Pushing the Envelope with CNC

Jonathans

Jonathans

Joined
Jan 9, 2008
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588
I pulled the trigger today on a CNC mill. I like old iron, and this Bridgeport Boss will be rebuilt and outfitted with the latest Machmotion controller and servos. The question is whether this old brain will be able to make the leap from manual machining to Gcode!?

For those of you here that do have CNC mills, I am curious as to how you utilize it for your bladesmithing, other than in MDC mode, which is basically the same as manual.
 
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Is the Boss going to be a 2d, 2.5d or 3d machine? My only experience with Bridgeport CNC is on an Easy Crash.

I've utilized my access to CNC mostly for guard making, though some blade profiling and beveling. I'm currently working on an integral guard/frame for a take down bowie.

What your machine is capable of and what kind of software you'll have to run it will dictate a lot of what is practical for you to do with it. Then it becomes a question of whether your capabilities drive your business offerings or what you want your offerings to be drives your capabilities.

Usually that question is answered prior to machine purchase :p
 
Hi Kuraki,
The machine is a 3hp, full 3 axis and will fit my non bladesmithing requirements (yes they do exist) very well. I have utilized my manual mill to cut guard and bolster slots, and to rough out some guard material. Sometimes I have had to utilize the mill with an endmill to save my a** when I forgot to drill a tang prior to heat treat, or take out a screwed up corby. As the software is Mach4 with the Machmotion plugin and conversational interface I am sure that its capabilities will be way beyond my own! I posted the initial question to see whether I am not seeing the whole picture as to how useful, or not, the machine will be, over a manual machine, in regard to my knife making.
 
If you have the time, the patience, and the money (fixture plates, broken end mills, etc...) there's probably quite a bit you can do with a CNC mill as related to knife making. I wouldn't say you could do ANYTHING, but there's certainly plenty that makers have done or are doing with them.

Take a look at some of John Grimsmo's older vids on his youtube channel. He got quite creative with a little mini-mill, and even more so with a Tormach. Aaron Gough also started getting into producing Resolute fixed blades on a Fadal VMC, which although it's a couple notches above a Bridgeport, still has some similarities I'm sure.
 
Jonathans said:
Hi Kuraki,
The machine is a 3hp, full 3 axis and will fit my non bladesmithing requirements (yes they do exist) very well. I have utilized my manual mill to cut guard and bolster slots, and to rough out some guard material. Sometimes I have had to utilize the mill with an endmill to save my a** when I forgot to drill a tang prior to heat treat, or take out a screwed up corby. As the software is Mach4 with the Machmotion plugin and conversational interface I am sure that its capabilities will be way beyond my own! I posted the initial question to see whether I am not seeing the whole picture as to how useful, or not, the machine will be, over a manual machine, in regard to my knife making.
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Probably the biggest asset in that case is walk away time. Even if you are only making 1 of something, you can set the machine up and program it to make 4 or 5 unique pieces with a little ingenuity and let it go, freeing you up to baby sit your heat treat, or hand sand a handle, or throw the dog a ball. The second biggest thing it can do for you related to knifemaking is give you some capabilities to have a feature made that maybe you could have done manually, or with multiple operations using multiple tools (example, milling a complex multi curve geometry for an artistic guard that would have been sawing, grinding, and eventually filing and hand sanding) almost complete and ready for hand sanding as it comes off the machine. Who cares if your milled guard didn't have a very efficient run time because you programmed around not having a tool changer and it took 2 hours to mill something that maybe you could have also made by hand in 2 hours, if you could then spend those two hours producing something else and also have a finished guard. With the added bonus of making a second one after you call it quits for the night and go in for supper.

Obviously, anytime you intend to make more than one of something, it will be a huge improvement. In fact, when it comes to making knives or knife components, when I'm utilizing CNC I rarely make one, regardless of whether I have a sale or not. I almost always make 4 or 5, because the material cost is minimal compared to the value of having 5 finished parts, and I simply haven't run into the problem of not being able to sell a complete knife once I've finished it. Most of my wasted time and material in this area has been from making 4 or 5 of something that really turned out to be not a very good design and I just canned the project :D
 
Thats some great feedback guys. Still not sure about walking away from the machine!😜 I'm sure that will come.
I'll be sure to check out the fellows Drew mentioned.
 
In my opinion the conversational control is a crutch given to old machinists so they can use a CNC. It's better to design and program on a computer and send Gcode. Your retrofit from an old shitty Boss control to the Mach control allows you run long Gcode and make smooth motion and feed through millions of points smooth and fast. This frees you up to use splines and go 3D. So, your limitation won't be you and your mill, it will be you and your computer and your ingenuity in setup. I recommend you start with low hanging fruit and find some kind of easy to use CAD/CAM to get your feet wet and profile blades. From there you can mills scales and bevels, though there is a learning curve to achieve results as good as simply doing it by hand.

But to answer your question, CNC can do every aspect of the process except final sharpening, but not in MDI mode.
 
Except Mazatrol. I believe that was developed to confound them :D
 
I have a full seat of Autodesk Ultimate that includes Fusion 360. I could download it and give it a spin if you'd like.
 
12345678910 said:
Do you have an opinion on Fusion 360 ?
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Sorry, I don't. I remember using "flashcut" 15 years ago when getting my feet wet. It could take a DXF file and create gcode to run my first CNC. I also used some kind of 3D software that could made 3D code from an STL file, the name escapes me. I only used it a few times but it worked really well. There was easy to use free-ware 15 years ago, I'm sure there are better options today, but I don't know what they are. I use Pro/E now, which it a great software but not something I'd recommend to most folks. I've never used Fusion 360.

I think if I were starting out now I might use Solid Works and one of the CAM plugins or perhaps Rhino and a CAM plug in.

Good 3D is important when you get to scales:

3.jpg~original


A lot of 3D engineering CAD software is cumbersome in organic 3D. This is important to overcome because good 3D CNC is one of the primary strengths of CNC, so it's important to "get there" in order to really utilize the capabilities of the process. Folks need to get their feet wet in something easy to use, but ultimately one needs to try to take advantage of what the process is capable of.
 
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kuraki said:
How does your tooling hold up to milling the G10?
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G10 wears a cutter very quickly but cuts okay with a less-than-sharp cutter. Most of our orders include a mix of micarta and G10, so we'll run a couple sheets in micarta (which needs a sharp cutter) then a couple sheets in G10 (which ruins a cutter for micarta almost instantly). So we'll typical get 20 scale sets out of a cutter. Something that helps is roughing with an older used cutter so the new cutters are only seeing the finish pass.
 
So Count, this is obviously very preliminary but I was able to download, install, model a simple shape and program and simulate a toolpath in about 20 minutes. My first glance is that the transition from modeling to CAM is seamless, and that while it's not intuitive to me how the program is laid out since I'm used to Inventor and FeatureCAM, there are quite a few similarities. Some things are quite simplified which is actually a benefit I think in a lot of cases. I'll try something more complex geometry speaking when I get more time.

beN4KtP.jpg
 
Nathan the Machinist said:
G10 wears a cutter very quickly but cuts okay with a less-than-sharp cutter. Most of our orders include a mix of micarta and G10, so we'll run a couple sheets in micarta (which needs a sharp cutter) then a couple sheets in G10 (which ruins a cutter for micarta almost instantly). So we'll typical get 20 scale sets out of a cutter. Something that helps is roughing with an older used cutter so the new cutters are only seeing the finish pass.
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That makes perfect sense. I hadn't thought about micarta, but I imagine it gets fuzzy if the cutter is dull, while G10 fractures cleaner. HSS for the more acute cutting edges or do carbide mills do ok?

I was thinking of roughing with carbide and finishing with HSS but maybe I'm just off kilter and the edge geometry is less impact than carbide life.
 
Thanks for checking out F360 Kuraki. I've been playing with a trial version an appreciate the integration of CAD/CAM in one package, at a somewhat reasonable cost. It'll be a steep learning curve for me, but worth it.
Nathan, you always produce the cleanest, IMO, machined blades. You were probably a wizard in a past life.
Whats the difference between a full 3 axis machine and 3D?
 
That's my fault for confusing terms. 3D is generally the term coined for modeling and toolpaths that occur in 3 dimensional moves. 3 Axis is a machine capable of making those moves.

Some knee type CNC mills and conversions are really 2.5 axis in that they are not capable of making 3 dimensional moves at the speed or accuracy required to be considered 3 Axis, even though they may move the Z axis up and down as programmed for things like drilling and boring.
 
We converted our Robotool controlled Bridgeport [1 1/2 hp] installing a MacMotion system from the servos back. It took my son and I about a week to do the work. We found it pretty straight forward work and the tech line at MacMotion was responsive. We use it in manufacturing the Bubble jig and ERU sharpener so have very little experience in using it in knife making.
We do like the system and have had very little down time over the last 4 years.

Good luck, Fred
 
kuraki said:
That's my fault for confusing terms. 3D is generally the term coined for modeling and toolpaths that occur in 3 dimensional moves. 3 Axis is a machine capable of making those moves.

Some knee type CNC mills and conversions are really 2.5 axis in that they are not capable of making 3 dimensional moves at the speed or accuracy required to be considered 3 Axis, even though they may move the Z axis up and down as programmed for things like drilling and boring.
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OK I understand now. 3D is the simultaneous movement of x,y, and z axis for smooth contouring. Machmotion has that covered up to 5 axi. Whether I do is a different question.
 
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kuraki said:
That makes perfect sense. I hadn't thought about micarta, but I imagine it gets fuzzy if the cutter is dull, while G10 fractures cleaner. HSS for the more acute cutting edges or do carbide mills do ok?

I was thinking of roughing with carbide and finishing with HSS but maybe I'm just off kilter and the edge geometry is less impact than carbide life.
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Both materials wear out HSS very quickly which leads to poor surface finish. We use carbide for the cutters, drills and reamers and polycrystalline diamond in some applications.
 
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