[rwskinner]

Is there a good way I can cheat and scan a part and import it into my CAM program so I have at least some vectors to start out with?

I want to make some Aluminum A Frames for my son's RC but it will take lots of work to design them from scratch in my CAD program.

Richard

[gd.marsh]

Richard,

There's a little utility program I downloaded from the net called 'OutlineART'
I haven't had the opportunity to use it a lot, but it seems to work fine.

TTF to DXF converter,OutlineART transforms TTF text and symbols to DXF polyline
$29.95

[cornbinder23]

Come on Richard 10 min and some calipers:stickpoke:stickpoke
What RC? I might already have the .dxf

JTCUSTOMS

[hoss2006]

Not going straight from a scan to CAM like you asked but Scan2CAD looks to do the job
of converting a scan into vectors that can make a dxf.
Haven't tried it yet but been meaning to.
Scan2CAD - Convert Raster To Vector - PDF To Vector & More
I've used Wintopo with ok results.
Tormach has their CNC Scanner.
http://www.tormach.com/product_cnc_scanner.html
Hoss

[gd.marsh]

Sorry My Bad ..

Gave you the wrong link .. the one I previously indicated is for tracing text ..
As I said I haven't used these a lot so mistakenly pointed you to the wrong program ..
This is the one I was thinking of .. 'TraceART'
There's many links if you do a google search ..

Gary

[geoffd]

You could try a 3D image, which would give you an stl file, then use OpenScad's 3D to 2D operations to create the DXF.

I've had some fair results creating 3D images with this: 123DCatch currently it is free.

[pete from TN]

Dunno if this helps or not but I have been faced with that problem before. I had to build a part from a picture I saw on the net. I finally found that I could take the picture and import it into my Cad software and once I have it loaded up I simply scale it to a KNOWN distance on the part. For instance if two holes are some specific distance I then just scale the whole thing to that distance and then I can simply draw over the picture on another layer of the drawing. Works pretty good and is simple. You still wind up drawing the whole part of course but at least you are not having to measure every damn feature. I know when I used to be a Professional high end cabinet builder the guys who did the granite counter tops used a system like this to measure and template the drawings. They had some special little plastic signs that they would lay all over the tops of the actual cabinets and that would show where the corners and whatnot were. Then they would take a bunch of high res digital pictures of the installation from different angles and take it back to the shop where they had software that could differentiate the distances based on the sizes of the plastic chips in the pictures. It was amazingly accurate and the guys we used always hit the marks with the installed counter tops. I have done the digital camera thing on a part or two and used it to draw from but it only works when you have a quality up close picture taken from the right perspective. Like right over top or right facing the side you want to machine from. It does work tho and for small parts you would be surprised at how accurate it can be.

I will need to look at that scan to cad software... looks interesting. Someday someone will build a CHEAP 3d scanner for guys like use to be able to use. I know that someone on machsupport was working on one using a laser pointer and a digital webcam but it looked pretty basic at the time I last looked at it. Still amazing but needs more work. Peace

Pete

[rwskinner]

Your better a CAD than me
We need to do them for a Tmaxx, however he has a XTM Mammoth, and a couple of Kocero? Buggies.

Richard

Come on Richard 10 min and some calipers:stickpoke:stickpoke
What RC? I might already have the .dxf

JTCUSTOMS

[rwskinner]

Thanks for all the input guys. I'm going to play around with a flatbed scanner and see how close that comes with some of the software you all pointed me to. I saw on the net where Eartaker did some RC parts for a Savage and used Ras2Vec and also seemed to have luck.

I also thought about using one of the touch probes like:
CNC4PC

I have looked at it for awhile and wasn't sure how well it would work. Most the others are priced in the thousands $$$.

I plan on doing some 3D stuff in the future so a probe may be handy for mapping other items as well?

Richard

[Fastest1]

That is Zarzul's probe. It works great and is adjustable. Well worth the money. I am sure it isnt the accuracy or quality of a Reinshaw but it works very good for a 20th of the price.

[jid2]

There is no silver bullet for this even with high dollar tools. We run into this problem at work. Sure you can scan and then convert to outlines etc, but there will always be alot of noise in the lines. Same with 3D, we get high resolution scans of products, and all you can use them for is a reference while creating the model from scratch in the CAD program.

A simple A-Arm or RC part should be easy to model. Spend some time getting good at your CAD package and it will payout in the longrun for sure.

[Pete Stenabaugh]

Listen to these guys, they have been there before..... The problem with a scan is that the scan is only a raster image made up of dots. You then have to convert the dots to vectors, and although there are several programs out there that will do most of the job..... in the end you always HAVE to clean up the drawing in a cad program. So dont bother wasting your time to piddle around with it, just draw the thing to start with and be done with it. An A frame drawing cant take more than a hour start to finish and you will easily end up wasting 3 or 4 times that with a scan.

Now if you want to talk about 3D scanning that gets a bit more technical and the easiest way to do that is to look at the 'David' software. This is best for the least when it comes to 3D scanning to create a point cloud file that you can now import into a cad program to create an .stl file for machining. This isnt perfect either, but it is pretty good.

Pete

[LowryIndustries]

Pete above is right.

I just finished using the last scan I will probably ever use. It was a 3d laser of a moderately complex part. The idea was to see if the laser (which is an expensive system) could produce a dimensionally accurate part which I could convert into a solid.

The file came to me as a huge STL file, but it was not "Closed", that is the scan did not have a continuous surface.

Because it didn't have a continuous surface it could not be converted into a solid.

As it exist today, current laser and touch probe scanning is limited to simple surfaces without any internal structure.

Scanning simply cannot "fill in" complex shapes adequately.

So why scan? It's easier, quicker, and more accurate to model from scratch a simple surface, and more complex surfaces simply don't work.

Take a picture or use a flatbed scanner instead as explained above.

[Pete Stenabaugh]

Laser scanning actually can reproduce very fine detail as this is done in several aspects of industry for reverse engineering. There are still likely some details that might be overlooked, but it all depends on what you need to create. As far as accuracy is concerned, 3D laser scanning can pick discrepencies and surface features as fine as about .004" - depending on the laser - and the software that is used to decode the information.

I have a friend in the oil industry who is writing software to decode such information. They are using an expensive ($15,000) laser scanner to scan a 3" wide path in a single pass, to pick up the surface corrosion on pipes. This information is then converted into a graphic file so that the pipeline owner can then visually see how much corrosion is on the pipe and determine how they might want to deal with it, repair or replace, or put it on the back burner for a couple years.

So you see, it can be done, but how much are you prepared to pay for the final information?

The 3D laser scanning process that is accomplished using the David software and system can be a bit expensive depending again on the laser used, and how complex your setup might be. There are several options one can use.

The David software now has the ability to completely stitch several scans together to create a full 360 degree 3D model, but I am not sure how accurate it will be when this comes down to surface irregularities and details. I am quite certain that like anything else, there is a trade off between what your end results are, and how easy and inexpensive it is to get them.

I havent tried the David software myself yet, but I do find it intriguing. I may take a look at it later on next year, and maybe work in conjunction with my friend who is writing the decoding software to see what can be done to use my 4 axis cnc router as a platform for the scanning.

Pete.

[LongRat]

I work for a company that makes scanners and digitising equipment, both laser and contact based. While these can be used for simple 2D and 2.5D parts, this is very rarely worth the investment and you need good quality post processing to turn the data into a vector format drawing or a solid model. This post processing it what most people lack when they say that scanning can not deliver the type of model they require. It is also the part that quite often can cost more than the scanner itself.
Our scanners are sold into the dental industry where the detail resolution requirements and accuracy are very high. The point to note is that the surfaces to be scanned are complex, free form and without primatic sides or straight edges like a normal engineering component might be. Large STL files are the norm here. Contact scanners currently win in both resolution and accuracy but take longer to capture large areas of data. Quite often the trade-off in accuracy isn't a problem and optical methods are preferred because of the speed. Scanner accuracy in this industry ranges for ±0.02mm over a 90mm spherical volume up to ±0.25mm depending on the scanner type, origin and cost etc.