- #1
In summary, the problem was that the magnets were not strong enough to move the rotor. The solution was to replace the magnets with rare earth magnets.
- #2
Borek
Mentor
- 29,045
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Please elaborate on the construction, please elaborate on what is happening when you try to switch it on, you can't expect people to know everything just by looking at one not-too-clear picture.
- #3
Adem
- 9
- 0
Hey, could the magnet strength be a problem? I’m using ferrite magnets which are pretty weak
Could rare Earth magnets do the trick?
The connection seems to be fine with the coil / brushes / commutator and battery.
Could rare Earth magnets do the trick?
The connection seems to be fine with the coil / brushes / commutator and battery.
- #4
Borek
Mentor
- 29,045
- 4,418
Everything can be a problem. If you will not give more details you will be just wasting time.
- #5
jrmichler
Mentor
- 2,318
- 3,172
You need to observe what is happening, then describe it.
1) Does the rotor spin freely when you flip it with your finger? It needs to.
2) Does the rotor pull noticeably when energized? It needs to. The rotor poles need to pass close to the field pieces.
3) Your design does not need permanent magnets to work. A couple chunks of steel will work as well or better.
4) You have a high current, low voltage armature connected to a (relatively) high voltage low current power supply. See my point #2.
I built these type motors a long time ago. They spin really good when you adjust them properly and put enough current through them.
1) Does the rotor spin freely when you flip it with your finger? It needs to.
2) Does the rotor pull noticeably when energized? It needs to. The rotor poles need to pass close to the field pieces.
3) Your design does not need permanent magnets to work. A couple chunks of steel will work as well or better.
4) You have a high current, low voltage armature connected to a (relatively) high voltage low current power supply. See my point #2.
I built these type motors a long time ago. They spin really good when you adjust them properly and put enough current through them.
- #6
NascentOxygen
Staff Emeritus
Science Advisor
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Hi Adem.Adem said:
Did you scrape or lightly sandpaper the enamel off the rotor's wire where the paperclip brushes need to make good contact? The varnish on the copper wire is an insulator.
The magnets need to be moved in closer, but I'm sure you have tried that
- #7
Adem
- 9
- 0
NascentOxygen said:Hi Adem.
Did you scrape or lightly sandpaper the enamel off the rotor's wire where the paperclip brushes need to make good contact? The varnish on the copper wire is an insulator.
The magnets need to be moved in closer, but I'm sure you have tried that
Yeah I’ve done both of them. I’ll change them with better magnets
- #8
Adem
- 9
- 0
Also my motor is pretty much this motor just with a different battery and different magnets
- #9
NascentOxygen
Staff Emeritus
Science Advisor
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Is each tower of magnets holding itself together without glue? I think that means you have N-S poles together, so external fields are cancelling. Furthermore, you might have them positioned side on to the rotor, when they need to be end on. Check that. You might also have accidently reversed one of the blocks of magnets to how it needs to be. Best start with a single magnet on each side, get that working first.
You'll need the magnets stacked the way they don't want to stack, and then force them to stay together using sticky tape.
You'll need the magnets stacked the way they don't want to stack, and then force them to stay together using sticky tape.
- #10
Adem
- 9
- 0
Found out the problem, magnets were too weak.
Replaced them with rare Earth magnets and it did the trick.
Replaced them with rare Earth magnets and it did the trick.
- #11
sophiecentaur
Science Advisor
Gold Member
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Put them closer together - right by the armature - and the motor will be much more powerful. That basic motor should work ok with simple magnets that were used in school labs.Adem said:
You will notice that all 'real' motors have an armature with iron in them. That concentrates the field marvellously and will give even more oomph.
FAQ: Need help with a homemade DC motor
How can I make a homemade DC motor?
Making a homemade DC motor requires some basic materials such as a battery, a magnet, copper wire, and a base to hold the motor. You will also need tools such as pliers, a screwdriver, and wire cutters. There are several tutorials and step-by-step guides available online that can help you build a simple DC motor at home.
What is the principle behind a DC motor?
A DC motor works on the principle of electromagnetism. The interaction between a permanent magnet and an electromagnet creates a force that rotates the motor. When an electric current flows through the coil of wire, it creates a magnetic field that interacts with the permanent magnet, causing the motor to turn.
How does a homemade DC motor differ from a commercial one?
A homemade DC motor is usually simpler and smaller in size compared to a commercial one, which is designed for more complex and heavy-duty applications. Homemade DC motors are also made with basic materials and tools, while commercial ones are made with precision parts and advanced technology.
What are some common problems when building a homemade DC motor?
Some common problems when building a homemade DC motor include difficulty in achieving proper alignment of the magnet and electromagnet, insufficient power supply, and difficulty in controlling the speed of the motor. It is essential to follow the instructions carefully and troubleshoot any issues that may arise during the building process.
What can I use a homemade DC motor for?
A homemade DC motor can be used for various purposes such as powering small toys, educational projects, or as a demonstration of the principles of electromagnetism. It can also be used in DIY projects such as building a small fan or a simple robot. The possibilities are endless, and the motor can be used in any creative way you can think of!