Thank you kind sir.
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it takes a village to raise a child
it take an entire group to elevate the hobby
if you are some guy down in your basement playing with a small hobby laser thinking you are are on the cutting edge of model ship kits you wrong. Bulkhead kits have been produced for decades first stamped out with a die then laser cut. The idea is old it is only the tool that changed. Laser cut plank on frame kits have been out for 20 years it's nothing new.
What is required is a fabricator, a 3d artist, A cad designer, a historian, researcher, draftsman, prototype builders it takes an entire group to raise the level of the hobby. One person can not have all the skills sets of everyone that is required to produce state of the art kits. It is when you look at others in the hobby as competition and you try to eliminate them that is being on the road to a grand fail. Here we see each other as team mates and by combining all the requires skills we move the hobby forward.
even comments from you average hobby guy building a kit is important. It is everyone out there that represent the prototype builders, feed back sparks the changes.
it take an entire group to elevate the hobby
if you are some guy down in your basement playing with a small hobby laser thinking you are are on the cutting edge of model ship kits you wrong. Bulkhead kits have been produced for decades first stamped out with a die then laser cut. The idea is old it is only the tool that changed. Laser cut plank on frame kits have been out for 20 years it's nothing new.
What is required is a fabricator, a 3d artist, A cad designer, a historian, researcher, draftsman, prototype builders it takes an entire group to raise the level of the hobby. One person can not have all the skills sets of everyone that is required to produce state of the art kits. It is when you look at others in the hobby as competition and you try to eliminate them that is being on the road to a grand fail. Here we see each other as team mates and by combining all the requires skills we move the hobby forward.
even comments from you average hobby guy building a kit is important. It is everyone out there that represent the prototype builders, feed back sparks the changes.
Let's continue today with the stern windows of our Alfred and explore a couple more aspects of CAD and laser technology. Yesterday, we cut out a row of stern window openings and 3D columns in 1/8" cherry. Then we glued them up to create a 3D assembly. Now it is time to add some window frames inside the window openings themselves.
The upper drawing shows Dave's original draft CAD drawings for the stern windows. If you recall, he had previously mentioned the problem of using high powered industrial lasers causing smaller parts to burn and crumble. Because of that, he increases the kerf size of the window frames in an attempt to compensate for this problem. Those of you who use saws already understand that kerf is basically the width of the cut left over by the blade passing through the material. A laser also has a kerf although much smaller than any saw. We know from looking at Hahn's drawings of Alfred, the window frames should be much thinner than in Dave's original draft drawing. He knew this but had to make up for the larger kerf of an industrial laser.
In the lower drawing, I have modified the frames to match the actual dimensions of Hahn's model to much more closely depict how the actual window frames looked. Since the frame shapes are trapezoidal, I used the transform - skew functions in CAD to adjust them. My goal was to get 0.05" spacing around all the window frame elements while keeping the overall symmetry as perfect as possible. Since the kerf on the Epilog laser is so very small we should not have a problem cutting this out.
We cut both sets of parts out on 1/16" yellow wood. This operation took 2 min 13 seconds. I used a different color wood in order to provide some contrast against the cherry although it will not show up that well in the upcoming photos.
As you can see there is a significant difference in the size of the window frames with the modified version looking much closer to scale.
Next, this is where the prototype builder would get involved. The window frame parts are punched out (no tabs) and glued into the window openings from the back-side. The CAD design include a tiny step allowing for a single drop of CA in each corner to hold the window frame in. You will notice the window frame is recessed into the 1/8" cherry billet (by design) and leaves room for a clear acrylic window behind the frame. Yes, the Epilog can cut out clear acrylic windows.
Once all the frames have been glued in we are left with a pretty nice looking result. Remember, this is only a prototype. We would want to refine this much further before it would be worthy of going on an actual model.
The overall effect of 3D Assembly begins to take shape.
As you can see, the window frames are approaching 1/32" wide. This is using my standard focus lens. I have a high definition lens that allows a focus of 1/3 the kerf size of this one. Also note, the laser char on the inside of the window frames actually creates additional depth and I believe is pleasing to the eye from an artistic viewpoint.
Questions, comments are always appreciated.
Sail on!!
The upper drawing shows Dave's original draft CAD drawings for the stern windows. If you recall, he had previously mentioned the problem of using high powered industrial lasers causing smaller parts to burn and crumble. Because of that, he increases the kerf size of the window frames in an attempt to compensate for this problem. Those of you who use saws already understand that kerf is basically the width of the cut left over by the blade passing through the material. A laser also has a kerf although much smaller than any saw. We know from looking at Hahn's drawings of Alfred, the window frames should be much thinner than in Dave's original draft drawing. He knew this but had to make up for the larger kerf of an industrial laser.
In the lower drawing, I have modified the frames to match the actual dimensions of Hahn's model to much more closely depict how the actual window frames looked. Since the frame shapes are trapezoidal, I used the transform - skew functions in CAD to adjust them. My goal was to get 0.05" spacing around all the window frame elements while keeping the overall symmetry as perfect as possible. Since the kerf on the Epilog laser is so very small we should not have a problem cutting this out.
We cut both sets of parts out on 1/16" yellow wood. This operation took 2 min 13 seconds. I used a different color wood in order to provide some contrast against the cherry although it will not show up that well in the upcoming photos.
As you can see there is a significant difference in the size of the window frames with the modified version looking much closer to scale.
Next, this is where the prototype builder would get involved. The window frame parts are punched out (no tabs) and glued into the window openings from the back-side. The CAD design include a tiny step allowing for a single drop of CA in each corner to hold the window frame in. You will notice the window frame is recessed into the 1/8" cherry billet (by design) and leaves room for a clear acrylic window behind the frame. Yes, the Epilog can cut out clear acrylic windows.
Once all the frames have been glued in we are left with a pretty nice looking result. Remember, this is only a prototype. We would want to refine this much further before it would be worthy of going on an actual model.
The overall effect of 3D Assembly begins to take shape.
As you can see, the window frames are approaching 1/32" wide. This is using my standard focus lens. I have a high definition lens that allows a focus of 1/3 the kerf size of this one. Also note, the laser char on the inside of the window frames actually creates additional depth and I believe is pleasing to the eye from an artistic viewpoint.
Questions, comments are always appreciated.
Sail on!!
I tend to agree. From an artistic viewpoint the char inside the frames does make them look much more realistic. Very nice work.
Really nice work, Mike!
Yeah, the char acts like a shadow line. It definitely adds depth. Those window rails, stiles and mullions look infinitely better at the smaller size. Almost looks like a simulation, but it's actually cut. -- It's a small, small world.!! (with apologies to Disney..).
Great work.
Great work.
Watch out!! You might be called a pirate!!
Well... what more can I say. Sensational work Mike.
Hello everyone. So let us jump over to the world of CNC carving. Computer Numerical Control (CNC) is a computer controlled machine tool that basically runs on and x/y (left/right) gantry and also has a certain amount of z-axis (up/down) travel. Educational/hobby style CNC tools might be purchased or assembled for several hundred dollars or you could see CNC machines in automotive, aerospace, or Formula 1 industries in the millions of dollars. Many people refer to them as CNC Routers because common woodworking or furniture making CNC machines use a router mounted in the gantry to spin the bits. For precise miniature model work we need higher end equipment. My CNC machine is made by ShopBot Tools right here in North Carolina USA and features a Bosch High Speed Spindle. For you woodworking fanatics my dust collection is provided by Festool. Gotta love German engineering. Ok, enough of the hardware... What are we gonna "make" today?
As we can see in the Hahn picture below, our 1:64 Alfred prototype needs some lettering on the stern. I haven't found those on Dave's massive CAD drawings yet so let's see if we can make our own and then carve them in 3D on the CNC machine. First, we had to search through our huge font library and find one that matches the Alfred lettering that was hand carved by Hahn. The match I found was Bodini Book Normal. I typed out the word ALFRED in my CAD software and then scaled it to fit the area below the stern windows we had already created. I found this font size to be 46.856pt for 1:64 scale. Ok, easy enough.
Next, I used Vectric Aspire's Create 3D Shape function - Flat and added about 9degrees of curve to the top. I set the overall thickness of the letters to be 0.125" and added .0625" to the base for a total of about 3/16" tall. I inserted the letters into a 1/2" virtual slab of wood and moved over to the tool path simulator to select bits and run simulations over and over and over until I got the results we needed. All of this work took several hours. But once done... it is done forever!! I sent the CAD over to my post-processor to create CNC code and warmed up the high-speed spindle for 10 minutes.
Some of us cannot carve like Harold Hahn so we need help!!
This project will consist of 2 jobs. First we will use a 1/8" Carbide Ballnose (upper bit) to rough out all the excess wood from the billet. Then we will change over to a 1/16" Tapered Ballnose for finishing and cutout. We will use an Onsrud 1/4" hardened steel shank holder to secure the bits in the spindle. Each of these bits go for nearly $100 a piece.
When CNC carving small, highly detailed parts we want to use the hardest, tightest grained wood we can. Boxwood and Pear are two of the best. For this prototype I have selected a 1/2" slab of hard maple. Clamp it down to the spoil board with some good Rockler clamps. We could also use screws.
Although the billet is labeled as 1/2", for precise CNC machining we must ALWAYS measure it. This billet is actual 0.518" thick. We install the first bit and then zero the z-axis against the touch plate on the spoil board. Since we will be carving all the way through the wood, we set our z-axis zero to the surface of the spoil board and not the surface of the billet. When the steel bit makes contact with the plate a small electrical circuit is made and the computer zero's out. The thickness of the plate is already factored in.
We fire up the job and we are off. The 1/8" ballnose bit will spin at 14,000 rpm while the CNC machine executes 7825 lines of code. We can monitor the job progress on the laptop sitting next to the machine.
The roughing job took 20 minutes to complete. This could have been greatly reduced had I used a 1/4" billet instead of 1/2". You see the result of the roughing job below. It looks horrible!!! What went wrong?????
Nothing went wrong. Time to install the 1/16" Tapered Ballnose, spin that sucker at 18,000 rpm, executing over 25,000 lines of code for 26 minutes. This is where the magic happens.
What emerges is this mess!! Ah, but looks can be deceiving.
The letters are removed from the billet attached to a paper thin wafer of hard maple.
This is where our prototype builders would get involved. The maple backing is so thin we simply cut the letter out with scissors.
Spend a few minutes cleaning them up. I really did not put much effort in here. After all, these are only prototypes.
Finally, we mock them up against the stern windows we already made. Looks pretty good for a first prototype. The letters are actually thicker than they would be on the final model. This is on purpose. The modeler would thin them down from the backside using their Byrnes Disk Sander to a final thickness of about 1/16" and then carefully glue them to the black planking wales on the stern.
Another view to see the carved 3D shape. The end result is just a hair over 1/8" thick at 0.14". These are in hard maple. We could easily get a lot more definition out of boxwood or pear. A few more prototypes and simulation runs and we could bang them out by the hundreds. As you can see, CNC is both much more complicated and a lot slower than using a laser. But the results that can be obtained are nearly limitless. I skipped over a lot of details, otherwise this would have been a book. But there you go.... questions, comments, feedback always welcome!!
As we can see in the Hahn picture below, our 1:64 Alfred prototype needs some lettering on the stern. I haven't found those on Dave's massive CAD drawings yet so let's see if we can make our own and then carve them in 3D on the CNC machine. First, we had to search through our huge font library and find one that matches the Alfred lettering that was hand carved by Hahn. The match I found was Bodini Book Normal. I typed out the word ALFRED in my CAD software and then scaled it to fit the area below the stern windows we had already created. I found this font size to be 46.856pt for 1:64 scale. Ok, easy enough.
Next, I used Vectric Aspire's Create 3D Shape function - Flat and added about 9degrees of curve to the top. I set the overall thickness of the letters to be 0.125" and added .0625" to the base for a total of about 3/16" tall. I inserted the letters into a 1/2" virtual slab of wood and moved over to the tool path simulator to select bits and run simulations over and over and over until I got the results we needed. All of this work took several hours. But once done... it is done forever!! I sent the CAD over to my post-processor to create CNC code and warmed up the high-speed spindle for 10 minutes.
Some of us cannot carve like Harold Hahn so we need help!!
This project will consist of 2 jobs. First we will use a 1/8" Carbide Ballnose (upper bit) to rough out all the excess wood from the billet. Then we will change over to a 1/16" Tapered Ballnose for finishing and cutout. We will use an Onsrud 1/4" hardened steel shank holder to secure the bits in the spindle. Each of these bits go for nearly $100 a piece.
When CNC carving small, highly detailed parts we want to use the hardest, tightest grained wood we can. Boxwood and Pear are two of the best. For this prototype I have selected a 1/2" slab of hard maple. Clamp it down to the spoil board with some good Rockler clamps. We could also use screws.
Although the billet is labeled as 1/2", for precise CNC machining we must ALWAYS measure it. This billet is actual 0.518" thick. We install the first bit and then zero the z-axis against the touch plate on the spoil board. Since we will be carving all the way through the wood, we set our z-axis zero to the surface of the spoil board and not the surface of the billet. When the steel bit makes contact with the plate a small electrical circuit is made and the computer zero's out. The thickness of the plate is already factored in.
We fire up the job and we are off. The 1/8" ballnose bit will spin at 14,000 rpm while the CNC machine executes 7825 lines of code. We can monitor the job progress on the laptop sitting next to the machine.
The roughing job took 20 minutes to complete. This could have been greatly reduced had I used a 1/4" billet instead of 1/2". You see the result of the roughing job below. It looks horrible!!! What went wrong?????
Nothing went wrong. Time to install the 1/16" Tapered Ballnose, spin that sucker at 18,000 rpm, executing over 25,000 lines of code for 26 minutes. This is where the magic happens.
What emerges is this mess!! Ah, but looks can be deceiving.
The letters are removed from the billet attached to a paper thin wafer of hard maple.
This is where our prototype builders would get involved. The maple backing is so thin we simply cut the letter out with scissors.
Spend a few minutes cleaning them up. I really did not put much effort in here. After all, these are only prototypes.
Finally, we mock them up against the stern windows we already made. Looks pretty good for a first prototype. The letters are actually thicker than they would be on the final model. This is on purpose. The modeler would thin them down from the backside using their Byrnes Disk Sander to a final thickness of about 1/16" and then carefully glue them to the black planking wales on the stern.
Another view to see the carved 3D shape. The end result is just a hair over 1/8" thick at 0.14". These are in hard maple. We could easily get a lot more definition out of boxwood or pear. A few more prototypes and simulation runs and we could bang them out by the hundreds. As you can see, CNC is both much more complicated and a lot slower than using a laser. But the results that can be obtained are nearly limitless. I skipped over a lot of details, otherwise this would have been a book. But there you go.... questions, comments, feedback always welcome!!
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Hello Mike, thats exceptionally well done.
This is the part that excites me.!! It seems there must be a lot of emphasis placed on material. In my experience, hard maple machines pretty good as long as there is not a lot of grain pattern. Curly maple or quilted maple would be a nightmare I would presume. This piece looks pretty "calm" though. So, I wonder about the chip outs.?? Some repairs were made along the way, I'm guessing. Tool needs sharpening..??? Rotational speed needs adjusting.??? Or...just a function of the maple.???
Thanks Brian. Of course they could also be 3D printed.... but the idea of hardwood strikes me better!!!
No chipouts as we only drive the bit into the wood no deeper than 1/2 the radius of the bit. We also use ramp-in, ramp-out functions.
Never. However, sometimes they break if you "crash" the bit. This is a user error caused by not running the simulations properly prior to machining.
Each bit has a specific speed and feed rate that is set when the tool path is created. The software has a library of all my bits. We call this "speeds and feeds"
The excess wood you see left over on the top of the pieces were easily sanded away. Think of them as flash on a plastic model part. They are not chip outs.
For miniature model work - hard, tight grained wood. Typically we use Boxwood, Swiss Pear, Hard Maple most common. Cherry perhaps but that begins to fray. I am only referring to detailed carvings here. We can CNC cut any kind of wood we want.
Well, I'm glad you know what you're doing.!! My little experience on CNC has been on metal. Wood looks to be a more troublesome media.!!
Very nice end product.
Very nice end product.
Thanks Janos. The nice thing about this software, I can export these same 3D objects as STL files for output to 3D printers!! Very cool.
HI MIKE FANTASTIC STUFF AND TO ME VERY IMPORTANT IS THE WAY YOU EXPLAIN IT, JUST SUPER, NOW FOR A QUESTION, WHAT AND HOW IS A STL FILE DO YOU NEED THIS IF SOMEONE PLACED AN ORDER FOR LET US SAY SIMPLY CANNONS IN A CERTAIN SCALE, AND WHAT WOULD HAPPEN IF SOMEONE WANTED SOMETHING FROM A SET OF PLANS HOW WOULD ONE GO ABOUT THAT IF SAY SOMEONE WOULD SEND YOU THE PLANS. GOD BLESS STAY SAFE TO YOU AND YOURS DON