# X2 mods finished



## Bill S (Mar 3, 2010)

I now have the mill where I can start using it. The last thing done was to fab a mill-head counter-weight. I weighed the head with the motor installed, and it came out to 32#. To make the weight I used an old rusty piece of 3"x3" rectangular tubing I've been saving for just this sort of thing (actually I forgot I had it and almost missed it in my scrap rack). I made an end cap for one side and then proceeded to melt 32# of plumbers lead into it. Then a short length of 1/4" rod was welded across the top to hang the weight from, a few bends were put in the rod to keep the hanging cable centered. A couple of pulleys, a bit of angle, a little band saw work, a length of cable and Viola! I can move the head up and down with one finger on the crank handle, and it stays put once there. I do make it a practice to lock the gibs whenever milling though.

Before I started the project I took some purely subjective benchmarks of the flex of the original column. It was just simply mounting a test indicator and then pushing and pulling on the top of the column and recording the results. When I repeated the test on the new machine (and it does seem like a new machine) flex was reduced by a factor of 4, but the real world test for me was cutting some steel. Before when cutting steel unless I took very small cuts (.010 - .015 doc) it would almost always result in poor cuts and chattering. For a quick test I put in a decidedly worn 3/8 end mill, set up for a cut of 1/4 in wide and started to take progressively deeper cuts, at .040 doc I could feel the motor starting to slow, but it continued to cut easily without any chattering or vibrating. Next I mounted a ½ roughing end mill and set up for a slotting cut. A .050 doc resulted nice cut with only slight slowing of the motor. There was no chattering and only a bit of vibration. After a few cuts the depth was .115". I moved the cutter over 5/16 and made a full depth cut, it cut easy, no problem at all. All test cuts were done dry and at around 1000 rpm. 

So all in all I have to say the operation was a complete success. The patient is much bigger and stronger and seems much more capable than before. Ill probably have to be careful not to overtax the motor, as that will now be a limiting factor. 

Bill 

link to web album:  http://picasaweb.google.com/billstupak/X2MillExpansion?authkey=Gv1sRgCKSBivqv_t2ungE&feat=directlink


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## compressor man (Mar 4, 2010)

Wow, that is one really capable looking little machine you have now. Is there anything at all left stock on it? I am afraid that you really must change the name of this thing as it really can no longer be called a mere X2, perhaps it should now be an X2 squared. If you ever get to longing for the old days I will be happy to swap mine for yours, even swap, mine is still shiny and red even!!


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## black85vette (Mar 4, 2010)

Very nice job. I really like the way the counter weight works.


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## Troutsqueezer (Mar 4, 2010)

I thought it was a big deal when I installed the belt drive on mine...


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## rake60 (Mar 4, 2010)

*NICE!* :bow:

I have the air spring mod on my X2.
I like your counter weight design much better!
I'll be copying that.

Thanks for the pictures of your mods.

Rick


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## compressor man (Mar 5, 2010)

I have a question about counterweights on an X2. Everyone knows how "rubbery" the whole column mount to base system on the X2 is, in my opinion it is the machines Achilles heel. I have built a bracket for mine that is similar to most of those seen on this forum, although it is nothing like the one Bill has created for his. Yes, stability was increased by this bracket but it is still far from being rock solid. My question is: if one had not already gone to great lengths to stiffen up this mount (such as Bill has documented in this post) wouldn't adding ~36 more pounds of weight to the top of the column make this problem much worse?


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## Bill S (Mar 5, 2010)

Thats a good question and I'm not sure of the answer. My feeling is that even though the weight of both the mill head and counter weight are bearing on the pulleys at the top of the machine I don't think that means the actual weight is located at the top. It certainly doesn't feel top heavy. Also because they are the same weight they are in balance and don't push or pull the column. The extra weight is also extra mass which should have a damping effect on vibration regardless of where is is located. If the same setup was installed on a stock machine I think it could still have the effect of damping vibrations. In its previous stock condition I had installed a lighter counterweight -15#- on my machine to assist the standard torsion bar and while it was an improvement in holding the mill head steady I never noticed or even considered if it helped or hurt the flex problem. Still it's an interesting point and I would like to hear other pros and cons 

Bill


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## compressor man (Mar 5, 2010)

> In its previous stock condition I had installed a lighter counterweight -15#- on my machine to assist the standard torsion bar



Bill, did this smaller counter weight make a noticible difference in assisting up/down movement? I like the idea of a counterweight better than the airspring. I do not know about the airsprings used in the mill mod but the company I work for owns about two dozen forklifts and these have airsprings to assist in lifting the motor hood, these seem to wear out fairly often. However, there is a lot of motor heat under this cover and this is likely to reduce air spring life. But having said that, I have never seen a counterweight wear out!


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## Bill S (Mar 5, 2010)

The small cw did make a difference. It was easier to raise the head after. My machine did have an annoying habit in whenever I used the fine adjustment to lower the head to the number I wanted the action of locking the gibs would drop it a couple more thou. The extra weight helped, but did not eliminate the problem. I haven't checked this out yet on my recent mods.

Bill


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## radfordc (Mar 5, 2010)

I removed the spring arm and installed a C/W on my mill, too. I mounted the pulleys to the ceiling joists in the basement and added enough weight so that the mill head doesn't want to rise or fall on its on. The mill is just sitting on top of a portable bench but doesn't move in use. As a result of this I can easily raise and lower the head and the amount of flex in the column seems to be less than before. This mod is second only to the belt drive in my opinion.

Charlie


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