It's not the grub screw (probably)

I got the lowrider moving, did some test pieces, then went to visit my family in Kentucky and decided to make a sign at around midnight the day before I left. It turned out ok, especially for a first go without much tuning.

Even though the fam didn’t notice, the letters are noticeably not vertical. I chalked this up to not starting out the y axis square and received admiration anyways. Got back and started routing 40 cm rectangles using the V-bit and lcd screen purchased from V1 (no g-code from estlCAM or other software). I clamped wooden blocks to the Y rails and moved one block a few inches in the positive and negative direction but didn’t see any improvement in getting right angles. All the sides were really close to 40cm and I recently tightened the Y grub screws and put loctite on them.

Saw a few posts about the wheels being out of alignment so purchased some 3/4" angle iron and put them on the wheels to try and straighten it out. That’s when I noticed this

The y rails seem pretty out of square with the wheels which seems like it’d create some issues. Any suggestions on how bad this is and how to fix it?

I printed my own parts (feel free to doubt their integrity, I do), had a buddy wood worker make the wooden y plates, and purchased all hardware and rambo board from Ryan.

Additional pictures of the build

Did ya check the grub screws?

Yes! (well not the z axis and only the x superficially) lol The lines do measure out to 40 cm consistently though so seems like it should be a different issue.

You need the table to be square. And you need to loosen the tube holders so you can square it up. Then every time you start it, hold it against something you know is square to the table and it will stay square under its own power.

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  • Loosen 1 or both of the clamps on the X tubes.
  • Bump gantry until wheels are square
  • Tighten tube clamp.

When you cut the tube, how careful were you to make both rails the exact same length?

Your X direction cuts look straight. The Y ones are pretty wobbly.

Thanks for the suggestions, I’ll try that out once I’m back in Indiana.

I had my tool and die maker buddy cut the x tubes so I feel like they’re pretty close in length. I couldn’t tell a difference standing them on end and looking at the tops.

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I’m thinking the xy main are warped a bit throwing everything off. I"m going to reprint at with higher quality settings and a skirt, after leveling the bed, and see if that helps.

I did loosen the x tube clamps and bump it, didn’t seem to help too much.
One wheel isn’t touching the rail consistently so another reason to take that section apart and try again! and then add hack tracks :slight_smile:

Two more theories I’d like to run by you guys.

Are the inside of the yz rollers supposed to be the same width?


The arm between the wooden y plate and bearing is thin.

the arm between the wooden y plate and bearing is thick.

My yz rollers have differing amounts of material on the same side of the pipe, seems like that could be an issue.

I’m wondering if I got some pieces swapped in the wrong area and that’s causing my wheels to be misaligned.

Theory two - y plates a bit warped. If I lay it on a flat table, push on one end, the other end raises up 2.86 mm. Doesn’t seem like enough to throw it that out of square but maybe it is?

Anyways, appreciate the help.

It would appear you have made a mistake with your Y Rollers.

On each Y plate you should be using one normal (YZ_Roller.stl) and a mirrored (YZ_Roller_M.stl) part so the thicker side of the part is touching the Y plate on all 4 rollers.

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Thanks.

I’m pretty sure I printed out both sides, just installed them wrong. I’ll switch them out and see how it goes!

(I love this place, so many helpful people)

I’m curious if the warped y-plate will cause minor tracking issues. Frankly, I’ve never come across a y-plate presented in this manner.

Before I took off the Y plate, I ordered some aluminum and gave it to my machinist buddy for milling. He’s been busy and hasn’t gotten to it yet.

I was going to wait for that to come back in but, since you are wondering, I’ll put the wood ones back on and make some more rectangles :slight_smile:

I wouldn’t worry about it. The way you demonstrated plywood warp and its impact on the y-plate was unique though the issue of warp is probably common. I used MDF to start, then plywood, then aluminum. I never gave warp any thought until now. Thanks for the post.

Did it anyways, I wanted to see how big the improvement was. Printing out the proper parts and swapping them definitely made my wheels pretty square with the x axis tubes

and made my 40 cm squares actually squarish


-moved my end stops a little bit with each square, bottom square was number one-

Still a decent amount of error in the system but at least now it’s in the fine tuning stage instead of gross build error stage (I think); belt tension, some y plate warpage,
Bolt clamp tension, etc. BUT NOT THE GRUB SCREWS because I loctited all axis and made sure they were seated properly; they should be good for a day or two at least lol

Thanks again for all the help!

One more pic.

Made a 40 mm part in inkscape, imported into ESTLcam and then stamped 2 more blocks vertically doing each part individually.

The bottom and middle measurement of the x axis cuts seems pretty decent +0.06 mm max but the top measurement is plus 0.14 mm.

Y axis seems to be about the same story 40mm up to +0.16mm

Since this is a relatively small square, I’m guessing I’ll need to straighten that out. But maybe that’s absolute error and I just need to make bigger parts so the error is less? I like that thought lol (I did do a finishing pass, chose a finishing tool and left the tolerance at 0.00 - so 5% of the tool bit diameter-1/8" single flute from V1)

More adjustment on the squareness as well.


Speeds and feeds


Measurements

Good enough for making some holding cams, and some other artsy stuff though. Off to have some fun!