creating a tool path from a pattern

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Platterivershark
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Joined: Wed Aug 04, 2010 5:31 pm

creating a tool path from a pattern

Post by Platterivershark »

I recently created a freehand pattern from a piece of foam board, and ground it to exact fit in order to make a wind deflector for a convertible when the top is down. This turned out so well that I have been asked to reproduce it. Rather than cut it on the bandsaw and file the edges I thought I might put the Shark to work.

I wondered if anyone has taken a pattern and created a tool path of exact proportion as the original. I have used photos and hand drawings to produce products, but I have never had to replicate a pattern to exact size.
Anyone have a starting point?

Not that it matter much but, I will be cutting these from acrylic sheets and finishing the edges.
Thanks in advance

Dave Kline
Platteriver Shark
From the only deepwater port on the Platte ;-}

jeb2cav
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Re: creating a tool path from a pattern

Post by jeb2cav »

Hi Dave - I have successfully reproduced a pattern I cut using a flat bed scanner. Even if I had to make several scans (I'd put some marks on the piece prior to scanning so that it was easy to piece them together), I was able to piece it back together. This was really 2D though. If this piece is 3D, the touch probe might work for you on this.

Platterivershark
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Re: creating a tool path from a pattern

Post by Platterivershark »

Thanks Joe,
This piece is 2D, but it is 22.5" X 9". All 4 sides have curves, so there is no real reference points. I have been thinking about laying it out as a graph in one inch squares. Does that make any sense?
Dave

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Re: creating a tool path from a pattern

Post by jeb2cav »

That would be another way - work out a grid and then use that as a reference when you draw it. I assumed it was bigger than a home scanner bed. I've done this twice, and in both cases I had to do 2 or more scans to get the whole piece. I placed a few black tick marks along the edges of the piece, you have to scan the tick on "either side" of 2 separate scans. Then used a photo program to merge the images using the tick marks as the reference points, then imported the picture into VCarve and generated vectors from that.

Another thing you might try is to trace this out on graph paper of some sort and scan the graph paper in chunks. You wouldn't necessarily have to merge in a photo program ahead of time, just line them up in VCarve and generate the vectors. Place some cross ticks outside the piece on the graph paper to use as a reference to ensure the picture is the "right size" when imported into VCarve (using the guides that you could set up in the VCarve window).

I'm trying to think of ways to avoid or minimize hand drawing...

And again, when I say reference points, I'm really talking about reference points to help you align the individual scans. If you have a flat bed scanner capable of letter size paper, you have a 1 x 3 or 1x4 chunk scan. If it can handle 14" long paper, you've got a 1x2 scan. You'd pick the reference points along the "chunk edges" as you're going to overlap the resulting jpg files using these marks. Hope that makes sense.

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rapiddawg
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Re: creating a tool path from a pattern

Post by rapiddawg »

Is it to big to use a probe?

jeb2cav
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Re: creating a tool path from a pattern

Post by jeb2cav »

According to Dave, the piece is 22.5" x 9" - so probe coverage is there.

Novexcomm
Posts: 1
Joined: Mon Jan 03, 2022 8:51 pm

Re: creating a tool path from a pattern

Post by Novexcomm »

You guys may be on the way to resolving an issue I have; I am a vintage radio collector and bought a 1938 radio chassis that is missing the original and very complex steam-bent plywood cabinet. You can see what this really incredible cabinet work looks like at the link below. Anyway; I recently visited a nearby fellow who owns the same radio and we traced his cabinet outline on paper and I wonder if there is a touch probe attachment I can use to get the Z axis for this as the cabinet could be milled in "slices" and stacked one atop the other and glued to make the 6.5" "depth" of it. Overall 14" wide X 9" height by 6.5" deep cabinet and here is the link to another fellow's radio to get some idea of what i am up against. Open to any crazy suggestion but I assume I get like 1" thick blocks maybe 10 X 15" size birch or maybe spruce and mill out the front for the tuning dial and speaker, 4 holes for knob shafts, you will get the idea here:

https://www.antiqueradios.com/forums/vi ... p?t=113829

Thanks! Bob Burchett
Calls are GREAT and appreciated to my cell phone 310.686.9973

JRonld
Posts: 2
Joined: Sun Nov 29, 2020 12:49 pm

Re: creating a tool path from a pattern

Post by JRonld »

Platterivershark wrote:
Sat Mar 05, 2011 4:29 pm
I recently created a freehand pattern from a piece of foam board, and ground it to exact fit in order to make a wind deflector for a convertible when the top is down. This turned out so well that I have been asked to reproduce it. Rather than cut it on the bandsaw and file the edges I thought I might put the Shark to work.

I wondered if anyone has taken a pattern and created a tool path of exact proportion as the original. I have used photos and hand drawings to produce products, but I have never had to replicate a pattern to exact size.
Anyone have a starting point?

Not that it matter much but, I will be cutting these from acrylic sheets and finishing the edges.
Thanks in advance

Dave Kline
Platteriver Shark
From the only deepwater port on the Platte ;-}
Hi Dave,
I'm a newbee so don't claim to be an expert at this, but I do enjoy a challenge. I enjoy Mark Lindsay U-tube videos (for absolute beginners); look for "importing" pictures. Sev different formats can be used including PDF files. Also look for Garrett Fromme U-tube videos. Both of these guys produce great instructional videos.
I will often open a VCarve file and work along with Mark's video. If I miss a point I can back-up for clarification.

If I were going to attempt your project I would just take a picture of the item, import the pic and go from there; the size of the image is not critical, the project size can be adjusted in VCarve to what you need. I use VCarve DESKTOP software.
Plan B would be to trace around the object, photo the tracing and import it, then adjust it to your needed size.
From my limited knowledge this seems to be a fairly simple 2D, flat carving basically doing on the CNC what would be done on a band saw.

Good Luck!
Ron

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