# Good wood and other newbie questions



## Billy Hill (Apr 24, 2015)

I've heard maple and cherry are good for CNC routing detailed images. What other woods should I be looking at? Or more importantly, are there any I should stay away from?

What about cutters? In a previous life I used to do 3d programming and machining on metal and graphite (electrodes for EDMs used to make injection molds) so I've got a selection of micro, long-reach tooling ranging from .062 x 1" ball EMs to .020 x .05" ball EMs, and a few single flute, 45 degree engraving tools. I also have some flat end mills but I'm not sure how well they would work. 

The first project I did was with a .062 ball EM and it came out ok. I want more detail. Much more (I also used to be a photog doing motorsports and have thousands of images worthy of wood). I got to thinking a 30 deg angle cutter with a .005 dia flat would do pretty good but how do those tips cut the wood? My first try with an angle cutter produced rather furry results.

Thanks for the help. Probably lots more ?'s to come.


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## DaninVan (Jan 1, 2012)

Hey, Will; don't know about CNC, but Poplar takes very sharp detailing. They use it foe making mouldings...great stuff if you don't mind the green colour!


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## DaninVan (Jan 1, 2012)

Same for Yellow Cedar.


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## Billy Hill (Apr 24, 2015)

DaninVan said:


> Same for Yellow Cedar.


That's awesome. Hand carving?


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## DaninVan (Jan 1, 2012)

Yes! But not by me. It's a favourite of Native carvers here in the Pacific North West...
Killer Whale Family Aubrey Johnson


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## Billy Hill (Apr 24, 2015)

I picked up a 1x2 foot piece of poplar from Lowes to do some engraving/experimenting on. It took a bit to find one that was straight and not cracked on the ends. Has an interesting green tint in the middle but only visible from one side. We'll see how it goes. 

Here's the first part I did. It's not pine but it's light like pine. Pretty grain, I think I went too dark on the stain.


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## Billy Hill (Apr 24, 2015)

Speaking of stupid newbie questions... Workholding? 

You should have seen what I went through to make that name plate for my wife! You'd be scratching your head going "WTF is he thinking?"

I started with a 2x4 about a foot long. I clamped it using the 1/2"-13 threaded rod steel clamp set I have in my machine shop. I clamped the two ends and machined the part in the middle then did a contour around the outside about a half inch deep. (if you look carefully you can see the top right wall had to be repaired because my router decided to take off on a tangent and lost about 1/2" in the Y, so far /wifie/ hasn't noticed.  )

When I finished machining it I tipped it up on its side and went to town with my bandsaw to cut the "carrier" off. I did better than I thought, total variance from the band saw cut was only about 1/4". From there I went back to the router and clamped two corners, milled everything flat, moved the clamps to the other two corners and finished the two islands. 

A serious PITA.

So, aside from clamping, what are the best methods to use when you want to have a net finish around the outside? I've considered monkey poop, hot glue gun, bias ply tape/foam tape, mitee-bite clamps, vacuum fixture and screws in pre-drilled corners that serve a dual purpose for mounting or riveting. 

I'm concerned about the glues, puttys and tapes because I'm afraid they will either hold too well or not well enough. Also, the material and table would need to be very flat for the tape to work.

Mitee-Bites work great for metal but tend to push the middle of the part up, bias ply tape might help there. Clamping I think will always be a PITA if doing net finish parts.

So... what's your workholding method of choice?


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## honesttjohn (Feb 17, 2015)

Billy, I have found that holding a work piece down is one of life's greatest mysteries. For small stuff I've used Scotch double sided tape and carpet tape (the brown thick stuff) from HD. I have also watched a 3' x 2' piece of oak start spinning on the bed midway thru a cut. Tape and sticky stuff doesn't work good on bigger pieces.

Stop blocks and clamping seem to work the best, other than screwing the piece to the bed, which will tear it up and then need replacing.

Check out our threads on clamping and CNC's in general, especially the posts by 4D, Timbertailor, Scottart, and a few others. You'll get an idea on the different ways that have been used.

HJ

Something so simple can be so hard


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## Frazil (Apr 21, 2015)

Holding the workpiece down is key to success. I keep a bucket full of shopmade wooden clamps in a variety of shapes and sizes near my cnc. I have used hot melt glue quite successfully at times. I would not trust double stick tape. I also have a vice like device that installs on my T-tracks. A common solution is to use a workpiece larger than the finished object and leave tabs in the cutout path. You can then cut through the tabs and finish the edge using a flush trim or roundover bit in a router table.


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## Billy Hill (Apr 24, 2015)

Thanks for the input John. I'll check out those threads. I just remembered something we used to do when I worked at a plastics fab shop... we would route these cast parts that were held in place by tabs molded in place. When we were done routing them we would break them off at the tabs then quickly finish sand the break marks. 

Probably wouldn't be too hard to program that in, I just have to make sure all my material is to the thickness, length and width I want before I throw it on the router. 

"Guess what, honey! I'm getting a table saw and a planer next!!" ROFL MAO!


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## Billy Hill (Apr 24, 2015)

Yes, Frazil, that is my fear about bias-ply/foam tapes, they won't hold well. 

I used to make alum microwave housings with covers and we had to use tape or vacuum plates to hold them down for machining. Each set of parts required roughly 15 minutes of prep to get everything ready for tape, and another 15 or so minutes to get the parts off the fixture without bending them then getting the tape off the finished alum parts. Not something I would trust to wood, especially if it's not really flat along with the table.


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## honesttjohn (Feb 17, 2015)

Don't forget the band saw. I know you can program the finished size to be cut and have tabs anywhere you want. But so far, I've just made the sign and cut the final size on the table saw and then routed the edges to take the sharpness out. I've also put the finished size on the bed and it "usually" comes out ok.

The real pistol is holding the project down on the bed. I ended up doing Rockler track as you can see on the other threads. Got some maple roughcut out to make some of my own clamps, too.

HJ

Stumbling foward


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## Shadowrider (Apr 1, 2015)

When I get mine I'll be using tabs and screwing the piece down. It's easy enough to trim them off flush. 

I did see some round buttons with an hole drilled off center to make an eccentric clamp that would probably work for some cases, especially if you had a groove to form a lip to go over your excess stock, that might hold it down well but you'd have to be picky about your stock thickness.


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## Billy Hill (Apr 24, 2015)

Shadowrider said:


> When I get mine I'll be using tabs and screwing the piece down. It's easy enough to trim them off flush.
> 
> I did see some round buttons with an hole drilled off center to make an eccentric clamp that would probably work for some cases, especially if you had a groove to form a lip to go over your excess stock, that might hold it down well but you'd have to be picky about your stock thickness.


Thanks Scott, I've been looking more closely at the tabs option. I'll just need to find a good size that will not be too weak. 

Those round buttons with the hole drilled off center are part of a mitee-bite system where it uses that off center screw to push a clamp against the side of a wall. This method creates some lift at the center of the part but for wood parts I don't think it will be an issue. 

MY next project will be done this way. It's a clock for the club I'm in (My drinking club has an offroading problem).


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## DaninVan (Jan 1, 2012)

"My drinking club has an offroading problem"
lol! Sort of like a tailgate party but no game?


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## Stick486 (Jan 4, 2013)

DaninVan said:


> "My drinking club has an offroading problem"
> lol! Sort of like a tailgate party but no game?


remember to close the tailgate before you move the bar...


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