Mini Lathe Motor Upgrade (three Phase, Brushless DC)
My lathe needs a new control circuit for 90 and a new motor for 86. Both +P&P.
Now my first thought is, \"Are you swearing? !
\"I can build one for one of those quarters . . . . . . Plus a solid weekend.
You can get better technology at a cheaper price.
The brushed motor is out of date.
There is no future!
I have been wanting to upgrade the motor and control to a three phase DC brush for some time.
It seems to be a perfect excuse.
I did this research and found that the original motor speed was 2500 rpm and the rated speed was 40vdc 2A.
The upgraded motor of the C3 small car bed is 350 w and the rotation speed is 6000 rpm.
I found a 149kv motor.
Kv means rpm/volt.
This will be around 3576 rpm at 24 volts, which will be ideal.
It also has a shaft of 8mm, so it will be a direct exchange for the original motor.
Find a 25 a 24 v power supply that pumps up to 600 W.
A 200A ESC speed controller was found for £ 30.
The power supply can only provide 25A and the motor can only pull 10A, so 200 is very excessive.
It\'s exactly what we want because it increases the robustness of the system.
The original motor screwed the flat head screw into the motor housing as a stand.
I have to make a motor bracket to hold the new motor so the shaft is the same as the original one.
I started with the mounting plate.
Use one that comes with the motor as a template to roughly measure the diameter of the motor and use the radius to define the depth.
I found a steel plate that fits exactly the lathe interface pate in size, fixed it in place and marked where the bolts need to be drilled.
I welded the two together and tested the installation. So far so good.
I know these motors produce a lot of torque, so I \'d love to step up the installation and make sure it\'s solid and durable.
I cut a few corner support boards and welded them up.
Your Eagle Eye may notice that the steel is different from other steel.
When I was ready to weld, I noticed that they were not magnetic. Fear not!
It turns out that there is no problem with stainless steel welding mild!
After that, I nailed it on the fixing nut and cleaned the weld so it could sit flat in position.
The test fits well and everything looks good.
I need some spade terminals.
I made some styling with some micro-porous copper tubes.
They work very well!
In order to control the motor speed, the speed controller requires a sine wave input modulated by the pulse width.
Fortunately, the hobby King did a servo tester for about 3 pounds.
50, this will produce one for us from the on-board potentiometer.
The servo Tester needs 5 v power supply to run.
I got 5 V, 5A regulators on ebay for 9.
Run like it should, good!
Some integration time.
I removed the old circuit and made room for the new electronics.
I connect the power supply to the emergency stop switch of the control box and then to the AC power supply
I took out the DC converter behind the lathe.
I remove the pot from the servo tester and the wire from the pot from the original lathe.
Since this is a pot, it doesn\'t matter what the resistance value is, I check with multiple resistors if they are reasonable
Just in case.
I want the forward and reverse to work, so I wire in the original switch with two phases, and if you swap the wires between the two phases of the brushless DC, it rotates in the opposite direction.
To do this, I bought some beautiful silicone wires for £ 7. 50.
The position of the speed controller, voltage regulator, and servo tester means the cable is a bit tight, so I bought some extension cables for the 2-pound test drive and everything works fine.
Now my main goal here is robustness and longevity, so I want to focus on the system and make sure I\'m not going to be too nervous.
The main concern is to pull too much amps from the power supply, the speed controller is too hot, and the motor is too hot.
Focus on the motor and ESC (
Electronic speed controller
Temperature I purchased two temperature sensors for 2 per unit: to focus on power consumption and amplifier, I bought an meter with 10 wires ready for the first Test.
I have an aluminum part on the lathe of the electric bike, so I made some cuts on it.
Don\'t worry, it\'s much smoother than the original system.
Now I need to put these wires together and install the electronics.
The easiest place is on the back of the chip protector.
I lined up the power supply, went through the mounting holes and drilled a bolt on each hole.
I do the same with the voltage regulator.
ESC doesn\'t have any mounting holes and it\'s late so I\'ll tape it right now.
I will make a mount for it next time.
When the tape fails.
I got my bolts here: here are the nuts: I need to check if the motor speed is normal and I bought a speed meter while I was there.
It only cost £ 10 and I\'m sure it will come in handy.
The motor speed is too high.
It\'s done, I \'ve done that part on the lathe, and there\'s another job.
So far, the system I have put in it has been well maintained.
There are no signs of any problems.
The only problem is making sure my motor mounting bolts are tight enough.
They are not nyloc nuts, so they have a tendency to loosen vibration.
I might consider a more robust installation solution on another occasion, but for now, I have an electric bike to complete!
Much better than the original.
When you load the stock, you can hear the sound of the stock motor slowing down.
The new brushless motor is more stable.
Lower end torque is also better.
I have not managed to delay it.
This is something that happens frequently on stock cars.
Both the motor and ESC have temperature sensors.
Also did not get more than warm.
There is no duty cycle problem so far.
The motor support acts as a radiator.
I can weld on some fins and fans if I feel in trouble.
This outrunner specifically has a impeller built into the box to move some air through it while still, although I\'m not sure if this is necessary.
I deliberately overestimate all components.
The upgraded motor for the lathe is 350 w.
The motor I use is able to output up to 2250 w.
5 times the power.
However, the power supply will only go off by 600 w.
But this is still twice as much as the original machine upgraded the motor.
The 350 w motor runs at 2500 (rpm)=261. 8(rad/s). 350(w)/261. 8(rad/s)= 1. 34(Nm).
The new motor operates at 3576 rpm @ 24 v quoted at 149Kv. 600(w)/374. 5(rad/s)= 1. 6Nm.
20% more torque.
I raised the original motor by 10A from a 240 watt basis.
The new motor at 24 v, 10A = 240 w, so this will be the equivalent power.
The rated power of these parts is like this, and I will damage something if I get too much power on.
I am tired of replacing the broken belt and pulley with the cut key tooth.
This often happens in old settings.
I have changed it from that strange, unique, Chinese pitch belt to a standard pitch belt with aluminum pulleys.
This way I can change the belt cheaper and the pulley will not reveal the key teeth. So far so good.
I might reset it.
Can fuse, limit current and protect elements.