As part of an antique tall case clock restoration, the two fretwork panels on the bonnet were missing or broken. The fix seems perfect for my primo mpcnc. It appears that 1/4 inch mahogany could be cut out to replicate the original damaged and missing pieces. My goal was to transform a pencil trace and convert to an svg or dxf file ready for Estlcam and cutting with a 1/16 cutter. I descended into a deep rabbit hole with my attempts to create the cnc ready file.
My cry Uncle plan B is to cut the design with a jewelers saw. Could be done, but why give up?
My first step was to pencil trace around one of the missing pieces and then fill in the remaining broken pieces with my limited artistic ability. I scanned the pencil drawing with my epson scanner and created a png image. Here is what the scanned pencil trace looks like (the piece sits horizontally on the top of the clock bonnet):
I then tried to use inkscape to convert to svg but the pencil traces are a bit jagged and not smooth. I then asked AI (heaven forbid) to smooth it out for me with strict instructions to keep the aspect ratio and dimension. The co-pilot AI did a good job with this but I had to re–scale back to proper size in inkscape. The flat edge at the bottom of the picture is 69mm. Here is the smoothed panel:
So far so good I thought, then the conversion effort to produce svg pushed me into a deep rabbit hole. Help files on inkscape told me to create paths, ungroup, combine or simplify and then save as plain svg or several other svg choices like R12 and R14. All of these attempts were rejected by Estlcam V11 upon opening and rejected by Libre CAD which I recruited to “clean up” the svg. I tried so many variations based on help files and even AI advice sent me round and round without a solution.
So a task to taking a pencil drawing to scale and convert to a file for CNC cutting seems impossible. But, how can this be? Surely folks do this all the time…
I turn now to my V1 forum friends with their collective wisdom to suggest a method for me to create a cnc ready file for Estlcam to cut outside of the panel and holes. Then I would clean it up with tiny files and careful sanding.
I took your SmoothLines004 image and imported into Inkscape. Did a centerline trace and exported as PDF. I then used an online converter and/or LightBurn to convert the PDF to DXF format. Opened in Estlcam 10. Are you sure that the straight bottom line isn’t ~96mm instead of 69mm? Scale it, if necessary.
Thank you all, these suggestions are really good. I tried the millmage trace which was straight forward but Estlcam scribbled messages when I selected the outline for cutting. It might be some tweaks in the trace settings to get Estlcam happy.
Next I’ll try dkj4linux’s method of centerline trace and pdf to convert to dxf. Clearly it works as in the screen shots. I’ll rescale to make sure that the flat edge matches my physical fretwork straight edge of 69mm. Then I’ll try a thin plywood cutout to see how it fits the clock bonnet.
Thanks so much for the rescue rope to pull me out of the rabbit hole!
Excellent, all these methods are working and Estlcam is happy for me to select outline and holes! Now to verify scaling and perform test cuts. Then onto mahogany for the real cutting.
