Developing a 1911 pistol grip profile without a 3D model

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NewAgent45
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Joined: Sun Sep 08, 2013 8:29 am
Location: Edgewater, Florida, USA

Developing a 1911 pistol grip profile without a 3D model

Post by NewAgent45 »

I have been wanting to make some custom grips for my 1911 pistols for a while. I found a DXF file for the grips on the Vectric forum. The file does not have any 3D data for the arc profile. I dug back in my engineering tools and developed a series of toolpaths to accomplish this task. There may be simpler ways.

First we created a table of cut depths to be used for a series of tool paths across the width of the grips. We used an online calculator to first calculate the radius and then the height or depth to cut for each profile pass. http://mathopenref.com/arcradius.html

Using the calculator, we calculated the radius using a width of 1.6” and 0.125” for the mid-point height. I plan on using 1/4" material for the grips. See the attached image of the calculation formula.
Radius Calulation
Radius Calulation
We drew a one line vector and then used the Array copy tool to create an array of 1 row and 81 columns with x gap of 0.020” then we created a mirrored copy for the other grip. The next part is tedious. I grouped 4 vectors together except the center two which were a group of two. We plan to cut progressively deeper from the center out. We created a series of 41 toolpaths, one for each of the depths in the table. We saved time by duplicating and editing the first toolpath. Be sure to select the desired tool and edit the pass depth in this first toolpath. Note, the a pass depth of 0.015” was used so that multiple passes would automatically be created at the deeper cuts. I used a 0.125” round nose bit for my tool. You will only have to edit the depth on the toolpath copies. Since the tool is the same you may select all of the profile toolpaths at once and save as one “tap” file. We used very conservative settings and will likely make changes to speed up the job.

We determined the depth values for each profile cut by back calculating height based on the width at 2 x 0.020 (array gap) = 0.040” intervals
See the attached image showing the simulator results and VCP settings.
Results
Results
From the simulation this looks like this will work well for cutting the base profile. I'll make a test run and make any changes if needed. I have some other design work that I want to do before the test. My 1911's all have ambidextrous thumb safeties installed. I may need to modify the design to accommodate this change. I also plan on some inlay designs and some 3d carving designs too.

Have a great day!

... Rod

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