New Build Specification (Plasma/Router unit)

[Profpinz]

I’m a newbie to CNC controlled machines, although I’ve using and building tooling and machinery for way too many years now.

Recently I decided to “bite the bullet” and build a CNC Plasma/Router unit, after joining and reading a lot of the posts on this Forum....I've got to say this is a brilliant Forum

Although I’m confident in designing and building the mechanical part of the project my knowledge and talent relating to the electrical/electronic side is minimal!....fortunately a mate, who is a retired electronics designer is willing to help with the detailed assembly, however he is not totally “au-fe” with the specifics of building such a machine, so I’d appreciate some help and advice!

I’ve approached this build in much the same way as any design project (I’m an Industrial Designer and Modelmaker by profession) with lots of research, but I thought it may be prudent to bounce my initial thoughts and specs off forum members who are far more knowledgeable and expert in this area than I am.....so as I don’t waste too much time and effort going down the wrong track!

After all my reading I must admit I’m somewhat confused as to the motor, Gecko and Breakout Board specs, required for such a machine, so I would welcome feedback on what members think would be appropriate electrical component requirements.

I’ve done some CAD designs (I’II post them for critique in the near future) but basically the design specs of my machine are as follows:
(BTW: I understand the downside (especially after reading various threads) of a combination plasma/router, but have some ideas for working around many of the problems)

• Gantry style plasma/router unit
• Steel base, Steel table (with insertable MDF for routing), Aluminium Gantry (gantry size approx 152mm X 64mm rectangular box, 6mm thick)
• Table size: approx 2200mm x 1500mm
• X travel 1900mm, Y travel 1300mm, X travel: Undecided
• X axis Ball Screw: Abba, 25mm dia X 5mm pitch, Y axis: Abba, 20mm dia X 5mm pitch, Z axis: Undecided
• Abba, 25mm Linear Guides on all axis’s
• Plasma (Miller Spectrum)....already have
• Router (either a: 1850W Elu or a 350W Bosch Spindle grinder setup)
• Material to be cut with the router: Cibatool, MDF laminate, Urethane Foam.

• To date I’m thinking 740 oz/in stepper motors maybe the best option, with Gecko controls (Model undecided) and either a Campbell or CNC4PC, C11T board.

Any feedback on the above specs (particularly the motor and control specifications) would be appreciated! ... Thanks!

Peter.

[TOTALLYRC]

130-150 mm on the z is a good range.
Use the same screw for the Z that is on the y.
Gecko g203v All sorts of oops protection and the morphing will give better top speeds which can be very helpful with plasma on thin materials.

75v power supply and steppers to match. High voltage means better torque at max speed than lower voltage.

www.candcnc.com for breakoutboards and torch height control.
or possibly a complete electronics package.
Make sure you have a great vacuum when using the router, the dust from mdf or many other things isn't any good for you lungs.

Check around but I have heard some speeds for plasma on thin material that are very fast. Your plasma user manual may give you an idea on how fast you have to go and make sure your screws and motors will go that fast but I think you are on the right track.

I can't wait to see the drawings.

Mike

[Profpinz]

Following even more research (mainly from builds on this forum) I've come up with a "concept" that works for me, but I'm sure people far more experienced in this field than me, will see problems... Excellent, that's what design critique is all about and a great way to get the best, most viable final design spec.....So fire away!

BTW...I'm happy to go right back to the drawing board if necessary

I know combo machines are seen as a compromise at best, but for me it is the only viable solution given the cost and the fact that I work in Cibatool and MDF as much as I do in steel and other metals. (the joys of being an Industrial Designer/Modelmaker )
Fire has come up as one reason NOT to combine the machines usage, but for me, time to switch from one mode to the next is not a problem....and if serious cleaning is required then so be it.


The specifications for the machine are pretty much as posted below with a few changes:

• Gantry style plasma/router unit

• Steel base, Steel table with a stainless steel "pan" underneath the plasma grid that is attached to an extractor for fume removal (with "insertable", laminated MDF table for routing, that can be stored under/the plasma table/within the base frame when not in use)

• Aluminium Gantry (gantry = 2 off beams, 100 mm square box, 6mm thick)

• Table size: approx 2200mm x 1600mm

• X travel 1800mm, Y travel 1200mm, X travel, total 300mm (230mm
clearance under the gantry in "router mode")

• X axis Ball Screw: Abba, 25mm dia X 5mm pitch, Y axis: Abba, 25mm dia X 5mm pitch, Z axis: 16mm dia X 5mm pitch (the ballscrews will be covered with protective shields)

• Abba, 25mm Linear Guides on all axis’s

• 740 oz/in stepper motors, with Gecko controls (G203V) and either a Campbell, C&CNC or CNC4PC breakout board (and torch height control if I can fit it to the Miller Spectrum 375)

• Router (either a: 1850W Elu or a 350W Bosch toolpost grinder setup)


The design concepts have been developed with the "manufacturing" machine in mind.
The steel frame is primarily made of welded, 100 X 50 mm steel RHS, (I have cheap access to this size material) ... the linear rails will be bolted to 75mm square RHS that will be bolted to the frame. This will be packed to remove any distortion from the steel frame and to allow for adjustment.
The gantry is 16mm aluminium plate with 100mm square aluminium, that are lightened as much as possible...two off, to give good width for the linear rails.
The steel powder coated covers are all under 1840 mm long because my folder can only hand up to this size.
The vacuum formed covers over the gantry have to be made in 2 pieces so I can fit them in my machine etc, etc

The pics btw are:
Router setup
Plasma setup
Plasma setup without metal side panels and vac-formed plastic covers
Base/Frame design
Gantry without covers


Any feedback on the above specs/pics would be appreciated! ... Thanks!

[Greolt]

For the size table and the fact that it is plasma you really should consider R&P on the X and Y.

Greg

[Profpinz]

Any thoughts Greg, as regards the best pitch.
Additionally do you know of a good R&P supplier here (I'm in Vic too.... Melbourne)
Ronson gears in Highett, do some sizes.
http://www.ronsongears.com/

Thanks.

[Greolt]

Peter

I have found Ronson to be expensive.

Try TEA in Q'land,

http://www.tea.net.au/welcome.aspx

"Module 1" for size

Greg (Geelong)

[Profpinz]

Thanks Greg.

I might look at modifying the design to incorporate R&P ..... I must admit in all my research I thought that might be one area that would create some debate.