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Yet another guy tries to fix his Sieg SX2 looseness
rythmnbls:
My mill column came attached to the side of my lathe, a Grizzly g0516, needless to say it did not belong there - so I bought an X-Y table from LMS, and, like most X2 mills it banged and thumped when making cuts in steel.
Here's a pic of my solution...
The new column is 4"x6" steel with a wall thickness of 3/8" and the base pieces are 2" x 3" by 3/8". It adds about 5" of Z travel.
A shot of it making a .250 inch doc with .150 inch in-feed using a .5 inch end-mill in 4140 chrome moly. There was still some noise, but no banging or thumping.
It's definitely a big improvement, I'm tempted to scrape it in and re-fit the gibs properly as they aren't the best.
Regards.
Steve.
superc:
Steve, I believe your homemade base has a lot to do with why your mill is improved. I mean not only did you eliminate the column flex, but you also gave it a much better base. I have been looking at the factory base on my own X2 and believe, since the best word to describe the Sieg type base is flimsy, improvement there is possible.
Clearly increasing the mass and rigidity of the mill body, regardless of whether we speak of the base or the column has an impact in reducing vibration. I had already decided I wasn't that impressed with the air spring design because it reminds me too much of the ones on my old Bronco II and my old Pinto. Every year or so I wound up having to replace them. They would work fine on the hatch for a few months, then one day you would notice the hatch slowly closing instead of remaining in position. The silly things wear out with use. Since the air valve looks to me exactly like the ones I used to replace in my Fords, I suspect the long term performance would be the same. Alternatively, I don't forsee much failure of the spring anytime soon. An article in the Yahoo groups about doing the epoxy fill suggests just filling the bottom 6 inches so as to leave room for the air buffer assembly. I did way more than 6 inches of fill and ran it up to just below the spindle shaft. Also I used steel and sand instead of just sand or gravel. I suspect that added a lot more mass than just sand with the epoxy. LoL, I was initially going to just cut and epoxy in place a steel bar about 3 inches by two and about 7 inches long, but I decided that would be a waste of a very nice steel plate.
Also there is enough on the web arguing about the discontinuity of a fill material, such as sand or granite chips, reducing the vibration that I decided to play it safe and use some sand, but also small steel parts.
Teegee, I am finding the head drop issue was two things. First of course column vibration allows the slop in the fit of the gib lock screw to move during vibration, then it backs out, which then drops the milling head. A drop of loctite blue or red on the screw threads of the column's gib lock screw may solve that for you. Even if you don't also do the epoxy fix. I would go ahead and try blue loctite on the lock thread and see if that eliminates that problem for you. On my own mill I observed many of the bolts had some slop and tended to loosen during vibration. <Also the column nut had some slop. Not enough to feel with your hand, but enough to allow the nut to loosen during column vibration. > I loctited them all to eliminate the slop, then did the epoxy fix of the column which greatly reduced the vibration.
Manxmodder:
--- Quote from: rythmnbls on February 13, 2014, 02:45:48 PM ---My mill column came attached to the side of my lathe, a Grizzly g0516, needless to say it did not belong there - so I bought an X-Y table from LMS, and, like most X2 mills it banged and thumped when making cuts in steel.
Here's a pic of my solution...
The new column is 4"x6" steel with a wall thickness of 3/8" and the base pieces are 2" x 3" by 3/8". It adds about 5" of Z travel.
A shot of it making a .250 inch doc with .150 inch in-feed using a .5 inch end-mill in 4140 chrome moly. There was still some noise, but no banging or thumping.
It's definitely a big improvement, I'm tempted to scrape it in and re-fit the gibs properly as they aren't the best.
Regards.
Steve.
--- End quote ---
Steve,
I can see how that setup you've made is a vast improvement over standard,but wouldn't it be even more so if you filled the box sections with strong concrete mix?
It would also give you better vibration damping due to the increased mass, as well.....OZ.
rythmnbls:
--- Quote --- I can see how that setup you've made is a vast improvement over standard,but wouldn't it be even more so if you filled the box sections with strong concrete mix?
It would also give you better vibration damping due to the increased mass, as well.....OZ.
--- End quote ---
That is something I have considered, but future plans for this mill include some small servo motors and Linuxcnc, so for the moment I'll hold off on the concrete while I'm still drilling holes and fitting bits 'n' pieces on it.
Regards.
Steve.
MetalMuncher:
I was blown away by reading how deep a cut you can make now in steel! :bugeye: I would never have ever dreamed of trying anything deeper than 0.050" on any kind of metal, let alone steel, on one of these mills. I'd really like to see that kind of improvement, but I have the Spring-Air modification on mine, so there needs to be a space inside for it. Has anyone found a way to do this yet (like maybe using a hollow tube in the center for the cylinder, then filling around that?)
I can't tell you how many hundreds of milling passes I have made at 0.010-0.015" just because I didn't think this little beast could go heavier on steel. Any time I have tried to exceed 0.020" on steel I would start hearing the Grim Reaper coming for my little mill. ;) I'd like to find a way to get even half way to where yours is in stability for heavier milling.
Before I even know what this meant, I actually "work hardened" a steel block I was milling to hold down my 3" Screwless Vise. I was even using Carbide, but was getting too much chatter and didn't catch it fast enough, being new to milling. Suddenly the carbide just couldn't cut the surface anymore. I was at a loss to figure it out, and started over with a new piece, and shallower cuts. My friend, a toolmaker, later explained what happened when I told him about it.
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