Questions come up all the time asking where to get a deal on servos. I often get mine at servo when they are having a sale or new models of servos are going to come out. Servo City is having a sale right now. Worth taking a look if your in need.

Thanks for the tip, but the SC sale seems to be only on selected Hitec servos which I tend to avoid using, just one of my silly little traits I guess.

Karol

Karol, usually when they are having a sale they have all the brands they stock with sale prices. I use Hitec, can't afford any new servos no mater what brand so I didn't even bother looking to see what they had this time. When I have caught them having a sale due to clearence or replacing old models with the new I have picked up high end servos for less then half price. Usually I will buy Hitec or JR when I find these deals but I will also buy Futaba. I'm not brand loyal. I haven't had any problems with any of the top three brands. SC is just one of those places not everyone knows about.

Thanks Gray Beard.............I'm like you............on a limited income so have to go where the deals are......... [8D]

Just bought some 425's and a handful of extensions and Y's. I was short tonight on a setup so its restocking time. Also bought a bunch of servo screws and washers with the rubber from RTL.
Edwin

They have the 5625s on sale,, those are one of my favorite servos

What are the new BH servos, a typo?
Edwin

For 1/4 scale I use HS-755HB's with karbonite gears and for 40 60 size planes I use HS-635HB's with karbonite gears...I dont care for metal gears because they are noisy and they wear faster . And I dont need digital. My radio will do almost everything that a digital can do for the kind of flying I do..Digitals use more power. And I have been told that digitals dont play nice with analogs and you arent supposto mix them..I have mixed them with no problems but dont any more just in case...So I stay away from digitals..

High voltage for 2s lipos

Check Tower or the Hitec site for info
http://www3.towerhobbies.com/cgi-bin...?&I=LXBKAJ&P=0

Carbonite gears are brittle and strip easily on planes with big control surfaces on things like a hard landing or vibration from some engines. Hitec does not recommend them for gas powered use at all. Hitec also says not to use them on giant scale planes. I have had to replace the gear trains on some 6985s I have that were used on ailerons of an 80 inch gasser. Big ailerons, brittle gears. I do like the servos though but these days I prefer different gear trains.

I just have to agree with Gray Beard.

All devices that I know using gears that work hardhave lubricated metal gears.
The gears in the servos are greased and should preferably be metal.

Think about the gears in the transmission and differential of your vehicle.

Of course if a servo manufacturer use plastic or other material to save cost and meet competition low prices they have to find some way of claiming some advantages. I think it is only a sales' argument.

Give me metal any time for precision, durability and reliability.

Zor

Yikes I better look into that I even have them on my 1/3 scale Cubs and have had for yrs..According to everything I read they wear 4 times longer but I havent read anything on them for some time now...I have never had one fail but a big Cub is pretty easy on them usually. I have 645 MG's on my 1/5 scale cub and they work great. They are just noisy..The gears are not quite the same stuff as the gears in a diff or a tranny though..If they were they would never wear out..Thanks for the heads up..I am going to do some research on this...

I just did a search and went to Servo City..It is a site that helps you decide what type of servo you need ..According to them Karb servos are 5 times stronger than nylon..and metal gears wear out several times faster than nylon. It says MG servos have two Cons..Weight and wear.....To start my search I typed in Metal gear servos if you want to check it out... It also talks about their motors etc...

Yes, they are much stronger than nylon but on the other hand they are very brittle, and are NOT recommended for gas powered models.

Karol

If I remember correctly there were several gear failures in the beginning when the HB series came out. After all that is when the specs were changed. I bought 8 to use in a TF P-47 gasser and sold them to someone using them on .60 sized sport planes. I wasnt gonna chance it. Metal gears on 120 sized and larger, nylon on my smaller .60 sized. Havent heard of any complaints when used on the smaller planes.
Edwin

A cub and somethng like an Extra are a bit different so I wouldn't give it too much thought. Only way I knew about the brittle gear train was someone on RCU mentioned it. I then sent off an email to Hitec and got a good reply. When I bought mine th4y were advertised as the wave fo the future and nothing was mentioned about gassers, vibration or surface size of controls. I still don't see it mentioned"?
I have had a number of high end JR servos with Nyon gears and I felt they works every way as well and any other gear set. etel is not a must have but on big planes I like them. As soon as I see any slop I open them up and check the train out.
When I'm looking for new servos I always go to servo City to get the specs and info. At the time they may not be where I get the best deal though. I do shop around.
When I posted this I just figured there may be something on sale people could use and save a few bucks.
Servo selection is like anything, it's up to you to pick out what will work best on your new bird. I tend to mix and match as I see fit.

I havent had any abnormal wear on my 645's so I am not convinced about the wear thing on metal gear servos..I think it might be over played....I have a bunch of DS 821 digital servos that I have had quite a few failures with though..Even cost me a plane..I dont know if it was because I was mixing them or not..I didn't know you werent supposto untill reciently..I think digital servos are fine but I just dont see the point because I can pretty much use my radio do adjust my servos for the kind of flying I do . And espially if you cant mix them and they use more juice...I have had no trouble with the Karb servos or the metal gear..Where is this info warning us against using karb servos in 1/4 scale..I am unable to find it..In fact I am not able to find any info on warnings about karb servos being too brittle and failing .. And I am not disputing the fact..I want to find out as much as I can..Believe me I do not want to lose one of my 1/3 scale Cubs to a servo failuer..I use a lot of 755's in the Cubs..I have never had any problems at all..They have huge ailerons and one servo per aileron .. I always figured if I had a failuer I would still have one to get me down however if I am using a servo that is not supposto be used in a gas plane , I should change it.. Where is this information? Thanks

Well while I was waiting for a reply from Hi tec I phoned Great hobbies and talked to the Tec dept and they assured me that there was no issues with the karb gears and they were safe to use on my 1/4 scale planes gas or not...He read the box to me over the phone where it says they are four times stronger than conventional white resein gears, and they are less likely to strip under the shock and loads that would usually break standard gears..However when I finally got an Email back from Hi tec they confirmed what you said about the use in gassers...I have sent them another question asking what they recomend as a replacment servo ..One that will bolt in with out having to change anything...Or if there is replacement metal gears...Thankyou very much for the heads up on this...

I got another reply back from Hitec informing me that there is a set of drop in metal gears available for the HS-755HB servo for around $20 . at servo city...They have replacment metal gears for many servos if a person wants to change over with out changing the whole servo..Somtimes it might be worth it ..

Learned something new today. I like that I can upgrade from plastic to metal. I use a lot of 525's and 545's in my .60 sized planes. I fly them pretty hard so I keep spare sets of gears around.
Edwin

Most every one of us can read a box as well as the people in a hobby shop but they are just stating what HT printed. How much carbon fiber is added to the gears to make them four times stronger?? What does stronger mean and how is it tested? I use HT servos, I like them a lot but even today there is no warning about the type of use for these servos or a warning about when not to use them. I have a box full of the 6985s I bought on a close out sale, super deal but they shouldn't be used in the planes I bought them for. It took a number of years before I ever read any warnings about them. I did break a couple of gear trains but it was from an RF flutter so I never gave it any thought. I saved the plane so therre was nothing lost. I did try to get a new brass gear set for them but they didn't make a replacement set for these servos. It may be worth my time to check again because the 6985s are very good but have there limits because of the gears. Karbonite gears may be four times stronger then nylon but nylons don't snap because they are brittle, they will strip but it takes a bunch to do it.

This has been my experience also.

Karol

You know what kind of pees me off is along with the e mail from Hi tec telling me that the karb servos are not recomended for gassers was a legal notice warning me not to reprint the email and show it to anybody...I think that is just Bull S.....Its no wonder nobody know much about it..Anything you read on the box looks good..I thought they were better than anything but titanum..If it haddent been for you guys giving me a heads up I never would have knowen..

[:@][:@][:@]

Karol

My big question is why are they still using that gear train. They don't stand up to vibration and planes with large controls even in 60 size planes and using glow engines get vibration and have sudden hard landings that will shear the gears. If I would have known about them not to be used on gas powered planes and large scale I would have bought different models of servos, still Hitec but with a different gear train. I would have to go look at the numbers but I bought the cheap standard size I think 67 in. lb. digitals with the Karb gears when they first came out. I have had great luck with them but on 60 size IMAC and Pattern planes. I would rather have nylon the the Karbonite gears.
They still use the gear train and advertise them as something special without any warning at all or advise on plane size or engine type. GHo figure??