CNC Machine Setup and Alignment Part 2: Leveling

Hello Tim. I'm trying to level my machine, as you suggest, on the casting itself. So my machinist level won't bridge the gap between the machined surface that the linear rails rest on. I'm assuming I would need to bridge it with a surface plate and then set my level on that? I think that is my only option, just thought I'd ask to make sure. Thanks for the great videos!

Hey bud, I've been watching your vids and some things you refer to are wrong, when you talk about aligning a box way machine you say to use shims, that is absolutely wrong, they are either ground or hand scraped for perfect alignment. The shims are used for plates on say the bottom of the saddle to base to keep it in full bearing, when the Machine is worn and is either reground or rescraped for alignment the shims are added to or decreased depending on what work was done and how the rebuilder went. for the most part I think your pretty informing. I have a video or two on my channel where I machine a cast iron master square from solid durabar, I don't have the scraping videos up yet...

how to measure it

I appreciate the effort, but this is a pretty poor effort. You didn't do much of anything to actually level the machine. You just checked the level and made up some excuses why it's not as bad as the level shows it to be. A linear guide machine should not have a hump in the ways like that. Something is badly worn or you didn't actually level it correctly.

Also, there is absolutely no reason to use the base casting for the rough level. You can use the table. It makes no difference. The machine doesn't even need to be "level" as you found out when you started monkeying with it.

Box way machines sometimes use shims for the clamps on the back side of the ways, but most adjustment is done with the gibs or by milling or scraping the turcite.

Absolutely awesome video! I just finished powering up from 3 phase to single phase (what a P.I.T.A. !)....now on to leveling (getting the ABBE error out). Great explanation! Thanks again!

Bob

This is one of the most underestimated channels on you tube .
Are you planning on doing any turcite replacement??

Where can I get those tools for leveling at?

So If I am understanding your video correctly, (I did watch the whole thing) You actually want to physically place the level onto the liner rail and level it that way as opposed to leveling the machine on the table. Once it is level on the liner rails, (both on the x and y) you then want to actually place the level on the table just to see the level of accuracy doing the tests that you did in this video. That determines the amount of error you are basically "going to have to live with" Am I on the right track?

Do you have your machine sitting on feet or directly on the concrete? I have some CRS 1x3 bar stock I am planning on putting under my machine where the adjustment bolts sit. Should I be using these bolts to level the machine or use them to just lift it enough to insert shim stock?

I'm betting that you are no longer checking the posts here but I figured I would give it a shot and ask you a question.

I love this series and learned so much about level and squareness of the machine. I have a hobbyist level bench top machine that I have converted to CNC (Started out life as a Precision Matthews PM-30) and it is a smaller machine with dovetail ways. I built and welded the stand myself and unfortunately did not watch this video before I did. The surfaces that the casting mount to on my stand are roughly level and straight but certainly not to the accuracy required now that I have seen this video.

I realized when tramming my Z head that I have twist in my table and am so glad I stumbled on your videos because I was about to fix the symptom rather than the root cause. I have access to a 10 arc second level and plan to shim between the casting and the stand so that the casting does not twist when the bolts pull the casting down to the stand.

There inlies the question. On a dovetailed machine, the datum I would imagine I have to use for level would be the dovetail as it is the only surface that the saddle touches. How would you go about positioning a level on a dovetail way machine to achieve the effect you got here?

Thanks in advance for any help you can give

you are amazing. thank you

I just discovered your channel, very interesting stuff, thanks. This was a great primer, for someone like myself who is fairly new to these concepts. It would be great to see you go through a machine and implement the techniques you're talking about. Maybe you already have such a video on your channel, I will look through the archives to see if you do.

Thank you very much.

Can anyone recommend a good book or two which specifically describes on how to rebuild or building a CNC from the ground up? I don't care about all the high tech bells and whistles, just want the theory and foundation of how to properly align and setup the linear rails x, y and z axis. With precision in mind.

is it possible to shim the linear rails to take out the sag on the ends?

Why did you stop making vids?
Even fadal is back building , you should too!

Just found this series, thank you for explaining in detail about the process, I couldn't find another one anywhere. Please keep making videos explaining these topics. Thank you.

Nice video sir...could you added English subtitles.for more understanding.

Camera typ?

Why don't you level off of the rails, instead of the table?

I feel like you talked a lot about the leveling but we never saw a level on the rails....that was what I was looking for....did I miss something?

Please let me know the procedure to level horizontal machining center HMC like Makino a81, a81nx etc.

This series is absolute gold! Thanks for taking the time to help us out!