variable speed motor

[Astroguy]

Is it possible to put a variable speed motor dc motor on a taig mill? If so has anyone here done it?

[project5k]

well i dont own one, and i've actually never even seen one in person, but doesent it already use a dc motor? something tells me its like my mini lathe, you plug it into 110ac, but theres a circuit board that converts this to dc and controls the speed... i could be way off tho....

[Stepper Monkey]

Yes, its quite easy. I have seen a number of people put Sherline motors and speed controls, and even whole Sherline heads on Taigs. I don't like this though as A) I like the Taig ER spindle better, B) I don't like the Sherlines power or difficult belt adjustments with the kit required for any decent speed range, C) It can't be controlled from Mach without external hardware and expensive mods, and D) its pricey considering what you get.

There are a number of good options for surplus brushed motors out there from 24v to 90v depending on your needs and budget. I have used a 1/3 HP DC brushless motor and PWM controller with the stock Taig pulleys and spindle myself though that can get expensive.
Another bonus is that they are easy to control from Mach, both for speed and to shut off the spindle when the toolpath is done as I leave my machine to run itself a lot when I am not there. E-stop and charge pump shutoff of the spindle are also other big advantages.

[Astroguy]

[

[Astroguy]

Originally Posted by Stepper Monkey Yes, its quite easy. I have seen a number of people put Sherline motors and speed controls, and even whole Sherline heads on Taigs. I don't like this though as A) I like the Taig ER spindle better, B) I don't like the Sherlines power or difficult belt adjustments with the kit required for any decent speed range, C) It can't be controlled from Mach without external hardware and expensive mods, and D) its pricey considering what you get. There are a number of good options for surplus brushed motors out there from 24v to 90v depending on your needs and budget. I have used a 1/3 HP DC brushless motor and PWM controller with the stock Taig pulleys and spindle myself though that can get expensive. Another bonus is that they are easy to control from Mach, both for speed and to shut off the spindle when the toolpath is done as I leave my machine to run itself a lot when I am not there. E-stop and charge pump shutoff of the spindle are also other big advantages.

How about a router speed control box on the stock motor?

[Stepper Monkey]

Originally Posted by Astroguy How about a router speed control box on the stock motor?

Works I guess. It's cheap but you'll lose all your torque slowing down an AC motor. Probably lose too much torque depending on what you are cutting, as the materials and mills you need the slow speed for are the ones you need some force behind to cut through.
That is why the variable speeds are almost always DC - they keep full torque even down to 0 RPM.

[Astroguy]

Originally Posted by Stepper Monkey Works I guess. It's cheap but you'll lose all your torque slowing down an AC motor. Probably lose too much torque depending on what you are cutting, as the materials and mills you need the slow speed for are the ones you need some force behind to cut through. That is why the variable speeds are almost always DC - they keep full torque even down to 0 RPM.

Makes sense. Thanks

[salzburg]

I believe the router speed control is for universal motors only.

[phomann]

Hi,

Yes it is possible, a lot do it. I have a 400Wdc motor, controlled by a KB Electronics KBIC controller (Same as in the Sherline). Have a look at;

http://www.homanndesigns.com/DigiSpeedProject.html

A lot use this motor;
http://www.surpluscenter.com/item.as...tname=electric

with the Minark DC controller from Surplus centre
http://www.surpluscenter.com/item.as...tname=electric


And if you want to control the motor speed via CNC , they work well with the DigiSpeeds I sell. :-)
http://homanndesigns.com/store/index...&products_id=2

Let me know if you have any other questions.


Cheers,

Peter.

Originally Posted by Astroguy Is it possible to put a variable speed motor dc motor on a taig mill? If so has anyone here done it?

[in2steam]

Originally Posted by Astroguy How about a router speed control box on the stock motor?

The stock motor may be one of two depending upon when the machine was built, both are PSC motors which although can be slowed in this method would in the end cause damage to the motor if the voltage reduction was to great. This is the method that variable speed grinders work, but they also have some desgin factors that make it work this way so they are more tolerable of that use. The proper way to slow down a PSC motor would be with a variable frequency drive, or VFD, or inverter, or drive, etc. These are not realy a practical method as the torque of a induction motor is not linear and the slower you get the torque drop is consdierable. It would be easier to change to a DC motor and get a DC controler, a PMDC motor will have a nearly flat line curve from 0 to rated range and even some above.

The other option is to go with a small 3 phase motor, and VFD, these can be gotten to run off household 110VAC single phase in the under 1 HP range. The only real advantage with that is there is a little less maintenace, but the amount of use most of these mills see you will never worry about brushes. Again these would suffer from torque loss at low speeds and heating problems also.

Also its been my experince with taig that if anything they don't spin fast enough, so I would go with DC, many people have had luck with the tread mill motors on the lathes, I don't know if that would work on a mill though as they are fairly heavy.

chris

[Astroguy]

Originally Posted by in2steam Also its been my experience with taiga that if anything they don't spin fast enough, so I would go with DC, many people have had luck with the tread mill motors on the lathes, I don't know if that would work on a mill though as they are fairly heavy. Chris

The Taig I have is rated at 10,000rpm at the high end, is this not fast enough?

[cartertool]

10k rpm is fast enough for most work, unless you are exclusively using extremely small cutters.

The stock motors can not be speed controlled.

Some users have retrofitted Sherline and other DC motors quite successfully.

I use the stock motor on both my CNC mills, the only real reason to do so is if you need slow speeds, or you just want to...