Servo Horn screws loose on body


#1

I am in the midst of building hexy with my son and have just started on the body.

I have put the servo horns on the “star” shaped peice, but the screws are not biting into the acrylic. The holes are too large and they are loose.

Is this common? Or is this going to cause a problem? I don’t know how much stress is on them. Should I hot glue them in (the screws into the holes that is)?

Thanks


#2

It was even worse when I flipped it over.


#3

some of the laser cut parts are not as accurate as one would hope.

I used a little hot glue in the holes, and just screwed into the glue after it cooled.


#4

I did that, but now some holes are not flush, either because it is hard to get the glue flush or because the screw doesn’t like to go through dried glue. (hot glue is very rubbery.)


#5

I used 20 gauge wire to secure two of my horns - screencast.com/t/ruSEaKJXG

Chuck


#6

@vanstrien Yah, I had that problem too with the hot glue. After a couple tries, I ended up putting hot glue on the hole from the opposite side with the screw in. Seems to have held ok so far.


#7

I like the wire suggestion; I got all of the main horns attached fine, but the ones for the sonar (step 27) didn’t bite at all. (The other helpful bit overall was to notice that the little screwdriver was hex-shaped at the top, compatible with a 7mm socket; a small ratchet made installing them much less tedious, as did ignoring the instructions and mounting the horns on bare plastic, before doing any of the other steps - a lot easier to hold one plastic piece down on a desk when it’s flat and doesn’t have other bolts installed already…)


#8

I stuck a bit of toothpick in the hole and the screw holds firm.


#9

All of the ones on mine are falling-out loose, and I’m wondering how many people have this problem and what the best solution is. I’m inclined to either go up a screw size (the supplied ones are #2 I think) or switch to machine screws and nuts (#2 should fit nicely :slight_smile:. Have to drill out the holes on the horn a bit though, which shouldn’t be a problem since they are in the wide part of the horn.

Also, is it possible to just get a replacement part?


#10

Replacement parts for what, exactly? Horns? Or whole servos?

We sell replacements servos, but not horns. However, you can find horns online if you look around, its not just something for it to us to stock.


#11

[quote=“roboalchemist”]Replacement parts for what, exactly? Horns? Or whole servos?

We sell replacements servos, but not horns. However, you can find horns online if you look around, its not just something for it to us to stock.[/quote]

Um. Replacement for the body, of course. The servos and horns are not defective. The body is (holes too large for the screws).


#12

By the way, I’m using 3/8" #2 machine screws for all the servo horns on the body and head. There’s enough clearance for the nuts. The horns have to be drilled out, of course. 3/32" worked nicely.

I also used it for the servo hold-down on the head. That hole is also too large for the supplied screws.


#13

Are you using two of these to secure each horn to the body parts? Are the nuts on the servo side or on the side opposite the servo?A picture would be great.
Thanks
Chuck


#14

[quote=“Untulis”]Are you using two of these to secure each horn to the body parts? Are the nuts on the servo side or on the side opposite the servo?A picture would be great.
Thanks
Chuck[/quote]

Yes. Two screws and the nuts on the bottom side.


#15

You can usually solve this by flipping the piece over. The whole on one side is bigger than the whole on the other side.


#16

Nope. Tried that.

The #2 machine screws slip right in so there’s no way a #2 tapered screw is going to bite.


#17

Go ahead and send a replacement request then: replacements@arcbotics.com


#18

I got machine screws and they’re working fine. Thanks for the offer though.