Super X3 conversion with 20mm Ballscrew?

[Kosa]

Hi all

Can anyone with X3 CNC conversions experience, tell me if there is enough room in this machine to use 20mm (0.79") ballscrews?

The Y axis looks like it may present a problem from some of the pics I've seen.

Looking to purchase a mill I can match up with some very nice THK screws I already have.

Cheers
Kosa

[SyilAmerica]

Possible.... but I wouldn't. You would be left we very little material in your bearing blocks. Could pose a problem on the rigidity side.

[syil]

please check here:http://koeienuiers.nl/
it is a customer of us from europe.he make good working and good report of our converstion kits.

[bones]

Hi Kosa,
I done/doing a conversion on a X3 at work with the Promica X3 kit using the 16mm ballscrews.
There is a little room inside so the screw will fit but I dought the nut will fit under there.
I have a small mill with the same problem at home and the only way I could see it to fit is if the nut is not on the table but mounted in front on the Y-axis.
Eg mount it to the base of the machine.
Then you only need clearance for the screw and the top of the nut under the moving slide.
I hope you can understand what I am trying to explain. If not let me know and I'll send a picture.

The only problem with this design is that you will need to make more room on the front of the Y-Axis to let the nut go into it.

I have a 20mm THK screw at work so I'll check the clearance tomorrow for you.

Other than that get a HM-45 and put the screws in it. A much bigger machine and will take those screws nicely.

Cheers
Bones

[Kosa]

Thanks very much for your comments guys. Yep I think I can see that the nut is most probably the main limitation.

Kosa

[phantomcow2]

Wait a moment...
I am converting using 20mm screws myself. The ballnut diameter is 35mm, they fit with no issue at all.
Only annoyance was buying the 60 dollar tap that I will only use 3 times.

[phantomcow2]

I should mention that my screw is a Hiwin ground, not sure if your THK has a different dimension for the ballnut. One nice thing was that instead of trying to turn down the end of this thru hardened screw, I was able to simply buy a 20mm ID bearing and after a little emery cloth sanding on the end, slip the bearing right on.

[Kosa]

Thanks for that info phantomcom2. The nut I have, from memory, (THK BNF2005) the max barrel dia is 44mm and the flange has a dia of 67mm but flatten at the top making the distance from to top to bottom 55mm and width 67mm. Does that make sense?

The top to bottom dimension is the relevant one I think. I can always flatten the bottom section of the flange if necessary, making the flange top to bottom about 42mm. That would still leave me 4 good mounting holes.

Still 7mm larger than yours. You think that would fit?


Cheers
Kosa

[phantomcow2]

Looking in there, I don't think 44 would fit. I have about 5-6mm to spare as far as height goes, you would need to mill away some material to have it all fit. I recall that my X axis had an even tighter fit, with maybe 1mm to spare.
It would work for your Z axis though.

If you want nice ballscrews, the same exact that I have, contact the seller here:
http://myworld.ebay.com/kit06035/

[bones]

Hi Kosa,
I checked the clearance and you have about 38mm under the slide as the nut is 46mm it's not going to fit under there.
Looks like the only way is too mount an alloy block in the normal position but make it long enough to come out the front a bit.
Drill a hole in it for the screw to come through. The nut will be out the front a bit and drop it down for clearence where the sloped part is at the front of the mill.

Otherwise these screws are great. A lot of guys here in Perth Australia have used these. Get the preloaded nut.

http://www.homeshopcnc.com/page3.html

Cheers
Bones

[Kosa]

phantomcow2 and bones, thanks for checking. Really appreciate your contribution.

I think I'll still go ahead and buy the Super X3 as it looks like the best Mill for its price. Should be able to use one my screw assemblies on the Z axis. I'll also check to see if THK has a low profile nut for these screws that will work. If not I'll buy something smaller for the X and Y axis.

Thanks again and happy milling.
Kosa

[bones]

Hi Kosa,
No worries, but before you go buy a X3 have a look at this.
http://cgi.ebay.com.au/DOVETAIL-GEAR...QQcmdZViewItem

I'm buying one of these instead of an X3. Heaps bigger. The next size up and cheaper than and X3 Super.
It was about $300 or so to get it to Perth, so not much more to get to Brisbane or the same.

I'm collecting 20mm screws for this one. It's the same as a Hafco HM-45.

A guy at work has this exact one and another mate has a genuine HM-45.
There is no difference between the two and probably came out of the same mold.
It will cost you a little more in motors but you have just saved heaps.

Check the specs the capacity is nearly double.
Eg. Max drill capacity X3 25mm-----HM-45 40mm
It's in a completely different league and cheaper.

Have a good look at the two.

Cheers
Bones