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Black Forest
08-31-2014, 11:52 AM
I have started on my CNC plasma table build. This is the gantry. The table will be able to handle a 3000 x 1500mm sheet of material. 5x 10 foot.

The electronics will come from CandCNC in Texas. It will have 5 axis with one being for a rotary table to enable pipe cutting. Two motors on the X axis. All 850 oz. servo's.

It will also have a boring motor mounted on the Z axis. I want to be able to drill and tap with the table so that is why it is so robust. The Z axis will also have a 850 oz. servo.
http://i853.photobucket.com/albums/ab91/burnandreturn/gantry1_zps9db56b5e.jpg (http://s853.photobucket.com/user/burnandreturn/media/gantry1_zps9db56b5e.jpg.html)
http://i853.photobucket.com/albums/ab91/burnandreturn/zaxis_zpsea9da05f.jpg (http://s853.photobucket.com/user/burnandreturn/media/zaxis_zpsea9da05f.jpg.html)

Old Hat
08-31-2014, 12:07 PM
Do you know some secret way to put more than 24 hours in a day, or what?:rolleyes:
Nice Build!

Black Forest
08-31-2014, 12:14 PM
Do you know some secret way to put more than 24 hours in a day, or what?:rolleyes:
Nice Build!

Pizza!

Old Hat
08-31-2014, 12:19 PM
Ow! ya got me.:p

Drilling and tapping? I hope to be pleasantly surprised. But by all means Go for It right?

MaxHeadRoom
08-31-2014, 01:54 PM
The electronics will come from CandCNC in Texas. Two motors on the X axis. All 850 oz. servo's.

I want to be able to drill and tap with the table so that is why it is so robust.

I thought CandCNC used Mach for S/W so how is the 2 servos geared together? As Mach does not do it on its own.
Same for the rigid tapping, unless floating tap is used?
Just curious.
Max.

Black Forest
08-31-2014, 02:09 PM
I thought CandCNC used Mach for S/W so how is the 2 servos geared together? As Mach does not do it on its own.
Same for the rigid tapping, unless floating tap is used?
Just curious.
Max.

The second X axis motor A is slaved to the X axis motor. As for the drilling and tapping I will probably use a second system to actually control the drill motor. But first I will get the Plasma and air scribe running perfect and then add the drill motor. Basically cross that bridge when I come to it!:cool:

MaxHeadRoom
08-31-2014, 02:47 PM
The second X axis motor A is slaved to the X axis motor.

But what are you using to slave it?
I am used to using motion cards and one axis encoder is used to slave the other off of it.
Max.

RussZHC
08-31-2014, 04:15 PM
I'm interested in the extrusions, assuming that is what makes up the gantry body/frame.

Are they off the shelf items sold in lengths or are they from something else that is being re-purposed?
Finding what you want, when you need it can be tough.

My limited experience with extrusions is that they seem to come in lots of shapes and sizes many good for smaller projects but you table is going to be quite large and obviously robust.

MaxHeadRoom
08-31-2014, 05:03 PM
Are they off the shelf items sold in lengths or are they from something else that is being re-purposed?
Finding what you want, when you need it can be tough.
.

I used to use Item Products they have since been taken over by Rockwell Automation so I imagine the price is going to be reflected in that, but they had very heavy duty extrusions with features such as tubular galleys through the extrusion for Oxy/Gas tables etc.
http://www.itemamerica.com/gantry-video.html
There is also Misumi but I am not sure what the largest is.
Max.

Black Forest
08-31-2014, 05:11 PM
Each horizontal extrusion is 80 x 80 mm. The main reason for using these is the linear rails are a hardened steel rod in a aluminum holder of sorts that goes in a slot on the extrusion. I am using those on the Y and Z axis. On the long 4000mm side I will use THK linear rails. I could probably build the whole table out of the aluminum extrusions but I will use steel for the table and X axis frame. Also I could build the gantry with the aluminum extrusions and get a very stable gantry and keep the weight down. The main table will benefit from the mass of the steel.

MaxHeadRoom
08-31-2014, 05:32 PM
The main reason for using these is the linear rails are a hardened steel rod in a aluminum holder of sorts that goes in a slot on the extrusion. .

That was exactly the method I used using Item Products.
Max.

Plain ol Bill
08-31-2014, 05:41 PM
I likely told you this before but having a cnc plasma changes the way you work! The servo package from CandCNC is a great choice for the electronics and I think you will be pleased with it. I have a friend locally that has a new Hypertherm 85 with the electronics to automate everything and he has fallen in love with it. Amperage, voltage, height, air pressure all in the software. Would love to upgrade to that myself but just cannot justify it currently. You ARE planning a water table or a high volume exaust system aren't you?

Glug
09-01-2014, 07:01 PM
That looks great. I'll be curious how much deflection you measure when you simulate the mass of your spindle/torch, etc. Or simulating the forces of drilling (which tend to be significant!). Rigidity in the various designs is a major interest for me, since I want to build a machine sooner rather than later.

It is unfortunate we don't have a standard method for making deflection measurements on certain types of machines. Like moving gantry vs. stationary gantry, etc. Though I am not a fan of a moving gantry. The same goes for how straight the machines are. I see a lot of builds but seldom does anyone report the rigidity or how true it is.

boslab
09-01-2014, 10:15 PM
I did build a machine years ago to drill and tap brass neutral bar for distribution panels for merlin gerin or however you spell it, they were brass with holes at 90 degrees, one for the cable one for the grub screw, 1/4 UNF, odd size in a metric only company, anyway i used ARO drilling and tapping spindles, they were air powered, but the air motor could be removed and a servo motor fitted to the spindle quite easily, very good units to use, an idea perhaps
Mark