Geocaching Logo from Corian

[JohnJackson]

My adult son asked me to make a Geocaching logo to be affixed to a piece of limestone and placed in a flower bed. Normally geocaches are meant to be hidden, but in this case the building owner wanted the cache to be obvious so cachers were not destroying the flower bed looking. For those who are unfamiliar with geocaching, it is a treasure hunt done with a GPS - see Geocachine.com for more info.

The logo needed to survive Canadian winters, slush, rain, etc.

I made the logo from 0.5" corian and painted it with rustoleum spray paint, masking off each zone and putting two coats for each colour, then removing the masking and a light sanding took care of any overspray. The final result was attached to the rock with silicone.

There are tool marks in the VCarving which has been suggested is due to my 90 degree bit not being 90 degrees - will test that out after I get back from the user group meeting.

The carved logo just off the CNC

Masked each colour one by one using painter't tape.

One colour done!

All colours painted and ready to sand off overspray.

Final product affixed to rock using silicone. You can see the tool marks clearly - I need to sort that out.

Thanks,

John Jackson

[Peter Stenabaugh]

Hey John, great looking project. Corian was likely the best product to choose for outside durability. The paint may suffer with the weather, but that is fixable if need be in a few years.

For the tool marks, you may have a small chip in the point of the tool, or it may not be totally sharp. I would think the tool has been ground at exactly 90 degrees as these cutters are all machine made. Another thing to check is to make sure that the spindle of the router is perfectly square to the table. One way to ensure that is to 'plane' the table or work surface, with a large diameter cutter to create a flat surface onto which you then mount your work piece. When planing the surface if you get a series of ridges as you cut, then you know the spindle of the router is not square to the table.... this would be the most likely problem you might have.

At any rate for those who notice the small marks, you can tell them that it is just part of the art form and ignore them. People that find fault with things like that are just too nosy I find. You might also suggest that they just make their own if they feel they can do better......

Keep up the good work.

Pete, in Calgary.

[JohnJackson]

Pete,
Thanks for the comments! The marks were not an issue for this item - it was already overkill for what the project needed.

My concerns were more how to get the devil out of the machine for the next project, where such marks could ruin it.

I have not had much time in the shop to do testing of late, but I want to try some tests with 88, 89, 90, 91, 92 degree angles. I looked at the bit tip under a microscope and it seems intact and not chipped or bent. It is a Freud router bit, so one test might be just to grab another one and try it.

The machine has a small 2.5" z clearance, so I tend to use 1/8 hardboard as a spoilboard, and be very careful about cutting depths. If I used thicker material, the height of the thicker spoilboard + workpiece thickness would not get me much room to get a router bit in there.

Thanks again for your feedback.

[Peter Stenabaugh]

If you want to test your squareness, put a 2" - 3" length of round bar in the collet and compare the squareness of the shaft to the table. It wouldnt take very much to make those marks. It has to be the squareness of the machine, or the cutter. Both are simple to check but squareness of the spindle may not be too easy to alter, depending on the machine design.

Another factor could be the size of the cutter. If the cutter is small enough that you cannot cut full depth in one pass (the last pass) then that could also be an issue. If you try cutting the same thing with a larger cutter that is deep enough to do it in one pass, then try leaving about 0.010" for a finishing cut and go in and do it all in one cut. With a light cut like that you wont get any chatter, especially if you are using an climbing cut, which you should be doing anyway with cnc.

Good Luck with it anyway.

Pete