digitizing problems

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shreddedcurbs
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digitizing problems

Post by shreddedcurbs »

I purchased the centroid controller and bundle. I cant for the life of me figure out how to replicate a skateboard deck contours and shape. I spent all this money just to replicate one skateboard deck.. i know i sound crazy.

anyways i mounted the skateboard deck, 'deck' being the wooden plank you ride, to my jig. the jig is 36" x 14" x 3/4". The 'deck' is 30.5" x 10.75" and 3". The actual thickness of the deck is a hair over 1/2" but its measured at 3" because both ends of the deck bend upwards.

How would I set this up to digitize? I thought grid would be best but maybe im doing something wrong
Muzzer
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Re: digitizing problems

Post by Muzzer »

Digitising apart, you might be better off modelling the board in Fusion, assuming your eventual aim is to machine a replica. That would allow you to modify it too, as a scanned model isn't going to be smooth and clean. To get a good resolution, you would require a lot of points which would take a long time and generate a large file.
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Re: digitizing problems

Post by shreddedcurbs »

I am unable to model it due to the concave of the skateboard. this is the longitudial bend of the skateboard from 'nose to tail'
shreddedcurbs
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Re: digitizing problems

Post by shreddedcurbs »

Muzzer wrote: Sun Nov 21, 2021 10:15 am Digitising apart, you might be better off modelling the board in Fusion, assuming your eventual aim is to machine a replica. That would allow you to modify it too, as a scanned model isn't going to be smooth and clean. To get a good resolution, you would require a lot of points which would take a long time and generate a large file.
wouldnt i be able to smoothen the probed model? if so, what would i use to do that? im trying to take the scanned deck and make 2 plugs, male and female, so that i can manufacture it on the small scale
Leo Voisine
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Re: digitizing problems

Post by Leo Voisine »

Shred,

I am with you on this.

I know what you are trying to do. I am trying to do the same thing. It sounds a LOT easier than it is in actuality. I am 95% sure it CAN be done - but the huge question is HOW.

Some folks will tell you that you can probe the surface - and you can. You end up with point cloud data, which is a series of points in X - Y - Z coordinates. Centroid does a really nice job creating G-Code with those data points - PERIOD - END of story. What can you do with those points? Well you can put a cutter in the spindle of your machine and recut the surface. That is the simple explanation.

But as Paul Harvey would say - Now for Page TWO. If you are too young for Paul Harvey he's a really cool story teller from my younger days - Internet search.

So Have I done what you want to do ------ NO.
Do I want to do it ------ YES
Do I know HOW to do it ----- NOT YET - but I will. I am persistent and I will most certainly learn HOW.

What I do know is very very small at this time, but maybe we can find the answer together.
I think there is "something" in Meshmixer - AND in MeshLab or something like that.
I was looking into it yesterday, but I was getting tired and a bit frustrated.
There is NOT going to be a quick easy answer. At least unless someone KNOWS how to do it.



There IS a way to take all those nice data points and create a model surface, either from the data points OR from the G-code and create an STL.
I also was able to backplot G-code to model in Cimco. Sweet - but not yet. I could not find a way to save an STL or other such 3D model.

I am digging, and digging pretty deep. In Centroid alone, I don't think it can be done. I can EASILY be wrong, but I don't think so. I don't see anything in Fusion 360 to be able to import the data points.

I have not yet upgraded to Centroid but I will be doing so this coming winter. With the upgrade I was planning on the probing and I am doing research BEFORE I jump into the probing.

I WILL be watching this thread and adding in anything I can help with. Kinda, like Blind leading the Blind.
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Re: digitizing problems

Post by Muzzer »

Fusion has powerful surface modelling tools. I suspect you may be thinking of this with a rectilinear / orthogonal CAD mindset. Using the spline tools and sweep operations and / or surface modelling tools makes the creation and editing of curved surfaces pretty quick and easy. You can even drive the design with a parameter table that will allow you to change the dimensions, angles etc from a set of variables in a table.

If you search for "Fusion 360 skateboard" you will find many examples of how you might approach this. As for Fusion surfacing examples, have a look at Fusion 360 School's excellent short videos to get a feel for what you can do. https://www.youtube.com/c/Fusion360School/videos.

For a more in-depth overview of surface tools in Fusion 360, Jason has done a typically excellent 101 video https://www.youtube.com/watch?v=HmgwKewMcw8.
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Re: digitizing problems

Post by tblough »

@Leo - I don't think STL will do what you need. STL is just tessellated points and not real surfaces. Most CAD systems can display then, but you will be unable to modify them.

@Shred - If it's just curved in two directions, you'd be much better off just measuring the curvature at various points both longitudinally and laterally and then creating a lofted surface using that curve data.
Cheers,

Tom
Confidence is the feeling you have before you fully understand the situation.
I have CDO. It's like OCD, but the letters are where they should be.
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Re: digitizing problems

Post by Leo Voisine »

Tom,

Yes 100% I can.

In Aspire I can import 3D .stl and modify it to my hearts content.

I don't know a lot about what happens in the C+ programming behind the screen, but the STL gets converted to an editable model.

I have done a fair amount of STL imports into Aspire.

Purely STL - yes I know it's a triangulation.
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Re: digitizing problems

Post by tblough »

Leo - great. You seem to have it worked out then. Don't forget that you'll need to offset your digitized surface one half the probe diameter to get back to the actual part surface.
Cheers,

Tom
Confidence is the feeling you have before you fully understand the situation.
I have CDO. It's like OCD, but the letters are where they should be.
Leo Voisine
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Re: digitizing problems

Post by Leo Voisine »

Tom, I have not yet figured out how to convert the point cloud data into STL.
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