Ultrasonic Alignment tool for Bed Leveling+zeroing of stage + Filament monitor

[dsayan]

dsayan, we've talked about accoustic metrics on bed level and zero position for years (my CTO has a lot of ultrasonic and megasonic experience), but never implemented anything. Since our heads are loaded by the user, their positioning can vary. Sonic detection is very interesting to us. I've forwarded your link to him.

Hey Davo,

Its glad to know you see the potential of this device and further talked with your CTO. Any update from him yet? And any suggestions to help promote our kickstarter campaign, we truly appreciate your help!

[curious aardvark]

I still don't see how you align the widget exactly with the print nozzle to start with and make sure it lines up with it each time you stick it back on.

I guess you could get the print nozzle to touch the bed and do the same with the widget, but it'll go out of alignment as soon as you change the print head temp, or the magentic strip shifts.

I'm obviously missing something :-)

Currently have 2 printers, both have different levelling procedures.

[dsayan]

Hey Curious, good question - for the purpose of bed leveling for your printers. With our sensor the position of the print head in respect to our sensor is not relevant, since we are measuring distance from a height above the bed plane. As long as the sensor is attached to the magnetic strip and not perturbed on purpose during the bed leveling procedure....Also to be noted the provided magnetic strip is industrial class and one has to really try hard to make it move from its position. It is one of its first kind so i totally understand your misunderstanding - with our device you wont need two different leveling technique for sure!
Hope it clears the confusion. Let me know if you have further questions!
And please suggest ways to get the word out to more people to make this project sucessful!

[dsayan]

Folks, Thanks so much for your support we have reached over 300 supporters of our project and have raised more than 25K, anyways good news is we have made some exciting changes on our project page - prices have been slashed for a limited time - check it out and let us know what you think? Here it is :
https://www.kickstarter.com/projects...or-3d-printers

[dsayan]

Check this Kickstarter project :


https://www.kickstarter.com/projects...or-3d-printers

Update : Folks, Thanks so much for your support we have reached over 300 supporters of our project and have raised more than 25K, anyways good news is we have made some exciting changes on our project page - prices have been slashed for a limited time - check it out and let us know what you think?

[curious aardvark]

prices don't look any different to me.

[ShadowX]

The concept seems very interesting. However, I think it can be a lot more successful and popular with 3D printer users if there is a rigid mount to maintain a fixed position on the print head and the device directly interfaces with the controller card probe interface.

The device should have the option to trigger at some set height above the bed and it should have an output signal that can be directly connected to most 3D printer probe endstops. If it can do that and maintain accurate/repeatable readings, it would be a great contact-less bed leveling tool that can use the automatic bed leveling systems already built into most modern firmware like Marlin, Repetier, DuetWifi, etc. The location of the probe in reference to the tip of the nozzle is critical and must be a fixed distance. Without a rigid mount, the measurements would not be repeatable if the device moved.

I honestly can't forsee myself doing a manual bed level each time I print with a separate software on a device that is attached with a magnet. Watching the video, the locations indicated for each spot is not even clear. Do you randomly pick a spot? The firmware in Repetier can probe over 40+ points on a bed and create a contour profile of the entire surface if needed. It can also do it without user interaction. Some beds are concave or convex and not planar. The leveling software in the video demo assumes the bed would be flat. I run an automatic bed level probing routine each time before I print. The height can change slightly just with temperature deltas between the hot end and the heated bed. Some of the changes can be enough to cause poor or too much adhesion on the first layers.

Another problem is most of the parts on or around my hot end are non-ferrous. I have a hot end cooling fin made of aluminum, a hot end block made of aluminum and fans and shrouds made of plastic. There is no place that is flat and magnetic for me to attach the device. I would have to design a custom bracket that is fixed or have magnets to use this device.

I hope you will be successful and become fully funded in your project. Its definitely a great endeavor. I would love to be able to use a device like this if it works seamlessly with the controller card.

[curious aardvark]

the device uses an adhesize magnetic strip that attaches to the print head. The measurer then magnetically attaches to the strip.
ie: no ferrous parts are needed. I've gota roll of magnetic sticky tape in my workshop, useful stuff.

So if the device doesn't need to line up with the printhead - how can you know how far the printhead is from the bed.
I know I'm labouring this point - but I just don't see how it works.

[wirlybird]

I am also a bit confused on how the device gets a registration point to use. When i used a dial indicator to level I would bring the bed touching the nozzle and then zero the dial. Back to paper now though!
I could see if the device was a more permanent mount that was a known distance but even then what if I change nozzles and it is a bit different than the last one?

[ShadowX]

It has to reference to the tip of the nozzle. Even if the device is accurate in itself, each level would be different if the device moves even slightly. I have not even factored the issue with the angle in reference to the nozzle tip. If the probe is at an angle, the distance measurement may change. It has to be rigidly mounted and the value between the sensor and the nozzle has to fixed. In fact, it has to be even more accurate than the measurement taken by at least a magnitude of 2 in order to provide accurate measurement.

i can understand if the device is useful for other types of machines such as CNC or routers, but for 3D printing, the distance of the nozzle to the print bed has to be less than the thickness of the print layer (typically, .2mm or .3mm). If it can not accurately measure to that level and be repeatable, it will not serve the 3D printing community well.

I provided a link to a typical use case for an automatic level probe in 3D printing. This is an IR probe that does not contact the bed surface. However, if this device can perform at the same level of accuracy and repeatability, it would be an interesting device to support. The IR probe in this video is around $25, so the price has to be competitive to it also. The IR probe does have limitations such as the the bed surface has to be reflective to the IR and not provide false readings. The probe also has to be very close to the surface the surface within 3mm. The ultrasonic sensor would eliminate some of those issues if it can compete at the same level. It also a tough market since there are other options such as mechanical switches, FSR sensors, and even a direct probe such as BLTouch.

The sensor may need to be as close to the tip of the nozzle as possible in delta printers. Delta printer effectors may have a tilt and you want the probe to be as close to the nozzle to minimize the effects of effector tilt. The size of the device is critical to be able to place it close to the nozzle without interfering with the air from the cooling fans.