Raised Bead

[nat_wheatley]

I need to duplicate just the triangular applied bead detail shown in the photo. You'll see the crack in the lower, curved piece.

I'd like to cut it from one piece of wood, instead of the three pieces, that now make it up. My thought was to cut it into a thicker piece, then send it throught the thickness sander, face down, to free the piece from the blank.

I've only done 2D cutting before so I'm looking for help with the toolpathing. I can draw the shape easily enough, but am not clear on how to go about adding the 1/8" radius to the face of it. Is this something that can be done in Partworks? Also looking for help on bit selection and feedspeeds.

Thanks in advance for any suggestions.


8549

[gene]

It can be done in aspire . or rip a dowell on your table saw . soak it in water to curve it

[myxpykalix]

The picture looks a little decieving but to my eyes it looks like an inset panel with quarter round moulding on the 2 straight and 1 rounded parts, is that correct?
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If that is in fact quarter round you might be able to buy it in foam and bend it but i'm not sure of its painting/staining qualities.

If you want to make it out of wood I would suggest you take the picture and make a vector out of the curve then cut that curve on the bot.
Then if you have a router table just load up a round over bit and run it on your router table.
That would be simpilest.
You could use the same vectors for a offset toolpath using a nonbearing roundover but trying to hold that down i think would be a hassle.

[nat_wheatley]

The current detail is 3 pcs of 1/2 round molding, applied to the face of a panel. I would like to replicate is with a piece cut from one piece of wood.

[beacon14]

You will have a lot of end grain to contend with. Unless it's painted it could be a finishing nightmare. At least one leg will be pretty delicate due to the short grain. Wear your safety glasses when you run it through the sander.

[john_hartman]

It seems to me that if this applied molding is only 1/2" wide and say about 3/8" to 1/2" high and long enough, then a straight piece should bend flat around a form cut to the curve you need. I have done this using double-sided tape or blue painters tape looped to mount a 3/4" ply form/curve, Titebond Molding glue and about 3 pin nails in the molding. (If stained; route a small channel about 3/64" deep x 3/8" wide to keep the glue from seeping out.) Glue/nail the first two 90 degree sections first then the curved piece will be locked in between the form and the straight ones while it sets up. The hardest part is cutting those low-angle miters. Keeping it all one piece will look and finish a lot nicer too.

[nat_wheatley]

Thanks for the posts. I may try Jack's suggestion of a using the non-bearing roundover bit. For finish, it just gets a clearcoat, so the endgrain shouldn't be an issue there.

The picture illustrates my first attempt. Clearly the 3 pieces, bending the bottom didn't work out for me (there were some other factors involoved also). Additionally, the site is located about an hour away. Trying to replace the broken piece would mean going there to fit a new one, working on it 7' in the air (duplicating the miters), bringing it back to my shop to spray it, then bringing it back to reinstall. If I'm able to machine it on the Bot, then spray it, it will save a fair number of steps. I have a template of the outside shape of the 'triangle'

I think that the key is going to be whether or not I can sucessfully free the finised part, from the blank, with the thickness sander. It may be that I need to get it close, then make the final release with a razor knife.

Thanks again for the feedback.

[bleeth]

Nat: If one piece doesn't bend without cracking try making the one curved part out of 2 slices glued up on a jig (as in laminated). Done almost daily with small moldings when I was knocking out semi-custom mantels. You can fabricate and pre finish in the shop and then just cut the miters by hand in the field.

[cabnet636]

use a non bearing roundover bit .375- 1/2" material, profile out at an offset of .03125 leave onionskin and cut by hand. we have a horizontal belt sander but it can be done by hand.

[beacon14]

Instead of trying to cut the entire triangle out of one piece I think I'd cut the curved part and the straight pieces separately out of solid stock, and pre-fit the miters in the shop. You could even cut the miters using a profile toolpath before cutting the piece loose from the stock.