[komatias]

Hi All

I have been asked to assist a UK University in getting their NM-200 up and running properly.

We will be working through the electronics at some point as they wanted to install a SmoothStepper and that is giving them some grief.

The more important question for me though is the head nod.

I have trammed the head in the X direction fine. But the Y is low on the front of the machine.

Use a dial test indicator as well as my trust Edge Tech. trammer.

The Z axis is spot on perpendicular to the bed as I use a granite square to see if the column was out.

The only way I can think of fixing this is by shimming between the swivel plate and the box that the linear carriages screw in to.

Any other ideas?

If this is the only way, how do I pull the head away enough to sneak the shim between the parts?

Thanks in advance guys.

[SCzEngrgGroup]

First you need to figure out if the problem is between the head and carriage, between the carriage and column, or between the column and base. What you're suggesting will only fix a problem between the head and carriage, and possibly between the carriage and column, but NOT between the column and base. If that is not the problem, then you'll only make things worse.

Regards,
Ray L.

[powerr]

since you have confirmed the z axis travel is square with the table using the granite block for both XZ and YZ square. The problem like Ray said could be between the. carriage and the bearing blocks, carriage and the head, or in the face where the spindle cartridge mounts.
It could even be between the bearing block and the rail, if there is a .0003 of play between the blocks and the rails move that out 11" any you are in the thous. you could take time and inspect all, but that would be intensive.

In the past on the big machines that we can not get to come in we have put a shim between the spindle cartridge and the mount, or scrape the spindle mounting flange on the head.
I have no scraping skills with the real tool but I did it on a five axis machine with a diamond knife sharpening stone, sucked but it can be done. Had to clean the stone off a lot, the cast iron really fills it up fast.
shimming the spindle cartridge works, had a machine that was .0017/12" spec is .0006/12", used a few pieces of gum wrapper on the back side of the spindle, it was .0004/12 when finished.

I think doing it between the head and the carriage may cause the head to rotate easier but have no proof of that.

How far out is the spindle tram, over how many inches or mm?

[kvom]

How much is it out? Given that the precision of the machine is around +/- .001", you likely won't want to chase it beyond that.

[mklotz70]

For your last question..... Can you put some blocks on the table, then lower the head down onto them....with the weight off the head assembly, I would think that you could loosen up the area you want to shim. Might need to "adjust" the Z axis up or down a bit to help. I'm guessing/assuming that the question was basically about how to deal with the weight of the head and getting shims in the bottom area where the load would be greatest. My apologies if I didn't understand the question or didn't explain this well enough.

[komatias]

Hi Guys,


thanks for the responses. Yes the XY plane is good and so is the XZ and YZ. The axis of the spindle is nodding a bit in the YZ plane which results in every so slightly oval holes when drilling and reaming and of course the usual steps/scallops on facing.

When sweeping the table with the Edge pro tram thing, I get 0.005" back to front which annoys the guys when they want to ream holes as they are ever so slightly oversized and oval.

Ray Is all good, not a noob with measuring up machines, just wanted to know what others have done to fix this issue before travelling out to the machine again. Does Novakon not have a standard solution to this?

MKlotz, thanks for chiming in. Watched your video That was the way I was thinking of taking the weight off.

Powerr, I have scraped machines in to alignment before and this one is not really worth the effort. Shimming the spindle flange may actually do it... Will need to make some measurements to see how much shim will be requiered in each of the locations.

[mklotz70]

MKlotz, thanks for chiming in. Watched your video That was the way I was thinking of taking the weight off.

Cool! Thanks!! ......but with 700+ vids on youtube, I'm not completely sure which one you watched. lol