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Simple DC Motor setup - NEWBIE HELP!!!

sbones

Oct 28, 2018
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Hello Engineers!

I am trying to build a grain tumblr for my home brewing system. I live in a climate where germinating barely is really difficult so after soaking the seeds, the must be put in a state of constant rotation.

I put together a device, mostly made of wood but using an empty 5gal water jug (like the kind for water coolers) that sets on a set of old luggage casters. It rotates pretty easy and even with he weight of the seeds added (3-4kgs) is turns well.

(Now for the electrical help part)

I need to get a motor to turn this thing. It will turn this jug, non stop for 2-4 days. I need it to have enough torque to turn the jug but enough power to turn nonstop for days.

Screen%20Shot%202018-10-28%20at%205.47.28%20PM.png


(if image doesn't work)
Here

The the motor part I need the motor (of course) but what size and voltage? I picked 12v because it looked bug enough to do the job. I also added a speed control. But lastly I need to soder this to a power plug. All the places I look, I can't find the type of plug I need. Keep in mind I am in a country that uses 110 / 220, so what ever plug I use needs to conform to that standard.

Long story short:

1. Do you think a 12v motor fits what I am trying to do. If not, what do I need?
2. What do I need to make a plug for this thing?

Thanks in advance for your help!!!!
 

duke37

Jan 9, 2011
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You will need a gearbox to reduce the motor speed and increase the torque. I would try a 12V DC windscreen wiper motor.
This could be powered with an old style 12V battery charger. This will give the required isolation.The speed could be pre-set electronically or by using one or more series bulbs.

The run time will depend on the power required and the energy available. If you run on the mains then run time will not be a problem.
 

Minder

Apr 24, 2015
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It is generally possible to find out the torque needed to turn the jug using measure length of rod etc axially to the shaft and then use a spring fish weigh scale etc to find the point that the drum begins to turn. In-lb, N.m etc.
I would have used a 24vdc or above motor, but the 12v version may work for you.
You can obtain simple/cheap PWM controllers on ebay if needed.
Is that 'germinating barely' or germinating barley'?;)
M.
 

sbones

Oct 28, 2018
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You will need a gearbox to reduce the motor speed and increase the torque. I would try a 12V DC windscreen wiper motor.
This could be powered with an old style 12V battery charger. This will give the required isolation.The speed could be pre-set electronically or by using one or more series bulbs.

The run time will depend on the power required and the energy available. If you run on the mains then run time will not be a problem.

So did you see the motor I have in the pic? It's a 12v gear box too. Is that not adequate?

I get the charger, great idea, thanks!

What about the speed controller?
 

BobK

Jan 5, 2010
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You need more than just a plug, you need a power supply that reduces line voltage to 12V. And it must be sized fir the max current that the motor draws and then some for a safety nargin.

How do you expect to couple the motor to the jug?

How many RPM does it need to turn at?

Bob
 

sbones

Oct 28, 2018
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You need more than just a plug, you need a power supply that reduces line voltage to 12V. And it must be sized fir the max current that the motor draws and then some for a safety nargin.

How do you expect to couple the motor to the jug?

How many RPM does it need to turn at?

Bob
Now that I've read these replies, I'm thinking I should go 24v.

Yes, power supply is what I searched for first. I guess what I'm asking for is a specific device I can search for on Amazon. Once I make a purchase, I will not be able to return it.

The jug has a axle made out of PVC through the center pivot. I will fashion one to fit the motor to it.

I'm not sure the about the RPMs, maybe one revolution every 5 sec.

Thank you!
 

Minder

Apr 24, 2015
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The G.B. in your link is 20rpm so a reduction to 12rpm is not far off, I see the link does include the PWM controller.
Saudi Arabia and you find germination difficult, temp wise? o_O
M.
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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Let's keep this in topic, I don't want anyone losing their heads.

Probably the easiest way to couple the motor to the axle is with a belt and appropriate size pulleys. Depending on the weight of the motor and the amount of torque required, it's weight alone may be sufficient to keep tension on the belt.
 

Bluejets

Oct 5, 2014
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Probably the easiest way to couple the motor to the axle is with a belt and appropriate size pulleys. Depending on the weight of the motor and the amount of torque required, it's weight alone may be sufficient to keep tension on the belt.

Bit like a tumble dryer.
In fact, why not use one of them...everything already set up.
Some have stainless steel tumblers.
Would handle 4kg no worries.

As far as duty cycle goes, no worries.
I've seen some that go for days non-stop.:eek:
 

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sbones

Oct 28, 2018
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Bit like a tumble dryer.
In fact, why not use one of them...everything already set up.
Some have stainless steel tumblers.
Would handle 4kg no worries.

I actually considered that. I was going to use a mesh baggy to keep the grain together and find a way to disconnect the heat cycle. The problem is no cycle goes beyond 2 hours, I need the grain to tumble non stop for days. that other problem is the mess. So, nope. But thanks!
 

Bluejets

Oct 5, 2014
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I actually considered that. I was going to use a mesh baggy to keep the grain together and find a way to disconnect the heat cycle. The problem is no cycle goes beyond 2 hours, I need the grain to tumble non stop for days. that other problem is the mess. So, nope. But thanks!

Why would that be a problem...simply bridge out the timer and add a two bob external one for $10, set for days.

Cement mixer then...:):)

Just no pleasing some....
 

sbones

Oct 28, 2018
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Hello, So here is my final configuration. Please let me know if anything looks out of place.

Set up.

Thanks!
 

duke37

Jan 9, 2011
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You probably do not need to rotate continuously, one minute in each hour should be enough. The germinating floors in the UK used to be stirred with a man with a shovel.

I do not need any nazal spray.
 

Minder

Apr 24, 2015
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Does 5a supply look OK for that motor? What are the spec's on it?
M.
 

Minder

Apr 24, 2015
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It is a 12vdc motor, but you need to know the current rating.
For this application a simple linear supply is best, transformer and a bridge rectifier.
No real need for regulation.
SMPS supplies are not the optimum P.S. for a motor application.
M.
 
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