[cata_tm_83]

Hello, this is my first CNC and i want to do it right from the start, I'll provide all the designs (Solidworks 2011) so if anyone has a suggestion feel free to comment and/or edit the designs. Please keep in mind that the design is not finished and some parts are just put there to show the design concept. Please comment on the design, precision, cost...

Main requirements:
1) cheep
2) light
3) 2x2 meters
4) must cut metal sheets of max 200 mm thick
5) 0.5 mm precision

I have:
1) Axis Electronics Kit (https://www.finelineautomation.com/store/show/EL-0007)
2) 3 planetary gear with 1:16 reduction and 10' backlash
3) aluminum profiles from mk Technology Group : Startseite
4) Profile Rail Linear Guides, size 15mm http://www.thomsonlinear.com/website...ries_guide.php


The project is here:
https://docs.google.com/open?id=0B9O...FZnYlJEMkltaDQ


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[ajclay]

200mm plate. Surly that's a mistake.... right?


you must mean 20mm..


AJ

[cata_tm_83]

200mm plate. Surly that's a mistake.... right?


you must mean 20mm..


AJ

Hello AJ,

No, it's not a mistake, the thickness must be 10-200mm. I need something like this:

[ame=http://www.youtube.com/watch?v=zStgnqwGABA]Oxy Fuel Cutting at Prince Precision Products - YouTube[/ame]

[ajclay]

Hello AJ,

No, it's not a mistake, the thickness must be 10-200mm. I need something like this:

Oxy Fuel Cutting at Prince Precision Products - YouTube

Cheap, light, accurate.... sounds like you have the work cut out for you. Usually what takes the longest and costs the most is the way to go.

Cutting 7.8 in thick plate is another story. Just the weight alone will distort a "light" machine... Then let's add some heat to make things worse.

Please keep the forum up to date on your build.

AJ

[cata_tm_83]

Cheap, light, accurate.... sounds like you have the work cut out for you. Usually what takes the longest and costs the most is the way to go.

Cutting 7.8 in thick plate is another story. Just the weight alone will distort a "light" machine... Then let's add some heat to make things worse.

Please keep the forum up to date on your build.

AJ

The Torch Table needs to be very solid indeed but, keep in mind that the cnc and the torch table are too different things. So when i said 'light' i meant without the torch table. The carriage weight must support 12kg(the weight of: oxy-gas torch, motor and the planetary). This weight is the same regardless of the metal sheet thickness.

[cata_tm_83]

Update.

SolidWorks 2011 project:
https://docs.google.com/open?id=0B9O...FZnYlJEMkltaDQ



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[WSS]

You will probably need a steel gantry for anything over 30mm. The heat from cuts like this is fairly high, more than enough to wrinkle an aluminum extrusion gantry. The cut speeds on 30mm (using a hi speed tip) is probably in the 10-15ipm range. Preheat (w/o a hi/lo system) on 30mm (using lpg) will be 1-2min. Just the preheat time, being stationary in one spot is going to be a problem. Even if the gantry is a floor rail, independent of the table, you will see flex that can't be compensated for due to the heat being in different spots every pierce. Steel will probably end up being cheaper too.

A servo system is also going to work better for the extreme cutting speed ranges you need. Servos have a wider torque curve than steppers for jobs like this, meaning you can have better quality on thinner and thicker plate.

WSS

[ajclay]

After I watched the little video you posted, I looked at several others that demonstrated the cutting of thick plate.

I was amazed how the torch pierced a 4in thick piece of plate. Did it a lot faster than I thought possible.. Once the steel got to burning it blew right through it. The cut quality was amazing to say the least.

I've got a complete torch set up for my plasma machine that I wanted to set up for thicker plate that my plasma couldn't cut... Just never have taken the time to set it up. 1 - 2 in thick stuff, not what you're talking about...

Aj

[cata_tm_83]

You will probably need a steel gantry for anything over 30mm. The heat from cuts like this is fairly high, more than enough to wrinkle an aluminum extrusion gantry. The cut speeds on 30mm (using a hi speed tip) is probably in the 10-15ipm range. Preheat (w/o a hi/lo system) on 30mm (using lpg) will be 1-2min. Just the preheat time, being stationary in one spot is going to be a problem. Even if the gantry is a floor rail, independent of the table, you will see flex that can't be compensated for due to the heat being in different spots every pierce. Steel will probably end up being cheaper too.

A servo system is also going to work better for the extreme cutting speed ranges you need. Servos have a wider torque curve than steppers for jobs like this, meaning you can have better quality on thinner and thicker plate.

WSS

I've uploaded the torque graphic for my nema23, so if i use 2000 rot/min (6600 pps) - (which has the highest torque) with a planetary of 1:16 and an pinion of 32mm diameter I'll get a speed of 12.5m/min. This speed is more then enough for my needs.

You have a good point with the heat, I'll measure it on the other machines


You can download the SolidWorks project from:
https://docs.google.com/open?id=0B9O...FZnYlJEMkltaDQ






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[rexcobey]

I've uploaded the torque graphic for my nema23, so if i use 2000 rot/min (6600 pps) - (which has the highest torque) with a planetary of 1:16 and an pinion of 32mm diameter I'll get a speed of 12.5m/min. This speed is more then enough for my needs.

You have a good point with the heat, I'll measure it on the other machines


You can download the SolidWorks project from:
https://docs.google.com/open?id=0B9O...FZnYlJEMkltaDQ







.

Like WSS said you need a steel gantry for this heavy material that you put inside your gantry...

Like the one i did on my gantry, my gantry has a 6mm thick plate and has water table. sometime i also cut 3in thick MSP plate on this cnc machine of mine...

here is the picture of my machine

[rexcobey]

here also the video,

[ame=http://www.youtube.com/watch?v=M5zNxsqYViE]CNC Plasma 10ft. x 6ft. controlled by USBCNC Edingcnc Cutting parts 1 - YouTube[/ame]

That is 25mm Thick MS Plate

[cata_tm_83]

New pictures: motor-planetary-pinion and clamping system. I hope that the backlash (10') is not to big


The SW2011 project can be found here:
https://docs.google.com/open?id=0B9O...UV0MkhkN3NQakk
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