Quality Problems With the Sieg sx2.7

[Nir SomthingParticipant @nirsomthing67828]

New updates! Ok, so as you know I couldn’t accept the deviation in the column of the head so I payed the seller another 150 USD to ship me the first mill again (since I believed that the fact that I didn’t touched the gibs could have caused the errors) he agreed to let me check them at the same time (which was a nightmare – a lot of tests and numbers) to choose the least worst option for me.

So, after I played with the gibs the accuracy on both x and y axis did improve (for example: right to left height relative to the spindle across the entire table changed to 0.28 mm instead of 0.42 mm) but the head moved even more! 0.3mm when locked and again if the gib was all the way in – I lost movement of the head at the top – same scenario. (So even if I tought I might just replace the column if the seller allows such a thing – it was no longer an option).

So, realizing I have to stick with one of them, I thought maybe I’ll just take the table which is more flat, and adjust the spindle relative to it (ignoring side movements of the head) so I knew that the second mill should be flat and the first has about 0.05 mm deviation along the y axis. But being me, I decided to check again, and for my surprise, I found out that it was exactly the opposite! The first was accurate and the second was flat! For a moment I thought I may have Alzheimer, then I thought it might be because of heat cycles, but after checking for a few moments I found that when I look the x axis the entire table bends! (more significantly around the lock) How much? Exactly 0.05mm! So both tables are flat when they are not locked, but when you lock them both table bend upward in the middle! Such that, at the end of the table the gap appear – how could they not check something like that before manufacturing 100,000 units?!? So If I have a vise on top it will tilt! I know this is hard to believe but I am not joking:

https://youtu.be/M3DXUQretLY

So, to summarize my thoughts, the table bends when locked (0.05 mm), the head moves sideways when locked (0.2 mm) and the spindle is not parallel to the head (0.1)! In otherward nothing here stands as it should! So I decided to comment my opinion on the matter so that newcomers will have an idea of what to accept the Sieg is cheap relative to other options and you get all the features one can whish for – silent step motor, tapping mode, led screen, low speeds and high torque but you will never get out accuracy in any parameter! So long as you make sure that your quill is normal to the table and you use a DRO you can get accurate results with in that plane. But once you have to change height for different tool all measurement will shift. If I knew that, I would have gone with the WABECO it only cost 80 % more (look at the German site not the international one) it has standard motor (torque comes with speed), no dedicated tapping feature and the lowest speed is 140 rpm and no screen, but! It is accurate! It comes with a test report and the maximum error one can get is 0.05 mm which is perfect considering the price and weight. – Shame I didn’t found anything like that online at the time.

About the gib problem in the z axis, Pioter complained about it as well but he only had one mill to look at, **LINK** I looked at both mills and they poses the exact same problem. As I see it, it is a well known problem, and very much not a dud.

Hope this helps to someone, it surely would have helped me.

Nir

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