# Sieg X2 Spindle Runout



## lock-ed (Jan 25, 2010)

First, thank you to all the contributors to these forums. As a complete novice, I have spent much time reading and learning. I Currently have a Sieg X2 and C3. No plans for CNC, but hope to add DRO's and belt-drive in the near future. My workshop holds a steady 13*C/55*F

I have tried searching, but have not found answers to how much runout is common on the X2?

At the moment, I am very unhappy with my mills performance. Runout at the tip of my engraving bit is 0.6mm/0.023 inches. I only have a cheap DTI, but I don't need it to see I have way too much tolerance. I am currently running a 3MT spindle, and a chinese ER25 collet chuck. I have made similar tests with the keyed chuck that came with the mill. All parts have been cleaned, without affecting tolerances.

The measurements I have made so far, are 0.01mm/0.004 inches at the upper spindle, 0.03mm/0.0012 at the lower part of the spindle(approx 15mm lower). These measurements are taken OD. ID gives the same numbers. When installing a small bit(my most precise object to mount in the collet), I measure 0.1mm/0.012 close to the collet, and it gets worse with a longer bit/further down.... The worst being 0.6mm/0.023 inches

The mill seemed fine at first(drilling and tapping M1.2), but on my second run, I noticed the centre drill making a "W"-hole, not the "V"-hole I would expect. On trying my engraving bit, it made a very rough 1mm wide track. Very far from my first 0.1mm lines.

My questions are:
What is expected runout at (ID) the mouth of the spindle?
Is this multiplied by distance(longer bits/chucks)?
Is there an easy way to measure runout in the collet-/chuck?
If the original spindle bearings have been damaged in any way, what do you replace them with? Sieg replacements, or any upgrades?

Any advice or hints on further steps to locate and minimize the runout would be much appreciated.

Brgds,
Edvard,
Norway


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## Kermit (Jan 25, 2010)

Something is loose or bent somewhere, if you are certain there is not a piece of swarf stuck somewhere hard to see. That is a very large 'run-out'. Seems to big and to sudden to be wear related. Bearing/bushing unseated somewhere. How much movement is in the shaft when you pull sideways on it?  You say the first run was fine?


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## lock-ed (Jan 25, 2010)

Thank you, for responding.

My first 8 holes were fine.

Then i did some side-milling, 4x40mm alu, light cuts. I discovered the runout when going back to my small holes after that. I cannot feel movement in the shaft sideways. However, with DTi mounted on the vise, i read 0.02MM on lower spindle. With two fingers, I can flex the spindle 0.07mm at the same position.

I have cleaned the spindle, chuck-/arbor, collets, all that I can think of.


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## black85vette (Jan 25, 2010)

Have you been locking down the table in both directions when you do your tests? Have you adjusted the nut on the spindle that tightens down the bearings?

Only other thing I can think of is to check run out with the DTI in the following order;

1. check head to spindle (DTI mounted on the head)
2. upright frame to spindle  (DTI mounted on the vertical)
3. table to spindle (DTI mounted on the table or vise)

That should help you isolate down to which part of the machine to troubleshoot. What may look like run out may be something loose or needing adjustment.


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## lock-ed (Jan 25, 2010)

Have not tried adjusting the nuts, but the runout is definitively not in the table.

Will try these good advice day after tomorrow.

Will report shortly.

Thx,
Edvard


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## black85vette (Jan 25, 2010)

Edvard;

Pardon me for just jumping in with an answer and failing to say "velkommen".  (did I get that right?)  Hope you enjoy the forum it is a friendly place with lots of good help.  Hope we can help you solve your mill issue.  I have a used X2 and even used find it to be a good quality machine.  wEc1


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## lock-ed (Jan 28, 2010)

B85V, "Tusen takk" for your hospitality. Your norwegian is perfect ;D

I have now tried DTI from head, column and table. No difference. 

I have also tried tightening the spindle nut. No difference.

I have tried to attach two pictures, showing my lines on my first and second run. Tooling and material was identical, and cut-depth.

As runout(or whatever it is) is increasing, the further down I get, I am suspecting something wrong with the lower bearing-area.

I also wonder how much clearance is common between drawbar and spindle? My drawbar is 11.8mm, while the spindle is 12.9. It is clearly not centered when tight.

I have also tried blueing(found on another forum, to check 3MT misalignment). This show that the taper grips most at the bottom, and very little towards the top.

Sieg responded also, with the inspection record for X2. It states runout at the end of spindle 0.02mm(same as mine), and at 50mm below the end of spindle 0.04(mine is 0.2mm 30mm below the spindle :-\)

I am preparing to pull everythin apart, and install new bearings. I have ordered some new SKF 30x62x16. Does anybody know of a "taper roller bearing" mentioned on the X2? Also, would the use of "angular" bearings improve anything?

Thanks to everybody helping in "doctoring" my X2. I am very much looking forward to getting it right.


View attachment X2 after.bmp


View attachment X2 before.bmp


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## Kermit (Jan 28, 2010)

lock-ed  said:
			
		

> ...
> I also wonder how much clearance is common between drawbar and spindle? My drawbar is 11.8mm, while the spindle is 12.9. It is clearly not centered when tight.
> ...



If you are still set up to check the spindle, look at this area again.  Loosen off the drawbar and try it. try keeping it centered as you tighten some, and check again. 

That's a big drawbar and I was just thinking... :-\


Good luck with whatever you do to fix it,
Kermit


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## lock-ed (Jan 30, 2010)

A slight progress 
I have suspected the drawbar, and decided to make a collar for it.

This reduced the runout to 0.10mm/0.004 inches at 50mm below the spindle. 

Good progress, but not good enough. I am still suspecting the drawbar/3MT, as the spindle is only gripping the lower 30mm of the taper(indicated by blueing).

BTW, Kermit, I have tried the drawbar at different torque, no difference.

Completely off topic, but I also took a snapshot of a quick DRO that I have use quite a bit, both on the lathe and mill. A $5 magnet superglued to a $10 caliper.

As a small thank you, I am sharing my glass of beer with you. Hope it´s not inappropriate( it is saturday night, after all 8).

Brgds,
Edvard


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## black85vette (Jan 30, 2010)

I have not seen a digital caliper mounted just like that. Very innovative idea.  :bow:


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## lock-ed (Feb 13, 2010)

A small update.

I have now tried, dismantled, cleaned, changed, assembled, tried, measured..... Many ,many times.

It seems that the drawbar was part of the problem. With the collar in place, runout was reduced significantly. To approx 0.12mm. 

However, it seems that my collets are also involved. Inside on the ER25 chuck i measure 0.03 mm runout. When I mount an engraving bit(my most precise object), in a 3/8 collet, runout is 0.12mm. However, if I mount my keyed chuck, -that came with the mill, runout is only 0.05mm. Measurements are the same when changing to different size bits, and another ER25 nut.

The collets and chuck are bought from CTC tools(ctctools.biz) does anybody have any experience with these? As per now, I have spent plenty of money buying myself more runout. I am in contact with CTC, and hope to sort things out.


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## rotaone (Feb 13, 2010)

Hi Edvard,
I am using an X2 mill with a set of ER25 collets and collet chuck from CTC tools.
I have measured my setup using a vice mounted DTI with the following runouts:

Inside taper of MT3 spindle = .0025mm
Inside taper of ER25 collet chuck mounted in spindle = .01mm
Shank of an 8mm end mill mounted in a 8mm collet = .02mm

I have done other tests in the past with other sizes of collets and found the same collet runout of .01mm
which for cheap Chinese stuff is very good.
It seems that you may have a set of collets made on a Monday or Friday :big:
I have dealt with Heine Johst from CTC tools and found him to be very helpfull with all the 
purchases i have made from him.
Hope this info helps & good luck with getting your problem solved
Regards Peter.


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## lock-ed (Feb 15, 2010)

Thank you, Peter!

This was just the information I nedded.

I am already in contact with Heine. 

My good-morning-espresseo just tasted even better Thm:

Next things on the programme are picking up my belt drive kit, new bearings and some DRO. Update will follow.

Thx again, 
Ed


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## don-tucker (Feb 15, 2010)

I intend buying the same set up and reading this forum expect some run out on the the er chuck,so thought I would dti the angle in the chuck and by tipping the head over obtain the correct angle,then a tipped tool clamped in the vice skim a few thou to true the chuck.Can't see why that shouldn't do the trick.
Don


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## spuddevans (Feb 15, 2010)

don-tucker  said:
			
		

> I intend buying the same set up and reading this forum expect some run out on the the er chuck,so thought I would dti the angle in the chuck and by tipping the head over obtain the correct angle,then a tipped tool clamped in the vice skim a few thou to true the chuck.Can't see why that shouldn't do the trick.
> Don



If the runout is caused by the MT3 ( or R8 ) taper,( instead of, or in addition to the collet-end of the chuck ) then you will have to mark both the collet chuck and the mill's spindle in order to be able to remove and then re-insert the collet chuck at the exact same register. Otherwise you could find that you would need to re-grind (assuming the collet chuck is hardened) or re-cut the chuck to be true each time you have to replace it after using another tool.

I would say if you intend doing this, buy an extra collet chuck in case the operation makes matters worse.

Just my rambling 2p ( or $0.03 ) worth


Tim


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## tmuir (Feb 15, 2010)

lock-ed  said:
			
		

> Next things on the programme are picking up my belt drive kit,
> 
> Thx again,
> Ed



If you are planning on getting the drive belt kit from LMS, its great and very easy to fit.
The air spring kit they sell is also worth getting.
I've got both fitted to my HM-10 (X2 clone)


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## don-tucker (Feb 15, 2010)

I am assuming that the chuck is at fault,as reading these forums and the problems I had with one I bought for the lathe it will be.You are right Tim,has to go in the same place.
Don


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## spuddevans (Feb 15, 2010)

Just to clarify, I was referring to the MT3/R8 taper on the chuck itself, not the taper in the mill's spindle.

If you do this, post up some pics of the process, I cant be the only one who would be interested to see it.


Tim


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## lock-ed (Feb 24, 2010)

Sorry, no pics this time. Have been busy working, climbing, kayaking, working and so on 

The belt drive has been fitted, and seems ok. However, the largest wheel was a very tight fit on the spindle, and is not perfectly aligned at the moment. While at it, I also swapped the lower spindle bearing with a SKF one. This reduced inner-spindle runout to 0.01mm/0.0004 inches, which looks promising. Hope to make some new measurements on the ER-chuck, and I am also awaiting answer from CTC tools.

Vertical DRO is also in place, seems OK, but will most likely have to modify brackets when I change to air-spring. I am learning for every swarf coming off my mill or lathe. 

Will be back next week with pictures and update. I have a date with a frozen waterfall 8)


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