Sieg X1 Spindle

[itsme]

Hi there,

I need to upgrade the spindle motor on my X1 mill to get a higher speed along with more power. I am aiming for a top speed of around 20000 RPM (only 10 times the standard speed... ). The reason for the high speed, is that I want to do some grinding work.

What I was thinking about doing was getting some stainless/ceramic hybrid bearings for the spindle which are rated up to 24000 RPM using grease for lubrication. This would allow me to use an almost standard spindle, which would be helpful (although I may need to do some balancing???). I was then thinking about using a router motor to power it. Most of the routers that I have looked at have a no-load speed of around 30000 RPM. I was thinking that I could use a belt drive from the motor to the spindle. This would allow me to reduce the speed slightly and would also eliminate potential alignment problems.

Does anyone have any useful comments or suggestions on this 'plan'? What power rating would be good for this small machine? I have my eye on a 550W router, but would more power be a better idea?

Thanks in advance
Warren

[ironDigit]

are you sure your x1 is square enough to do grinding ?
or is the surface finish most important to you instead of dimensions ??

good lukk m8

[itsme]

Hi,

Surface finish is very important and dimensions are also reasonably important. I need to spend some time setting the machine up properly to ensure everything is as square as possible and I don't think that will be a big problem (I hope so anyway). I've done some grinding on it before using a Dremel attachment with fairly good reults, but it took ages. I need more power and something a bit more robust.

Regards
Warren

[phantomcow2]

If you can get the bearings, go for it.
At lowes, there is a Hitachi Router for 114 dollars. I foget the model #, but it is mentioned all around the forum, especially the DIY router section. Its variable speed from 10k to 25k RPM I think, somewhere close to that. I use it, and like it. And its 2.5Hp peak, plenty of power and RPM.

[LongRat]

Are you sure a belt drive is going to be comfortable at 20-30k? I have my doubts, although I have not done it myself.

[phantomcow2]

Yea that is quite a bit of RPM for a belt.
He might be better off to somehow directly couple the router to the spindle.

[itsme]

Hello again,

It is approaching an uncomfortably high speed, however a belt 'should' be able to cope. According to information provided by the manufacturer, the toothed belts that I am looking at can handle linear speeds of up to 80 m/s. If my calculations are correct, then it should be safe with a pulley of up to approximately 50mm in diameter at 30000 RPM.

Having said all that, I am now having second thoughts about doing what I initially thought was a good idea. The bearings that I would like to use cost US$70 each before they are even in the UK. I'm not sure if it is worth spending that money on this machine, when success is not guaranteed.

For the time being, I'll keep looking around at other options.

Regards
Warren

[digits]

Originally Posted by itsme Hello again, It is approaching an uncomfortably high speed, however a belt 'should' be able to cope. According to information provided by the manufacturer, the toothed belts that I am looking at can handle linear speeds of up to 80 m/s. If my calculations are correct, then it should be safe with a pulley of up to approximately 50mm in diameter at 30000 RPM. Having said all that, I am now having second thoughts about doing what I initially thought was a good idea. The bearings that I would like to use cost US$70 each before they are even in the UK. I'm not sure if it is worth spending that money on this machine, when success is not guaranteed. For the time being, I'll keep looking around at other options. Regards Warren

Did you get anywhere on this in the end? I'm beginning to think I could do with a bit more power, but I don't need a much larger, 3x heavier mill, just a bit more speed (3-4000 rpm) and a bit more power.

I read this thread http://www.cnczone.com/forums/showthread.php?t=20573 on beefing up a tiny Taig mill, and it got me wondering about what might be possible on the X-1. I find it amazing that he got 0.1" 1/4" wide cuts in Al on such a small mill!

[philbur]

Have you considered fabricating a new head to mount a router directly.

Regards
Phil

Originally Posted by itsme Hello again, It is approaching an uncomfortably high speed, however a belt 'should' be able to cope. According to information provided by the manufacturer, the toothed belts that I am looking at can handle linear speeds of up to 80 m/s. If my calculations are correct, then it should be safe with a pulley of up to approximately 50mm in diameter at 30000 RPM. Having said all that, I am now having second thoughts about doing what I initially thought was a good idea. The bearings that I would like to use cost US$70 each before they are even in the UK. I'm not sure if it is worth spending that money on this machine, when success is not guaranteed. For the time being, I'll keep looking around at other options. Regards Warren

[digits]

Originally Posted by philbur Have you considered fabricating a new head to mount a router directly. Regards Phil

Yes, I did think about that - but can a router cut slow enough to handle big cutters, and how long can they run continuously?

I can currently manage 300mm/min at 0.5mm deep in alu. with a 6mm 4-flute but at that depth of cut it takes ages to contour even 1/2" thick stock. It is also very noisy even when not cutting, so I'd quite like to swap to belt or direct drive if possible.

I am half tempted to raid the X2 and X3 spares bins at Arc Euro, but the motors and driver boards are very expensive compared to variable speed routers...

[itsme]

Hi there,

I haven't done anything with the spindle on my X1 yet. I still want to do something, but I seem to be having trouble finding time at the moment.

I had also thought of directly mounting a router, but the only thing I was not sure on was how accurate the bearings would be and what kind of runout could be expected. That is part of the reason why I was leaning towards a good, solid spindle/bearing setup that is powered by the router.

As far as raiding the X2/X3 parts bin goes, would you not be better off getting a 3 phase motor and VFD (especially if you're only looking for 3 - 4000RPM)? When the motor on my lathe went bang a few months ago, I looked into the 3 phase with VFD option. I didn't go with it in the end, but the prices were not too outrageous. It gives you accurate electronic variable speed and will run off a standard household supply. It can apparently even be controlled by your computer - a nice little 'extra'.

I was looking at 370W motors and a VFD of the correct size to drive this motor. Through a dealer, I was quoted somewhere around £210 for this setup (motor and VFD). I can't recall what brand these items were, but I do remember that they were both European. This is a little more than the X2 parts cost from Arc, but less than the X3 parts.

I would think that a 370W motor would be a nice size on the X1 when compared to the standard 150W motor. Physically this motor should fit (at a guess) without looking ridiculous.

I'm going to keep searching for alternatives in the mean time (when I have time, that is...).

Regards
Warren

[digits]

Originally Posted by itsme Hi there, I haven't done anything with the spindle on my X1 yet. I still want to do something, but I seem to be having trouble finding time at the moment. I had also thought of directly mounting a router, but the only thing I was not sure on was how accurate the bearings would be and what kind of runout could be expected. That is part of the reason why I was leaning towards a good, solid spindle/bearing setup that is powered by the router. As far as raiding the X2/X3 parts bin goes, would you not be better off getting a 3 phase motor and VFD (especially if you're only looking for 3 - 4000RPM)? When the motor on my lathe went bang a few months ago, I looked into the 3 phase with VFD option. I didn't go with it in the end, but the prices were not too outrageous. It gives you accurate electronic variable speed and will run off a standard household supply. It can apparently even be controlled by your computer - a nice little 'extra'. I was looking at 370W motors and a VFD of the correct size to drive this motor. Through a dealer, I was quoted somewhere around £210 for this setup (motor and VFD). I can't recall what brand these items were, but I do remember that they were both European. This is a little more than the X2 parts cost from Arc, but less than the X3 parts. I would think that a 370W motor would be a nice size on the X1 when compared to the standard 150W motor. Physically this motor should fit (at a guess) without looking ridiculous. I'm going to keep searching for alternatives in the mean time (when I have time, that is...). Regards Warren

Yep - a 3-phase motor was another idea that crossed my mind, but I did see a few posts on here about them being unsuitable for delivering high torque at low speeds and that they might overheat at low RPM. I found a UK website via ebay doing VFD's and 3-phase motors for about £150 for a 3/4 HP kit :

http://www.drivesdirect.co.uk/Produc...r_Packages.htm

I can't tell if the motors could be mounted with the spindle vertical though...

I was actually wanting to get the parts for the spindle from an X2 or X3 - it should be stiffer than the X1, and I was planning to connect the new motor via a belt drive. Looking at Littlemachineshop.com, I could get the X2's spindle box and a belt drive kit for $274 + VAT + duty - which isn't too insane given the strength of the pound.

Still, a variable speed router and a DIY pulley drive conversion would be a whole lot cheaper - the X2 spindle without bearings etc is £25 from Arc and they have a wide range of other little bits and bobs that might be useful...