Which router is best for the spindle?

[Jeff]

I've got several routers listed as possible options for the Lobo CNC spindle.  All have a nominal 2.5" (actually closer to 2.530") diameter body.  While they range in power from about 1/4HP to 1 1/4HP, the more important considerations are the type of collet and speed control.

Collets: All the routers have 1/4" diameter collet for common router bits, but the style is different, which can make a big difference in the runout.  The cheaper router spindles have a short initial taper followed by a 0.250" straight bore.  A relatively tiny tapered split ring clamps the shank in place.  This type of collet system can have a pretty large runout of a few thousadths.  The better type of collet found on the Makita RT0700 is longer and has 4 slits.  This clamps the shank more uniformly, and the runout should be less than 0.001".  The Makita RT0700 also includes a 3/8" collet.  This collet, however, is of the simple split ring variety and has pretty sloppy runout.  For the many applications, a few thousandths of runout is not a big deal, but if you are trying to do fret slots with 0.023" dia bit, it's far from ideal.

You'll also want to get some sort of 1/4" to 1/8" shank collet adapter.  Most of these commonly available adapters have a single slit which sometimes doesn't accurately center the bit.  stewmac.com, however, has one with 4 slits which should give less runout.

Speed Control:  The thing to be aware of here is that there is a big difference between built-in electronic speed control and those external router speed control boxes.  The build-in electronic speed control (like on the Makita) constantly adjusts the amount of power delivered to the motor as your cutting load varies so that the spindle always operates at a constant speed.  You can operate down to 10,000 RPM with full torque.

The simple speed control boxes merely set the router voltage, and as the motor has to work harder, the spindle slows down.  The result is that if you try lowering the speed to, say, 10,000 RPM, the minute you encounter any cutting load at all, the motor may stop altogether!

All that said, one of the less expensive routers from Grizzly or Harbor Freight can work fine if you are doing light cutting and aren't demanding super high precision.  These routers, despite their low price, seem to get pretty good reviews.  However, the Makita will give you far more flexibility if you can spring for the extra $$$.

[galin...@gmail.com]

HELLO

I AM A MACHINIST AND I WANT TO DO SOME SMALL PIECES IN SMALL SERIES FROM HOME.
THE MACHINE IS IT ABLE TO TAKE METAL.
CAN I ENLARGE OR STRENGTHEN THE MILL.
NEMA 17 MOTOR IS THIS A BIT SMALL ,WHAT ABOUT TORQUE.
I HAVE ALREADY DONE THE PURCHASE OF LINEAR BEARING AND WORM RECTIFIED SCREW AND I WOULD LIKE TO KNOW IF I CAN include them in THE MILL MODEL BEEN PROPOSED .
ANY OTHER TYPE OF SPINDLE I COULD HAVE INSTALLED FOR , FOR HAVE THE POSSIBILITE OF CUTTER DIAMETER LIKE .750 & 1.00 INCH

THANK YOU FOR YOUR HELP BECAUSE I'M IN A REAL KNOW WHERE ,I'M IN DILEME TO REALLY MAKE A REAL SMALL MACHINE BUT IN THE SAME TIME ONE THAT DO WHAT YOU EXPECT IT TO DO, I WANT TO HAVE THE CHANCE TO HAVE A DEGREE OF ACCURACY + / - 0002.''

the text is google translator because I am French Canadian.
hoping that the answer to my questions will

[Jeff]

Alain, The Lobo CNC mill is probably too small for what you are wanting to do.  You would be better off starting with a mill/drill machine and retrofitting it with CNC controls.

-Jeff

[Alain Roy]

hi Jeff

1  I want to understand some thing, if i want to feed at 200 in/mi witch size of motor should use ?

2  can you(seller or brand name item) transform any quid of stepper motor in to servo motor ?

3  So if I use servo I only need your card to use ,a power supply and the pc will do the rest.(no need as the stepper motor to use the boxe i don't remember how it call , for making it work.

4  the system that i want to build is practically the same a (simpsons36  (https://www.youtube.com/watch?v=QsuJgCCPSl0)

   but smaller.

Can you answers each line that will help me to understand the concept, and yes if you have something to read (simple info not to technical ) i will be very please.

thank you again Jeff for your help.

Alain Roy

[Jeff]

Alain, For a benchtop milling machine, you'd probably want to use something like 250 oz-in stepper motors.  Picking the exact motor, though, would depend on the pitch of your drive screws and how you connect the motor.  1000 RPM is about the fastest speed you can easily get stepper motors to go. Depending on your stepper driver, you may need bigger motors to get up to 200"/min.

It is possible to use almost any stepper motor as a servo motor, but there aren't many controller boards available that will do this.  Unfortunately, the board I designed is for much smaller motors than what you would need.

-Jeff

[ted.m...@gmail.com]

Nova Labs is using the Makita spindle in its LoboCNC. The router comes with a 1/4" collet - we made step down adapters for other tool shank sizes.

The measured no-load spindle speeds (in RPM) for the Makita router are...
1: 9470
2: 12280
3: 16870
4: 22175
5: 27035
6: 29800

The Makita 1 1/4 HP router is highly recommended! We got ours at our closest HomeDepot.- ted