Concept: Calibration Jig

I’ve mocked up a concept that I’m about to do a test print of, but I wanted to share the idea and reasoning behind it.

Calibration Jig

Idea: An option to hold the scanner and calibration board for calibration, rather than handheld method

Detail: I’ve worked professionally with imaging systems that utilize multiple sensors working in sync, and as such have a lot of experience with the different calibration methods. Revoscan’s calibration method is actually extremely similar to methods I’ve used previously, with the only difference being relying on the individual completing the calibration to handle the device during calibration.

The methods I’ve used previously had a commonality: The calibration pattern was on a fixed point that rotated along 2 axis. The imaging device being calibrated was fixed to a stable platform of some kind and only moved between calibration steps. This removed a wide amount of potential error that could occur due to coordination / instability of an individual trying to maintain smooth and steady motions.

  • Scanner can only slide forward and back
  • Scanner’s imaging sensors are centered to middle-point of board
    • Different scanners may require different heights. Carriage could be used with model-specific risers to perfect alignment
  • Calibration Board on dual axis rotation platform
    • Grooves and matching extrusions use friction to hold board in 30 degree angles

Gallery of Concept


I still need to print and test this, but if my experience with similar calibration processes holds true, this should allow for a higher quality calibration.

I could also be completely wrong, but I’m open to feedback and would love to discuss this with anyone who has any thoughts on the concept.

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That looks great. I love the idea.

Looking great ! I am actually always moving the board in place of the scanner , much easier .

Nice concept ! But how you address the far mode with the big boards ? That are a true challenge .

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I think it’s a great idea for the Revopoint Scanners.

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3d printed a jig for the fun of it. Not perfect but it does the job. No idea if it improves accuracy, but it definitely makes the process faster and simpler.


Geir

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2 side screws to hold the plate and a bottom screw to swivel sideways. The shoe fit is not perfect, but I managed to squeeze it in :grin: should have bothered to measure twice…

Needs to have some kind of minor scanner tilt & swivel adjustment as well to hit plate perfectly

  • scratch last comment, my height is off…

Great idea, thanks Kentacles!

Geir

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@PUTV Unfortunately I don’t have have the far mode calibration boards, so I can’t test those. :frowning:

@grukx Fantastic! I built mine but found I did have a little bit of vibrations on the board from the thin arms. Yours certainly looks sturdier!

Calibrating using mine was super quick, although I think I do need to modify the design to allow for a slight adjustment of the board on the horizontal and vertical axis, to account for slight deviations based on the angle of the sensor / position of the scanner. I’m thinking a pair of thumb screws beneath the board holder…

As an aside, how do you like your spacemouse? I’ve been considering getting one for a couple years but just kind of haven’t.

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Cannot live without my spacemouse, it’s like missing a limb… I have both the one you see and the small one without the extra buttons. They both do a great job. Takes a little to get used to, but even for a hobbyist like me it’s totally worth it.

Built mine with some random tubes I had lying around. It got a little bigger than I wanted, so printing was a bit of a pain time wise.

Great job ! We need that for yesterday ! :smile:

A question for the engineers at Revopoint: Does this accessory make sense? Will it help? Could you conduct some tests?

It makes sense and it is very helpful, it don’t matters if you move your device or you move the calibration board instead , the most important thing is you follow the calibration process .

The gear will actually calibrate much better than hand held calibration as it will avoid shaking .

Revopoint engineering team do not have the time for testing users stuff , they are very busy .
But I am Revopoint official Beta Tester and I do approve this gear .
I do calibrate all my devices this way since the begining .

I find the project interesting. Would anyone be willing to share their projects, either here or somewhere online? Thank you

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I will make such a preparation. But to make it work better, could a function be made to confirm the point that I’m on it?

What function ? What point ? Sorry , can you be more specific ?

The calibration process works by aiming at a target, and once you stabilize the position for a moment, the point’s result is recorded. However, when using such a calibration jig, it would be advisable to adjust the position and then manually confirm the current calibration point on the PC so that the calibration can continue to the next point.
Is it clear now, or should I create some illustrations?

The calibration process is taking pictures of the calibration board in specific position then calibrate the results between left and right sensors in relationship with the RGB camera , there is nothing else mysterious about .

It does not matters where the scanner in in space or where the calibration board is in space as long it can take a proper picture at specific distance or angle .

There is not need for anything else .

yes I understand the principle. but you defended this jig by using it too. Do you understand what function I want?

As seen in the video, the point is automatically confirmed at that moment. If there were a button and you had a jig, you could fine-tune the position precisely, ensuring both are stable, and then confirm the point

I understand , but sadly this will not happen .
With the reason that every firmware and scanner would need to be updated and everyone would need to buy a jig . I don’t see that happening.

It might be a language barrier or perhaps a difference in thinking. I’m saying there should be an option to switch it. I’m definitely not suggesting to redesign the calibration concept as you mentioned. There should be an option in the menu to switch from automatic confirmation to manual; it’s not that much work. I’m a programmer myself