Sieg X1L CNC Conversion

[Doug]

I have been working on the mill again, this time to fix the whole electrical panel. The CNC had been built up then the spindle swapped twice added a 4th axis and the electrical panels were a bit a hoc so I decided that it was time to fix them into one panel and rewire the machine.

I have fitted both power supplies in and fitted a PNOZ estop relay to make it a bit more reliable. I have a few more guards to fit and it will be done, I want to control the swarf a bit better stop it getting to the y axis.

[Doug]

Bit of an update, swapped the spindle motor again in the hope of getting enough torque

Got to tidy the wires up a bit but it works a treat, need to figure out a two speed box though as the max speed is a little low currently. Nothing too bad at approx 750rpm as I can do most cutting operations really well now, just the small cutters have to run a bit slow. Also added a new depth stop to the quill which is super handy,

[runner42]

Hi Doug,

to say that swapping the motor to get more torque is a 'bit of an update', I would classify it as a significant update. What motor size have you chosen and does that increase in weight effect the rigidity of the milling machine and the ability to raise the spindle?  More details would be of interest.

Brian

[Doug]

Hi Brian
The motor size is 750w 200v three phase ac previously it started with a 150w 240vdc motor then 250w 50v dc and then 350w 70vdc and as I blew the drive up on the last one I decided to stop messing around and get something that will definitely not stall with a 12mm cutter doing a 1mm cut!
The rigidity has been a major issue hence the strong back I fitted to the machine base and removed the tilting column and tied the top of the z into the frame it is still no where near as strong as I would like it to be but it works better than it ever has so definitely an improvement.
As for weight the main z axis is on a ballscrew and motor which has an assist ram fitted so doubtful the axis is having a hard time and the quill which takes the weight of the motor as well still moves freely and returns under the spring (if I allowed it to) I have the quill fairly tight to improve accuracy.
In hindsight it would have been a lot easier to buy a bigger mill but at the time I could not afford to so, I just work with what I have and it is now a useful bit of kit. If I ever find a larger spindle head I will swap the column for this bad boy I made from scrap parts,

But that’s for another day.
All the best Doug

[jasonb]

Interesting way to go, I would have thought a higher speed spindle and smaller tooling would have been the better option as the lack of rigidity in the small machine would be better suited to smaller cutters and if the spindle were 5000rpm plus you could feed the smaller tool much faster and get the job done as quick or quicker than slogging along with a big 12mm one.

[Doug]

I have tried small cutters (and do use them even now) however the lack of rigidity in the past has been a very big issue, I am sure I mentioned it earlier in the build, but the tendency was for the mill to bite jump/deflect and break the cutter. I now have an acceptable method and run at 20mm/m and 0.5mm cut depth with my go to 6mm end mills this works well and will no doubt improve as the head is improved yet further. I very rarely use 12mm cutters but would like my setup to be able to handle them when I need to. The benefit of CNC is your not constrained by time, you can set up the machine till it seems happy and let it do its thing.

[jasonb]

I did have a look back through the old post after replying as I had not seen it before and can see that you have stiffened things up. I have a KX3 and my goto cutter is a 3-flute 6mm carbide that does all my adaptive clearing tough I tend to run and feed a lot faster, typically 5000rpm and maybe drop to 4000 on steel and CI with feeds of 3-500mm/min. Where possible I tend to use more of the side of the cutter but looking at where you were making the conversion brackets it looks like you cut downwards at full width and shallow vertical DOC. I would be cutting from the outside working inwards using say 6mm high cuts x 1mm stepover. If just a profile then I would do a taller cut and reduce the stepover so a similar volume is being removed eg 12mm high x 0.5 wide per pass.

With just the adaptive for a part using 500mm/min feed some of the things I do can take an hour, that would be over a day at 20mm/min which is loner that I personally would want to be keeping an eye on the machine.

[Doug]

Adaptive cuts would be ideal, I have so far been guided by my CAM (CAMBAM) which is not very good, my profile cuts were usually done as you say with a slow deep cut with a 3-5deg slope and then a 0.5mm stopover for chip clearance if it was deeper than the dia of the cutter. I did get to play with another CAM program the name of which escapes me that was over £20k for the licence and that was just amazing. It knew what material it had cleared and didn’t mess about cutting air, the roughing and finishing were all dealt with properly too, but I work with what I have and when I spend time on it I can get the programs to run much better by adding manually code that can trim the program down. I did have a commercial job on there once cutting electrodes for an EDM diesink machine and it payed for the machine and the CNC conversion. I in no way profess to be a good machinist my talents lie at the background building and repairing CNC equipment, which is why I understand the limitations of my machine it is not even close to an industrial level. This has been a very good and interesting project and I have some exciting new ideas for it, including some closed loop steppers and the massive z axis upgrade. Maybe then I can spend some money on the software side and enjoy some “proper machining” as I feel like I have a lot to learn in that area

[Doug]

Ok so been quite a while since I last updated on this but the Seig X1L CNC is no more, I got an almost complete Amadeal AMA25ML missing the spindle electronics and the casting joining the head to the Column
Came with a full 3 axis dro and a stand.

This is the last photo of the seig before I put it back to standard

So upgrades galore but I could not get away from it being to small and not rigid. So I put all the original pieces back on it and sold it for £300 on its stand and with the Z axis raising block

Oh and the new mill only cost me £20 at auction.
I will start a new blog with the new build.
Sad to see it go after over 12 years of good service.