the most pressure on the servo so I avoid them on these controls. I'm using them on my small electric plane I'm building right now but it's not going to be putting any strain on the servos so no big deal. For a few bucks more I may buy the servos with the metal gears, not needed on this plane but sometime down the road I may use them in another plane for other reasons.

Jetdesign

My Feedback: (8)

Thanks Gene

Gray Beard

My Feedback: (-1)

Joe, I haven't ever tried them but last week I had a tower talk and noticed the price difference on the HS 81 and 82 so I think I'm going to try the 82s. That little pattern plane I built, the Daddy Rabbit is one of my odd balls. I used an 81 for throttle and the front wheel for steering. I have never had a problem with these servos until one day I landed a bit { Bit, loose term} nose down. Read front wheel first. That took care of the gears in that servo!!!! I'm just thinking the 82s may be a better choice for me in the future. Not sure any gear train would have taken that hit but what the heck, it's just a couple bucks more.

ro347

My Feedback: (13)

I have an hs-81 mg servo that buzzes alot - without any linkage attached. Ive used it for a single season without issue so far on throttle of a saito 100.

You mentioned cleaning the pots resolved the buzzing. How do you do that?

snuts

I have say 10, HS81's. I like them, and have had good service out of them, with the exception of being very suseptable to hanger rash. If you bump a surface while ground handling the gears strip very easy. For that reason I have been moving towards HS82mg's. As for the single mounting hole, not a strong enough servo to require anything more.
Hope this helps. -Snuts-

Jetdesign

My Feedback: (8)

I think the HS82's make a lot of sense.

Just got resigned to TH Super Savers, so with my $60 savings I'll grab a set of the HS 82s and fix up that Venus 40.

jooNorway

You open the servo, the bottom cover. When you lift the small board you see the potmeter. There is a screw which hold it in place. Mark the position of the cover, unscrew and open. Clean with a contact cleaner, using a Q-tips. I also make sure there is enough tension on the bushes.
This job isn`t easy to do, everything is narrow and tiny. I work with electronics, thus I am not afraid opening things, but you have to be careful.
I also have seen the servoes could buzz if the servohorn screw is tightened too hard...