First sign project
First tiling project (2 tiles X 18”(x) X 17”(y) for a total of 34” long)
First time using foam material - Professional foam board was a little bet to costly so we decided to try common foam material (Dow Chem. 2 inch thick Blue foam board)
First time painting foam board
First time using the Create Texture Vector Tool for wood grain background.
I learned a lot during this project and know there is room for improvement. I think the sign is adequate for the intended use for local craft shows.
- My first sign
Things learned:
(1) Foam board machines very easy and can run maximum tool feed rates. I’m listing my tool setting values for the slowest part of the job and would like hear how I might improve the time.
I’m cutting a pocket ½ inch deep between the text, 3D model and border so there is a lot of material to remove. I’m using a 1/4 inch diameter end-mill. A larger diameter bit I would lose detail.
Current Tool Settings are:
Tool” 0.25” 2-Flute Up-cut carbide endmill
Cut depth: 0.5”
Pass depth: 0.125” for 4 passes. Not sure if we could increase pass depth without sacrificing quality.
Stepover: 0.1 (40%) I think I may be able to increase this as I’m adding a separate texturing step to the bottom of the pocket to achieve a woodgrain effect. Any advice would be welcomed!
Spindle speed: 20,000 RPM
Feed rate: 250 ipm. Doesn’t the controller limit this to about 200 max?
Plunge rate 100 ipm
Tool path takes about 4 hours to complete.
At this point in the project the foam has taken all my more aggressive moves.
Someone on another forum has suggested selecting use large area clearance tool. Can someone comment with details on use of this feature?
(2) I learned that common foam board he some surface anomalies that should be considered. I ignored them for this project. These are most visible in the larger uncarved area like the outside boarder of the sign. One thought to eliminate this problem is to surface plane the entire face of the foam first. I’m not sure the material would handle a large (1 ¼ inch dia.) surface plaining bit. Any thoughts!
(3) Create Texture Vector - I had to stop the machine and change some settings for this tool path as follows. When I first started it the tool was overcutting the texture. As I understand the tool is running to the end of the vectors so I assumed I neglected allowing for the tool radius. I created offset boundaries for the boarder, text-curves and 3D model. Offsetting by 0.125 or the radius of the ¼” endmill. This helped but did not completely eliminate the problem. Am I missing something or do I just have to increase the offset? In this case I saw the small errors as adding to the rustic look of the sign. I used some standard wood filler to patch the outside boarder.
(4) I share my foam painting technique as follows. I used only water base latex paints applying the primer and background color coat with a commercial type airless sprayer with a 0.013”tip. None of the paint was thinned. I applied one coat of primer to the entire two sided sign allowed the primer to dry about 1 - 1.5 –ours. Then I applied one coat of color and allowed to dry overnight. The 3D bear was painter by hand with a brush with Black semi-gloss latex paint. WE used the same black paint to paint the face of the letters using a small 1” dia. by 3” roller. I minimized the paint loading on the roller. I took a 1” wide piece of ¼” MDF and loaded it with some paint using a brush then rolled the paint onto the roller I did this several time to control the amount of paint on the center portion of the roller. The paint I used was thick and did not have any tendency to drip. I hung the sign while painting it so the surface was perpendicular to the ground. I was delighted no touch-up of the color coat was needed.
(5) Tiling – Worked well here and the match line between tiles was almost invisible. I clamped a piece of aluminum to my table parallel with the y axis. When I slide the material to line-up for the second tile I positioned the material with the cut x boundary centered with the tool position at (x, y) = 0.
I’m kind of a retired hobbyist and welcome all constructive comments and advice.
Have a great day!
… Rod
