Society of Robots - Robot Forum

General Misc => Misc => Topic started by: izua on August 23, 2008, 11:06:47 AM

Title: Servo sizes - standard?
Post by: izua on August 23, 2008, 11:06:47 AM
Do servos come in standardised sizes?
I want to use MG 995 in a design, however, I don't have one available. It's sizes however (Dimensiuni: 40 x 19.8 x 37.8 mm) seems to match the sizes of other such as a HS325 or HS311 (for which a sketchup model is readily available).

So - do servos come in fixed sizes? If a design for a "standard" or "micro" size, can I easily interchange servos in the same range?
Title: Re: Servo sizes - standard?
Post by: Gertlex on August 23, 2008, 12:54:15 PM
They seem to come in sets of very similarly sized servos.  Beyond that, I don't know for sure.  I'd check out the holes in particular, to see if they line up between sizes.  I'm pretty sure the output shafts and attachments are standardized sizes (at least among a given manufacturer).
Title: Re: Servo sizes - standard?
Post by: izua on August 23, 2008, 05:29:18 PM
Well, I'm talking about different servos, from different manufacturers, in the same range (micro, mini, standard, etc).
What about distance between mounting holes? I have 48 mm on mine (hitec standard clones). Does that value rings a bell? :P
Title: Re: Servo sizes - standard?
Post by: ArcMan on August 23, 2008, 08:40:12 PM
They seem to come in sets of very similarly sized servos.  Beyond that, I don't know for sure.  I'd check out the holes in particular, to see if they line up between sizes.  I'm pretty sure the output shafts and attachments are standardized sizes (at least among a given manufacturer).

That's true for a given servo size for a particular manufacturer, but output shafts are not necessarily the same between manufacturers.  For example, Futaba and HiTec have different output shafts.
Title: Re: Servo sizes - standard?
Post by: Ai-bot on August 23, 2008, 09:54:58 PM
HI

The MG 995 screw hole is not the same placement as the Hitec standard size.
I have the MG995, I bought 6 to try out, they are not that good.
Title: Re: Servo sizes - standard?
Post by: izua on August 29, 2008, 03:15:20 PM
Crap, I just ordered one MG995 to try it out too. It looked really cool with the metal gears.
Title: Re: Servo sizes - standard?
Post by: MarkBrown on August 29, 2008, 04:52:39 PM
Yes, there are standard sizes to servos.  An example of a micro servo is the Hitech HS55, and the standard size is something like the Futaba S3004.  Keep in mind that these sizes are standard for using them in RC vehicles, like planes and helicopters.
Title: Re: Servo sizes - standard?
Post by: izua on August 29, 2008, 05:15:56 PM
Oh, yeah, I know MG995 is standard.
My question was how the fixing holes, overall dimensions, shaft position etc, are realted (ie: widely varying or strictly similar) between different brands and models of servo sizes. It should allow me to force a screw in if it's a little off between different brands, or add some paper to compensate for a lower length.
Title: Re: Servo sizes - standard?
Post by: Admin on September 01, 2008, 03:44:39 PM
There really is no standard size.

Basically look at the servo datasheet for dimensions. But both Hitec and Futaba datasheets tend to not show some of the important dimensions, like screw hole locations . . .