Cost of Digitising Plans

I have some old drawings of a 23 foot launch that I did by hand many years ago that I'd quite like to get digitised so I can have some temporary mold frames CNC cut.
Boat is intended to be strip plank construction... nothing too fancy, just a little displacement hull with an open cockpit.
Can anyone tell me approx how much I ought to expect to pay to get the lines plan digitised (or from offsets) and the cut file for the frames?

 

If you want get a price send me on email with pictures of boat

 

I don't have any pics of the boat, sorry.. only drawings that are too big to scan.
I'm not after a quote as such... just an idea of what is typical cost....

 

Time required will depend on:

1. Completeness of the plans and offsets.
2. Fairness of the lines in the plans.
3. Quality of the offsets including how well the sets of lines intersect.
4. Complexity of the shape. A counter stern will add some time.
5. How close the digital result needs to be to the drawing.

Can you take a photo of the plans and post it?

 

Engineering firm charges about U.S. 20-25 per hour for drafting work. For a lage plan, it will have to be commercially scanned first, imported to ACAD, redrawn, then faired. That takes about 5 days per plan, about 40 hours work. An ACAD student graduate can do it for much less. Maybe 8 to 10 dollar per hour but slowem say 2 weeks.

 

Thanks guys...

Haven't been able to get a pic of the plans, but the boat is similar to the Bristol 22 - in appearance anyway.
I have a full set of lines and offsets.
How accurate they are I guess can only be determined by lofting them... but I think they should be reasonably accurate.
The resulting shape doesn't need to be a 100% copy of the original... but a close representation thereof.

By the way... would a designer normally use the offsets to create points then curves for a 3d model, or get the lines plan scanned and do it from that? (I'm assuming you'd need to go to a copying centre or something to get the drawings scanned? These for instance are on A1 or A0 paper...)

 

If the offsets were taken from the lines then it depends on the quality of the offsets vs the quality of the scan of the lines though I've worked from both. Quickest for me is usually to start with the offsets and refer to the lines as a backup.

If the offsets were taken directly from a lofting (not the case here) followed by drawing the lines, then I work from the offsets. I've found in such cases the lines may be more "illustrative" than accurate.

 

Also should note that there are two different approaches to "digitizing" lines. One is recreate the individual curves of the lines as splines, and then fair and reconcile the curves so they intersect to the degree desired. This is analogous to lofting but in electronic rather than physical space.

The other approach is to create an electronic 3D surface based on the lines and/or offsets and then fair the surface to the degree desired. Lines can then be very easily recreated by section the 3D surface, either with the stations, waterlines, buttocks etc in the original locations or in new locations. Same for curves representing CNC cutter paths and the like. Going from lines/offsets for the outer surface to the inner surface or vise-versa is also very straightforward and quick.

 

Thanks David... really appreciate it...
So what sort of numbers are we talking?
I'm not trying to pin anyone down to a quote here... especially not publicly.... just a ball-park figure....
Would expect that the 2nd procedure would be fine here....

 

If you have the offsets, it does not need to be scanned. The draftsman can work from the offsets. Just a little bit faster. Saves half a day's work. Needs electronic fairing though.

 

Why don't you do the job yourself?

Put some reference markers on the old drawing, fold it to fit the flatbed scanner and save the files as bitmaps. Then use a program like CorelDraw to put the parts back together again so you get an A1 or A0 bitmap. The program also has a utility named CorelTrace that makes vector graphics on another layer within a few minutes.
Some repairs must be made because the bitmap nearly always has some flaws like spots or broken lines and also the reference markers mus be removed.

Once you are satisfied, remove the bitmap and export the vector graphics in a file format your CAD program can read.

 

Another great technique is to get a copy of Freeship, or Delftship.

You can create a text file with the chine offsets, when you import it, it will create a 3d line drawing of the hull.

If you save that as a .dxf file, you can send that to the Cad guys to finish off the details, and for the NA to do the calcs.

 

I'm not a designer... just an interested boating enthusiast...Yes, I probably could get hold of a bunch of low-cost or freeware programs and learn how to do it myself. But I've always been a firm believer that it is usually less expensive and almost always more succesful to pay a professional to do stuff that you aren't trained to do yourself. I'm not saying I wouldn't have a go at it... but I'd probably still get a pro to check my work....

 

If you simply want to digitize the plans, there are programs available that can do that from a scanned file of your drawings. Search on Google. Adobe Illustrator is one such program. You can take your plans to a printing company that runs AutoCad prints for architects. Have them feed your drawings into their printing machine and save them to a PDF file. Open the PDF file in Adobe Illlustrator and then save it in DXF format. Open the DXF format file in AutoCad, and you can manipulate the drawing, set up patterns, print them back out at full scale back at your printer.

When I have done patterns for others, from scratch, drawings, or their 3D model, the cost can be anywhere from US$500 to US$2,000, depending on the amount of detail required. The better the original data or drawings, the lower the cost to convert. But these are pretty realistic prices.

I hope that helps.

Eric

 

Thanks Eric,
"Digitising" was probably the wrong word to use. What I meant was to take a set of (hand drawn) lines &/or offsets and turn them into a 3D model (Rhino I guess?) and then make a cutting file for mold frames etc.....