Duplicating a replacement carving

[johnm]

Folks -

Okay, I am *still* a newbie, but have a student that wants to build some chairs to add to a pair that she has. The crest rail of the chair has a carved rose and foliage. I have taken the original chair apart, and was wondering if somehow a photo of the crest rail could be imported as a starting point for producing a file for carving new parts on the SB. The total depth of the carving in the rail is abou 1/2" deep, and I am using ARTCAD for the design work. Thanks in advance!

John

[rookie432]

John,
You have a multitude of options here.
1st you can probe the original carving to create a 3d replica. Requires a probe, the carving has to be mounted on the Bot table and plenty of time.

2nd. You can make a mold of the original and probe that or send it away to have it digitized or laser scanned. Contact Bill Polumbo for this service.

3rd. Take a good pic. Trace over the pic in a decent vector graphics software to create a vector drawing. Extrude that drawing to match the carving in artcam or another 3d program.

4th AND THE EASIEST. Use the 3d simulation program that comes with the newest version of shopbot software. You can take a good photograph of the carving and convert it into a B&W shaded photo. The software (from what I can tell) assigns depth to the different shades and wala you have a 3d file.

Each of these solutions depends on the level of detail you wish to attain.

Good luck
Bill

[garyb]

I think Bill has covered this well, another option if you have vetorized the image.
I did this some time back when I did a rose pattern to match an existing bedhead, I traced the part I needed, scanned it and imported into my software where I vectorized it, I then used a center line V carve toolpath set to one depth and used a large pointed round over to create a matching rose carving. Basically you can obtain the same look using different cutters.

[bleeth]

How long do you think it would take to cut a 270,000 line file of a 5 x 7 with an 1/8" bit at .08 stepover Produced by the SB converter? Total depth of cut about.1
Dave

[billp]

Dave,
That's a pretty big stepover if this is a 3D file. For most 3D work we start at 10% of the bit diameter and work down to about 5%, so your stepover would be closer to .008".
You should be able to get a fairly accurate preview of the cutting time in the Windows preview software, or in Artcam.

[garyb]

Dave, 6 min 14 @ your step over, 1 hr 9 sec @ Bill's.
Thats using 1.5 IPS

[bleeth]

Bill, the difference between your suggestion and my Number is .002- May not seem like much but I'll go with your experience and cut it down. I do know that the last file I cut at .01 took a little more sanding than I would have preferred.

Gary-thanks for the numbers-How did you get them?

Following is the image I want to work with. Any other tooling suggestions are appreciated.




2405


Dave

[billp]

Dave,
10% of a .125" bit is .0125", so your .08" stepover is really large (more than 60%). Maybe you left out a zero...If you did that when you cut the last file you will definately have some sanding to do. And if you can't get the detail you want with that bit, you're going to have to step down to a .0625" bit. Yes it will take twice as long, but it will give MUCH better detail.
I did a lithophane recently which was an ellipse of 6" by 8.5" with the .0625" bit. The maximum cutting depth was .23", and I used a cutting speed of 3 IPS. it took 2 hours and 25 minutes to finish, but it had GREAT detail when it was done...

[bleeth]

Whoops-I originally meant .01!!!
I think I will increase the depth also. The .1 depth was just the default number on the SB converter. Bill, with that much depth and that small a bit, what kind of stepdown did you use? I don't have a time constraint on the piece as much as a desire for a good clean job with minimal cleanup.

Dave

[garyb]

Dave,
Being a little more realistic with a .013 stepover will take 40 mins I grabed your image above sized it and ran it through Artcam

Relief Dimensions

Width: 5.39037 inches Height: 7.00000 inches
Min X: -2.69519 inches Min Y: -3.50000 inches
Min Z: -0.24340 inches Max Z: -0.13082 inches

Material Thickness = 0.7500 inches

Z Zero = Top of material

Machining Time: 00:40:45

------------------------------------------------------

Machine Relief - Ball Nose 1/8 Inch

Tool: [1] 0.125 inches dia. ball nose
Feed Rate: 1.500 inch/sec
Plunge Rate: 0.500 inch/sec
Safe Z: 0.200 inches
Spindle Speed: 15000 r.p.m
Stepover: 0.013 inches
Tolerance: 0.000 inches
Allowance: 0.000 inches
Home Position: X:0.000 Y:0.000 Z:0.200
Comments: Machine Relief

Feed Rate Length: 3053 inches
Plunge Rate Length: 0 inches
Rapid Rate Length: 5 inches
Machining Time: 00:40:45

[billp]

The bit I have here has a stepdown of .3" which fell within the .23"range of my lithophane. I'll try to take a few pictures here in the next hour to show you the same file cut with both a .125" and .0625"bit so yu can SEE the real difference. By the way the lithophane I mentioned above was cut in Corian, and the smaller bit ran fine without breaking.

[garyb]

.0625 = 1hr 7min .007 stepover.
Not much detail by using your posted image but here goes!!!

2406

[billp]

Dave,
Here are two shots of the same file cut with different bits. (The only difference between the two is that they are cut out of a different color Corian). The first shot was done with a .125" ball nosed bit, and a .008" stepover. the second one was done with a .0625"bit and a .005" stepover. I think you can see the difference in detail quite easily.
I never asked; are you doing this as a lithophane, OR as a raised relief? If you are sanding it I'd have to imagine the latter. And the down side of using a smaller bit is that it's going to be almost impossible to get into the recesses with that one to do any sanding at all....
2407
2408

[bleeth]

Hey guys: Thanks for all the input. I see I'm not the only one with Friday afternoon fever!!

Gary: I have a much higher res copy of it for actual cutting use. What is the rapid feed rate reference in the summary?

Bill: This is a family deal (It's my namesake paternal grandfather) and I'll probably end up doing it both ways as learning lessons.

I see what you mean about the detail with the .0625 bit. Are you using dark corians now? That would mean a pretty small z range and tight control on z zero setting too!

This is so much more interesting than laying out the shelf dadoes and WH arch patterns I'm supposed to be doing it's unreal!!

Dave

[stickman]

Bill Jarvis: You talk about this software? Where is it located, what is it called?

4th AND THE EASIEST. Use the 3d simulation program that comes with the newest version of shopbot software. You can take a good photograph of the carving and convert it into a B&W shaded photo. The software (from what I can tell) assigns depth to the different shades and wala you have a 3d file.

[bleeth]

Jay: in SB 3.4 go to FC (File Conversions) and select BMP for file type in the window that opens and then follow your nose.

Dave

[billp]

Dave,
That second picture is actually WHITE Corian. The REAL deal with lithophanes is to get as much contrast as you can, which is why I cut down .23" in a .25"piece. This makes my dark (uncut) areas VERY dark, and the light (cut) very light.
I KNEW there was a family resemblance....

[garyb]

Dave, I must have cut the rapid feed rate (jog speed) off the bottom of the txt file but I had it set @3.5 IPS.
Bill, nice lithophanes as usual.
And in the theme of cats its been raining cats & dogs here all day hence the Friday-itis.

[bleeth]

Well Gary (et al), The Artcam Users Group has been set for Orlando this year-Care to come back?
The weather here has been warm and sunny.

Has anyone out there actually cut photos using the SB converter to generate toolpath and if so was it a relief or a litho and how did it do?

Dave

[garyb]

Yea I see that they selected Orlando, will have to wait for the rest of the info to see if I can work it into my schedule. I have some other things booked already which falls around the same time frame and I had hoped to squeeze a trip to Australia in so hope they don't clash.

[rookie432]

Jay,
Looks like Dave's got you on the right track. I wish I could tell you more but I just found out about the converter software at the Jamboree. Did a real nice job on a seashell,but not too sure about other pics. As with all software you have to play with it and practice to master I assume.
Such is why Bill P., Brady W. and many Botters have excelled. All the excellent work starts with "I wonder if...?" and a drive to find a way. I think that's the real beauty of CNC. It is so open ended that it gives any person with a little drive and supplies them the means to answer the " I wonder if...?" question.

Woa! One after dinner drink and I get all philosophical.


Bill

[bleeth]

I think it comes out within the same time frame as Mike John's camp too and I've already all but promised my wife a trip home (England) for that. I hope I can do them both as they would be good for my health. I need more Artcam input and if I don't take my wife to see her family soon I may not live much longer!

[Brian Klassen (Unregistered Guest)]

Hi, I am new to this.
I manually build model yachts but am unable to meet demands with this labour intensive method so I am contemplating a Shop Bot purchase.
If the yachts are modelled in a Rhino type program from architects, could I theoretically import this to a Shop Bot and cut a 3D yacht model? I assume there will be some toolpath considerations as well as having the file in a STL or 3D DXF format. If the entire yacht is modelled in Rhino as a whole, how (and with what program) would I separate the hull and cabin components for ease of finishing afterwards?

Thanks in advance

[ron brown]

Brian,

Rhino can "do it all". I would seperate the hull and deck in Rhino, probably define the tool-paths in Rhino and then "order" the tool-paths in Vector.

Each of us have tools we know and use. We tend to continue using these tools rather than learn new.

I would probably rough mill the "lifts" - however you like to build - Buttocks or waterline, glue together, mill to the point where sanding will be faster than additional CNC milling time then finish.

Cabins and decks might be better off 'built up' - especially if they are developed surfaces. And, Rhino can define those parts too.

Good Luck,

Ron

[stickman]

Bill,

The two pictures of the cats, do you have more details, more pictures of those as they are being cut.

Awesome...

[paco]

Bill,

how large are they (cat lithophane)?

[billp]

Guys,
The lithos are 8.5"wide, and 6.25"tall. They were both cut out of Corian to a depth of .23"(in .25" material).
I use Artcam Pro to generate my cutting files for lithophanes, although the new Shopbot converter by Bruce Clark will supposedly allow you to do a similar process ( I haven't tried it out yet...)
I only have a few pix of them being cut, but in all honesty lithophanes are not very interesting to watch as they are in progress.
However you CAN see how I use my vacuum rig to hold the Corian in place, and also how I use masking tape to close off the opening in my dust collector which makes it MUCH more effective (it also minimizes the chance of hitting the sides of the collector with the spindle collet...).
I'd be curious to hear if anyone has tried to use Bruce's converter yet...
2409
2410

[bleeth]

Brian:
If you are going to do true faired hulls then you have the choice of a program like Rhino (Do a search for Cliff Estes in Seattle for good info on that) or Prolines by Vacanti ( my old favorite.) Both will output files so you can carve half hulls or full hulls with great accuracy via the bot without going too deep in your pocket. You can also get some good shareware for developable hulls. I've been out of the boat biz for a few years now but one of the reasons I chose the shop bot is the large number of current and former boatbuilders working with it.

Dave

[jerryp]

These are pictures of my grandkids using the new converter program I did over the weekend. I've had my ShopBot about a month and had problems with long maching times until I found my ramp settings were set too low, but I'm learning
2411

[paco]

Hey Jerry!

Thoses are lookin' p'etty good! Keep up the good work... you're in the right way!

[propellers]

Jerry, I really like your doors and have wanted to do similar. Could you possibly step us thru the process you used to accomplish this? I have seen the converter but never took the time to learn the process. I would be happy to give you a call if you prefer.
Lonnie Prince
419-877-5557

[fleinbach]

Jerry

Absolutely great-looking job. I also want to do something similar but haven't found the time yet to figure out how. Any information you could give would be greatly appreciated.

[mikejohn]

Jerry
I would be interested to see the original photographs. Did you do much to the contrast or brightness levels?
...........Mike

[jerryp]

Frank & Mike
Here are to original photo if I can get the uploaded right. I increased the brightness and contrast very little. I sized the photos to 5x7 and kept the white level cut at 0 and black depth of cut at .035. I used a 1/8 ball end mill with a stepover of 10% with a horizontal raster path. I had about 248000 lines of code and machine time was 1hr50min
2412
2413

[fleinbach]

Jerry,

The detail is incredibly accurate. What new converter program did you use?

[jerryp]

Frank
I used the new Shopbot bmp converter that is in the latest update

[jsfrost]

Jerry,

What were the X and Y move speeds?

[gerald_d]

Jerry, did you rub any stainer on those great looking doors?

[jerryp]

Jim and Gerald
the xy move speed was 1.25 z was.5 and I used maple stain on poplar piece of lumber. Thanks everybody.

[mikejohn]

Jerry
You did of course cheat getting such a good result by starting with real pretty children!
..............Mike

[jerryp]

Mike

I would have to say that I had the advantage there

Jerry

[ckurak]

Jerry,

What finish did you use on the wood?

I have a similar project (carving on hardwood) that is likely to have lots of hands-on usage. In otherwords, I expect lots of people to touch and run their fingers across the surface. I am looking for something that will hold up to the wear and tear. Any ideas?

Thanks,

Charles

[jerryp]

Charles

I used several coats of lacquer for the finish

[stickman]

Bill P,

You mentioned about you were using 1/8" and 1/16" ballnose bits, what where you using for stepdown and move speeds?

Jay

[billp]

Jay,
On lithophanes the 3D stepdown is usually determined by the file generated through Artcam. It is never deeper than .23", and can rise up to the surface in "darker" areas. The stepovers are mentioned above in this thread...
I will usually run the first few lines of a lithophane at about 1 IPS, and then pause the machine and change the feed rate to between 2.5-3IPS. I also "ramp" my entry into the material
to further minimize the potential for bit breakage. The idea of starting slow and then speeding up is because over 95% of the time I have broken bits while cutting lithophanes has been in the first line of code as it plunges in to full depth, and then tries to move in the "X"direction.
After the first few lines you are really only cutting with the SIDE of the bit tip, so there is much less resistance, and that allows me to move much faster. I did that last lithophane above with the .0625" bit at 3 IPS NO problem...(With stepovers of .005" anything slower would take a Veeeerrrrrryyyyy long time....)