To sandblast or route?

[blackhawk]

I am bidding on a job to make the attached 5/8" high font sample out of sign foam. They want raised letters and a border, so the background will be pocketed out about 1/4" deep. The problem is that I will have to use a 1/16" endmill in order to get around the detail of the letters. The other thing is that some of these letters are only .08" wide in certain spots. My question is this something that I can even get to carve well with the sign foam? Any material for that matter. If it is not going to carve well, would this be better suited for sandblasting? (I don't do sandblasting and don't want to start. I just want to know if sandblasting would even work.)

By the way, the design and font came from the customer.

[steve_g]

Brad…
Would they let you do something like this?
It’s V-Carved with a 30° bit and a ¼” limit to depth. A ¼” flat area tool was specified…
Using a V-bit lets you get the shape of the letters perfectly. My rendering shows a little roughness in the tight areas, you’re seeing the 1% step-over of the v-bit. Because it’s V-Carved the letters flair out wider down from the surface… nice for those narrow spots!
SG

[blackhawk]

Steve - That is hopefully a possibility. They originally told me that they didn't want a bevel on the lettering, but I am not sure how rigid they are on that. It is worth asking.

[steve_g]

The 30° side walls make a fairly steep bevel… You could possibly even get a steeper angle… I’ll bet if they saw a sample of a V-Carve and a straight bit, They realize how much more durable the V-Carved one will be…
SG

[scottp55]

Brad, Here's a 30 degree VBit.
I think it was .1"depth in maple
No idea on sign foam, but have carved font height to .08" total height with the 30. Nice Crisp sharp corners when VCarved

[blackhawk]

Scott - That looks good. I have always used Centurion's V cutters. Is that what you used? If not, can you let me know what you are using?

Thanks

[scottp55]

Brad, Unfortunately that was a .125" engraving bit,
http://www.ebay.com/itm/30-degree-bits-for-scoring-or-engraving-sharp-point-narrow-tip-Kyocera-Tycom-/151386398234?pt=LH_DefaultDomain_0&hash=item233f551e1a
And would take you forever and a day.
I did order his .25" 30
http://www.ebay.com/itm/30-degree-angle-x-1-4-carbide-bits-engraving-and-scoring-tools-/381104004934?pt=LH_DefaultDomain_0&hash=item58bb919f46
But have been laid up for a month, so haven't had a chance to cut with it, AND it's not labeled as a Kyocera, so really can't recommend it until I try it.
Just started using 30's recently, and love the results in that 1/8" in Maple,B.Walnut,Padauk, and Bloodwood, but I'm doing all Tiny stuff with them. Next in quality of cut for me is Vortex, but only have their 60.
Also like the cut with Onsrud engraving 37- series, but again only used the 60(all inlays), and only in hardwoods at 17K.
Hope this helped.
scott

[scottp55]

Oh, Onsrud finish was great! , but then Padauk always cuts nice:)

[blackhawk]

Scott - Was that the Onsrud single edge engraving tool?

[scottp55]

Yup, That was was the Male obviously. First time I ever used it. On recommendation from Vectric forum.
1 F and the male which is why I used 17K and .3" IPS MZ speed. Vinlay males totally ignore pass depths as you've told it nothing is there for 1/2 of your flat depth.
Got same results in Bloodwood,black Walnut, and Curly Maple from Ocooch. Nice bit. Even at 17K it was cool to the touch after 35 minutes. Don't like running spindle at 18K max, so just tweaked feeds for 17K. Seems pretty forgiving, even in end grain walnut.
Nice bit, lots of life left. edge looks good under 10X Loupe after 20 hrs use.

[blackhawk]

I just ordered some of the Drillman bits off Ebay. I am hoping that they will gut my paint mask crisply. The Centurion cutters cut the foam well but they just chew up the Avery paint mask.

[joe]

My 2 Cents:

Wish I could open your attachment to see what you're doing.

Sandblasting on HDU will almost always be sharper with fine grit. There are a couple of issue's. The first is you'll have a hard time determining the depth of the blast without some trial test. The second unknown is if the blast mask will pull up the paint.

Detailed carving on HDU is more difficult with a V bit. Just think what you're doing. It's a big flat spade. For precision work with mask you want a small fresh down spiral like an O flute making shallow passes.

I'd probably consider corian or a harder surface material bud have no idea about sizes or budget. After all this is only a bid proposal.

[blackhawk]

Joe - The tough thing about this lettering is that a 1/16" endmill is not even small enough to get all the detail. With a 1/16" endmill you can't cut out the middle of an "A" for example. The text on one panel is 20" long and 4 lines tall, so going to a 1/32" endmill would really get into some high cut times with the 1/4" depth that they require. This is why I am leaning toward the V-bit route.

[RossMosh]

Sandblast or laser engrave it. You can route it I'm sure but what's the point if it takes 2 hours? Based on the design posted, I'm guessing it would take maybe 20 minutes to laser.

Without a full design it's hard to say exactly what I'd do, but my guess is I'd route the border and cut the shape on the CNC. Then do the text on the laser.

[blackhawk]

I don't sandblast and I don't have a laser.

I have done a practice run V-carving and I can get all the fine detail, no problem. My only problem now is getting the paint mask to cut crisply with a V bit. Worst case is that I will just have to paint the face of all the letters by hand.

[RossMosh]

I don't sandblast and I don't have a laser.

I have done a practice run V-carving and I can get all the fine detail, no problem. My only problem now is getting the paint mask to cut crisply with a V bit. Worst case is that I will just have to paint the face of all the letters by hand.

I thought the post was about which process would be best for the job. Sorry.

[blackhawk]

Ross - No problem, I was just really asking if sandblasting could get better detail than carving, out of curiosity. I know nothing about sandblasting, but my thoughts would be that the sandblast mask would break apart if it was only .08" wide in areas.

[RossMosh]

Ross - No problem, I was just really asking if sandblasting could get better detail than carving, out of curiosity. I know nothing about sandblasting, but my thoughts would be that the sandblast mask would break apart if it was only .08" wide in areas.

As Joe mentioned, the detail on sandblasting is not a concern. You can get very high detail with sandblasting. It may take a bit of testing to find the right mask that sticks but doesn't stick too well. With sandblasting I'd assume about ~20mins per sign to cut, apply, weed, and blast the signs. Cost involved is probably less than $5 if you can use vinyl.

The reason why I mention laser is fairly simple. It's fairly idiot proof and have the option of picking whatever transfer tape you want as a masking. A medium tack would probably work well in this application.

Either way, coming from someone that offers all three processes, I'd put the router as my last choice. I feel confident saying that it will take at least 3x as long to do each sign with the router.

[wayne_walker]

Brad,

Is this the file you were trying to attach?? I got it open, I think, so others could see it. If this is not it, if not disregard.

Wayne

[joe]

Brad,
What's current on this project?

The letter style on this panel leaves much to be desired. Do you have an option for a more readable font? If the answer is no, there still could be an adjustment that would help. Since the copy is all caps, it would really help to reduce the main body text a point or two smaller. Try it and see if that doesn't help.

The way it sets now, I'd probably decline the opportunity to quote.

Joe Crumley
www.normansignco.com (http://www.normansignco.com)

[blackhawk]

Joe - I won the bid for this sign. I agree that the font on this sign is not the best, but it was specified by the customer. I couldn't change the font but I did manipulate the size just a little.

[scottp55]

Brad, Did Drillman1's bit cut paint mask clean, and whose paint mask (and tack?)are you using for my future reference? Never used paint mask before, so just wondering.

[joe]

I agree,
Lots of questions.

How about a photo?

[blackhawk]

Scott - Yes, the 30 degree bit that I got from Drillman1 worked very well cutting the mask. I found that a conventional cut kept down on the number of stringy mask leftovers that I had on the corners of the letters. I attached a picture of my testing. This was on 15lb Sign Foam, which I am glad that I am not using on this project. It is way too soft.

I use the white Avery mask. I works great on super smooth surfaces, but only good on slightly textured surfaces. I would really like to find something with just 20% more tackiness.

[scottp55]

Whew:)
Glad it worked, makes sense for conventional.
Need more experience on "Tackiness" though.
scott

[chadagmsign]

I try and stay away if at all possible to font thickness that are less than .125 (1/8") when normally machining typical depth which is normally .200. Worse case and if someone is stuck on the font i will try to change depth to .100 or in extreme situations to .050 height. The less height will work but make a pain to paint without getting on the background.

[joe]

I'm with Chad on this one.

Fussy little letters take more time and any little mistake costs money. We all learn as time goes by.

[blackhawk]

Here is a zoomed in shot of the final product. The Avery mask worked really well on the 30lb Precision Board. I painted the letters with an airbrush. I thinned down the latex with a little water and added Floetrol in order to spray.

[scottp55]

Brad,
To a non-Sign Person..THAT came out pretty D*** Nice!!:):)

[David Iannone]

Looks great Brad.