[BLOG] DIY hardware store CNC Router, Part 4.5 design update
Part 4.5
This is really just a design update for the table.
As you can see the linear rail has changed. I’m now using a boxed steel extrusion. I have some concerns about using these extrusions. It has the strength I’m looking for but not the exact flatness I want. Now it is flat enough to get me some pretty good results. Working on wood wouldn’t be a problem at all. But I want everything to be butter smooth. To get that flatness will take some ingenuity.
People who have built a DIY cnc machines will tell you from the get go, know in advance, you will use your fist machine to build your second. Eventually, I know I will build another machine but before I do that I’ll use this machine to make this one even better.
To get that butter smooth flatness I want, I’ll use this cnc, once it is built, to machine flat a second pair of rails. Then once the second pair is on the machine, I’ll use the second pair to machine the first pair to even more exact standards. The process will go back and forth a few times till I’m satisfied. Each run will only be removing maybe .1mm at a time. Basically my machine will be building itself.
I’m attaching pictures for you to see the updated parts. The rails are marked in red. This weekend I plan to have what is in the picture done. Next weekend, I’ll attempt to make the linear rollers. If you wondering where are the other two axis, I’m still working on them. I’m also not going to post my roller design up yet. Think of it as a surprise . Hopefully I’ll have another update on Sunday.
PS, if anyone sees any design flaws just let me know.
This is really just a design update for the table.
As you can see the linear rail has changed. I’m now using a boxed steel extrusion. I have some concerns about using these extrusions. It has the strength I’m looking for but not the exact flatness I want. Now it is flat enough to get me some pretty good results. Working on wood wouldn’t be a problem at all. But I want everything to be butter smooth. To get that flatness will take some ingenuity.
People who have built a DIY cnc machines will tell you from the get go, know in advance, you will use your fist machine to build your second. Eventually, I know I will build another machine but before I do that I’ll use this machine to make this one even better.
To get that butter smooth flatness I want, I’ll use this cnc, once it is built, to machine flat a second pair of rails. Then once the second pair is on the machine, I’ll use the second pair to machine the first pair to even more exact standards. The process will go back and forth a few times till I’m satisfied. Each run will only be removing maybe .1mm at a time. Basically my machine will be building itself.
I’m attaching pictures for you to see the updated parts. The rails are marked in red. This weekend I plan to have what is in the picture done. Next weekend, I’ll attempt to make the linear rollers. If you wondering where are the other two axis, I’m still working on them. I’m also not going to post my roller design up yet. Think of it as a surprise . Hopefully I’ll have another update on Sunday.
PS, if anyone sees any design flaws just let me know.
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Comments
But anyways, when I machine the second one it'll be twice as flat (for lack of a better description) as the first one because it'll be running on 8 bearings on top and bottom. So it'll average out. Each swap out will be better and until I get a completely uniform finish.
Now that I think about it, each pass will be a lot more accurate because it'll be the average of 3 axis. Those 3 axis will be between 5 and 7 rails depending on how I do my Z axis. On each of those rails there will be bearings under pressure making contact at 8 different places.
Now, there is the one in 800 million chance that they all hit a 1mm high spot at the same time. But I can take those odds...lol
ALL comes down to averaging it out.