/diy/ - Do It Yourself

Why don't you cut slots in the metal so the cross arm fits inside

>>1651814
the metal piece weighs one or perhaps two kg, the servo cross can't handle this weight, I assume.
The white rod is a hollow plastic tube.
But I see your idea and will think about ist: I could cut slots in the plastic rod.

>>1651825
>the servo cross can't handle this weight
I want to add, that at the moment the metal piece (it is a ship's screw / that all is part for a "submarinecar" for my kids) is holded by the plastic tube which is attached or holded by the two bent metal strips (you see onbe n the picture)

>>1651829
>you see onbe n the picture
you see one on the picture

>>1651802
can you post pictures of the full assembly? From what I see here it looks like >>1651814 would be the easiest solution but maybe I don't understand how the thing is built

Bolt a piece of wood to the cross.
Bolt a couple of L brackets to the wood and run a bolt through both brackets and the tube.

>>1652166

>>1652188
thankyou, good idea, perhaps I#ll try to manufacture a small U-bracket, because all is quite small, standard L-brackets I think are too big

>>1652350
>that huge ship prop
>that tiny servo
>servo at all
What are you trying to do here?

>>1651802
"mechanisms and mechanical devices sourcebook"
Get this book, pirate* if you have to, there are dozens of techniques used to couple motors to shafts.

(/diy/ is a board of peace that doesn't condone piracy, but just google the book with pdf)

>>1652371
http://160592857366.free.fr/joe/ebooks/Mechanical%20Engineering%20Books%20Collection/THEORY%20OF%20MACHINES/Mechanisms_and_Mechanical%20devices%20sourcebook%205e%20NEIL%20SCLATER.pdf

>>1652359
only clockwise/counterclockwise rotation for kid entertainment - it worked till the wires between servohorn and rwhite plastic rod prolonged themselves, it is not as heavy as it seems
(and I think ist a good idea tgat the servo is no so strong to prevent accidents)

>>1652351
it's some sort of boat desk?

>>1652377
>>1652371
thank you very much!

>>1652388
Alright, in that case just do >>1651814
If you carefully twisted the wires, even the current approach would work, but cutting those slots will help with longevity.

>>1652389
I'm buildung a submarine-car-something for the pleasure of my kids. Since years I'm collecting all type of switches (did you know that there is an switch called "sleeping eye switch"( in german),
I don't know what it is for, but now I have one and I'll use it :- )) buzzers and led lights and digital and analog measurement devices.
devices and I'll construct a cockpit with steering wheel, the motor compartment is almost ready, seatbelts/sidemirror/flashers, there be a mast(sailingmast...OK...my submarine has sails...)
and there'll be a submarine part.
I'm sure I'll need till decembre and probably I'm more excited than my kids...I'm happy

>>1652395
>cutting those slots
ok so I try this,
but would it be a good idea totwist again the wires and hotglue them?

>totwist
to twist

>>1652397
and there'll be a robot arm with three servos,
the servos with joystick and poti worked well on the breadboard, but with the long thín cables through the old lamp-arm now they are jittering... so probably decembre 2020 :- )

>>1651825
just do >>1651814
the weight should not be a problem since it is already supported by the brackets

>>1651802
What kind of Scheiße construction is this?

The cross comes off the servo with a screw in the center.
Make a fricken shaft coupler!
It can be plastic, wood or metal.
One end fits over the servo axle, the other end in or around the large shaft/pipe.

Make some real bearings not U-brackets!


Can't wait to see the robot arm........

>>1654597
>shaft coupler
good idea, will see how this can be possible, because it is not as easy because of very different diameters

>Make some real bearings not U-brackets!
I'll look into that, although the hardware stores I know dont't sell this.

>>1654815
here's a diy shaft coupler, just add screws

Maybe you could do something like in the video, but less shit. As you can see it is very forgiving if your shafts aren't lined up accurately.

https://youtu.be/6YVtwE-2cEk

>>1654899
that's nice but pointlessly overcomplicated for OP's thing

>>1654901
>pointlessly overcomplicated
I disagree, universal joints were developed for a reason, and that reason was to simplify coupling two shafts that were not accurately aligned. If OP looks into >>1654597 idea of shaft coupling he will run into binding issues and excessive wear due to the shafts not being accurately aligned. I'm not being mean here but OP's project seems to be aligned by eyeballing it, he already had issues with the wires being stretched, presumably due to excessive drag because it was only eyeballed, instead of being right.

>>1651802
>How would you do it better?
Cut 4 slots in end of pipe.
Heat with heat gun or hair dryer bend tabs out to make ears.

If the shaft is perpendicular to the servo screw the ears to the servo horn.

If the shaft is not perpendicular, screw the ears to a thick fabric disk. The screw the servo horn to the disk too. It's called a rag joint and old cars used it at the bottom of the steering shaft.

-ellie

>>1654893
thats nice, i like this kind of solutions

>>1654899
supercool and a little bit overkill, but I'll look at this later when I'm on an computer with audio

>>1654963
so many good ideas here.
I have a redundant piece of plastic so I can try if it is formable by heat,
If I choose this option I have to cut a little bit into the desk because now the servo horn is so nearby the desk plate bottom that I had to make more space that it can rotate

>>1651802
Juan, you are NOT dropping the extract of coca leaves into florida with this sub! Please instead consider agriculture as income and leave logistics to more capable fellas.

>>1652371
we don't condone piracy, but op is clearly trying to build a boat.

>>1654963
>-ellie
Nice blog, ellie.

>>1655011
Hey, I'm german: the sub is not for cocaleves, it's of course for nuclear war heads :-)

>>1655022
call me dread pirate servor horn

>>1652388
You need a WAY stronger and faster servo if you hope to blend a kid

>>1656143
What is green and becomes red on button press?
A frog in a mixer(food processor).

What is green and stays green on button press?
A frog in a mixer who is "mitrennen" (runs with (the blades))


...difficult to translate jokes

>>1654815
>good idea, will see how this can be possible, because it is not as easy because of very different diameters

A shaft coupler is a piece of metal or plastic rod with a hole to accept the motor and driven shafts.
You just drill the holes to fit the different size shafts. 1/2 of the rod has small hole, the other half large hole.


Bearings can be blocks of wood or plastic with a hole that the large shaft just fits through. The blocks guide and hold the shaft straight and can be lubricated for smoother turning

>>1657345
Verzeihen Sie mein schlechtes Deutsch, ich schreibe, damit andere nicht verstehen.

Was ist Ihre Ausbildung, dass Sie nichts von Mechanik wissen?
Warum bist du mit so schlechten Konstruktionen zufrieden?
Ihr Kind könnte dadurch verletzt werden!

Wie wirst du den Arm bauen? Es ist so viel komplexer als das.

Ich bin ein Maschinenbauingenieur mit 20 Jahren Erfahrung im Bau von Industrierobotern und Kinderspielzeugen.

Wenn Sie möchten, kann ich Ihnen einen Plan erstellen, dem Sie folgen können.
Sie können mir Ihre Idee sagen, ich kann Ihnen zeigen, wie man baut.

>>1652350
You are going to have way too much friction.
The problem with your design is that the weight of the propeller will cause the shaft to place undue force on your saddles.

A bearing and pillow block is a very simple solution, you can find all these sort of parts very cheap on aliexpress

OP here, pic not related:

>>1657351
I don't understand the meaning your post:

>>1657345 war nicht von mir geschrieben (was not my post and he had good intentions.)
Are you trolling?
Your offer is nice if serious, but I am happy with an easy and ugly solution - I am sure the kids are not in danger because of weak servo.
And lets talk in english so more people have the possibility to use solutions from this thread.

>>1657363
this bearing seams nice, I'll try aliexpress or something similar if not to expensive.
I never had the idea because I never saw bearing in our hardware stores or in any instructions about servo-using in the internet

>>1657351
>Wie wirst du den Arm bauen? Es ist so viel komplexer als das.
The arm is an old desk lamp, at the top I'll put one servo and then a piece of wood, at the end a servo for rotation of the gripper which will follow at the end of the construction (gripper is a bought piece with a servo to open and close)

And I know you are trolling because you wrote
"Verzeihen Sie mein schlechtes Deutsch, ich schreibe, damit andere nicht verstehen."
Why the fuck you used a goolgle translater so that the others shouldn't understand you?

>>1657401

I offered help in good faith.
Not trolling, you misunderstand my intention.
So fuck you.

You are too stupid to know you're too stupid!

You'll never make this because you don't understand shit.

I'm out of here..........

>>1656312
si

>>1657397
>this bearing seams nice, I'll try aliexpress or something similar if not to expensive.
You are going to buy a bearing for this shit that the dumb kids will use once?
Put butter over it, here now you have a bearing.
>>1657363
What kind of autist even suggest a fucking bearing for this shit?

>>1657459
>"I offered help in good faith"
... and writing in other language with pupose that others can't understand:
"Verzeihen Sie mein schlechtes Deutsch, ich schreibe, damit andere nicht verstehen."(>>1657351)

Haha

so, thank you all for the constructive posts and helpful proposals, I think I have enough suggestions for continouing the work.
Perhaps I post in some months some pictures from the car-submarine, if anybody is interested.

>my motor doesnt spin fast enough
>this thread: "buy bearings and use a u-joint"

kek

get a better motor and move it closer to the propeller, pajeet

>>1658738
>my motor doesnt spin fast enough
are you too dumb to understand simple sentences?
that wasn't OP's problem