Author Topic: Adding a high-speed spindle to my CNC mill  (Read 2043 times)

Offline kvom

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Adding a high-speed spindle to my CNC mill
« on: July 24, 2017, 11:05:39 PM »
Although my Novakon NM200 is a quite capable mill, it's max spindle speed is only 4000 RPM.  For small endmills and engraving, the lack of sufficient RPMs means slower feed rates and less than optimum chipload.

I recently purchased a Makra electric spindle after doing some investigation/design on how to mount it to the head of the mill.  I determined that the ring at the bottom of the head is an oil/chip seal for the spindle cartridge, and that it could be removed without problem.  It's attached to the bottom of the head by 6 screws.  So I wanted to make a bracket that would fit around and under the ring and use the same 6 screws for attachment.

Got to work on this over the past couple of days.

Stock is a piece of 6x12x1/2 CRS I had laying about.  After machining the holes and pocket, the spindle ring was checked for a fit, along with the screw holes.



Finished bracket:



Test mount onto the mill:



With the Makra spindle mounted:



In principle, if I use the NM200 spindle to locate stock zero, then the Makra zero will be at X0 Y-5.  I'll do some tests in the next couple of days to verify.

Online Vixen

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Re: Adding a high-speed spindle to my CNC mill
« Reply #1 on: July 24, 2017, 11:50:09 PM »
Hi Kirk

Can you tell us some more about the Makra electric spindle you selected. I tried a net search without any success.

Thinking of doing something similar with my Austrian Emco F1 mill, so waiting to see how it works out for you.

Mike
It is the journey that matters, not the destination

Offline kvom

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Re: Adding a high-speed spindle to my CNC mill
« Reply #2 on: July 25, 2017, 12:12:36 AM »
I bought it from a member on HMEM.  It's from Germany, but had little success looking up any info myself.  Motor is rated at 500W, 220V.  I bought a 1000W stepup transformer on eBay to run it.

Offline fumopuc

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Re: Adding a high-speed spindle to my CNC mill
« Reply #3 on: July 25, 2017, 04:58:24 AM »
Hi Kirk

Can you tell us some more about the Makra electric spindle you selected. I tried a net search without any success.

Thinking of doing something similar with my Austrian Emco F1 mill, so waiting to see how it works out for you.

Mike


Hi Mike, never heared MAKRA before, but I found this application.
http://www.fwt-gmbh.de/en/Inventory-Equipment/Machines/Edge-deburring-device/Edge-trimming-machines/
Another sources for different spindels https://www.sorotec.de/shop/Spindles/

Kind Regards
Achim

Offline Stuart

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Re: Adding a high-speed spindle to my CNC mill
« Reply #4 on: July 25, 2017, 08:56:50 AM »
You have me puzzled why not just use the new spindle to zero up the job ?

Hang on a wee while just guessed to where you are coming from main spindle offset WCS 54 high speed WCS 55 then the both can be used on the same job with the offsets applied to the gcode

My aim is for a accurate part with a good finish

Offline jadge

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Re: Adding a high-speed spindle to my CNC mill
« Reply #5 on: July 25, 2017, 10:53:57 AM »
I fitted a 24000rpm induction motor spindle, plus VFD, to my Tormach last year. It's transformed the use of small cutters. So far I've made some small bevel gears with a 1mm ball nose cutter, and an experimental heatsink for an inverter using silicon carbide semiconductors which needed 38 slots 1mm wide and 4mm deep. The system seems happy running for hours at 24000rpm with no issues. And it is quiet; important to me as I live in a rural village.

The downside is that the system has no quick change tool system (ER11 collets) so tool tables can't be used, and the spindle offsets vary each time the unit is fitted. However, these issues are over-ridden by being able to run cutters at a sensible speed and feedrate, thus reducing the effect of granularity in the table feed due to the stepper motors.

I tried CNC engraving some years ago. After breaking a lot of cutters I came to the conclusion that I simply wasn't able to run an engraving cutter fast enough.

Andrew

Offline kvom

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Re: Adding a high-speed spindle to my CNC mill
« Reply #6 on: July 25, 2017, 11:47:02 AM »
Makra spindle came with some metric collets, but only one 1/8" collet that's useable with the tooling I have.  I can't mount an edge finder.  So calibration procedure will  be to drill a tiny depression in some scrap with a 1/8" spotting drill.  Then use a center finder in the mill spindle to determine the offset.

I did find some larger imperial collets that fit the Makra.  They are EOC8 and go up to 5/16.  However, I have a set of 1/8" engraving bits.  Plus. all my endmills smaller than 1/8" have a 1/8 shank.

Offline kvom

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Re: Adding a high-speed spindle to my CNC mill
« Reply #7 on: July 25, 2017, 01:34:45 PM »
With the table nearly all the way to the front, the Makra spindle is over the vise's fixed jaw; thus the workspace will cover the full normal capacity of the vise.  I don't anticipate needing more than this.  I could certainly make a second bracket to fix it to the side.  It would be 2" longer to clear the width of the head.

Offline Firebird

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Re: Adding a high-speed spindle to my CNC mill
« Reply #8 on: July 25, 2017, 08:30:48 PM »
Hi

A very usefull attachment Kvom.

I did a similar thing to my X3 a while back

http://www.modelenginemaker.com/index.php/topic,5643.msg108361.html#msg108361

Cheers

Rich
« Last Edit: July 26, 2017, 07:51:42 PM by Firebird »

Offline Admiral_dk

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Re: Adding a high-speed spindle to my CNC mill
« Reply #9 on: July 25, 2017, 09:20:27 PM »
I have a Kress FM6990E - it's not in production anymore, but they still make high quality spindles, see :
http://www.kress-fraesmotoren.com/ - several languages there, see top flags.

A nice thing is the fact that hey fit a standard 43mm. holder as almost all electric drills use to do before accu-drillmachines.

Offline kvom

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Re: Adding a high-speed spindle to my CNC mill
« Reply #10 on: July 25, 2017, 10:31:59 PM »
The Makra is also 43mm