Tramming the head on a X4+

[Mac Tech]

I was getting poor results while surfacing some stock cutting in along the Y axis, so I checked the alignment. The head is off side-to-side around .008" over a 9" distance, and that's after loosing the screws to try to rotated the head a bit. I'm fairly new to this, but that seems like a lot. The head looks to be pinned in place so it can't be rotated.

Has anyone come up with a way to adjust the head on the X4?

[widgitmaster]

loosten all the screws, and insert a strip or two of shim material, like that of a POP-TART wrapper. It's about .0005" thick. Shim it until it's tramed perfect when all the screws are tight!

Widgit

[Mac Tech]

widgitmaster,

Just want to make sure we're on the same page.... I loosened the screws holding the head to see if there was any play to rotate/adjust the head. You're saying to loosen the bolts on the column and shim the SIDE of the column?

[Journey_Man]

Hey Is the head out in the"X Axis Plane" or "Y Axis Plane"?
If its "Xaxis plane"...you can loosen the bolts and not have to "pulltheplug" and Tram it in Perfect.
after you loosen the bolts,snug them back abit..(make the one on the "0 ref.side" a little tighter it will keep you from overshooting)and swing the indicator to find the "high Side"...swing the indicator back 90 deg. and set your indicator to "0" swing back 90deg and bump the head to bring the needle say .004 if its .008 out...swing back 90deg..re set "0"...Swing back around 90deg and adjust accordingly...Always go back to the side you established "0" and use it as your ref.(resetting "0") tighten the bolts and re-check things...If you have to adjust the "Y axis", you will have to determin how much it is out and loosen the Column Bolts and Shim it.....

I sure wasn't on That Page
Well....Uhhhh....I needed to post something anyway....Forget all of the above...:rolleyes)

Looks to me like you need to do the shim thing as the other person said...As I go back to My Lathe and Make somemore chips....

[widgitmaster]

Actually, It may be to your advantage to disassemble it an clean all the rust, paint and metal burrs off the mating surfaces. This looks like it may be a sloppy factory assembly problem! Probably made on a friday, and everyone was tired - ready for a weekend

Shimming along one side of the colum will tilt it back where it belongs.
And when its done, you should never need to do it again!
Widgit

[Mac Tech]

Widgit, thanks for the idea. If I still need more precision, I will give that a try.

So here's how I got the head trammed a little closer.....

After getting a new adjusting screw (bent the old one), I tried adjusting the Z-gibb again. First I pulled the gibb out to take a look. None of the 4 faces of the gibb were even close to being smooth. I tried to use some fine emery cloth to smooth the faces a bit. They were certainly not perfect, but MUCH smoother than before. Cleaned things up and reinstalled the Z-gibb. I tightened the gibb up until the Z-axis motor just started complaining on a rapid movement, then backed off just a bit. Then tightened the bottom "stop" screw for the Z-gibb.

Ok, time to take some measurements......

- two 1-2-3 blocks, 9 inches apart
- I took 3 measurements, between each measurement I moved all axises of the mill returning back to the same position.
- The 3 measurements were..... .0025, .002 and .002

So, over a 9" (228.6mm) span the average variation was .00216" (.054864mm)


HOW DOES THIS COMPARE TO OTHER MILLS? Should I be content that it's this close or should it be better?


NOTE TO SELF.......... In the future, do not buy mills that can not be adjusted for wear and manufacturing flaws!!!....

[MadMax]

I've spent a fair bit of time getting my own X4 in shape. First off, the Z axis gibbs seem to be complete junk coming out of Syil. I've gotten a replacement (through the great service at Syil.ca) but alas, Syil just makes junk gibbs. I machined a replacement out of bronze lined wear plate (used in injection moulds) and tragically missed the thickness dimension because I had made the fatal mistake of assuming that Syil went with a 60 degree dovetail. Not so... Anyhow, I shimmed the new gibb and got half decent engagement until I pulled out the prussian blue to check contact and do some fitment.

I found that my Z axis slideways had about 0.009" of taper in them. A lot of cursing, blueing, grinding, and scraping and I've worked the taper out of the slideways and gotten halfway decent engagement between the saddle and slideways. Nothing like putting super accurate stuff on a bed of bubblegum to get things right...

Anyhow, when setting up your X4, you're going to have to take a methodical approach and approach each axis separately. I suggest the following order of adjustment:

Axis definitions facing the mill: left to right (X axis), front to back (Y axis), up and down (Z axis)

1. Check Y axis to table parallelism: Mount an indicator in the quill. Do not rotate the quill, but move the table in the Y direction and measure how out of parallel your table top is too the Y axis movement. Unfortunately there is no way to fix this deviation, but you can at least account for it with code adjustments or by shimming your vise. Your indicator needs to measure deflection in the Z direction.

It's bloody annoying that the table top may be out of parallel to the slideway, but on my machine it's out by about 0.0005" per inch! I've got a beautiful genuine Kurt vise sitting on shims to put it in parallel to the X-Y slideways.

2. Check X axis table parallelism with the same setup as step 1 only moving the table in the X direction.

3. Place a reference square on the table to provide a Z axis reference. Shim the square so it sits perpendicularly to your X and Y axis movements based on your measurements taken in step 1. Large 1-2-3 blocks are good for this measurement. If your reference is properly shimmed, measuring Z deflection on the top of the block will show no deflection when moving in the X-Y plane.

Remount your indicator in your quill to measure in the Y direction. Move the head up and down (Z direction) to measure perpendicularity in the Y-Z plane. Do the same with the indicator measuring in the X direction to assess perpendicularity in the X-Z plane.

These measurements will be used to tram your Z axis post in the X-Z and Y-Z planes so it is perpendicular to the X-Y plane.

4. Shim your post accordingly and repeat measurements to confirm perpendicularity.

5. Mount your indicator in your quill to measure in the Z direction and offset it say 1.5" from the quill axis. Rotate the quill and indicate on a parallel ground block sitting on the table to indicate quill perpendicularity to the table. Shim the ground block so it is parallel to the X-Y moving plane *IMPORTANT*.

Making adjustments to the head to tram the quill axis perpendicularly to the X-Y moving plane will probably require you to pull one of the dowel pins registering the head to the saddle. If you really want, drill and ream in another dowel pin hole after you tram in your head. Be sure to do the pitch adjustment shimming (Y-Z plane) before doing the X-Z plane tramming or you may end up drilling your dowel pin hole prematurely so your hole gets bent when you stuff in shims to fix the Y-Z plane.

I use steel shim stock with machine setups. Plastics creep and sometimes react with coolant or oils in funny ways. You REALLY don't want your shims to turn to mush in the middle of an aggressive cut so try to use steel shim stock in your adjustments. I have a habit of keeping extra feeler gauge sets on hand in case I need to cannibalize a piece of shim stock. I've also got a shim stock assortment on hand, but feeler gauges have finer gradations between thicknesses. It drives my tool and die guy nuts, but I'm an arrogant engineer who's supposed to do that

My order of operations is specific for a reason. Doing these operations out of order will make consequent adjustments to other planes of alignment. If you do these steps out of order, you'll find that you'll have to repeat your adjustments after making adjustments in other directions because, they're all linked. Doing these adjustments in the sequence I've proposed allows you to do each tramming ONCE and end up with a machine which respects the Cartesian coordinate system.

[BobWarfield]

Some thoughts about how I went about squaring my mill up:

http://www.cnccookbook.com/CCMillTipsTechniques.htm

Cheers,

BW