# 3D Design / 3D Scanning / 3D Modeling > 3D Modeling, Design, Scanners >  Want to modify a complex shaped plastic part; need a good, inexpensive, scan/service

## robosmith

It's black plastic and shiny. Double whammy.

I tried coating it with flour and using the Makerbot digitizer again, after it failed with just a big glob the first time.

While the Makerbot digitizer produced something which looks similar to half of the original part, correcting the imperfections is still a large job.

Does anyone know of a service which can handle this job?

Mods: if this is the wrong place for this post, please move it.

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## JSenior

What is it/can we see a pic?

Developer spray is normally the best thing to use for coating an object

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## robosmith

> What is it/can we see a pic?
> 
> Developer spray is normally the best thing to use for coating an object


It is a tray for my refrigerator ice/water dispenser. I'll post the pix when I get home.

IMG_1132.JPGIMG_1131.JPG

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## LambdaFF

Man you're better off designing it yourself. Seriously.
Put it on a sheet of paper with 5mm squares, trace the outline and measure a dozen points. These will serve you as a reference for a spline. The inside groove is probably just as simple to design.
I'm guessing it won't take more than 30 minutes.

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## curious aardvark

well if you have to learn a cad package first - could take a bit longer than 30 mins. But yeah looking at it. 
that's the route I'd go. 

bit trickier in openscad, but easily doable.

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## LambdaFF

Just put a sketch with a few measurements.

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## robosmith

> Man you're better off designing it yourself. Seriously.
> Put it on a sheet of paper with 5mm squares, trace the outline and measure a dozen points. These will serve you as a reference for a spline. The inside groove is probably just as simple to design.
> I'm guessing it won't take more than 30 minutes.


IME, your estimate is wildly over-optimistic. I've already spent more than 30 min and I have the rough shape from the Makerbot digitizer.

I'm using Sketchup, which does not seem to have a spline curve tool.

Doesn't anyone here know of a service which can scan this?

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## beerdart

Take a pic of the item import into sketchup and trace it with the follow me tool.

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## robosmith

> Take a pic of the item import into sketchup and trace it with the follow me tool.


Thanks for the suggestion. I've only used "follow me" to make a sphere (from a circle and a curve). It's not clear to me exactly how to use it as you describe.

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## LambdaFF

> IME, your estimate is wildly over-optimistic.


Put here a sketch with key dimensions, I'll design it for you.

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## robosmith

> Put here a sketch with key dimensions, I'll design it for you.


Thanks for your offer, but I have imported a photo into sketchup, scaled it to the major dimensions, and attempted to trace the outlines. 

I spent 3+ hours on it, including the enhancement pieces, and printed out the base part. Unfortunately the photo did not scale exactly and some of the features I missed were critical, so I'll be investing more time to get it right.

I was hoping to avoid this by getting a dimensionally accurate scan, but I guess that's hard to come by.

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## LambdaFF

... Probably not that hard but definitely expensive.

My company has several such scanners and the handlers have become "experts" with time and experiments : they get requests from the Group to do things on a steady basis. It would be hard / costly for a small company to keep that kind of expertise.

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## JSenior

As above, there's plenty of companies that can do it, but I'm not sure it's going to be cost effective assuming it's just for a personal project (you're talking an hours work using $100k of specialised equipment and software.)


Saying that: if you want to send in to Britain (and don't need me to return it  :Smile:  ) then I'll do it for beer tokens.

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## Marm

Ok, getting the outer shape is easy, you're making this way to hard on your self.   Do the same steps as above, but when you take your photo, put a ruler in the pic, say a 20mm length.  Then when you import the photo into SU, draw a 20mm line, and scale the photo to match that line.  Bingo, 100% scaling.    Then use the arc tool to make the arcs, tracing the picture.  If it's a number of arcs with different radii, then make multiple arcs, but only half the item.  Then copy/rotate the half arc into a bigger one.  

As mentioned.   30 minutes.  

But to be honest, I'm guessing every dimension is not critical.  There are probably some parts that are open to the air, so design a new one to fit the attachment points, and the rest just needs to be close.

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## LambdaFF

> Ok, getting the outer shape is easy, you're making this way to hard on your self.   Do the same steps as above, but when you take your photo, put a ruler in the pic, say a 20mm length.


Works too. Splines are cleaner. :-)




> As mentioned. 30 minutes. .


 Yep.

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## Marm

You need a reference point, to know how long your scan/photo is.

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## robosmith

Thanks for your offer J. If I can find the part for purchase in the UK, I'll have it shipped to you. So far, I've only found it in the US. It's a drip tray for a Frigidaire refrigerator water dispenser.

http://www.searspartsdirect.com/part...FUWVfgodLGcA7g

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## JSenior

No Problem.

I can't see anywhere in the UK that does it (we don't really have fridge freezers.) There are plenty of places that will ship to the UK but want $25 or so for postage.

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## Marm

Hmm... at that cost, the time spent making one may not be worth it!   That said, I'm still intrigued by reverse engineering it.  A set of calipers should do you fine, and it looks like, to my eye, there only 3 radii to deal with , so you might be able to get it into SU, and use the arc tool to semi-easily create those radii.   Oh well....

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## robosmith

> Hmm... at that cost, the time spent making one may not be worth it!   That said, I'm still intrigued by reverse engineering it.  A set of calipers should do you fine, and it looks like, to my eye, there only 3 radii to deal with , so you might be able to get it into SU, and use the arc tool to semi-easily create those radii.   Oh well....


Yeah, I'm well past the major radii. I spent a few more hours on it last night and am almost there. The key was those two tabs in the corners which hold it in place. 

Of course the 5 hours I've already spent include the enhancements, not just the original part.

Seems like there may be a major market developing for inexpensive scanners that really work reliably.

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## robosmith

> You need a reference point, to know how long your scan/photo is.


You know, I probably should have used a 2D scanner instead of a photo.

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## Marm

> Seems like there may be a major market developing for inexpensive scanners that _really work reliably_.


And there's the rub.

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## Marm

> You know, I probably should have used a 2D scanner instead of a photo.


Yeah, When recreating bulkheads for my boat (Which have a lot of radii in them, I gave up trying), I used a flatbed scanner, that way it gave me the exact edge.

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## robosmith

Well, I think I've finally got a part that's close enough fit.

One surface that looked flat is actually sloped. My first cut had a same sized edge overhang all the way around, but the actual part varies continuously with a couple of notches.

All told I spent a good 5 hours and 3 prints. Would be nice if there were a good scanning service.

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