HiTech Servo - How to connect something to it? (Screw size)

Projects Discussion and Showcase Robotics
1

I bought a Hitech servo from a shop online... http://www.robotshop.com/hitec-hs81-servo.html
I've found all sorts of discussions online for replacing the center screw that holds the arm to the servo. However, I need to know how to actually attach something to it.
I went to ACE to try to find the right screw size to get through those holes and even their smallest one didn't fit.

Does anyone have any advice on how to attach something to this? I want to attach a flat piece of metal to it. I thought about screws for glasses but those don't have nuts so I'm not sure how to make that work anyway unless I just super glue it (not what I want to do).

Any advice? I've looked all over.

2

Attach the servo arm to the servo as usual, and then attach the servo arm to the flat plate?

3

The large online RC stores have servo horn screws for the various makes of servos (but with postage you really need to want them). As the previous post mentioned usually one would attach the piece of metal to the existing servo horn. Hot glue can be used to attach things to a servo horn and is generally removable.

4

Chagrin... I think you misunderstood...your answer is so obvious that I'm not sure what you were even answering.
I'm looking for the screw size that would fit through the holes in the arms of the servo horn. Zoom, I'm going to try to check in the RC stores... do you know what they market them as? Is there a special name for them? "Servo horn screws" seem to always refer to the screw in the center that holds it in place. I'm looking for the screws that would allow me to actually attach something to it.

(I'll still try checking those stores again, I very well could have overlooked that because I don't remember seeing anything close to that)

5

The screw holes aren't tapped. So you could put any size screw in it within reason. If you have some larger screws laying around, just drill the hole out alittle.

6

Thanks Cod,
It's a mini-servo so the holes are pretty small...drilling is absolutely an option, I am just afraid to crack the thing. I've never seen holes this small on anything (and neither had ace) so I might give up soon. Is there a name for these? I thought they might be called mounting holes or something but that just pulls up the screws for mounting the servo to a bracket where I'm just trying to mount a piece of metal to the horn.

To be honest, I'm just waiting for someone to tell me that I'm doing something stupid, because I feel like this should not be so difficult. I'm not the first person in the world to use one of these servos so you'd think there's be an obvious screw size to fit through the holes on the arms.

7

Your really just over thinking it. Go to a nearby hardware store and take the servo with you. Match up the screws to fit your needs. Since the holes aren't tapped, you could use any thread you want.

8

pezz:
Thanks Cod,
It's a mini-servo so the holes are pretty small...drilling is absolutely an option, I am just afraid to crack the thing. I've never seen holes this small on anything (and neither had ace) so I might give up soon. Is there a name for these? I thought they might be called mounting holes or something but that just pulls up the screws for mounting the servo to a bracket where I'm just trying to mount a piece of metal to the horn.

To be honest, I'm just waiting for someone to tell me that I'm doing something stupid, because I feel like this should not be so difficult. I'm not the first person in the world to use one of these servos so you'd think there's be an obvious screw size to fit through the holes on the arms.

You might try these places for screws to fit:

http://www.amazonsupply.com/

EDIT: Hey! When did smallparts get bought up by Amazon? Did anyone else notice this?

9

I usually drill the holes out to 1.6mm and then run an M2 tap through the hole. You can then use any M2 machine screw.

Or

drill 2.5mm hole and tap with an M3 tap

RS Components have a large range or taps

10

pezz:
Thanks Cod,
It's a mini-servo so the holes are pretty small...drilling is absolutely an option, I am just afraid to crack the thing. I've never seen holes this small on anything (and neither had ace) so I might give up soon. Is there a name for these? I thought they might be called mounting holes or something but that just pulls up the screws for mounting the servo to a bracket where I'm just trying to mount a piece of metal to the horn.

To be honest, I'm just waiting for someone to tell me that I'm doing something stupid, because I feel like this should not be so difficult. I'm not the first person in the world to use one of these servos so you'd think there's be an obvious screw size to fit through the holes on the arms.

Hi All,
I am new to Arduino and facing this same problem. Did you manage to attach it? How?

11

The holes on the servo horn are simply guide holes for 1) nails, if you nail the horn onto wood, 2) a tap, if you find a tap small enough, or 3) a drill, if you want a larger thread tap or just want a bolt or a screw to run through.
I prefer nailing or screwing the horn onto something else, not caring for threads in the horn, instead of creating threads in the horn and screwing something onto the horn.