Dumb artist needing your guidance on making a slow rotating device!

[tyzoone]

Hey all,

As the title states I am trying to fabricate an extremely slow moving device for a school project I am doing. Also I feel it's important to state that I'm VERY new to this mechanical world you all thrive in.... I just learned how to change my own cars oil the other day and I'm over 30 years old HA!

To explain further, I need to be able to rotate a very light weight plastic lid on top of the motor one full rotation over the coarse of 4 to 5 days respectively. I've been looking into stepper motors but I get lost as they seem a bit more complicated than I can handle... Are there other options or is there even anything in this world that rotates that slowly for cheap (again I'm a student)?

Your help is very much appreciated!

 

[MikeMl]

**broken link removed** has a 120Vac powered gear motor whose wheel (shaft) rotates once per 24 hours. Maybe a 1:5 belt-drive or gear reduction behind that?

 

[tyzoone]

**broken link removed** has a 120Vac powered gear motor whose wheel (shaft) rotates once per 24 hours. Maybe a 1:5 belt-drive or gear reduction behind that?

I like it! And I've been looking into these actually but have no idea how to add a gear reducer to it... Would this be complicated? Does that get installed between the power and the actual timer itself?

 

[Les Jones]

A gear or belt reduction is a mechanical device - not electrical. You would need to fix a gear wheel to the knob on the timer. (Mounted concentrically ) and have that meshed with another gear with five times as many teeth connected to your rotating disk. You could also use a belt drive or friction drive with the pulley diameters in the ratio of 1 : 5 or a rubber roller driving a disk with a diameter of five times the diameter of the roller.

 

[KeepItSimpleStupid]

Here's https://www.google.com/url?sa=t&rct...CzKBdI7mFJ48kL_FQ&sig2=6l4LBiqdRv95wm-rGUYpGw a good source of mechanical parts.

 

[tyzoone]

I think my brain is starting to grasp this. So I need to attach a gear with an axle (translate into the proper terms within your smart brains lol) attached directly to the center of the rotating timer; and then I need to add a gear with 5 times as many teeth to that gear which will be attached to my actual product I need to rotate? So I need the two gears and axles correct?

 

[Diver300]

You could run one of those timers from another timer. If you find a timer that turns on for 1 minute and off for 4 minutes, it would make a 24 hour time take 5 days to do one turn.

 

[tyzoone]

You could run one of those timers from another timer. If you find a timer that turns on for 1 minute and off for 4 minutes, it would make a 24 hour time take 5 days to do one turn.

Ha inceptitimer! I like that as well! I'll have to see if they have timers that you can control to the minute. The one I currently have is in 30 minute increments only.

 

[KeepItSimpleStupid]

Are you interested in a "weekly or 7-day" timer by chance?

 

[tyzoone]

Are you interested in a "weekly or 7-day" timer by chance?

I'm open to a 7 day timer yes.

 

[tyzoone]

Keepitsimple you have lived up to your name! I have found several weekly timers on amazon for dirt cheap that have a rotating dial! This solves my problem!

 

[dr pepper]

Do a google for MFA (model flight accesories) geared motors, they arenot that expensive and can be got with 1000's:1 gear ratio's, if your rotating disc has a drive belt around the outside of it to the motor shaft that would also give you a good reduction.

If you can sope with movement evey so often then you could use a couple of 555 timers to pulse the motor every so often.

If you need good rotational speed accuracy then google for sidereal drives, they are used on telescopes to track stars.

 

[killivolt]

An Ice Maker from a fridge is free; you can find junk ones. Go to a used appliance store; the motor has mount holes then mount it to a plate with the shaft going through and then find the correct gear ratio.

kv

 

[Tony Stewart]

First define the following, I call a design spec....

1) rotation resolution or smallest increment required in degrees or percentage of 1 rev.
2) size and weight limitations required ( support what weight and size of object)
3) Any other limitations ( power, portability, etc)

 

[tyzoone]

Do a google for MFA (model flight accesories) geared motors, they arenot that expensive and can be got with 1000's:1 gear ratio's, if your rotating disc has a drive belt around the outside of it to the motor shaft that would also give you a good reduction.

If you can sope with movement evey so often then you could use a couple of 555 timers to pulse the motor every so often.

If you need good rotational speed accuracy then google for sidereal drives, they are used on telescopes to track stars.

So these 555 timers actually send a pulse of power that rotates and then stops the rotation every so often? The device I'm making doesn't need a constant movement so this could very well work as well.

Thanks for your help guys! I've got amazon sending me about 50 packages to test with

 

[Tony Stewart]

IF you dont start with a spec, we will have no way of advising if you are going to achieve the desired results.

 

[KeepItSimpleStupid]

Just a note. Unloaded motors coast. Synchronous AC motors are pretty good at stopping quickly. Dynamic braking can be used for DC motors. If your using a relay, have the relay short the motor when the relay is turned off.

 

[Tony Stewart]

unless we know the resolution of your rotation every minute or hour as you need, things like bearing stiction, gear backlash will cause big problems.

One of the biggest problems with Questions is the lack of Purpose, from which we make "design Spec". THen multiple solutions are easy to avoid or include.

From what I read of your 1st question... "very light weight plastic lid on top of the motor one full rotation over the coarse of 4 to 5 days respectively"

So you need a turntable that rotates 1/5 Rev per day.
or 72 degrees per day or 3 degrees per hour.

Is 3deg sufficient resolution or do you need 1 degree?

**broken link removed**
If 1 hours is sufficient resolution then a simple 1 pulse per ? hour can increment a stepper motor a microstep. but more details are need as requested.

With more expertise... **broken link removed**

 

[dr pepper]

Yes a pair of 555's can be confugured to switch on the motor evry so often, you can make the time between switch on, and the on time adjustable.

You can get clock movements with high torque output, if you removed the clock movements 32khz crystal you could run the clock from a seperate frequency source that would give the correct rotational speed.
If you google I remember there was an article that showed you how to mod a standard clock movement so that the hour hand became a tide indicator, I think it might have been Karen Orton.

 

[tyzoone]

Ok all, the link above shows visually what I'm trying to build. I built this concept in maya and you can disregard the contraption below the dispenser with the mesh that the crickets climb up on. This is sitting atop a chameleon cage (or really any reptile that eats live insects) and releases live feeders in to the cage for the chameleon to have access to. Hopefully this adds some context for you guys.

Tell me if this will or won't work. I have purchased this 7 day timer (thanks user "keepitSimpleStupid"):

https://www.amazon.com/Woods-50002-...TF8&qid=1435085383&sr=8-3&keywords=7day+timer

I'm going to attach this compartment....

https://www.amazon.com/gp/product/B007BKSY2S?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00

....to the flipped upside down timer and then cut holes in the bottom of each compartment pushed directly up against a base plate that keeps the feeders in. As it rotates it rotates/slides the compartments and feeders towards the hole in the base plate to release the feeders into the funnel and down into the cage.

Using other components already manufactured was the only thing that made sense to my brain but please chime in if you have any simpler solutions or if you see any major flaws etc. I'd like to hone in this idea and send it off to manufacturing eventually and perhaps run a business of it in the near future as well.