[chronic]

Here are some pics of the plate I siliconed and bolted to the back of my column.

It makes such a big difference! I'm thinkin if I gave up on the idea of having head tilt, and welded some tabs onto the bottom then bolted it straight to the base it would be pretty solid. But I'm not sure if I need too, i'm positive any further movement is just the rest of the flimsy mill.





Edit Haha, I did get a shot of the wasp that was hovering around my mill while I took pics.

[nofx]

So thats a 1 x 5 peice of flat, 1018? I think your column is now stronger then the table. Nice work very clean.

[Dougal]

Looks good, but until you tie it into the base you're only practising.
Did you measure the difference before and after?

[Dano523]

Want the truth, you did not go far enough,

Granted that the column does have flex in itself and needs to be resolved, the bigger issue is the way that it's mounts to the base, and that is where you will see the big pay out instead.

The greatest first step is just a 1/8" plate that has been bolted to the back of the column about 12 " up, then that plate bolted to the base as well.
http://www.cnczone.com/forums/showthread.php?t=87969

Don't get me wrong, your support is a step in the right direction to stiffen the column for less flex in it itself, but should have been about 7" wider at the bottom so you could bolted the reinforcement plate to the base to take the base to column flex as well.

If you don't want to start over, then mill a section of steel that will fit in between the new back plate and the base, then bolt them up rock solid.

Also, when doing such, make sure to tram the column up as well (front to back) before finalizing your bolt pattern holes since I have yet to see a X-2 that did not need to have the front column mount that didn't need to be shimmied (so the head is level to the table front to back.

[chronic]

For sure, I'll definitely do this now that you guys are pushing me in the right direction. I have looked at the base and wondered...
I have a rotary table that can tilt so I usually use that vs the column anyway.

Believe it or not, it's actually within a thou front to back. Its pretty good which is cool, I've never needed to shim.

I didn't measure the deflection before and after. I should have. My test was a 5/8" 4 flute finishing end mill plunging through an aluminum block 1/4-3/8"ish doc.
I used to have to use a fine rougher for deeper cuts like that, 2 or 4 flute finishing end mills that big used to buck like crazy. It still had some vibrations, but not nearly as bad! It plowed through much nicer than it ever did before.


Oh yeah, its .750 X 4" 1018. I kind of guessed the depth of that under cut for the column bolt too, worked out good I went down .125 about. Probably could have gone a little deeper to give full thread engagement on the nut. But I'm sure it'll live with one missing thread.

[Arich0908]

I wouldn't weld any thing to it if it were me. I would worry bout it being out of tram or having to tram it. Maybe you could bolt some tabs to the column and base. Why not just do away with the front tilting feature, the whole yellow part. Make a bracket that some how removes that part and maybe you can raise your Z axis at the same time.
I have only a SX1 with long table but when I bought my new base I had the option to have the tilting head I said no thanks I seen you guys with X2s have enough problems so I passed.
Do you not keep you mill bolted down? Bolt it down and add rubber feet under it and you wont believe how well your mill will preform.

[Dougal]

Here is my solution:

http://www.cnczone.com/forums/showpo...&postcount=207

[alex781]

Here is my solution:

Hehe dropping it off the edge of a table? Seriously though that is a good idea, I guess all those bolts remove the need for the 'dish' shape washer.

Shame a floor standing drill press seems to be required for drilling the holes in the base.

[Dougal]

Hehe dropping it off the edge of a table? Seriously though that is a good idea, I guess all those bolts remove the need for the 'dish' shape washer.

Shame a floor standing drill press seems to be required for drilling the holes in the base.

I drilled and tapped all the base holes by hand. With an electric drill but you get the idea.
The top hole group is 1mm oversize, the pivot and lower holes are 2mm oversize. This gives heaps of movement for final tramming. The standoffs between the back of the base and the channel have their length tuned by hand when finally tramming.

There are a range of solutions from maximum stiffness to almost wasting time. I went for maximum benefit and minimum effort. I'm very happy with the results.
I'm not a believer in filling columns with concrete/epoxy/lead either. I consider higher stiffness (shift natural frequencies higher so resonance doesn't happen) to be of far greater value than trying to damp out vibrations once they've occured. Extra mass without extra stiffness lowers the natural frequencies and can make for more vibration.

[knudsen]

Hehe dropping it off the edge of a table? Seriously though that is a good idea, I guess all those bolts remove the need for the 'dish' shape washer.

Shame a floor standing drill press seems to be required for drilling the holes in the base.

Both look great to me. The latter looks a bit easier, maybe cheaper??? I was going to triangulate with 1 1/2 x 1 1/2 square tubing, since I have it. I might go for channel, I could use some for my lathe and justify a 6 ft length.

Alex, the cup washer is there so there is something between "loose" and "tight" for easier adjustments. It is not a locking device like a toothed or split washer. In practice, I doubt it much matters, but wave or cup washers are nice on smaller applications, like a QCTP height adjustment.

[rkovvur]

I'd love to do the bracing, but can anyone tell me where i can buy these steel C channels in Austin, TX ?

I opted to buy the 6"x6"x6" L bracket from enco, but am suspecting i might need a bigger brace.

[alex781]

Both look great to me. The latter looks a bit easier, maybe cheaper??? I was going to triangulate with 1 1/2 x 1 1/2 square tubing, since I have it. I might go for channel, I could use some for my lathe and justify a 6 ft length.

Alex, the cup washer is there so there is something between "loose" and "tight" for easier adjustments. It is not a locking device like a toothed or split washer. In practice, I doubt it much matters, but wave or cup washers are nice on smaller applications, like a QCTP height adjustment.

Not sure if you're suggesting building a column brace out of tubing? I guess it should be ok, the cheapest brace that appears to work is the one made by simpson36 out of 1/8" steel plate. I'm thinking it would be even cheaper and maybe stiffer to use two pieces of steel Angle, either side of the column nut. One would have to remove the cup washer (thx for the correct term!) but hopefully as you say it has no locking function anyway.

Did a 5 minute mockup in paintbrush

[chronic]

Doug I like your's!

Arich, it is bolted down. I have one on the front of the side you can see and another on the other side. I just didn't have any more long bolts lol
I'm kind of confused when you say dont worry about it being trammed in though?

[Arich0908]

I think you misread what I said.
I was saying I would not weld it because I would worry bout tramming it. I use my column bolts at the base to tram mine.
SO yes worry bout it.

[chronic]

Ok, yeah we're both misunderstanding each other. No, I would never weld it straight to the base. What I meant was weld tabs to the bottom of the plate I installed so I could bolt those tabs to the base of the machine.
Although there might be enough material over hanging the bottom that I could just make up some spacers and bolt the base to my plate. I'll play around and let you guys know what I come up with.

I think you misread what I said.
I was saying I would not weld it because I would worry bout tramming it. I use my column bolts at the base to tram mine.
SO yes worry bout it.

[hoss2006]

check out Petes version here, still allows column tilt.
http://www.hossmachine.info/Shop_Info.html#x2%20column
Mine has oversize holes to allow a couple degrees adjustment for the column.
Hoss

[Fastest1]

http://www.google.com/url?sa=t&sourc...XWGlJSP_XYD7lg
Try a metal recycler in your area. It is amazing what you will find for very inexpensive maybe even free. I usually get laughed at when standing at the cash register for having such a small piece or weight of metals.

[flak-spammer]

Chronic, is that the craftex version of the x2 from busybee tools? If so how is it?

[Tall Man]

For a solid column mini mill such as King KC-20VS what would be the values of column flex - did anyone measure?
I am deliberating buying a KC-20VS but rigidity is bothering me. The column to base of the table joint is intentionally weakened as if Chinese engineer was trying to save 4 cubic inches of cast iron to earn a red star.
I got an idea. It would be possible to beef up the column to table rigidity by rigging a plate for the machine to sit on that would extend a few inches out back and bolting a stout square column to the plate and bolting the column to the machine like in the Chronic's pictures.

Could the owners of KC-20VS post a sideways picture of the column to table joint for this discussion? I once found one on google but lost it.

[Flexo!]

The column to base of the table joint is intentionally weakened as if Chinese engineer was trying to save 4 cubic inches of cast iron to earn a red star.
I got an idea. It would be possible to beef up the column to table rigidity by rigging a plate for the machine to sit on that would extend a few inches out back and bolting a stout square column to the plate and bolting the column to the machine like in the Chronic's pictures.

The column mounting isnt too much of an issue for the G0704 & their brothers. Its the column width & depth that cause all the issues. I'll post my solution shortly (in a new thread).