What CNC machine would work best?

[Bryan Cowan]

Before purchasing a machine, what software is available that I can "practice" on? By practice, I mean writing the G-code, setting the speed/feed settings, and then simulating the machining to determine process times.

Thanks

[Steve knight]

to cut aluminum you need a better then low end machine. even then the cut will not be super smooth. plus it is pretty slow. you can't take much off in a pass.
getting someone to make you jigs on a cnc and investing in metal working tools would be the way to go. a metal cutting bandsaw like so
http://www.grizzly.com/outlet/Vertic...-Bandsaw/G0621
use a template to guide it. then use a table router with a flush bit for the final work.
it would be faster then doing it on a cnc machine.

[Keith Outten]

Bryan,

Visit the Vectric web site, you can download VCarve Pro (2D) or Aspire (3D) software and try it out for free. Forget having to write G-code, modern software has removed that burden.

Steve,

I can't imagine a situation on a production job where manual routing would be faster over an eight hour period. Even if i could hand route a part faster then a CNC I can't hold a router in my hands eight hours per day. As already stated above a CNC machine allows the operator to work on other things while the router is running thus another job function can be implemented simultaneously.

Without specific details I guess we are shooting in the dark here but its brainstorming none the less.
.

[james mcgrew]

www.vectric.com will allow full demos of all of its software, try vcarvepro and do not let the name fool you, while it is not parametric it has yet to not do any thing i have needed. full demo files can be run on your machine prior to purchase. as far as aluminum with the right "0" flute bits, feed speeds and coolants it will cut with some amazing property on many different machines. if the current method is with a sharpie then the accuracy will amaze you!! all of the parts on these machines (1",3/4", 1/2") are cut on the same machines

jim

http://www.youtube.com/watch?v=v2DRltiqAw0

[Bryan Cowan]

Steve,

The aluminum is no more than 1/8" thick and is 6061/6063 grade; very good machinability. If the hobbyist/bench top tools I'm using now can do the job, I would hope a low-end CNC could as well. Also, I'm trying to remove the human element as much as I can without breaking the bank. Of course there are other manual methods of what I am currently doing, but I believe that will only have me move sideways rather than forwards. While I would like the CNC to speed up processes, I won't be heart broken if it doesn't. If it provides consistent parts with a better finish AND removes me from all the manual labor I'm currently doing, I'll accept slower times.

Slightly off-topic, at my day job, we used to roll stamp our metal parts with our logo and part number one piece at a time. With a competent operator, they could knock out 100 pieces in 8 minutes. Trying to improve processes, we brought in an Epilog FiberMark laser system that will mark all 100 pieces at once, completely removing the operator and freeing them up to perform other duties, but also slowing down the process. Those same 100 pieces now take 20-30 minutes to complete. We accept the slower time because of the consistent results from the laser as well as the time is frees up for the operator. With the roll stamper, 100 pieces took 8 minutes for the machine and 8 minutes for the operator (16 minutes combined). With the laser, it's 20-30 minutes for the machine which then freed up the 8 minutes the operator used to spend stamping the parts. Theoretically, the laser only takes 12-22 minutes for 100 pieces...Understand my reasoning? So while the process isn't faster, it does improve other aspects of production. Now, if my manual labor now of 2 minutes per part skyrockets to 10 minutes per part, maybe this isn't the way to go. That's why I want to play with some simulation software to determine the end results.

Keith,

Thanks, I will look into those programs. As I said in my first post, the only CNC experience I've had is with G-code for a semester many moons ago. I'm open to new technology

And yes, we are brainstorming and it's great. I value everyone's opinion and thoughts on what I'd like to accomplish. It allows me to think about everything without (hopefully) missing any details. It will help me make an informed decision down the road.

Jim,

As always, thanks for your replies and nice video collection on YouTube. After watching a few, I searched YouTube for "camaster aluminum" and came back with this - http://www.youtube.com/watch?v=cjvTUJ1lSPY

Aside from that material being much thicker than what I'm going to use, that is exactly what I need this machine to do. It drilled the holes and then routed out the shape -- PERFECT!

[Robert Alexander]

Steve,

If the hobbyist/bench top tools I'm using now can do the job, I would hope a low-end CNC could as well. Also, I'm trying to remove the human element as much as I can without breaking the bank.!

Bryan If you have the skills and want to save some money look at building a MecMate router. It will cost $4000 to $5000 to build. I am looking in to building one in the near future.

[Bryan Cowan]

Bryan If you have the skills and want to save some money look at building a MecMate router. It will cost $4000 to $5000 to build. I am looking in to building one in the near future.

While I consider myself handy, I also appreciate the out-of-box product and don't mind spending the extra $$ on knowing what I bought is going to work and the tech. support behind it when it doesn't.

[Steve knight]

I have cut aluminum on my shopbot. but it is slow and messy and only looks ok. you only take about a .03" deep pass at about 1 to 1.5 inches per second. that's about 8 passes to cut it.
even though I do so many things on my cnc router sometimes other methods are faster. rounding over I can do far faster on a router table.
cutting stock in basic shape is faster on a tablesaw. cutting aluminum is faster on a decent saw.
a small cnc machine will not do well with aluminum. without a spindle rpms will be very fast and cause issues.
the best tool is a cnc mill. it would be faster more accurate quieter and cost less to run. plus the edges would be far nicer too right off the machine.

[Bryan Cowan]

the best tool is a cnc mill. it would be faster more accurate quieter and cost less to run. plus the edges would be far nicer too right off the machine.

Steve,

Being new to this entire venture, can you suggest any CNC mill companies that may accommodate hobbyists/small businesses?

I'm not going to limit myself to a CNC router; if it's not the best tool for my needs, then I need to know that and move on. So I appreciate you taking the time to explain all this to me.

Thanks,
Bryan

[Bryan Cowan]

What's the difference between a CNC router and CNC mill?
With the router, the work piece stays in one position and the tool moves. With a mill, does the tool stay in one position and the work piece moves?

[Steve knight]

well a mill is for metal working. it is far more massive. even my mill/drill is 600 pounds. they are far more ridged. the tool speed is far slower and thats what you want for metal working. here is a sample http://www.grizzly.com/products/10-x...ive-Head/G9904
the biggest problem is getting a large enough one and getting a cnc model. used would be the most cost effective.

[Guy Mathews]

There is a fellow over at CAMheads.org User ID Unabiker. He cuts aluminum all day long and into the night. He could probably help you out with the specs that you would need based on what you want to do. He has a website unabiker.com as well. You can probably just email him through there.

Guy

Bryan,

Now that you seem frustrated and confused, I am reminding you of my original statement. Unabiker has left a link at CAMheads.org to one of his Youtube Videos.

http://www.youtube.com/watch?v=Ax8YDKhmoHA

Normally I would not post another person's video or work, but I feel that you need to see this. Unabikers work is fantastic in my eyes. The only reason I could think of that he may not help you is if you were making a competing product.

If you have not contacted him already, I am beginning to think that is your best bet.

These threads about "Which CNC machine should I get?" always seem to drift off the original question of "What do you want to do with it?" This happens because we all have our favorite machine or we have been doing it for a long time and we just figure everyone should know what we are talking about.

As far as I am concerned any machine you get "needs" to do 4 things.

1. Run code accurately.

2. Have enough power in the steppers and the spindle/router to run the code accurately.

3. Meet the size requirements for the work that you will be doing on it.

4. Be within your budget.

Anything after that is called "wants"

In Unabikers video, it appears that he is cutting the aluminum with a 1/4 inch end mill but I am not positive. The nice thing is, with that type of bit, you can also bore holes.

Holding the piece down is the only thing that you would need to figure out.

The few times that I have cut aluminum I just screwed it down to my table. That will not work so well for you because of the time it takes to screw each piece down. Not to mention what it does to your spoil board. You can only put so many holes in an area when cutting lots of the same parts.

That being said, I stand by my original statement. I will back it up by saying, you need to talk to someone who cuts aluminum all the time, not just now and then.

Don't give up hope, you'll get there.

Guy

[Bryan Cowan]

well a mill is for metal working. it is far more massive. even my mill/drill is 600 pounds. they are far more ridged. the tool speed is far slower and thats what you want for metal working. here is a sample http://www.grizzly.com/products/10-x...ive-Head/G9904
the biggest problem is getting a large enough one and getting a cnc model. used would be the most cost effective.

But if a CAMaster for $8500 can cut aluminum (http://www.youtube.com/watch?v=cjvTUJ1lSPY) why would I want to look at something more massive and expensive? You say the tool speed on the mill is slower; couldn't I slow the CNC router speed down?

[james mcgrew]

because all camasters are built to industrial quality standards whether they are small or large!!!

jim

[Steve knight]

you need to find a used machine. they can be had for pennies on the dollar. the mill could cut that faster in less passes. with a much cleaner and smoother end. the tooling would last a lot longer too. a mill will run from say 40 rpms to maybe 1200 rpms. you can cut aluminum and steel and most other materials on it. look how clean the cut is http://www.surfcam.com/show_metal_cutting_video.aspx?url=videos/data_flute_cnc_machining_video_aluminum_6061.swf&s oftware=TrueMill%20in%20SURFCAM%20Velocity&materia l=Aluminum%206061&spindle=14000%20RPM%20%281832%20 SFM%29&feedrate=600%20IPM%20|%2015240%20MMPM&tool= .500%20Inch%20Dia.%20-%20Data%20Flute&depth=0.500%20In.%20|%2012.7mm