Routing acrylic w/ applied vinyl faces.

[Cadman]

We are currently doing some tests trying to do as the title suggests, route our push-thru copy with the vinyl already applied. Too often this results in scratched faces due to the pressure foot, which we could keep up, but it's messy, and we have also considered a brush foot as an alternative. The other issue is often ragged edges on the cut vinyl even when using fresh bits. I have considered using a down-cut bit or possibly a v-groove to run a shallow pass to cut out the vinyl and then cut the letter/shoulder. I know eventually we will find the right combo, but just thought I'd ask here and see if anyone else is doing this and how successfully and if you wouldn't mind sharing some tips.

Thanks!

 

[CanuckSigns]

Try cutting with an up cut bit, with the vinyl facing the bed of the router, that's what gives me the best results.

 

[Cadman]

Yeah, that is how we usually handle it as well, except in this instance because it's push-thru with a routed shoulder you can't really do it with the face towards the bed, but thanks for the reply.

 

[letterworks]

Downshear helps. Premask helps. I think (but I am not a regular sign guy) that leaving the vinyl for a day probably helps too. Sharp corners are an issue but push through should have those rounded off some. Usually I just cut with regular bit (upshear 63-725 onsrud) but always with premask on so the bits don't restick. Double so with a pressure foot.

 

[JBurton]

Leaving the vinyl applied overnight helps a great deal, if not a couple of days. Cut an initial pass along the letter's edge, just deep enough to score the acrylic, say .020", then cut the pockets for the lip and do the final pass as you normally would. I use a belin upcut plastic bit, .125" diameter. (belin p/n 13317A)
The problem with an upcut bit is all of the material flying across the edge of the vinyl. If you can do that initial pass carrying the minimal amount of acrylic out of the sheet, it will stay adhered better. If you're pocket operation is set up right, it should start from the outer edge and work it's way in, by the time you get to the edge of the part, it should only have half the bit's worth of material to cut.
Downcut bits don't work so well, the material has nowhere to go, and eventually finds it's way between the vinyl and face. Premask only helps with the damage to the face surface.
And all this to say, don't use the brush or pressure foot, they will both drag acrylic over the vinyl and cause scratches.
Do a series of boxes, going different directions, different speeds and feeds, and find the one with the least lifted edges, that will be your ideal feed rate and rotation and directionality.

 

[unmateria]

If u want perfect results you need to wait 48h before cutting it and use a thin compression bit. It will let you all particles inside (sorry for my english) so you will have to balance both speeds so it doesnt melt and you can remove them easily later. Anyway if you have a láser (much better) just laminate the vinyl with paper and cut it from the acrylic side with a proper air pressure (about 2 bars, not more)

 

[JBurton]

If u want perfect results you need to wait 48h before cutting it and use a thin compression bit. It will let you all particles inside (sorry for my english) so you will have to balance both speeds so it doesnt melt and you can remove them easily later. Anyway if you have a láser (much better) just laminate the vinyl with paper and cut it from the acrylic side with a proper air pressure (about 2 bars, not more)

Only problem is he is leaving a lipped edge on the acrylic, so no laser, and a compression bit with kinda work, but as you say, they are finicky to nail down feeds and speeds.

 

[MikePro]

you would need to use a downcut bit to make this work. upcut pulls the vinyl up with the chips and shreds.
downside, is that you need room for the chips to go so pre-filling an offset path before applying the field of vinyl would be ideal, before downcutting through the vinyl but then finishing your ledge fill with upcut bit...ultimately a headache.
OR you can just apply the vinyl after the shape as been cut:
trimming to the letter face is exhausting and potential for ruining the edge/face with your knife, so i've always just inline'd my vinyl cut by ~.015-.030" and wet applied individual letters.

I've done it both ways.

 

[JBurton]

you would need to use a downcut bit to make this work. upcut pulls the vinyl up with the chips and shreds.

In my experience, this only applies to printed medias. 3m 3630 translucent and presumably other brand's cast lines should be thin enough and have enough adhesion to behave like the top surface of the acrylic. This has been one of my most profitable concepts to execute, especially when your push through is cut on an older router (that makes no smooth curves), or when you have a boat load of text on your sign.
Printed media with lam (and I suppose air egress colored vinyls behave the same) is so much stretchier, thicker, and has had its adhesive baked in a printer already, that it almost never works without cutting upside down or with a downcut bit.

 

[bowtievega]

We cut push thrus with vinyl faces all the time. 3/16" single spiral flute up cut bit. We mask the vinyl with normal vinyl application tape and just leave the tape on the vinyl after we apply it to the acrylic sheet. If it is a sharp bit you should get a nice clean cut on the acylic and the vinyl without lifting. Make sure you are doing a climb cut, not conventional.

 

[Mr.Signboy]

We cut push thrus with vinyl faces all the time. 3/16" single spiral flute up cut bit. We mask the vinyl with normal vinyl application tape and just leave the tape on the vinyl after we apply it to the acrylic sheet. If it is a sharp bit you should get a nice clean cut on the acylic and the vinyl without lifting. Make sure you are doing a climb cut, not conventional.

I’ve been doing the same way for years with no issues on Printed/Laminated or just translucent vinyl. The only thing I find is wound up bits of masking get wrapped on the bit sometimes or stuck in the vacuum, otherwise works great. I will agree with some previous posts that it helps if you let the vinyl sit overnight before cutting.

 

[AndreaRotela]

To prevent ragged edges on the cut vinyl, consider using a down-cut bit or a compression bit. Down-cut bits pull the chips down and away from the surface, resulting in cleaner edges on top surfaces like vinyl. A compression bit has both up-cut and down-cut flutes, providing a clean cut on both the top and bottom surfaces of the material. You can experiment with different bit types and choose the one that gives you the best results with minimal edge ragging.

 

[netsol]

i have had the same issue, but, due to my wife being hospitalized/bedridden i have left this project on hold.
MY INTENTION WAS, to do an initial pass, or a final pass
with a dragknife, to clean up that edge.

 

[GaSouthpaw]

Yeah, that is how we usually handle it as well, except in this instance because it's push-thru with a routed shoulder you can't really do it with the face towards the bed, but thanks for the reply.

The only way I ever got usable results was by doing an outline of the letters/shapes just slightly bigger than the diameter of the finishing bit and doing a rough out of that. Once that was done, I'd do the final clean out with the inlay using a downcut bit.
That said, the results weren't perfect, and I got much better results with painted faces. That's assuming, of course, that your paint department can provide you a good painted surface to start with (and good luck if it's a translucent color on the face, because that sort of painting is a lost art in a lot of shops).