planer or drum sander or...?

[Rocco.G]

Folks,

I've been playing around with doing some v-carved items. it's not that I want to sell stuff at craft fairs. i know a few people who already do that an am looking to sell "stuff" wholesale to these people. i've found that wood stock, (even the "good" stuff from someplace like Rockler) isn't very flat. See the attached photo. The skull is 8" tall x 5" wide so any variations from side to side are obvious. This partuicular piece of wood was only off by about .05-.07 from left to right, varying a bit from top to bottom. Another test run (four of a similar skull) had details completely missing, or cut much too deeply between the different units. Even though we're only talking about a few hundreths of an inch variation, the v cuts just don't look good. and yes, I am making sure that there isn't any crud under the blank. The very first one of these that I cut was even worse because of "stuff" under the blank.

On other non-symetrical designs, the variations on the blank aren't as noticable.

Would a planer be a good investment to get this stuff as flat as possible, or would a drum sander be a better tool? I make electrical signs so wood is a new area for me. Ask me about steel, lighting, concrete etc and I have half a clue. Wood, not so much.

black sugar skull reject.jpg

[8Ball]

No, a planer or drum sander isn't intended to flatten, it's to smooth the surface. On both of these machines, the infeed/outfeed rollers will press the cupping out of the board, and as it exits, the cup rebounds.
A jointer is intended to make boards flat, or try what I do, and on intricate designs, I have a 3" surfacing bit that I run over the face to flatten it before running the engraving. Using this method, ensures the board is parallel to the v-bit and gantry, even if there's crud underneath.

[Rocco.G]

8ball,

I was afraid of that. As i said in the OP, I'm more experienced with metal and illuminated signs. Working with wood is fairly new territory for me. I do have a couple of surfacing bits - 1.25" that came with the machine and a 2". The 2" was a good investment because it dropped my bed surfacing time from ~45 minutes to just over 20 minutes. Maybe next year I'll put a 2.5" or 3" surfacing bit into the shop budget.

Thank You!

[Rocco.G]

BTW, what feed rates and rotation speeds do you use to flatten slabs? i did a piece of Fir last evening and ran it at 3.5 IPS with12500 RPM. I think I could have run it much faster but since it was a first try I went fairly slow. IIRC it took about 8-9 minutes for a piece that was 9" x 45". I'm reclaiming some old furniture pieces for some signs.

[dlcw]

I flaten slabs all the time using a 1.5" diameter flatening bit. The feeds and speeds will vary depending on wht type of wood you are working with. For my MDF table I run 9K RPM at 1IPM. For hickory and other hard woods I run 14K RPM at 5IPM. I normally flaten with the grain in passes about 1/32". These keeps from getting blowouts (chipout) in the wood. Of course your mileage may vary according to your machine setup.

[8Ball]

I agree with dlcw. It will depend not only on the material, but also the diameter of the cutter. The larger the diameter, the lower the rpm(speeds) should be.
But it's made up in the amount of material removed per pass.

The last time I ran a flattening file, I was using spalted red oak, and I believe my settings were 3000-3500 rpm, 50ipm, and 1/16" per pass.
It came out real smooth, but I use new inserts for anything figured or spalted, etc.

Let us know your results.

[scottp55]

I agree to flatten(and sand surface to finish?) the piece beforehand...
Like Brady says "Flatness is King"

I like this vid by TJ as some of the first pics are my "Firewood"
https://www.youtube.com/watch?v=SbIzd1Ij_EA

Most of the production stuff we did on 2 Desktops,
the VCarve was only .1" deep.
But even most of the one-ofs called for flat.
scott

[coryatjohn]

Like others, I use my SB as a very large and expensive planer. Typically, I'll flatten the bow out first, then flip it and take out the cup. When doing the bow, I use index cards to prop up the corners to take out the "rock" and to lessen the amount of material that has to be removed. The SB is quite excellent as a planer, probably better than a real one.

[Rocco.G]

Thanks all. Once I get something complete I'll post a pic or two. The pre-thanksgiving rush hasn't ended so I only have a few hours each way to play around with non-work projects.