Best woods for 3D work

[MaxFrenzy]

Howdy,

I was wondering if some of you could chime in on which species of wood you have had the best success doing 3D work on. MDF works great, but is kind of limited in terms of its finishing capabilities outside of paints. I tried using red oak in the past and it was a disaster. Pine was also so-so (too soft it seems). I'm assuming tightly grained species are best, but I'm not really an expert working with many varieties yet.

I have some nice Poplar in the garage that I'd like to use, but don't want to waste it (S4S is EXPENSIVE here) if it will tear out bad.

What are some suggestions?

Thanks
Matt

[gc3]

sapele, makore machine very clean...we have cut many, many species, final outcome of any blank depends on machining strategies...

[steve_g]

Matt…
As you already guessed, higher density woods machine, or hold detail, nicer. My favorite is Mesquite, but that’s likely hard to find in Illinois… Next on my list is another Texas local wood called Bois-D’ arc or Osage-Orange. These two woods are very dense, but I’ve also gotten amazing results with Cedar (Western) by rough cutting close and then treating with Minwax wood hardener before finish cutting.
The biggest challenge with 3D cutting is hold down… wood not dried well will move as the interior is exposed to the air and dried out, hot router Air, directed at the project only make it worse!
Don’t completely give up on MDF, products like Plum Creek and Exteria machine very well and can be creatively finished with many techniques like sculpt nouveau.
SG

[Xray]

I like walnut, purple heart, padauk, red oak, wenge.

I love poplar, cheap and easily available here, but it can be a challenge finding good grain patterns without green - When you do they come out looking like marble. Cedar is very workable too, smells good while cutting as well.

Cedar, poplar in iron patina mdf frame, 2 padauks and another poplar

[Xray]

a few more - walnut with a blonde streak, red oak and burled walnut.

Only thing I use for finish on all is rattle can matte clear coat [ 2 coats]

[Brian Harnett]

Like Gene said sapele I have had good luck with hard maple and cherry and catalpa I mill my own catalpa cant find it around here as lumber.

Gene do you have an issue with irritation from the makore? I have made furniture and did our bedroom floor in it very irritating to breath the slightest amount of dust.

[Davo]

I've heard cedar is cancerous/ or bad for the lungs to breath the particles in, is this true?

X-ray - what size bit are you using and your stepover ? I really like the finish of your work

[steve_g]

Is Cedar cancerous… Well, it’s certainly an irritant!
http://www.wood-database.com/wood-articles/wood-allergies-and-toxicity/
SG

[Davo]

Good info - made myself a PDF of it

[robtown]

I've had good luck with walnut and mahogany.

[scottp55]

I don't think there's any such thing as a Good dust, but just want to mention that a lot of woods are sensitizers.
My foreman on my house had worked Cedar clapboards for 20 years, and on my house he collapsed one day on the compound saw and we had to call the ambulance.
Never bothered him before, but he just reached the threshold. Now he can't work Cedar, and has to carry an Epi pen and stay away when his crew does siding.
Good luck here with Hard Maple,Bloodwood,Black Walnut,Cherry,Purpleheart.
Walnut pores once in while can cause problems with small details.
Small pores and dense woods seem better for my small stuff.
scott

[Xray]

I've heard cedar is cancerous/ or bad for the lungs to breath the particles in, is this true?

X-ray - what size bit are you using and your stepover ? I really like the finish of your work

Good to get the mindset of no dust is good to breathe in. I doubt if its carcinogenic.
I usually use a 1/32 tapered ballnose from precise bits, stepover 8-14%, depending on how much time you want to put into it. Going from 8 to 14 can easily shave an hour or more off a 6 hour cut, and the difference in quality is not readily discernible. But you do reach a point where it would be. Mine come off the table almost ready to coat, just a little sanding requited to get rid of stray fuzzies. If machining lines are noticeable, you'll know you took it to far with stepover.
There is always a balance between time and quality, likewise there is a happy medium between the two. The "flat" styled ones, "standing proud" designs, take the most time of all as the entire surface is being machined.

[Davo]

1/32.... I can only imagine how long that would take

Seems those would break easy to

But that is super clean, very smooth

[Xray]

Doesn't take all that long, 3-6 hrs average.
No danger of bit breaking, you do a roughing pass to hog out the majority of material before the finish pass.

There are some tricks to optimize, but there is no way around the time factor. Quality cuts take time.

[Chuck Keysor]

X-Ray, I agree with Davo. The fine detail on your machining is first rate. Thanks, Chuck

PS: (Should I call you Ray, or is that what you used to be called?)

[Xray]

I respond to Xray, holmes, bro and Doug !

[MaxFrenzy]

So really it sounds like a variety of woods will work. I've had problems in the past doing roughing passes and then coming back in with a ball nose. I'm not exactly sure why as I leave a sufficient tolerance (skin) for the finish pass. The best results I had was when I said screw it and just let the ball nose run the whole piece. Now, that was just a small 4x4 3D anchor in MDF I was testing out, but it came out great.

@Steve_G - what products are you referring to from plum creek/exteria and how are they different from a sheet of MDF from anywhere else? I went to the exteria website and it looks like they do siding. I'd love to just do 3D on MDF because it comes out great, but when people want a wood sign...they are expecting grain. I will say that MDF takes well to different paint products though...just look up the cool cubes sample tutorial off the vectric site. They use some spray paint to give the cube a metallic look.

@X-ray, you seem to be able to machine any wood and have it come out brilliantly. What kind of machine do you have? I have the same bits from precisebits as you do, but I'm assuming my 2002 benchtop PRT is no where near as good as your machine.

Here is a general question regarding the PRT. When I'm doing a raster job on something, there is pretty good pause period as it goes from one side to the other. I.E. it will go across the piece...wait at the edge....then go back the other way. When I watch raster machining done on some of the shopbot videos, there is practically no delay as it goes back and forth. I'm assuming a v4g upgrade on my machine would help this problem, but that seems to be more of a bread board/mobo fix (as well as delivering a little more power to the motors if I recall). Is the latency due to software? Is there anything I can do about it? I have my eyes on the Desktop Max and the latest word is that it's still on track to be released in Q4 2015. The difference between the prt I have now and the desktop max should be amazing I suspect.

[Brady Watson]

Max,
Avoid softwoods if you can, like pine & cedar (Exc. Western Red) as they tend to tear out and splinter. The way to reduce this is to lighten the chipload by cranking up the RPM and using fresh sharp high quality tools.

Premium/professional MDF is leaps and bounds better cutting in every way than the junk sold at the big box stores to consumers. Find a professional sheet goods distributor and get professional grade materials.

Your BT32 would be like a newer tool with a 4G or RBK upgrade. You'd get 2.5x better resolution right off the bat and smoother cutting. In the meantime you can tune your tool a bit to reduce the dwell at the end of a raster by adjusting your VR values (http://www.shopbotblog.com/2008/03/a-ramping-the-vr-command-and-how-to-tune-your-tool-for-maximum-performance/). I would focus on the Slow Corner Speed first and adjust it somewhere in the 25 to 65 range. The higher the number, the more aggressive the moves will be. However, the caveat is that those 3G setups don't have a lot of power and you can stall the motors and lose position if you cut too aggressively. This is not as much of an issue on a 4G setup as there is more power going to the motors. Get the 4G upgrade...and say goodbye to your tool sounding like a diesel...

-B

[Davo]

Brady what's your recommended rpm for 3D work for the cleanest finish?

I use the porter cable router - I choose 13k because the router Noise screams like a demon from hell at higher rpm

[Brady Watson]

Brady what's your recommended rpm for 3D work for the cleanest finish?

It depends on a number of factors. The density of the wood, the scale of the project, the diameter of the bit, how many flutes the cutter has, etc.

Since it is a CNC router and not a milling machine I tend to run at routing speeds, typically in the 15-20k range; usually around 18k for 3D finishing. Higher RPM becomes important for fine work with small diameter tools (sub-1/8").

Larger scale models and jobs with larger tools are adjusted appropriately. I nearly always rough out and prep the model for a proper 3D finishing pass, eliminating as much resistance and ambient material as possible. This results in a phenomenal finish with little to no sanding required right off the machine.

You'll never hear the 'raster screech' in my shop...Time spent roughing and properly prepping for 3D finish machining, leaves you with results you are proud to put your name on. Plus, the robot works faster than I could or would ever sand.

-B

[Davo]

I've been keeping with the dish models to skip a roughing pass and letting it slowly work to the depth

Would it make much difference for me to rough it first? def. saves me some time to skip roughing with the dish models... But I do sand some... So I should probably try it

I would run my rpm faster but I fear it would kill my router after hours and hours

Gets hot enough as it is on the motor area

[Brady Watson]

I only have spindles on my CNCs and I have 3ph. I can't stand the sound of a 110v router. It grates my nerves. I know not everyone can afford one, so that's not meant to sound smug.

The only real way to tell one way or another is to try one with roughing & one without & compare the two - side by side in the same wood, same bit, same feeds.

Usually the low dished clipart reliefs don't need roughing, but this of course depends on scale.

-B

[steve_g]

Matt…
Professional grades of MDF are denser and have higher resin content than big box goods. Plum Creek is a brand designed to be made into molding, Medex is a brand of MDF used in damp locations and Exteria Sheet goods are just plain water proof! Your supplier may not carry all varieties… Here in the Dallas TX area I’m unable to find Exteria.
Using these products is night and day difference from the big box goods! Fine details don’t crumble away. Perhaps others in the Chicago area can suggest suppliers…
I’ll attach some product photos of items made with Medex, They were finished with various stain techniques and sculpt nouveau. Feel free to ask more about anything that catches your eye!
SG

[Brady Watson]

Fantastic examples, Steve. Gotta love the SN stuff.

Here's Extira's site: http://www.extira.com/

I used Medex moisture resistant MDF for my spoilboard early on...I can get the same product, but it was the absolute best material. Super stable & machined cleanly.

-B

[Xray]

@X-ray, you seem to be able to machine any wood and have it come out brilliantly. What kind of machine do you have? I have the same bits from precisebits as you do, but I'm assuming my 2002 benchtop PRT is no where near as good as your machine.


Not a SB, I don't like to ruffle any feathers so I avoid talking about my machine.
Its no where near top of the line, but more modern than 2002. I'd like to think that with some tweaking and trial & error, you can produce works every bit as good, maybe better.

[scottp55]

Excellent examples Steve!
Still remember that "Fish" fossil from when I first started scoping out CNC forums:)
off topic...sorry Matt;
Brady or anybody, Medex for spoilboard substrate on Desktop better choice than BBply? Using Bill Young's "Wedging Top" with inserts and getting Very slight flexing when clamping hard, as the outside of cutting area fences are not supported by the extrusions. Is it as stiff/stiffer than BBply? Can 2 layers be glued together using PU glue(Gorilla). Used PU because it foams when it reaches dowel/insert holes, and easier to pluck out excess,and only one surface has to be glued which reduces excess.
Picked up a sheet of 3/4" HDO as well, but not sure how PU would bond to the epoxy coating or Medex.

[danhamm]

I have had pretty good return from Pine and cedar.http://www.talkshopbot.com/forum/attachment.php?attachmentid=26098&stc=1http://www.talkshopbot.com/forum/attachment.php?attachmentid=26099&stc=1 the wolf is blue lodgepole pine and the bears is big its 4x6 ft. and of cedar.

[dmidkiff]

Dan I like the bears but the blue pine makes the wolf really pop for me. Is that the beetle kill pine we've all heard about?

[cowboy1296]

Thanks to the tree huggers we have lots of beetle kill in Colorado. I did some 3-d in poplar once and it was really stringy, so i dont care for the softer woods. I tend to stick with black walnut or cherry and have some african mahogany on hand to do a 3d plaque in the near future. Anyone want to weigh in on African Mahogany and with pictures if you have them. I had toned my speed down to 10k recently but noticed that my flat area of a plaque was not flat so i increased to 13k. but with Bradys suggestion i just ran out to the garage and stopped a project and sped it up to 16 k. Almost everything that i do is 3-d and still have the same router after 5 years. but i do tend to change my brushes fairly often, so i always keep an ample supply on hand. Loosing steps because of bad brushes can be costly.

[Davo]

Dan: how long did those big pieces take?

[danhamm]

The bears, was a long cut @109 hours total, the wolf sized is 10 hours done with just a finish pass, yes that's the beetle killed pine, there are 2 main pines up here Jack pine and Lodge pole pine, lodge pole pine has no limbs for quite a distance up the tree, if you can get the slow growth lodge pole it carves more like birch than pine. I'm lucky enough to be in the place where it grows and own enough acres to supply my needs.

[cowboy1296]

This one is in its final few minutes. The finishing was done with a sixteenth inch ball nose. The plaque is eighteen inches round and has a lot of z height in it. The finishing tool path took about eleven and a half hours. Due to he nature of the receiver of this plaque i opted to remove the deputies raised name and badge number and show only a computer image.http://www.talkshopbot.com/forum/attachment.php?attachmentid=26100&stc=1http://www.talkshopbot.com/forum/attachment.php?attachmentid=26101&stc=1

[Davo]

Wish I could live in Colorado and have work here

Heck I live here and am trying to get work!

Good stuff as usual cowboy - can't wait to see the finished product

[cowboy1296]

After suffering the heat of Houston Texas all my life i finally retired. Not to rub it in but its 59 here right now with 14% humidity. Thanks for the comments. Even after all of these years i am still struggling with finishing. About the time i like what i am doing something goes wrong.

[Davo]

It was 92 here today...

[cowboy1296]

92 whats that

[dmidkiff]

Dan and Cowboy, you both do excellent work. I normally don't like pine for a project but I really like the way the beetle kill looks. I bet the humidity was closer to 92% in Houston.:D

[Davo]

The temp will be about 91 today...humidity will be similar

I shouldn't break too much of a sweat walking to the truck

[cowboy1296]

Thanks for the compliment but Dan is way beyond me. I try to learn from him when i can. Enjoy that humidity. Currently 38 here with a 43 % humidity.

[Davo]

Cowboy how far are you from Durango or pikes peak?

I took the steam train in Durango one year, then the next year drove to silverton.... Took 1500 pictures....

Can't wait to go back

[cowboy1296]

i M 60 miles due west of Pueblo. 100 miles south east of Pikes Peak and roughly 180 from Durango