Scanning plate parts for plasma cutting

[kn612]

What are some tips for scanning stuff you want to duplicate? Are there tracing tricks in inkscape that avoids the shadows that show up after scanning?

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[acourtjester]

there are 2 things I would do to get accurate parts sizes. First orientate the parts so it fits inside the box shown so you can check its dimensions better.
A slight rotation as the right side upper corner needs to match the left side upper corner. This will allow Inkscape to give you an top to bottom and left to right accurate size.
Next would be the holes in the part, using the circle tool make copies of each hole size and place them over the holes in the part to insure you are getting the correct sizes. Again allow Inkscape to show the hole sizes to check on your part when placed over them. Use a small of a line width for the holes to be sure you are accurate. You may need to break the part into its elements to get each hole size dimension in Inkscape. hope that help

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[Joe Jones]

When you use a copier, it will produce the shadows when you lower the lid directly onto the part.

Try to copy the part again, and place a pure white smooth plastic bowl over the part instead. You will get a copy of the part profile without the shadows.

Joe

[kn612]

Appreciate it guys! I can work with it now. Pretty neat trick with the white bowl

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[Joe Jones]

Sorry. Make the edge of the white bowl BLACK and the scanner will brighten the image of the shape you are scanning. You can place a strip of black electrical tape over the bowl edge, or color it with a black marker, etc.

Joe

[Joe Jones]

I assumed a smaller hole diameter of .375" to trace it. If that hole is smaller (or larger) then scale the entire drawing to suit your needs.

Joe

JJ GASKET DXF.dxf

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[kn612]

Eagle eye Joe. Yeah they are 3/8". Fits like a glove. Thank you!

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[Joe Jones]

Eagle eye Joe. Yeah they are 3/8". Fits like a glove. Thank you!

It was an educated guess.

Joe

[adbuch]

All the techniques offered are great! I'm glad the finished part worked out for you. It all depends on exactly how accurate the hole spacing needs to be for proper fitment. I often resort to using pins in the holes to measure the exact dimensions between holes and adjust the drawing accordingly. I'm not sure exactly what the end use is for this part and how closely the mating part fits. Sometimes we get lucky, and other times need to make edits to the drawing. It looks like you hit it out of the park on your first swing.

David

[sonbakler]

That bowl trick of Joe's is a great idea and something I would never have thought of. I always traced the part with a pen onto a piece of paper and then scanned that to eliminate shawdows. Thanks for the tip Joe.

[Joe Jones]

That bowl trick of Joe's is a great idea and something I would never have thought of. I always traced the part with a pen onto a piece of paper and then scanned that to eliminate shawdows. Thanks for the tip Joe.

I am glad it helped. The white edge of the bowl adjusts the scan exposure, which is why the part is slightly dark. With a black RIM around the white bowl, the exposure of the part should probably be better, although I have not personally tried it to verify my suspicion.

Joe

[tinspark]

When you use a copier, it will produce the shadows when you lower the lid directly onto the part.

Try to copy the part again, and place a pure white smooth plastic bowl over the part instead. You will get a copy of the part profile without the shadows.

Joe

Wow, that is a great tip Joe.. Will try to remember that one

[kn612]

Yep, a black tape edge on the bowl makes the image even sharper.

[Joe Jones]

"The years force a certain amount of wisdom upon you, whether you like it or not." - Charlie Evans Jeffers (Barney Miller)

Joe

[adbuch]

Yep, a black tape edge on the bowl makes the image even sharper.

This is a great technique for scanning smaller parts. Unfortunately it does not work for parts larger than the scanning bed - typically 8 1/2 x 11 in size. Yes - there may be larger flat bed scanners, but for many this is not an option. For larger objects one option is to work from a photo. Other more expensive options are to use something like the Calcomp digitizing board, or perhaps the Scanything program from Les Newall combined with an inexpensive digital camera/lamp attached to a cnc router/plasma table. I have both of these options available to me and they can work quite well.

David

[Joe Jones]

A friend in Tennessee has his own private movie theater. It is awesome, with a 14'x10' screen. 24 seats, a full snack bar, a kitchen, a game room, a weight room, his and hers bathrooms, a kiddie room (when the movie may be too violent for small kids), a billiard room, and a large workshop/storage area. He has movie nights, and invites church folks over to watch live telecasts of revivals, etc. We used to do THE WALKING DEAD weekly viewing in the theater on Sunday nights!

I discovered (by accident) that when the projector is on and no movie is playing, I can hold up something in the projection light and get a razor sharp profile shadow of the item on the white screen. I can photograph the profile and the proportional, undistorted profile converts easily into vector software. So I can suspend a rifle from two wires under a PVC frame for example, and get an exact profile of the gun with the scope and grips, and any other accessories that are on the gun. I can then cut a custom foam insert for a gun case using my lasers. I am going to experiment with people profiles for Christmas ornaments soon. I think I can create some neat ornaments with detailed profiles of kids and family members.

Joe

[Joe Jones]

This is a great technique for scanning smaller parts. Unfortunately it does not work for parts larger than the scanning bed - typically 8 1/2 x 11 in size. Yes - there may be larger flat bed scanners, but for many this is not an option. For larger objects one option is to work from a photo. Other more expensive options are to use something like the Calcomp digitizing board, or perhaps the Scanything program from Les Newall combined with an inexpensive digital camera/lamp attached to a cnc router/plasma table. I have both of these options available to me and they can work quite well.

David

Thanks for reminding me ... I really need to unpack my 44"x60" LogicTrace board and set it up. I bought the thing in 2018, and it has been sitting in my wood shop in the original box for ... five year now!

Joe