Routing woodgrain help

[pcampbell86@charter.net]

Hello all
what i need to know is i have been asked if i can get the same effect as sandblasting a sign in cedar...on a shopbot....
you know the wood grain backgroud with raised letters...i have been told artcam can do this ..but how long does it take and how good is the finish etc can anyone help me with all this

thanks

[rookie432]

I haven't tried this but I've considered using a high angle vee vbit and pocketing or planing the whole piece with a small stepover then roughing it up wit a wire brush to get the effect. It would be a little more difficult with trying to cut around letters. It might be easier to apply cut out wood letters over a smaller letter you carved around to get a smooth mating surface.

Cutting a thin stencil and actually sandblasting it is goung to be much quicker though.

[papadaveinwy]

Outland.and Bill What about just routing the sign in an iland rout, that is the background routed and the letters left raised along with a border then use a torch to heat the background grain and then a heavy wire brush. It worked for me.David in Wyoming P.S. be careful with the torch not to burn the fiber only scorch it.

[gerald_d]

For raised letters, we sometimes cut loose letters and glue them into SB-routed (precision) pockets. The purists may think that this is cheating, but it saves a heck of a lot of routing and makes the preparation of the background very easy.

[rookie432]

OOOH!
I like the torched backround idea. I haven't considered that. I'll definitely be giving that a try. Gerald, I'm with you on the applied letters. I did that with part of the attorney sign on the previous post. The name was cut out corean letters. I actually pocketed the shadow line for registration purposes and then applied the letters. I got much sharper edges that way than the raised letter wood. Less sanding too!

[rgbrown@itexas.net]

Another way to do raised letters is to index with small dowels on the back side. The bamboo skewers I use are 1/8" diameter. I put the register holes on the back of the letter material (mirror image) and the receiver holes are routed after I paint the background. I then glue the raised letters on. Clamping is by weights or vacuum bag.

Methods of doing things on a ShopBot are limited more by your imigination than by the tool.

Ron

[Joe Crumley]

outland86,

I have considered and am considering this technique and have identified hurdles for your consideration.

After getting the desired background pattern, you will need to have a stop cut at letters edge. I have considered texturing the complete background and then pocketing for letters. That way you could use pvc or other materials for the letters.

We sandblast HDU and Redwood and would like to move to our SB for some of this work, but haven't seen anyone doing real clean demensional backgrounds with any CNC.

Tourching the background will get some depth, especially on the flat grain side of wood, but sandblasting with 100 CFM on vertical grain is the way to go.

Good luck and if you see any good grained backgrounds from a router, let me know.

Joe Crumley

[cncrouting@attbi.com]

Artcam pro will take an image and convert it into a texture or background, I believe. Only hurdle for this is $7500 front fee
Maybe if you have a buddy with the software, he can try it for you. Anyway, keep us posted (all pun intended)

[papadaveinwy]

You Know if you don't want ot spend 7500 you can do the same thing with Corel Draw in a week or so (when I have time) I will post a pic of one done this way David in Wyoming.I have to create it

[Joe Crumley]

I would love to see a photo of a sign done this way. We can't figure out how to get a V bit up next to a letter without gouging the sides. A pocket cut would do the job, but takes extra time and looks like what it is, an inserted letter.

The first step could be to hatch out the background with a flat bottom bit, leaving the copy standing. Texturing with a V bit could start from here if I could figure out what to do with the sides of letters.

Joe

[rgbrown@itexas.net]

Joe,

If it were not a "Pocket cut" but an applied letter on a flat pad after the "graining", it would not look like an inserted letter. I have put dowel holes in the back of letters and then glued them to a painted surface. I don't see why one couldn't do the same with a "grained" background and just not "grain" the letter areas.

Ron

[rookie432]

Joe and Ron,

I just tried this recently and got fairly good results. I'm just finishing a Poplar sign where the logo looks like sandblasted cedar. I just formed a shape around the logo to create an island. Then I pocketed that shape to raise the letters. The trick was that I told partwizard to pocket the shape in raster format using 1/8" straight bit then chucked a 45degree vee bit into the bot and let er rip. The stepover gave a sandblast cedar look( tight grain) and actually gave the raised letters a slightly beveled look. I think the grain of the poplar lends itself to this as well beacause if I wanted I could go over with a wirebrush and sharp knife/gouge and make the pattern irregular and more rustic.

Bill

[joe]

Ron,

I agree with your technique. One could reduce the background down, lets say 1/2", from the border , and then using a v bit to get a woodgrain. Then pocket out the letter area, cut the letters to be placed in that pocket. The affect should look very good but, the time and effort is questioable.

Lets say you have a 3'x 6' sign with 6" letters for the body copy, and 1 1/2" letters in the body.
I think you would be going in the wrong direction trying to cut small letter and glueing them in the holes.

Our experience has been that, sandblasting vertical grain redwood is fast and superior over routing. Cedar is questionable at best. It will not stand the test of time. Especially with small serif letters. The serifs go first.

We continue to experiment with HDU to get the Redwood look. The grain frame works fairly well but routing solution yet.

Joe

[KSimmerer (Unregistered Guest)]

Joe,

I've not done this, but it seems to me that to vcut the background up to the letters without gouging, and to avoid that squared off pocketed, stuck on letter look that what you need is a transition area. Contour a step around the letters or objects with a height of about half to 2/3 the depth of your area clearance. Your step width will be a judgement call based on character size, vbit angle and height of the step. Do your graining effect right up the the transition step, don't worry if it clips into it slightly. Then take a dremel and radius the transition area by hand to a convincing blend. Another idea would be to cut your step with your favorite small diameter cutter to get you crisp top edge. Then take a round nose cutter and contour around the letter to the target area clearance depth. Now take your vbit grain effect up to the centerline of your roundnose cutter path. If your v cutter has a steep enough angle you could bring the v cutter into the ramp created by the round nose bit without clipping the object. You will have to do a little preflight planning to determine compatible vbit angle, roundnose cutter diameter and total depth of your area clearance but this could help ease the "Stuck on Letter" look and enhance the blasted or carved effect. Sorry I have problem with using 100 words to describe a 3 word thought.

Just thinking out loud.

Keith

[artisan]

Unless sandblasting is just totally impractical, it is still by far the better way to achieve the look. Yes, you can use an Artcam or Corel pattern to achieve something similar, but on say, a 2 x 4 ft sign, you're looking at hours of 3D routing time versus an hour to stencil and blast the sign. Sandblasting is also cheap. Where we've been able to leverage the Bot, is on specialty signs with dimensional letters attached to the flat blasted surface and other 3D ornaments. Find yourself a local signshop, tombstone guy or rust removal type business that already has the equipment (messy) and outsource it. You can work out liasons with other shops and cash in on more work as we have done. For the most part, using the Bot to do sandblasting seems like using a thoroughbred as a plowhorse. Just a thought....D

[K Simmerer (Unregistered Guest)]

Actually, the woodgrain effect that you may have seen done with Corel is a relatively simple 2d routine and would machine fairly quickly. I love a job where I'm making good bucks for a couple of hours of machine time. If my shopbot horse isn't racing I'm sure not gonna go out and buy a mule, or pull the plow myself or hire my neighbor's mule to pull the plow. I can usually find something else to do while the machine is running, the machine shuts itself down with output relay switches and I don't hear it unless I peek in on it once in a while. If your machine is tied up running other things though, you certainly could farm the job out and still make money.

[franniboy]

Reading back on these techniques... there is a local sign shop that first sandblasts signfoam backgrounds (with fine sand) using a 1/4" nozzle to a depth of approx. 1/4" or more and then changes to a smaller nozzle, say 1/8" and reduces CFM to cut in random woodgrain lines. This is a larger woodgrain pattern merely to (effectively)give texture to the background of the sign, viewable from a distance; it is not, however, a realistic grain affect as some people may desire. The exact formula for blasting...I'm still trying to figure out. I've prepared Corel grain files for the Bot, but the hog-outs can be time consuming...whereas blasting... much quicker (and messier). Signs I've seen using a combo of CNC and blasting are really nice, though. Will send pix to anyone who would like to see.

[joe]

Darrell has my vote.

I try to stay away from cutting small serifed letters from redwood or cedar. The failure rate is way up there. HDU works very well but then you have to start glueing.

No thanks.

A router is great for some work, but making it do what sandblasting does so fast is, in my opinion, folly.

Roll out the sandblaster, and a few minutes you're finished.

Joe