Attaching gears to motors and mounting motors

Hi :slight_smile:

Ive bought this stepper from adafruit and want to mount a normal gear like this one on it. How do you do this the best way? Glue?

Also I would like to know the best way to mount a stepper motor like this one. Im trying to build something like this. The person who made it had screw holes on his motor, but obviously the adafruit stepper doesn't. Could you help me with coming up with a way to mount it?

Thanks

Those gears are designed to be a friction fit on standard electric motor shafts.
They are not designed for steppers

Your stepper has threaded holes in the face , they are for mounting

This guy used them for his steppers. Anyway, if they don't work, what other gears would you recommend?

Ask him how he did it.

Appears he has posibbly drilled it out and forced it on.

Gears arema de from a slippery material deliberatley.

They are almost impossible to glue.

bestanamnetnogonsin:
This guy used them for his steppers. Anyway, if they don’t work, what other gears would you recommend?

What would be ideal would be a gear meant to fit that shaft; either one with a D profile and/or a shoulder with a setscrew (grubscrew) to secure it on the shaft.

So - you need to look for such a gear - one with a bore (the hole thru the gear) of 5mm to fit the shaft.

A good (though not cheap) place for gears is SDP-SI:

http://www.sdp-si.com/

I was able to find a part there that is close to the gear you posted (SDP-SI #S10Z10M040T0505) - but it wasn’t very cheap ($31.00 USD for a qty 1); there are likely lower cost options if you look, though. The key words for such suppliers is “power transmission”.

With some small plastic turnings around the shaft hole, looks like the gear hole may have been drilled out a bit and then the gear tightly threaded on the shaft.

Are you sure you cannot use for example epoxy to glue the gears? Couldn't I buy these gears, drill the bore a bit wider and glue it on?

You see, I want to keep things as simple as possible. If I search for "power transmission" and "gears for electric motors", only complicated stuff comes up, and i don't understand a thing. Thats why I like this site. It says wich gears go together and what linear bearing to use for specific gears. Is there a different (but simple) site which has gears specifically for motors? What gears have you bought for your motors?

EDIT: I just found this gear. Its made out of metal and comes (as an option) with a 5mm bore. Under "custom machining" below the product I found this:

"We currently only offer one method of shaft fixing which is by way of tapped hole(s) for grub screw(s)."

My questions: 1)What is a tapped hole?
2) What is a grub screw?
3) I have a feeling, this sentence may be of importance... But what is the english translation of it?

bestanamnetnogonsin:
Are you sure you cannot use for example epoxy to glue the gears? Couldn't I buy these gears, drill the bore a bit wider and glue it on?

You certainly could try to do that (after re-drilling the hole of course); the problem doing this is two-fold:

  1. This would be a rather permanent solution if it works - should the motor burn out, or the gear break for some reason, it may be difficult to easily fix. That's a trade-off decision you'd have to make. If I was going to do this, to make it as strong as possible - i'd knurl the shaft of the motor a bit, re-bore the hole slightly undersized, then use a cyanoacrylate-base adhesive to fix the gear to the shaft (simply because it's more watery than most epoxies, so it will wick in between the voids of the shaft and hub).

  2. It would also depend on the type of plastic the gear is made of; the metal of the shaft won't be much of a problem (provided the surface is prepared properly to receive the glue), but some plastics can be very difficult to glue (mainly polyethylenes and some nylons) with epoxy or otherwise - sometimes you need special glues that aren't easily available to us "regular joes".

bestanamnetnogonsin:
You see, I want to keep things as simple as possible. If I search for "power transmission" and "gears for electric motors", only complicated stuff comes up, and i don't understand a thing.

I agree that it can be complicated to understand at first, but with a little reading and research, it becomes easier. It's just another bit of engineering knowledge. If your goal is to build a machine which will work reliably over the long term, as well as being able to purchase replacement parts easily if needed in the future, then using commercial/industrial quality components is the better way to go - if the cost isn't too high (and yes, such gears can give you a heart attack when you price them at times).

bestanamnetnogonsin:
Thats why I like this site. It says wich gears go together and what linear bearing to use for specific gears. Is there a different (but simple) site which has gears specifically for motors? What gears have you bought for your motors?

Most places that sell "only gears" typically require you to purchase large quantities (they also sometimes do custom gears - so you /know/ that your gears will mate, and they'll be to your needed specifications); which isn't something you would want or need for a "one off" hobby project (besides, it would be way too expensive).

Do you -have- to use gears? That chess-playing robot system looks real similar in operation to an X/Y gantry system some 3D printers use. Those typically use timing/toothed belts and pulleys, and such components are easily and cheaply available all over online (given the tons of people making and using 3D printers).

Ok thanks :slight_smile: . Have a look at the edit at the top, I hadn't seen your post while writing it

EDIT: Another question. Im having trouble finding the actual shaft diametre on the datasheet (its below the description). Can somebody tell me what the diameter of the shaft the motor has (so I know the right bore width).

Here the picture

Bildschirmfoto 2015-01-28 um 15.33.42.png

Look under technical details, its 5 mm

You need to under bore it i would suggest starting with 4.2 mm

As iv already said glue does not work well with these plastics.

Heat from a soldering iron might be better.
At least you could engage with the flat to reduce the possibility of twisting off

A grub screw is simplt a screw without a head, ofte requiring a hex wrench.

The rest you should really be able to find for yourself.

Well as I said im thinking of using this gear instead. Under "custom machining" below the product I found this:

"We currently only offer one method of shaft fixing which is by way of tapped hole(s) for grub screw(s)."

My questions: 1)What is a tapped hole?
2) What is a grub screw?

NEMA17 steppers are all 5mm in my experience.

NEMA23 steppers can be 8mm (or possibly 1/4") - second shafts are often 1/4" for
encoders.

Note that motors come in variants and shaft diam/length/style is one of things that varies, so
look up the entire part number…

Ok but what I need help with most of all right now is understanding this text I found in the description (of this gear):

"Shaft Fixing
We currently only offer one method of shaft fixing which is by way of tapped hole(s) for grub screw(s). For high torque applications and improved security of fixing, two tapped holes are recommended but for simple applications such as fixing onto a 'D' shaft (like that found on many motors) a single grub screw fixing should be adequate."

What i do not understand:

  1. What is a "tapped" hole?
  2. What is a "grub screw"?

What i do not understand:

  1. What is a "tapped" hole?
  2. What is a "grub screw"?
  1. A hole drilled in the gear collar that is at 90 deg to the motor shaft. It is threaded to take a screw which screws in against the motor shaft.

  2. A screw that goes in the above hole. Might be referred to as a set screw.

Ok. so I guess I'll buy one of those with a 5mm bore.

A "tapped" hole, is a hole with a screw thread made in it, so you can screw some kind of screw or bolt into it.

There are two ways of making a screw thread inside a hole. One way, is to make the screw thread with a lathe. The other way, is to screw a device, called a tap, into the plain hole, which is made of harder metal than the metal of the object which has the hole in it.

Timing belt pulleys are often supplied (in metal) with grubscrew supplied and hole drilled for a specific purpose.

As already said they can be had as spares for the like of makerbots a reasonable prices.
As makerbots use stepper motors they come predrilled for 5mm stepper motors.

Industrial suppliers will charge much more but they are out there.

Looking at that chess machine, it works was probably cheap but a bit kludgy maybe , those gears look like working "educational toys".

Timing belts can provide a much better engineered solution at a lower cost than gears.

Main reason is gears work best in mass production, obtaining the correct gears for a one off is very expensive.