Model Boat Mayhem

Dry Dock / Shipyard: Builds & Questions => Yachts and Sail => Topic started by: slug on July 01, 2012, 05:36:10 PM

Title: re servo
Post by: slug on July 01, 2012, 05:36:10 PM
could anyone please help,my marblehead sail arm servo has broken.futaba fp-s125 no longer made,what can i use to replace it,like to keep to the arm servo.could i use a large servo with a suitable arm,power hd 1501 mg be any good? thank you slug  tony
Title: Re: re servo
Post by: pompebled on July 01, 2012, 10:07:43 PM
Hi Tony,

Where did you search?
I found one here:
http://www.gravesrc.com/ProductDetails.asp?ProductCode=FUTSFPS125&CartID=1

Regards, Jan.
Title: Re: re servo
Post by: triumphjon on July 02, 2012, 08:00:51 AM
whats the matter with your servo ? i have three of them now , although one has a damaged pot shaft ( broke when i was trying to take the gears off ) the only problem i was finding is getting hold of the old square drive servo horns , so have made a punch to fabricate my own alloy servo arm !
Title: Re: re servo
Post by: slug on July 02, 2012, 07:34:50 PM
thank you all for the help ,i found one forsale in the us .the other week i was sailing and the arm ended the wrong way round the arm feels loose on top of servo havent taken it to bits yet . slug  tony
Title: Re: re servo
Post by: triumphjon on July 02, 2012, 09:14:27 PM
id imagine the small machine screw has worked loose , from memory they are an odd diameter thread size , the last time i needed one i ended up buying ten so ive a few spares ! jon
Title: Re: re servo
Post by: tigertiger on July 03, 2012, 01:32:57 PM
Ref funny thread sizes, and other strange dimensions.

Sometimes this can be metric Vs imperial standards.
I've seen this with US manufactured bicycles.
Title: Re: re servo
Post by: rickles23 on July 03, 2012, 02:13:28 PM
Hi,

I go through a few servo arms during the sailing season.

It is quite easy to make your own.

Regards
Title: Re: re servo
Post by: triumphjon on July 03, 2012, 03:52:29 PM
im sure its a metric size but seem to remember they were something like 2.5 mm ?  i know ive a few extra ones in my storebox
Title: Re: re servo
Post by: slug on July 03, 2012, 06:54:43 PM
thank you all for the help,would a powerhd1501 mg fitted with an arm do the job,17kg on 6 volts.does it have to be a proper sailarm servo?
Title: Re: re servo
Post by: triumphjon on July 03, 2012, 07:12:34 PM
on paper it has plenty of torque , i know both hitec and futaba sell purpose made arms , weather either would fit the powerhd servo im unable to tell you . at least its of greater torque than the servo thats giving you problems  as the old 125 is only 9 kg/cm
Title: Re: re servo
Post by: slug on July 03, 2012, 07:54:49 PM
triumphjon thank you for that, if i used the disc from the new servo and attached the arm to that with screws it should be o.k,as per the original should be ok  tony
Title: Re: re servo
Post by: triumphjon on July 03, 2012, 08:51:37 PM
thats what ive been doing with my 125 , screwing the new multi splined horn onto the old square stock horn , the only problem ive been getting is the old stock square drive futaba horns are getting brittle and have been breaking ! jon
Title: Re: re servo
Post by: essex2visuvesi on July 04, 2012, 06:34:21 AM
thats what ive been doing with my 125 , screwing the new multi splined horn onto the old square stock horn , the only problem ive been getting is the old stock square drive futaba horns are getting brittle and have been breaking ! jon

I may have some in my "might come in handy one day" box.... I'll take a look over the weekend

If not.... we are awaiting delivery of a thing-o-matic 3d printer and I found this
http://www.thingiverse.com/thing:19249

If these are any use let me know and I'll run a couple off
Title: Re: re servo
Post by: tigertiger on July 04, 2012, 12:31:16 PM
thank you all for the help,would a powerhd1501 mg fitted with an arm do the job,17kg on 6 volts.does it have to be a proper sailarm servo?

If you are not racing, you could swap out the sail arm servo for a sail drum winch servo.
But you may need to think about the routing of the sheets.

Sail arms are much faster when re-setting sails to a new position. Unless you are racing there is no benefit in doing this in less time. Some drums are also much cheaper as they do not need to be as powerful or strong as an arm servo that needs to use more torque.
Title: Re: re servo
Post by: slug on July 05, 2012, 06:14:13 PM
tiger tiger thank you for that,had asail arm sevo from the start,would like to keep to it that way thanks anyway   tony