V-cutting non flat signs

[ernie]

When V-cutting signs I often find problems with non flat substrates. A shallow 150 degree cutter really gives me problems with variations in the letter width. Often I wind up shimming the substrate to get it flat.

How about some tricks to make cutting easier? The obvious one is to use a steeper cutter like 130 degree.

What do you do in this case?

ernie

 

[Bob Rochon]

Ernie,

In reality any degree bit you use will give you varying stroke thickness in an unflat substrate because both the cnc and the substrate are " fixed ", and to the trained eye it will be noticeable.

I do not own a router so I cannot contribute a work around but it will say I have seen signs done like this and it sticks out like a amateur carver did in the day.

I still hand carve to date and the beauty of that is to adjust as you go.

Off the top is there any cost effective way to "plane" the substrate first on your cnc?

 

[ernie]

We could use a surfacing bit to achieve a flat surface on the sign but we like to paint the sign first then apply paint mask and rout it. At this point we prime and sand the letters. Next we gold leaf then peel the mask for a finished sign.

ernie

 

[Bob Rochon]

I see how that could pose a problem,

I guess I'm so behind the times, haha

I prep the wood, carve, then paint, then gold leaf and any finishing touches.

Ernie do you use a quill? there could be many advantages to planing the wood, carve, prime and paint, then gold leaf the letters applying the size with a quill.

1) you solve your uneven stroke problems

2) you seal the sign in primer and paint without breaching the seal at all.

It isnt that hard to follow the shape of the letters with a quill

Just an idea.

Good luck

 

[ernie]

I'm thinking of writing a program that modify's the g-code file to accomodate the substrate surface height variations.

In practice I would mount the substrate on the vacuum table then measure the z height every 6" with a touch sensor. This data would be input to a post processor that corrects all the z values depending the location.

ernie

 

[Bob Rochon]

oK Ernie,

So your not your typical sign maker now are you hahahaha.

Geez while your at it can you invent a way to enter text into chat windows so we can all wip these annoying keyboards in the trash? lol

 

[dennis j]

Ernie,

I have had this problem also when I use wood I don't have any work around either. :