2+2+3 More Plasma builds, double the joy ! 3X2M and 2.5X1.5M cnc plasma build.

Built another two of the reductions for the big machine ( big = 3X2M cut area, small = 2.5X1.5M cut area ), so i took some pictures.
L shaped alu profile 90X50mm, 8mm thick, 200mm long, 2 pieces, holes drilled for the shaft and bearing screws:

Two bearing with holder and two screws/nuts for each side:

GT2 60 teeth for the motor side, motor pulley is already on the motor, and T3 15 tooth pulley for the driving side, for 15mm wide belt.

Two Nema 23 stepper motors, used ones till they are mounted on the machine, then new ones double length:

Two 8mm shafts, both sides have two ground parts to prevent slipping:

Finished gearing with the proximity sensor installed:

Another picture of the working side, missing an added 10mm thick 50X10mm alu part with idler bearings installed, out of bearings, so will do more pictures when i get to that:

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On the small one i also installed the wide belt on the other side and sensors, will have to do some more cabling and sort the homing and limits for both sides tomorrow, see if i can pull that with just two sensors.
Regards,
Tom

less is more with these machines i believe. lighter the better and you have it down to a science Tom. i had to watch the video twice just to figure out how you were driving the gantry not only is it done to be light and just enough to do what it needs to but very cost effective in design. your a smart cookie

machinedude wrote: less is more with these machines i believe. lighter the better and you have it down to a science Tom. i had to watch the video twice just to figure out how you were driving the gantry not only is it done to be light and just enough to do what it needs to but very cost effective in design. your a smart cookie

Yes it is when it comes to plasma cutting, the lighter the gantry/ head assembly, more acceleration = sharper corner without slowing down.
And cost effective is a must here, labour got to be cheaper than in China, and knowledge is worth nothing here. Pretty much same as US !

to put things into perspective the gantry on the machine i am building is close to 300 lbs steppers work ok but not in the sense of the acceleration needed on the long axis moving the entire gantry. no good for plasma. the other two would be good but not as good as a gantry sized like yours. servo's might do it with adaptive tuning and electronic gearing but at a very steep cost curve to get there. i might be further ahead to do a smaller dedicated table to be honest. light and cheap in design to make up for added cost in electronic and plasma cutter.

don't get me wrong i like what i have built i see it doing well at milling and can add a wood router with no problems. in that respect i kept it realistic on the spindle and spent more on the frame work end of it. with any kind of milling you run out of rigidity before you max the spindle load out and if you want to have any chance of milling mild steel you better have the right speeds to run the tooling at and a frame that does something to negate vibrations steel and aluminum extrusion is not enough.

Tommy, what dimensions is that gantry extrusion. Is that what you are going to use?

machinedude wrote: to put things into perspective the gantry on the machine i am building is close to 300 lbs.

You and Stefan have too much machinist in you thinking bigger is better.

Mine is heavier than Tommy's but with all motors and gantry ends, I think it came in at just over 30 kg (75 lb). A lot of that weight is the linear rails and gear rack. so only 100kg or 220 lb lighter than yours.With hindsight, I'm sure it only needs one linear rail, but Tommy's belts are way lighter again!

My rapids are about 21 m/min (825 in/min). I chuckled when Stefan asked if one of my videos had been speeded up

that's why Tommy is so smart driving with the belts. it cuts a lot weight out of the machine and makes it do it's job that much better. very clever without a doubt

it just reinforces two things.

1. Routers and Plasma's have totally different design parameters. Dual purpose machines don't work out well.
2. Velocity and Acceleration is King for plasma cutting.

rodw wrote: Tommy, what dimensions is that gantry extrusion. Is that what you are going to use?

That is Bosch 45X45mm, and no i am not using that for the gantry, i will be using this:


if i ever get them in the lengths i need, they are 128X44mm, thin walls at 2.5mm and thick ones at 6mm, so at 210 and 270cm lengths should be plenty strong.
BTW i got the big guns out getting ready to do some damage! I mean the big Lam Technologies drives.

cool, I used 80x40mm RHS. I think the wall was 4mm, but it could have been 3mm.

And hurry up ans slam the Lams. I wanna see them fly.

why the expensive AL profiles not a cheep Square steelbody 3mm wall 2x2"