Making a servo rotation 180°

Started by Bill B
21 replies 112 likes Last activity: 1 year ago
#22

Making a servo rotation 180°

Correct Roy. There are continuous running servos or one cat take a standard old servo and make it run continuously.
I converted two old servos to turn the props on my 1/35 scale LCM. Got fwd/r⁸ev plus speed control.
If the servo turns too fast (i.e. a turret) there are devices that allow one to reduce the speed of the servo electronicly.
Lew
Florida ⛱️, USA 🇺🇸
Lew
Florida, USA
Home page: https://www.RCFlorida.org/lmb
Liked by Mike Stoney and Len1 and
#20

Making a servo rotation 180°

Thanks for the response Bill B. Yes in some cases I just use a "Y cable" to get two movements at once.
You can bring "all guns to bear" with one command.
Toradog showed what I was looking for a simple connector from Gobuilda
The sure way to succeed is, just try one more time
Liked by Len1 and hermank and
#19

Making a servo rotation 180°

Thanks, Tora Dog that is just what I was looking for, excellent!

Gobuilda
The sure way to succeed is, just try one more time
Liked by Len1 and hermank and
#18

Making a servo rotation 180°

For some reason the rest of my post disappeared.
Another way to achieve connection is to mount a drum, sized to fit your needs, to the servo output wheel. Somewhat like a sail drum servo, but smaller.
Another way is to use some of those left over servo output wheels, or crosses and adapter them for you output. I've glued shafts to one and screwed it ti the wheel already mounts to the servo.
Lastly, there are linear servos still available and they can have their throw increase through the use of bell-cranks which will increase their throw.
Liked by Len1 and hermank and
#17

Making a servo rotation 180°

Commodore H,
There are lot's of ways to accomplish attaching to a rotational servo. One is a direct shaft connectionas here:https://www.gobilda.com/25-tooth-spline-servo-couplers
Another way is to mount a wheel or gear to the servo output shaft, something like a drum sail servo, but sized to suit your needs.
Also, multiple servos can be Y'd together to accheive the effect one desires, ie, moving a rudder and a steering wheel.
Another method is to take some of those left over servo output wheels that we al have lying around and making up an output adapter with them.
Liked by Len1 and Black Shoe and
#16

Making a servo rotation 180°

CommodoreH,
If I understand correctly you could have a y-splitter cable to make 2 servos mimic movement? (say in the case of rudder/wheel)
If this is the case, would it be possible to piggyback cables to control searchlights & gun turrets.
Sorry if I'm missing the point 👍
Liked by Len1 and hermank and
#15

Making a servo rotation 180°

Anyone have an easy idea to connect stuff directly to servo output to shaft? It would be very useful to rotating things like, searchlights, guns, water cannons,etc. I have accomplished this in many ways but it would be nice to find a simple straightforward method. Some of my models have a visible steering wheel that rotates with rudder.
The sure way to succeed is, just try one more time
Liked by Len1 and hermank and
#14

Making a servo rotation 180°

Looking on Aliexpress the other day I came across another similar unit but you could set the end points for the servo so the exact amount of turn could be set, it was about a fiver.
Roy
Liked by Len1 and Peejay and
#13

Making a servo rotation 180°

Another way to skin the Cat... poor Cat.
Looks great.
Liked by Len1 and Peejay and
#12

Making a servo rotation 180°

For anyone interested. Ordered off AliExpress for £2.01 each (got free postage for ordering 4)
Converted my servos rotating at 90° to 180°
Before/After - works a treat 👍
Liked by Mike Stoney and Len1 and
#11

Making a servo rotation 180°

I guess that I could have been more clear in my comment.
Two thing effect the degree of servo rotation, the transmitter and the servo. I covered the transmitter OK, but I was less clear on the servo. Almost all servos are capable of greater degree of rotation than they convey when first hooked up. For instance, a 60 degree servo will easily rotate to 90 degrees if the electronic signal to it is applied as such. Beyond the 90 degrees is or was not possible due to mechanical stops inside the servo. Nowadays, servos have much greater capability.
If a radio is digital and allows access to the output signal adjustment then the servo can usually be "extended" by the transmitter, but if not then the "old" analog signal extender, ie a servo morph, servo extender, ect, will do what the transmitter is not doing for you.
How is THAT for muddying the waters?
😀😀😀
Liked by RodC and SouthportPat and
#10

Making a servo rotation 180°

Thanks all for the useful replies.
I have placed a low risk order of £8.04 for 4 servo expanders from AliExpress.
(£2.01 each free shipping)
I understand I could fiddle around with the pwm, by reprogramming, if I knew how, I could solder a thingummyjig between 2 pins, I could file down a physical limiter inside the servo gubbins ...🤪
But what I really want when I order a pint of bitter, is a pint of bitter.
Not a half.
I will be more careful when ordering stuff of Amazon when it says "180° rotation" I know now not to believe it. 🤣
Again, thank you all for your quick and informative replies 👍
Liked by SouthportPat and premecekcz and
#9

Making a servo rotation 180°

I suppose I should add that my transmitters often rotate around various models. At the last count I have 18 transmitters and around 40+ rx's. I do not use 2,4Ghtz as all the other ones I have still work!

When the 2.4G frequency came out there were many 35Mhtz sets going cheap and I bought a few. Just put in a 40Mhtz crystal and you are legal for boats. 99% of all 40 Mhtz sets are 35Mhtz ones!

I have a new Futaba 6EXAP 40 Mhtz set some of it still wrapped in original cellophane. (It was donated to the club and is for sale, with 4 servos, batteries and charger). Looks like it has never been used.

The instructions are all for flying an aircraft and that is for 35Mhtz, it does include mixing, but the servo adjustment does not go as far as 180 degrees.

Under the servo end point adjustment it allows the servo to extend from 0 - 120 degrees. So previous mention of servo travel adjustment may not go as far as 180 degrees.

Perhaps someone could check?

Regards
Roy
Liked by SouthportPat and premecekcz and
#8

Making a servo rotation 180°

Going back 20+ years I used to repair the electronics inside the servo and also used Fleet rc servo electronics kits. The simple way is to extend within the servo the resistance values either side of the feed-back potentiometer. I found a 1000 ohm resistor soldered each side and the existing wires reattached to the ends of each resistor would extend the angle the servo could reach.
I have 4 servos which are virtually the same size as a standard servo, in use as sail winches, they are incredibly old, at least 50 years and were themselves part of a Wind Tunnel in use at a government establishment which was dismantled and the servos removed.

Angle came out to about 180 degrees. Note the servo morph I mentioned previously costs just £2.13 plus postage.
Most of us use just a couple of channels for model boats and although I have a couple of sets with computers in, I just can't be bothered to work out how to do it as a few months later I will have forgotten how anyway!

regards
Roy
Liked by RodC and SouthportPat and
#7

Making a servo rotation 180°

There are a number of things one can do with servos. If you just want to add a few more degrees of rotation some of the transmitters can adjust that as well as reduce the number of degrees by setting limits. That doesn't mean you can get 180 degrees out of a 90 degree servo, but you could pick up a few degrees. There are also ways to make the servo rotate unlimited in either direction plus vary the speed. I did this to my 1/35 scale LCM (18" long). Two motors each driving a prop in either direction at various speeds.
you can also use different length arms to gain some more angle, but still must be well under 180 degres. Another option is adding external gears or belt drives.
Lew
Florida ☀️, USA😎
Lew
Florida, USA
Home page: https://www.RCFlorida.org/lmb
Liked by RodC and SouthportPat and
#6

Making a servo rotation 180°

Set up via Transmitter, there will be menus and sub menus to navigate but it can be done quite easily once you get the hang of your radio gear..
If it don't fit, use a hammer to make it fit....
Liked by SouthportPat and Bill B and
#5

Making a servo rotation 180°

There are two things to consider here. One is if the servo is capable of 180 degree rotation, which the manufacturer says it is. Second is the channel output range as set in the transmitter.
IF you have an analog radio, yup, one of the old ones( I have two) you will need a servo morph, or servo extender in order to get the servo to travel +- 90 degrees.
IF your radio is a computer radio, you should be able to enter the channel output section and extend the range of rotation of that channel. You can also use that function to reduce the servo range if so desired.
There are servos available, GoBilda.com, that provide 180 degree rotation, out of the box so to speak. If coupled with a servo extender,(GoBilda makes one as well), the servo is capable of 300 degrees rotation.
I use these servos on my builds to rotate turrets,+-135 degrees as well as gun directors, torpedo tubes, ect.
An added advantage is that the servo can be programmed to rotate 360, fwd/rev at variable speed.
Without turning this into a sales pitch( I have not connection with GoBilda) the price runs about close to a decent name brand servo.
Liked by SouthportPat and Bill B and
#4

Making a servo rotation 180°

Hello Bilbo1, Your query about 180 degree servo.
The servos are sold as 180 degrees but as you have found just work with a receiver at 90 degrees.
You need a small device called a servo morph or servo extender unit which plugs into the receiver and the servo is then plugged into the morph.

I bought mine from AliExpress here is a similar unit very cheap, hope the link works. Very cheap as well!
Check postage as it might be simple to buy 4 when you get past the £8 minimum for free postage.
Good luck
Roy

https://www.aliexpress.com/item/1005008522188268.html?spm=a2g0o.productlist.main.11.4d2c7e92LGuFow&algo_pvid=49f24e6d-5307-413f-81c7-6a14ce3779b7&algo_exp_id=49f24e6d-5307-413f-81c7-6a14ce3779b7-10&pdp_ext_f=%7B%22order%22%3A%221%22%2C%22eval%22%3A%221%22%7D&pdp_npi=4%40dis%21GBP%213.55%212.13%21%21%214.62%212.77%21%402103919917478647948126557e19b3%2112000045546375183%21sea%21UK%213761680132%21X&curPageLogUid=sTI8tktolc5y&utparam-url=scene%3Asearch%7Cquery_from%3A
Liked by SouthportPat and Bill B and
#3

Making a servo rotation 180°

If you google how to do it I am sure it something will come up. Alternatively go into Youtube and ask a similar question. There is so much assistance for all sorts of things on the net. Cheers Ian
Ian Langley
Liked by Bill B and Mike Stoney and
#2

Making a servo rotation 180°

Hi BilboB1, can you post some pictures of this servo showing the make and model?
What did you want to use it for? What did you need it for?
Liked by SouthportPat and Mike Stoney and
#1

Making a servo rotation 180°

Hi all

Newbie here, although I joined whilst COVID was on....
I've bought a couple of metal geared servos along with a servo tester off Amazon.
They were advertised as 180° servos but when I plugged in to the receiver or the tester, the best angle I could get was 90°.
When I asked the seller, they said I would have to program the signal......blah ...blah...blah 😁
I was zoning out with the explanation...is this something I can do simply, or have I wasted £14.
(I don't see it as a waste actually, thought they were a bargain and I'll use elsewhere in the future)
TIA
Bill
Liked by SouthportPat and Mike Stoney and

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