[Deviant]

Started the cleanup tonight and lapped the y-axis.

Does anyone have a good fix for the cheesy little circlip that retains the y-axis.

I put it back on, but it tends to pop off. I guess it's not seating good, or it's slightly deformed.

I'll cleanup and lap the x-axis tomorrow.

All in all the machine hasn't needed much work. I just want to make sure I take care of it now.

Is there anything special that I should do with the antibacklash nuts? I.e. How do I know if they are adjusted right, and not to much.

Thanks.

[phantomcow2]

I threw away that C clip, I hate those things.
Antibacklash nuts, just tighten them to the point where you have little or no backlash. It does not help to overtighten, this just makes more wear and drag. So tighten the bolt a tiny bit, test for backlash.

[Deviant]

Lol, I set the c-clip over to the side and kinda looked at it.

How do you keep your y-axis from coming off? Just be careful/limit switches?

I figured that if I tighten the anti-backlash nuts to much I'd just wear them out fast. That's why I wanted to ask here. There really wasn't alot of backlash in the y-axis, without any adjustment. There was a little bit in the z, but I haven't gotten to it yet.

Will work on the x-axis tomorrow and try to finish cleaning it up.

Little leary about how to clean/lap that axis. Not sure if I want to take the headstock off just yet.

Elbow still giving me greif, doc gave me a steroid injection and drained off some fluid today. *weridness*

Anyway, 3-day weekend. Hoping to collect all the x3 info that I can. Get it up to a manual machining state. Might build a stand for it. My mini mill stand looks a lil bit wimpy for it.

[Greolt]

Does anyone have a good fix for the cheesy little circlip that retains the y-axis.

If you mean the one on the original acme thread I found it was of very poor quality.

Once taken off it wasn't going to go back on.

I would just go to a bearing service and get a new one. They are a very standard item.

It will be much better quality and will retain it's shape.

[Deviant]

I'd considered picking up a replacement c-clip. I haven't called around to see if anyone closeby sells them.

In the meant time, I'm not terribly worried about it. It's easier to remove the saddle with it off. Since I'm still cleaning and polishing. That's more important. I'll just have to remember to get one.

Is there anything I need know about adjusting the z-axis. It appeared to have the most backlash, but didn't have any side to side play that I could tell. I guess the weight of the head may cut down on that.

[triump]

where did you get your X3?

Pat

[phantomcow2]

He got his X3 from Grizzly.

You really don't need a clip for the Y axis. It should be pretty obvious that when the spindle center is almost at the end of the table, you are almost at the end of your screw. If you only have a little backlash, you might just want to let it be.

Your Z axis may be alright. My setup had not even .002" of backlash, others report similar #'s. There is an antibacklash nut on hte Z axis as well, you need to remove the cover.

I suggest you remove the cover plate on the left side of the head and lubricate the gears with a good spray of white lithium grease. I found no internal lubrication with my mill. You only need to remove four little screws to get into this plate, there is not a lot to mess up there.

[Deviant]

Ok, so I got the dial indicator out.

I have 0.005 backlash on the y-axis. From either the anti-backlash nut, or the handle.

How much should I have. Is that good? It's spot on if I zero and don't change direction. On direction change I'm loosing .005".

Also, I haven't lapped the x-axis, but I'm getting about ~0.002" if I shove the table, and about ~0.002" if I tug on the table. For total table shift of ~0.004" When the table is centered within it's backlash range. I wanted to add, that I have snugged down the x-axis so that it can't move. That 0.004" play appears to be in the y-axis somewhere.

Is this good? I'm not sure how to adjust that out, if it's the backlash of the screw letting the table move back and forth. I have the gibs adjusted to where the table will move slowly with no real side to side play. I could tighten them more, but if the movement is in the screw, that wouldn't help much. Would it? I've snugged the anti-backlash nuts down, but I haven't really put any torque on them. Just good and snug.

[Deviant]

where did you get your X3?

Pat

I ordered it from grizzly.com. Ordered on Monday, got it on Wednsday by picking it up at the terminal. They wanted to delivery it on Thurs/Fri.

My precious!

[phantomcow2]

Ok, so I got the dial indicator out.

I have 0.005 backlash on the y-axis. From either the anti-backlash nut, or the handle.

How much should I have. Is that good? It's spot on if I zero and don't change direction. On direction change I'm loosing .005".

Also, I haven't lapped the x-axis, but I'm getting about ~0.002" if I shove the table, and about ~0.002" if I tug on the table. For total table shift of ~0.004" When the table is centered within it's backlash range. I wanted to add, that I have snugged down the x-axis so that it can't move. That 0.004" play appears to be in the y-axis somewhere.

Is this good? I'm not sure how to adjust that out, if it's the backlash of the screw letting the table move back and forth. I have the gibs adjusted to where the table will move slowly with no real side to side play. I could tighten them more, but if the movement is in the screw, that wouldn't help much. Would it? I've snugged the anti-backlash nuts down, but I haven't really put any torque on them. Just good and snug.

.005 is not bad at all. You might even be able to get a little less if you tighten the nut to preload the thrust bearings, mine was not really preloading when I got it. Do not crank down on it, this just makes life more difficult on you and the bearings.

When you say shove and tug, do you mean you are trying to rock the table around to test for play in the table itself? This can be solved my tightening the gibs. Don't crank down on them. Just tighten them until you just feel the resistance, then get the locknut.

Every manual (acme screw) machine will have backlash. If you are experienced, you will be able to compensate for the backlash while operating the machine and get excellent results. If you are not so confident, I suggest a DRO. If you plan to go CNC soon though, I would say it is not worth a DRO. If CNC is something you plan to do in the long term,you really might want one.

[Deviant]

I was just concerned with the .005 because I will be doing some circle milling. I'm not as concerned with it on straight milling. Since it moves in all directions, I wasn't sure how that would have an additive effect on the outcome.

There isn't really any side to side play on the table now. I got rid of most if not all of that from lapping the dovetails. What I'm talking about is the linear movement that is inline with the screw. If I take my dial indicator and put it on the z column and center it in the table. Then push and pull on the table with the y-axis. There is about 0.004 play in the table. I'm assuming that this is from the nut moving on the screw.

I have the preload on the handle bearings tight enough to be snug, but not enough to interfer with turning the handle. I'm thinking about putting a wave washer or two in there. To see if that helps.

As for the dro. I won't be doing that, because I plan to cnc the mill as soon as possible. I just need to lay out the materials and start machine. Also I need to decide if I'm gonna start with the acme screws to get it going, then make another kick later for ballscrews. I've spent all of my allowance for a while. *grins*

I have to pick out a breakout board then track down some instructions how to wire all of this stuff up.

I also need to decide on a cad/cam solution. I have mach3 for driving the machine and a 2.8ghz pc to power it.

Coming down the final slope!

[Deviant]

Got the x-axis all lapped down and cleaned up. Looks like the x-axis is going to have more backlash than the y. Will have to fiddle around with it some more.

x-axis should be the easier of the 2, to convert to ball screw.

Anyone have some pretty cad drawings of their cnc conversion? Or do I need to start inventing the wheel. =)

[S_J_H]

I was just concerned with the .005 because I will be doing some circle milling. I'm not as concerned with it on straight milling. Since it moves in all directions, I wasn't sure how that would have an additive effect on the outcome.

I am not sure why you are concerned about the factory backlash if you are converting to cnc. Unless you are keeping the factory ACME screws and bearing setup?

Steve

[Deviant]

In the short term, I'm looking at convert the mill to cnc as is.

Long term I'll be looking at replacing the acme screws with ballscrews/preloaded nuts.

However, I more or less blew all of my money getting the mill. I won't have much extra liquid cash to spend on the ballnuts for a while.