SoliForum - 3D Printing Community — App-controlled Smart Thumb-Screw idea

Re: App-controlled Smart Thumb-Screw idea

2018-02-08T16:21:12Z

I agree with Carl that bed leveling should not need to be done regularly. You should identify the cause of unstable bed leveling so that you can get consistent print quality.

In my experience, depend on the model of printer, the problematic part can be different. For those printer with dual z-axis, z-axis squaring before bed leveling are critical to achieve stable bed leveling. Unstable bed leveling can also caused by loosing z-axis endstop mounting and bed leveling spring pressed too tight or too loose. You can identify the best bed leveling spring by adjust the combination of z-axis endstop and bed leveling screw. Addition of 3D printed spring cups also helps for those don't come with spring cups.

The bed adhesion method also impact the stability indirectly. If you have to use strong force to remove the print, then it is hard to make the bed leveling stay the same. In my experience glass bed + glue is better than blue painters tape for example.

Put your printer on stable and leveled surface may also help. The vibration of the printer frame and movement of y-axis while print at high speed can also impact the stability of bed leveling.

I don't think there are anything wrong with the mechanism of auto level feature in Repeitier and Marlin, it does not work well for many people often because the calibration is off or reproducible measurement issue with low quality distance/pressure/proximity sensor, I don't think NASA will send cheap 3D printer to mars due to cost concern.

Re: App-controlled Smart Thumb-Screw idea

2018-02-08T00:41:45Z

Alternative idea would be to simply use the thumbscrew like a gear, or replace the thumbscrew with a lead screw nut and spring mounted to the board and use cheap 28BYJ-48 steppers with a small linear threaded rod to adjust it, mount them to all corners permanently, and just use an encoder to count/control rotations.
I don't see it as a bandaid, I see it as a solution to the problem of controlling another dimension on all printers that use manual thumbscrew adjustment.
It may not need readjustment very often in optimal conditions, but eventually it will.
If we really want to use 3D printers like automated machines with unattended remote prints, especially for things like building on mars, then we need to remove the human element.

Btw, the Mx2 comes with CAD files. Maybe we could get them printed by shapeways or embed them into plastic?

Re: App-controlled Smart Thumb-Screw idea

2018-02-08T00:30:59Z

There's a cluster-fuck of problems related to auto-levelling from what I've read so I don't know where to start.
Mine is measuring >4.6mm on all corners and I'm able to get the 3 measurements within .3mm to get it to print, but only because the hairspray makes ABS stick so well to the glass. The first layer is still printing in the air.
I have a feeling the sensor is not touching the contacts at all, but that doesn't make sense because it should fail, and when I adjust the clips I always get failed readings and from memory both the nozzle and sensor kept smashing into the metal plates / bed on auto-levelling and printing.

Re: App-controlled Smart Thumb-Screw idea

2018-02-08T00:11:03Z

It's a good idea but most controllers only have the capacity to handle 5 motors max while few can handle 7. Why not just adjust once and leave it? I am not sure why so many of our users seem to need to adjust their machines so often.
I have done 20 prints in the last few days making a moderator for an air rifle and I have yet to need to level from the last time I leveled over a year ago and have been printing near daily.

Rather than trying to put a band aid on the problem to make it easier to deal with, why not try and find the root of the issue and fix it for good or fix it so it needs to rarely be done? Either your screws need to be secured so they can't work loose, or you need to address the way you are removing your prints and handling the bed.

I have a mirror plate and I use hairspray. It heats to 90c. I wait till it is below 40c before I even attempt to remove the remove and it lifts right off with no issue at all. The bed never gets disturbed and my calibration stays consistent well for right now all year long.

As for the the auto level feature in Repeitier and Marlin, I think some are misunderstanding how it is supposed to function. You should not have to adjust your bed other than getting it near level. The auto feature will then probe your bed before each print in a preset matrix marking in memory the Z at each point. Once the print starts it is supposed to vary the Z in the region of each probe point by the value it recorded. You should not have to do anything yourself as far as adjusting goes.

No if your machine is not able to do that then chances are you need a main board with a 32bit controller so it can handle the calculations for the Z variance with out effecting the movement calculations. You could also consider getting a controller that runs Smoothieware as well as it is designed to do this leveling on the fly by adjusting the Z. unlike the others that had it added in as a beta function.

App-controlled Smart Thumb-Screw idea

2018-02-07T23:41:19Z

Hey guys. Long time reader, first time poster.
It seems retarded to me that we are manually adjusting the thumb screws to level an automatic machine.
We have the numbers to work out how many turns per mm offset.
I suggest we install these in place of the thumbscrews, take apart and reverse-engineer the MiniMag device to make an open source version, put an AS5048 hall effect sensor and an ESP8266 in it, and sync it up with repetier autoleveling.