(UPDATE- SOLVED!) HELP! Vertical Lines not cutting correctly

UPDATE 5/21

SOLVED! TL;DR needed more weight on the sled. More info below original post.

Hello Everyone!

I’ve just finally set up my first Maslow and I want to love this thing so much….but I have not been able to get a decent cut out of it.

My main issue is that vertical cuts on the far left side of the board pull to the right by about an inch…meaning my straight lines 90º very quickly become squiggly near- 45º inclines. I’ve attached a couple photos of what I’m getting.

(Green = What the cut should look like / Red = what I’m getting)

My horizontal lines are perfect and vertical lines in other areas of the cut look good…it just seems to happen within 4-6 inches from the edge of the board.

I am using a triangular, ring kit from Maker Made with a z-axis. Here is what my setup looks like:


(with spindle and vacuum)

Things I’ve tried:

  • Recalibrating automatically (Literally 10s of times)

  • Recalibrating Manually (Probably about 30 times)

  • Ensuring the correct measurements between motors, the top of the work surface to the motors.

  • Resetting the correct chain length (More times than I can count)

  • Manually adjusting the chain sag correction (Though truthfully I have no idea what I’m doing here)

  • Manually adjusting the Chain tolerance

  • Adjusted spindle speed (best at about 12,000 RPM)

Just in case it is helpful, here are my measurements and settings:

I hope all of this information is helpful! I really want to get my Maslow up and running and have been beating my head against the wall for the last few weeks over this issue. ANY suggestions you may have would be greatly appreciated!

Thanks everyone!

UPDATE 5/21

Thank you all so much for all of the great ideas and comments. It ended up looking like @Gero and @dlang were right on the money. While I did not end up lengthening the top beam, I did upgrade from those bricks to some weights I found at Walmart (inspired by a bunch of threads here). I increased the weights from 5lb on each side to 7lb and that instantly solved the majority of the issue.


It is still pulling to the left about 3 mm…but I think that has more to do with what @dlang suggested about better centering the ring on the sled.

Thank you all again for the quick and helpful comments! I’m excited to FINALLY start cutting!

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If the first picture the bottom left corner? Vac-hose touching the floor?
Inside of the ring sanded, or does it have craters?

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If the top beam is 10ft, make it 12ft. The left chain cloud not enough force on the left side.
Increase weight to test.

Edit: bring the sheet up 100mm to test. (Motor-Y-offset ~350mm)

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Thanks for replying! Yes, the first image is of the bottom left corner, the Vac hose just barley touches the floor but I tested with the vac hose disconnected and still had the same cut trouble. Also, the ring is sanded and smooth.

So you are saying, change the top beam to 12ft in the settings (not the hardware) and increase the weight on the sled…as well as bringing the sheet up 100mm in the settings?

no, he is saying that you need more force in the bottom corner, so the right
answer is a longer top beam (in hardware and software) but you can verify it by
doing one of two things

  1. move the sheet up to avoid the problem area)

  2. add weight to the sled (you will need to calibrate again due to the added
    weight)

I am not at a place where I can see the pictures, just explaining what was
suggested.

David Lang

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Either could work or a combination. OSB is has also lots of friction.
@dlang has a spreadsheet where you can enter the numbers and get the forces, just can’t find the link right now.

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Thanks for the clarification! I’ll try this now!

I’ll test the weight now and will move the sheet. Also, what is OSB?

NVM just figured out OSB (Amazing what a quick google search can do!)

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from Gero’s comments, it sounds like you are running into the typical problem
when there isn’t enough force from gravity to overcome the friction of the sled.

you can increase the force available from gravity
wider top beam
heavier sled
tilt the system closer to vertical

or you can reduce the friction

 make the bottom of the sled slipprier, sand it till it's slick then wax it 

or something like that
make the surface it’s running on slipprier (avoid OSB, or at least sand it
well)

David Lang

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You might also get some improvement by making the bottom surface of your sled smoother. But the real solution is to lengthen your top beam as others have suggested.

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I second all the opinions about friction being a likely cause. The router bit is another place I would look. A dull bit can cause too much friction as it pushes through the wood. If you run the same file with the router retracted so it is not cutting do you see the same pattern?

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Now that the bit is mentioned,I think it could also be a to deap cut. How deep did you go and what is the bit? It could be pulling the sled to the side.

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Also make sure the router bit is perfectly centered in relation to the ring and chains, if your router is a just little bit low (as it looks from your pic) the drag will make the sled rotate ccw or cw depending on the direction of the cut.

It would make the cut path very similar to what you are getting.

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And also check the direction of cut. Sometimes cutting from lower to higher helps so that the cutting resistance works in your favor. This can sometimes be accomplished in the CAM step. Slowing the cutting speed can also help, but may also wear the bit prematurely. As stated above, a longer top beam is the best bet, if you have room for it.

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I wasn’t able to get a chance to look at the pictures last night (traveling and
unable to access a lot of stuff from work at my new job), but extending the top
beam will only help if the sled was trying to move sideways into the corner,
couldn’t move, and then was pulled up to make the angle

if the sled was trying to move down, extending the top beam won’t help, only
making the sled have less friction or heavier will help (tilting the frame
closer to vertical will reduce the friction)

David Lang

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From my side the biggest question is, was this total material in one cut?
(the material itself is worth a separate discussion)
This picture suggest it:


Just reducing the cut depth to half of bit diameter would be for me worth a test.

What strikes me more is that i see a familiar pattern that i used to know only at the top of the sheet, before upgrading shield and power supply. To see this " Déjà vu" at the lower bottom was not expected.
Shield over-powered because of Z-depth?

Edit: Not on the down move, on the horizontal.

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@jonas Depth of first cut please :slight_smile:

Video of the cut in that area would also help

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